From d52d165d67c5aa26c8c89909003c94a66492d23d Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Sat, 28 May 2022 12:38:11 +0100 Subject: [PATCH 01/34] KVM: arm64: Always start with clearing SVE flag on load On each vcpu load, we set the KVM_ARM64_HOST_SVE_ENABLED flag if SVE is enabled for EL0 on the host. This is used to restore the correct state on vpcu put. However, it appears that nothing ever clears this flag. Once set, it will stick until the vcpu is destroyed, which has the potential to spuriously enable SVE for userspace. We probably never saw the issue because no VMM uses SVE, but that's still pretty bad. Unconditionally clearing the flag on vcpu load addresses the issue. Fixes: 8383741ab2e7 ("KVM: arm64: Get rid of host SVE tracking/saving") Signed-off-by: Marc Zyngier Cc: stable@vger.kernel.org Reviewed-by: Mark Brown Link: https://lore.kernel.org/r/20220528113829.1043361-2-maz@kernel.org --- arch/arm64/kvm/fpsimd.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c index 3d251a4d2cf7b..8267ff4642d36 100644 --- a/arch/arm64/kvm/fpsimd.c +++ b/arch/arm64/kvm/fpsimd.c @@ -80,6 +80,7 @@ void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu) vcpu->arch.flags &= ~KVM_ARM64_FP_ENABLED; vcpu->arch.flags |= KVM_ARM64_FP_HOST; + vcpu->arch.flags &= ~KVM_ARM64_HOST_SVE_ENABLED; if (read_sysreg(cpacr_el1) & CPACR_EL1_ZEN_EL0EN) vcpu->arch.flags |= KVM_ARM64_HOST_SVE_ENABLED; From 039f49c4cafb785504c678f28664d088e0108d35 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Sat, 28 May 2022 12:38:12 +0100 Subject: [PATCH 02/34] KVM: arm64: Always start with clearing SME flag on load On each vcpu load, we set the KVM_ARM64_HOST_SME_ENABLED flag if SME is enabled for EL0 on the host. This is used to restore the correct state on vpcu put. However, it appears that nothing ever clears this flag. Once set, it will stick until the vcpu is destroyed, which has the potential to spuriously enable SME for userspace. As it turns out, this is due to the SME code being more or less copied from SVE, and inheriting the same shortcomings. We never saw the issue because nothing uses SME, and the amount of testing is probably still pretty low. Fixes: 861262ab8627 ("KVM: arm64: Handle SME host state when running guests") Signed-off-by: Marc Zyngier Reviwed-by: Mark Brown Link: https://lore.kernel.org/r/20220528113829.1043361-3-maz@kernel.org --- arch/arm64/kvm/fpsimd.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c index 8267ff4642d36..6012b08ecb14e 100644 --- a/arch/arm64/kvm/fpsimd.c +++ b/arch/arm64/kvm/fpsimd.c @@ -94,6 +94,7 @@ void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu) * operations. Do this for ZA as well for now for simplicity. */ if (system_supports_sme()) { + vcpu->arch.flags &= ~KVM_ARM64_HOST_SME_ENABLED; if (read_sysreg(cpacr_el1) & CPACR_EL1_SMEN_EL0EN) vcpu->arch.flags |= KVM_ARM64_HOST_SME_ENABLED; From e3fe65e0d3671ee5ae8a2723e429ee4830a7c89c Mon Sep 17 00:00:00 2001 From: sunliming Date: Thu, 2 Jun 2022 10:48:05 +0800 Subject: [PATCH 03/34] KVM: arm64: Fix inconsistent indenting Fix the following smatch warnings: arch/arm64/kvm/vmid.c:62 flush_context() warn: inconsistent indenting Reported-by: kernel test robot Signed-off-by: sunliming Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220602024805.511457-1-sunliming@kylinos.cn --- arch/arm64/kvm/vmid.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm64/kvm/vmid.c b/arch/arm64/kvm/vmid.c index 8d5f0506fd87f..d78ae63d7c15f 100644 --- a/arch/arm64/kvm/vmid.c +++ b/arch/arm64/kvm/vmid.c @@ -66,7 +66,7 @@ static void flush_context(void) * the next context-switch, we broadcast TLB flush + I-cache * invalidation over the inner shareable domain on rollover. */ - kvm_call_hyp(__kvm_flush_vm_context); + kvm_call_hyp(__kvm_flush_vm_context); } static bool check_update_reserved_vmid(u64 vmid, u64 newvmid) From 2cdea19a34c2340b3aa69508804efe4e3750fcec Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 7 Jun 2022 14:14:25 +0100 Subject: [PATCH 04/34] KVM: arm64: Don't read a HW interrupt pending state in user context Since 5bfa685e62e9 ("KVM: arm64: vgic: Read HW interrupt pending state from the HW"), we're able to source the pending bit for an interrupt that is stored either on the physical distributor or on a device. However, this state is only available when the vcpu is loaded, and is not intended to be accessed from userspace. Unfortunately, the GICv2 emulation doesn't provide specific userspace accessors, and we fallback with the ones that are intended for the guest, with fatal consequences. Add a new vgic_uaccess_read_pending() accessor for userspace to use, build on top of the existing vgic_mmio_read_pending(). Reported-by: Eric Auger Reviewed-by: Eric Auger Tested-by: Eric Auger Signed-off-by: Marc Zyngier Fixes: 5bfa685e62e9 ("KVM: arm64: vgic: Read HW interrupt pending state from the HW") Link: https://lore.kernel.org/r/20220607131427.1164881-2-maz@kernel.org Cc: stable@vger.kernel.org --- arch/arm64/kvm/vgic/vgic-mmio-v2.c | 4 ++-- arch/arm64/kvm/vgic/vgic-mmio.c | 19 ++++++++++++++++--- arch/arm64/kvm/vgic/vgic-mmio.h | 3 +++ 3 files changed, 21 insertions(+), 5 deletions(-) diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v2.c b/arch/arm64/kvm/vgic/vgic-mmio-v2.c index 77a67e9d3d14b..e070cda86e12f 100644 --- a/arch/arm64/kvm/vgic/vgic-mmio-v2.c +++ b/arch/arm64/kvm/vgic/vgic-mmio-v2.c @@ -429,11 +429,11 @@ static const struct vgic_register_region vgic_v2_dist_registers[] = { VGIC_ACCESS_32bit), REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_PENDING_SET, vgic_mmio_read_pending, vgic_mmio_write_spending, - NULL, vgic_uaccess_write_spending, 1, + vgic_uaccess_read_pending, vgic_uaccess_write_spending, 1, VGIC_ACCESS_32bit), REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_PENDING_CLEAR, vgic_mmio_read_pending, vgic_mmio_write_cpending, - NULL, vgic_uaccess_write_cpending, 1, + vgic_uaccess_read_pending, vgic_uaccess_write_cpending, 1, VGIC_ACCESS_32bit), REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_ACTIVE_SET, vgic_mmio_read_active, vgic_mmio_write_sactive, diff --git a/arch/arm64/kvm/vgic/vgic-mmio.c b/arch/arm64/kvm/vgic/vgic-mmio.c index 49837d3a3ef56..dc8c52487e470 100644 --- a/arch/arm64/kvm/vgic/vgic-mmio.c +++ b/arch/arm64/kvm/vgic/vgic-mmio.c @@ -226,8 +226,9 @@ int vgic_uaccess_write_cenable(struct kvm_vcpu *vcpu, return 0; } -unsigned long vgic_mmio_read_pending(struct kvm_vcpu *vcpu, - gpa_t addr, unsigned int len) +static unsigned long __read_pending(struct kvm_vcpu *vcpu, + gpa_t addr, unsigned int len, + bool is_user) { u32 intid = VGIC_ADDR_TO_INTID(addr, 1); u32 value = 0; @@ -248,7 +249,7 @@ unsigned long vgic_mmio_read_pending(struct kvm_vcpu *vcpu, IRQCHIP_STATE_PENDING, &val); WARN_RATELIMIT(err, "IRQ %d", irq->host_irq); - } else if (vgic_irq_is_mapped_level(irq)) { + } else if (!is_user && vgic_irq_is_mapped_level(irq)) { val = vgic_get_phys_line_level(irq); } else { val = irq_is_pending(irq); @@ -263,6 +264,18 @@ unsigned long vgic_mmio_read_pending(struct kvm_vcpu *vcpu, return value; } +unsigned long vgic_mmio_read_pending(struct kvm_vcpu *vcpu, + gpa_t addr, unsigned int len) +{ + return __read_pending(vcpu, addr, len, false); +} + +unsigned long vgic_uaccess_read_pending(struct kvm_vcpu *vcpu, + gpa_t addr, unsigned int len) +{ + return __read_pending(vcpu, addr, len, true); +} + static bool is_vgic_v2_sgi(struct kvm_vcpu *vcpu, struct vgic_irq *irq) { return (vgic_irq_is_sgi(irq->intid) && diff --git a/arch/arm64/kvm/vgic/vgic-mmio.h b/arch/arm64/kvm/vgic/vgic-mmio.h index 3fa696f198a37..6082d4b66d398 100644 --- a/arch/arm64/kvm/vgic/vgic-mmio.h +++ b/arch/arm64/kvm/vgic/vgic-mmio.h @@ -149,6 +149,9 @@ int vgic_uaccess_write_cenable(struct kvm_vcpu *vcpu, unsigned long vgic_mmio_read_pending(struct kvm_vcpu *vcpu, gpa_t addr, unsigned int len); +unsigned long vgic_uaccess_read_pending(struct kvm_vcpu *vcpu, + gpa_t addr, unsigned int len); + void vgic_mmio_write_spending(struct kvm_vcpu *vcpu, gpa_t addr, unsigned int len, unsigned long val); From 98432ccdec9f178ba041e1e5f9f32dbd71576504 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 7 Jun 2022 14:14:26 +0100 Subject: [PATCH 05/34] KVM: arm64: Replace vgic_v3_uaccess_read_pending with vgic_uaccess_read_pending Now that GICv2 has a proper userspace accessor for the pending state, switch GICv3 over to it, dropping the local version, moving over the specific behaviours that CGIv3 requires (such as the distinction between pending latch and line level which were never enforced with GICv2). We also gain extra locking that isn't really necessary for userspace, but that's a small price to pay for getting rid of superfluous code. Signed-off-by: Marc Zyngier Reviewed-by: Eric Auger Link: https://lore.kernel.org/r/20220607131427.1164881-3-maz@kernel.org --- arch/arm64/kvm/vgic/vgic-mmio-v3.c | 40 ++---------------------------- arch/arm64/kvm/vgic/vgic-mmio.c | 21 +++++++++++++++- 2 files changed, 22 insertions(+), 39 deletions(-) diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v3.c b/arch/arm64/kvm/vgic/vgic-mmio-v3.c index f7aa7bcd6fb8c..f15e29cc63ce1 100644 --- a/arch/arm64/kvm/vgic/vgic-mmio-v3.c +++ b/arch/arm64/kvm/vgic/vgic-mmio-v3.c @@ -353,42 +353,6 @@ static unsigned long vgic_mmio_read_v3_idregs(struct kvm_vcpu *vcpu, return 0; } -static unsigned long vgic_v3_uaccess_read_pending(struct kvm_vcpu *vcpu, - gpa_t addr, unsigned int len) -{ - u32 intid = VGIC_ADDR_TO_INTID(addr, 1); - u32 value = 0; - int i; - - /* - * pending state of interrupt is latched in pending_latch variable. - * Userspace will save and restore pending state and line_level - * separately. - * Refer to Documentation/virt/kvm/devices/arm-vgic-v3.rst - * for handling of ISPENDR and ICPENDR. - */ - for (i = 0; i < len * 8; i++) { - struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i); - bool state = irq->pending_latch; - - if (irq->hw && vgic_irq_is_sgi(irq->intid)) { - int err; - - err = irq_get_irqchip_state(irq->host_irq, - IRQCHIP_STATE_PENDING, - &state); - WARN_ON(err); - } - - if (state) - value |= (1U << i); - - vgic_put_irq(vcpu->kvm, irq); - } - - return value; -} - static int vgic_v3_uaccess_write_pending(struct kvm_vcpu *vcpu, gpa_t addr, unsigned int len, unsigned long val) @@ -666,7 +630,7 @@ static const struct vgic_register_region vgic_v3_dist_registers[] = { VGIC_ACCESS_32bit), REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(GICD_ISPENDR, vgic_mmio_read_pending, vgic_mmio_write_spending, - vgic_v3_uaccess_read_pending, vgic_v3_uaccess_write_pending, 1, + vgic_uaccess_read_pending, vgic_v3_uaccess_write_pending, 1, VGIC_ACCESS_32bit), REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(GICD_ICPENDR, vgic_mmio_read_pending, vgic_mmio_write_cpending, @@ -750,7 +714,7 @@ static const struct vgic_register_region vgic_v3_rd_registers[] = { VGIC_ACCESS_32bit), REGISTER_DESC_WITH_LENGTH_UACCESS(SZ_64K + GICR_ISPENDR0, vgic_mmio_read_pending, vgic_mmio_write_spending, - vgic_v3_uaccess_read_pending, vgic_v3_uaccess_write_pending, 4, + vgic_uaccess_read_pending, vgic_v3_uaccess_write_pending, 4, VGIC_ACCESS_32bit), REGISTER_DESC_WITH_LENGTH_UACCESS(SZ_64K + GICR_ICPENDR0, vgic_mmio_read_pending, vgic_mmio_write_cpending, diff --git a/arch/arm64/kvm/vgic/vgic-mmio.c b/arch/arm64/kvm/vgic/vgic-mmio.c index dc8c52487e470..997d0fce20883 100644 --- a/arch/arm64/kvm/vgic/vgic-mmio.c +++ b/arch/arm64/kvm/vgic/vgic-mmio.c @@ -240,6 +240,15 @@ static unsigned long __read_pending(struct kvm_vcpu *vcpu, unsigned long flags; bool val; + /* + * When used from userspace with a GICv3 model: + * + * Pending state of interrupt is latched in pending_latch + * variable. Userspace will save and restore pending state + * and line_level separately. + * Refer to Documentation/virt/kvm/devices/arm-vgic-v3.rst + * for handling of ISPENDR and ICPENDR. + */ raw_spin_lock_irqsave(&irq->irq_lock, flags); if (irq->hw && vgic_irq_is_sgi(irq->intid)) { int err; @@ -252,7 +261,17 @@ static unsigned long __read_pending(struct kvm_vcpu *vcpu, } else if (!is_user && vgic_irq_is_mapped_level(irq)) { val = vgic_get_phys_line_level(irq); } else { - val = irq_is_pending(irq); + switch (vcpu->kvm->arch.vgic.vgic_model) { + case KVM_DEV_TYPE_ARM_VGIC_V3: + if (is_user) { + val = irq->pending_latch; + break; + } + fallthrough; + default: + val = irq_is_pending(irq); + break; + } } value |= ((u32)val << i); From efedd01de475e126e43a07d0b1221bb65e497163 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 7 Jun 2022 14:14:27 +0100 Subject: [PATCH 06/34] KVM: arm64: Warn if accessing timer pending state outside of vcpu context A recurrent bug in the KVM/arm64 code base consists in trying to access the timer pending state outside of the vcpu context, which makes zero sense (the pending state only exists when the vcpu is loaded). In order to avoid more embarassing crashes and catch the offenders red-handed, add a warning to kvm_arch_timer_get_input_level() and return the state as non-pending. This avoids taking the system down, and still helps tracking down silly bugs. Reviewed-by: Eric Auger Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220607131427.1164881-4-maz@kernel.org --- arch/arm64/kvm/arch_timer.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c index 4e39ace073af0..3b8d062e30ea4 100644 --- a/arch/arm64/kvm/arch_timer.c +++ b/arch/arm64/kvm/arch_timer.c @@ -1230,6 +1230,9 @@ bool kvm_arch_timer_get_input_level(int vintid) struct kvm_vcpu *vcpu = kvm_get_running_vcpu(); struct arch_timer_context *timer; + if (WARN(!vcpu, "No vcpu context!\n")) + return false; + if (vintid == vcpu_vtimer(vcpu)->irq.irq) timer = vcpu_vtimer(vcpu); else if (vintid == vcpu_ptimer(vcpu)->irq.irq) From ea6c1213217dec65a8f9f396752b4d8bbcf226ea Mon Sep 17 00:00:00 2001 From: Julia Lawall Date: Thu, 9 Jun 2022 09:18:15 +0530 Subject: [PATCH 07/34] RISC-V: KVM: fix typos in comments Various spelling mistakes in comments. Detected with the help of Coccinelle. Signed-off-by: Julia Lawall Signed-off-by: Anup Patel --- arch/riscv/kvm/vmid.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/riscv/kvm/vmid.c b/arch/riscv/kvm/vmid.c index 9f764df125db9..6cd93995fb65e 100644 --- a/arch/riscv/kvm/vmid.c +++ b/arch/riscv/kvm/vmid.c @@ -97,7 +97,7 @@ void kvm_riscv_gstage_vmid_update(struct kvm_vcpu *vcpu) * We ran out of VMIDs so we increment vmid_version and * start assigning VMIDs from 1. * - * This also means existing VMIDs assignement to all Guest + * This also means existing VMIDs assignment to all Guest * instances is invalid and we have force VMID re-assignement * for all Guest instances. The Guest instances that were not * running will automatically pick-up new VMIDs because will From 1a12b25274b9e54b0d2d59e21620f8cf13b268cb Mon Sep 17 00:00:00 2001 From: Lukas Bulwahn Date: Thu, 9 Jun 2022 09:18:22 +0530 Subject: [PATCH 08/34] MAINTAINERS: Limit KVM RISC-V entry to existing selftests Commit fed9b26b2501 ("MAINTAINERS: Update KVM RISC-V entry to cover selftests support") optimistically adds a file entry for tools/testing/selftests/kvm/riscv/, but this directory does not exist. Hence, ./scripts/get_maintainer.pl --self-test=patterns complains about a broken reference. The script is very useful to keep MAINTAINERS up to date and MAINTAINERS can be kept in a state where the script emits no warning. So, just drop the non-matching file entry rather than starting to collect exceptions of entries that may match in some close or distant future. Fixes: fed9b26b2501 ("MAINTAINERS: Update KVM RISC-V entry to cover selftests support") Signed-off-by: Lukas Bulwahn Signed-off-by: Anup Patel --- MAINTAINERS | 1 - 1 file changed, 1 deletion(-) diff --git a/MAINTAINERS b/MAINTAINERS index a6d3bd9d2a8d0..e549a84e21c88 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -10863,7 +10863,6 @@ F: arch/riscv/include/asm/kvm* F: arch/riscv/include/uapi/asm/kvm* F: arch/riscv/kvm/ F: tools/testing/selftests/kvm/*/riscv/ -F: tools/testing/selftests/kvm/riscv/ KERNEL VIRTUAL MACHINE for s390 (KVM/s390) M: Christian Borntraeger From ae187fec75aa670a551d9662f83e3947d3f02a69 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Thu, 9 Jun 2022 13:12:18 +0100 Subject: [PATCH 09/34] KVM: arm64: Return error from kvm_arch_init_vm() on allocation failure If we fail to allocate the 'supported_cpus' cpumask in kvm_arch_init_vm() then be sure to return -ENOMEM instead of success (0) on the failure path. Reviewed-by: Alexandru Elisei Signed-off-by: Will Deacon Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220609121223.2551-2-will@kernel.org --- arch/arm64/kvm/arm.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 400bb0fe2745b..0da0f06037dbb 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -150,8 +150,10 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) if (ret) goto out_free_stage2_pgd; - if (!zalloc_cpumask_var(&kvm->arch.supported_cpus, GFP_KERNEL)) + if (!zalloc_cpumask_var(&kvm->arch.supported_cpus, GFP_KERNEL)) { + ret = -ENOMEM; goto out_free_stage2_pgd; + } cpumask_copy(kvm->arch.supported_cpus, cpu_possible_mask); kvm_vgic_early_init(kvm); From fa7a17214488ef7df347dcd1a5594f69ea17f4dc Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Thu, 9 Jun 2022 13:12:19 +0100 Subject: [PATCH 10/34] KVM: arm64: Handle all ID registers trapped for a protected VM A protected VM accessing ID_AA64ISAR2_EL1 gets punished with an UNDEF, while it really should only get a zero back if the register is not handled by the hypervisor emulation (as mandated by the architecture). Introduce all the missing ID registers (including the unallocated ones), and have them to return 0. Reported-by: Will Deacon Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220609121223.2551-3-will@kernel.org --- arch/arm64/kvm/hyp/nvhe/sys_regs.c | 42 ++++++++++++++++++++++++------ 1 file changed, 34 insertions(+), 8 deletions(-) diff --git a/arch/arm64/kvm/hyp/nvhe/sys_regs.c b/arch/arm64/kvm/hyp/nvhe/sys_regs.c index b6d86e423319f..35a4331ba5f31 100644 --- a/arch/arm64/kvm/hyp/nvhe/sys_regs.c +++ b/arch/arm64/kvm/hyp/nvhe/sys_regs.c @@ -243,15 +243,9 @@ u64 pvm_read_id_reg(const struct kvm_vcpu *vcpu, u32 id) case SYS_ID_AA64MMFR2_EL1: return get_pvm_id_aa64mmfr2(vcpu); default: - /* - * Should never happen because all cases are covered in - * pvm_sys_reg_descs[]. - */ - WARN_ON(1); - break; + /* Unhandled ID register, RAZ */ + return 0; } - - return 0; } static u64 read_id_reg(const struct kvm_vcpu *vcpu, @@ -332,6 +326,16 @@ static bool pvm_gic_read_sre(struct kvm_vcpu *vcpu, /* Mark the specified system register as an AArch64 feature id register. */ #define AARCH64(REG) { SYS_DESC(REG), .access = pvm_access_id_aarch64 } +/* + * sys_reg_desc initialiser for architecturally unallocated cpufeature ID + * register with encoding Op0=3, Op1=0, CRn=0, CRm=crm, Op2=op2 + * (1 <= crm < 8, 0 <= Op2 < 8). + */ +#define ID_UNALLOCATED(crm, op2) { \ + Op0(3), Op1(0), CRn(0), CRm(crm), Op2(op2), \ + .access = pvm_access_id_aarch64, \ +} + /* Mark the specified system register as Read-As-Zero/Write-Ignored */ #define RAZ_WI(REG) { SYS_DESC(REG), .access = pvm_access_raz_wi } @@ -375,24 +379,46 @@ static const struct sys_reg_desc pvm_sys_reg_descs[] = { AARCH32(SYS_MVFR0_EL1), AARCH32(SYS_MVFR1_EL1), AARCH32(SYS_MVFR2_EL1), + ID_UNALLOCATED(3,3), AARCH32(SYS_ID_PFR2_EL1), AARCH32(SYS_ID_DFR1_EL1), AARCH32(SYS_ID_MMFR5_EL1), + ID_UNALLOCATED(3,7), /* AArch64 ID registers */ /* CRm=4 */ AARCH64(SYS_ID_AA64PFR0_EL1), AARCH64(SYS_ID_AA64PFR1_EL1), + ID_UNALLOCATED(4,2), + ID_UNALLOCATED(4,3), AARCH64(SYS_ID_AA64ZFR0_EL1), + ID_UNALLOCATED(4,5), + ID_UNALLOCATED(4,6), + ID_UNALLOCATED(4,7), AARCH64(SYS_ID_AA64DFR0_EL1), AARCH64(SYS_ID_AA64DFR1_EL1), + ID_UNALLOCATED(5,2), + ID_UNALLOCATED(5,3), AARCH64(SYS_ID_AA64AFR0_EL1), AARCH64(SYS_ID_AA64AFR1_EL1), + ID_UNALLOCATED(5,6), + ID_UNALLOCATED(5,7), AARCH64(SYS_ID_AA64ISAR0_EL1), AARCH64(SYS_ID_AA64ISAR1_EL1), + AARCH64(SYS_ID_AA64ISAR2_EL1), + ID_UNALLOCATED(6,3), + ID_UNALLOCATED(6,4), + ID_UNALLOCATED(6,5), + ID_UNALLOCATED(6,6), + ID_UNALLOCATED(6,7), AARCH64(SYS_ID_AA64MMFR0_EL1), AARCH64(SYS_ID_AA64MMFR1_EL1), AARCH64(SYS_ID_AA64MMFR2_EL1), + ID_UNALLOCATED(7,3), + ID_UNALLOCATED(7,4), + ID_UNALLOCATED(7,5), + ID_UNALLOCATED(7,6), + ID_UNALLOCATED(7,7), /* Scalable Vector Registers are restricted. */ From cde5042adf11b0a30a6ce0ec3d071afcf8d2efaf Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Thu, 9 Jun 2022 13:12:20 +0100 Subject: [PATCH 11/34] KVM: arm64: Ignore 'kvm-arm.mode=protected' when using VHE Ignore 'kvm-arm.mode=protected' when using VHE so that kvm_get_mode() only returns KVM_MODE_PROTECTED on systems where the feature is available. Cc: David Brazdil Acked-by: Mark Rutland Signed-off-by: Will Deacon Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220609121223.2551-4-will@kernel.org --- Documentation/admin-guide/kernel-parameters.txt | 1 - arch/arm64/kernel/cpufeature.c | 10 +--------- arch/arm64/kvm/arm.c | 6 +++++- 3 files changed, 6 insertions(+), 11 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 8090130b544b0..97c16aa2f53fd 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2469,7 +2469,6 @@ protected: nVHE-based mode with support for guests whose state is kept private from the host. - Not valid if the kernel is running in EL2. Defaults to VHE/nVHE based on hardware support. Setting mode to "protected" will disable kexec and hibernation diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 42ea2bd856c60..79fac13ab2efc 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -1974,15 +1974,7 @@ static void cpu_enable_mte(struct arm64_cpu_capabilities const *cap) #ifdef CONFIG_KVM static bool is_kvm_protected_mode(const struct arm64_cpu_capabilities *entry, int __unused) { - if (kvm_get_mode() != KVM_MODE_PROTECTED) - return false; - - if (is_kernel_in_hyp_mode()) { - pr_warn("Protected KVM not available with VHE\n"); - return false; - } - - return true; + return kvm_get_mode() == KVM_MODE_PROTECTED; } #endif /* CONFIG_KVM */ diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 0da0f06037dbb..a0188144a122b 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -2273,7 +2273,11 @@ static int __init early_kvm_mode_cfg(char *arg) return -EINVAL; if (strcmp(arg, "protected") == 0) { - kvm_mode = KVM_MODE_PROTECTED; + if (!is_kernel_in_hyp_mode()) + kvm_mode = KVM_MODE_PROTECTED; + else + pr_warn_once("Protected KVM not available with VHE\n"); + return 0; } From 112f3bab41113dc53b4f35e9034b2208245bc002 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Thu, 9 Jun 2022 13:12:21 +0100 Subject: [PATCH 12/34] KVM: arm64: Extend comment in has_vhe() has_vhe() expands to a compile-time constant when evaluated from the VHE or nVHE code, alternatively checking a static key when called from elsewhere in the kernel. On face value, this looks like a case of premature optimization, but in fact this allows symbol references on VHE-specific code paths to be dropped from the nVHE object. Expand the comment in has_vhe() to make this clearer, hopefully discouraging anybody from simplifying the code. Cc: David Brazdil Acked-by: Mark Rutland Signed-off-by: Will Deacon Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220609121223.2551-5-will@kernel.org --- arch/arm64/include/asm/virt.h | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h index 3c8af033a9976..0e80db4327b60 100644 --- a/arch/arm64/include/asm/virt.h +++ b/arch/arm64/include/asm/virt.h @@ -113,6 +113,9 @@ static __always_inline bool has_vhe(void) /* * Code only run in VHE/NVHE hyp context can assume VHE is present or * absent. Otherwise fall back to caps. + * This allows the compiler to discard VHE-specific code from the + * nVHE object, reducing the number of external symbol references + * needed to link. */ if (is_vhe_hyp_code()) return true; From 5879c97f37022ff22a3f13174c24fcf2807fdbc0 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Thu, 9 Jun 2022 13:12:22 +0100 Subject: [PATCH 13/34] KVM: arm64: Remove redundant hyp_assert_lock_held() assertions host_stage2_try() asserts that the KVM host lock is held, so there's no need to duplicate the assertion in its wrappers. Signed-off-by: Will Deacon Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220609121223.2551-6-will@kernel.org --- arch/arm64/kvm/hyp/nvhe/mem_protect.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c index 78edf077fa3b6..1e78acf9662eb 100644 --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c @@ -314,15 +314,11 @@ static int host_stage2_adjust_range(u64 addr, struct kvm_mem_range *range) int host_stage2_idmap_locked(phys_addr_t addr, u64 size, enum kvm_pgtable_prot prot) { - hyp_assert_lock_held(&host_kvm.lock); - return host_stage2_try(__host_stage2_idmap, addr, addr + size, prot); } int host_stage2_set_owner_locked(phys_addr_t addr, u64 size, u8 owner_id) { - hyp_assert_lock_held(&host_kvm.lock); - return host_stage2_try(kvm_pgtable_stage2_set_owner, &host_kvm.pgt, addr, size, &host_s2_pool, owner_id); } From bcbfb588cf323929ac46767dd14e392016bbce04 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Thu, 9 Jun 2022 13:12:23 +0100 Subject: [PATCH 14/34] KVM: arm64: Drop stale comment The layout of 'struct kvm_vcpu_arch' has evolved significantly since the initial port of KVM/arm64, so remove the stale comment suggesting that a prefix of the structure is used exclusively from assembly code. Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220609121223.2551-7-will@kernel.org --- arch/arm64/include/asm/kvm_host.h | 5 ----- 1 file changed, 5 deletions(-) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 47a1e25e25bbc..de32152cea048 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -362,11 +362,6 @@ struct kvm_vcpu_arch { struct arch_timer_cpu timer_cpu; struct kvm_pmu pmu; - /* - * Anything that is not used directly from assembly code goes - * here. - */ - /* * Guest registers we preserve during guest debugging. * From d2263de1372a452cb64666990043b8be5c40b2a1 Mon Sep 17 00:00:00 2001 From: Yuan Yao Date: Wed, 8 Jun 2022 09:20:15 +0800 Subject: [PATCH 15/34] KVM: x86/mmu: Set memory encryption "value", not "mask", in shadow PDPTRs Assign shadow_me_value, not shadow_me_mask, to PAE root entries, a.k.a. shadow PDPTRs, when host memory encryption is supported. The "mask" is the set of all possible memory encryption bits, e.g. MKTME KeyIDs, whereas "value" holds the actual value that needs to be stuffed into host page tables. Using shadow_me_mask results in a failed VM-Entry due to setting reserved PA bits in the PDPTRs, and ultimately causes an OOPS due to physical addresses with non-zero MKTME bits sending to_shadow_page() into the weeds: set kvm_intel.dump_invalid_vmcs=1 to dump internal KVM state. BUG: unable to handle page fault for address: ffd43f00063049e8 PGD 86dfd8067 P4D 0 Oops: 0000 [#1] PREEMPT SMP RIP: 0010:mmu_free_root_page+0x3c/0x90 [kvm] kvm_mmu_free_roots+0xd1/0x200 [kvm] __kvm_mmu_unload+0x29/0x70 [kvm] kvm_mmu_unload+0x13/0x20 [kvm] kvm_arch_destroy_vm+0x8a/0x190 [kvm] kvm_put_kvm+0x197/0x2d0 [kvm] kvm_vm_release+0x21/0x30 [kvm] __fput+0x8e/0x260 ____fput+0xe/0x10 task_work_run+0x6f/0xb0 do_exit+0x327/0xa90 do_group_exit+0x35/0xa0 get_signal+0x911/0x930 arch_do_signal_or_restart+0x37/0x720 exit_to_user_mode_prepare+0xb2/0x140 syscall_exit_to_user_mode+0x16/0x30 do_syscall_64+0x4e/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae Fixes: e54f1ff244ac ("KVM: x86/mmu: Add shadow_me_value and repurpose shadow_me_mask") Signed-off-by: Yuan Yao Reviewed-by: Kai Huang Message-Id: <20220608012015.19566-1-yuan.yao@intel.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/mmu/mmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index e826ee9138fa8..17252f39bd7c2 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -3411,7 +3411,7 @@ static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu) root = mmu_alloc_root(vcpu, i << (30 - PAGE_SHIFT), i << 30, PT32_ROOT_LEVEL, true); mmu->pae_root[i] = root | PT_PRESENT_MASK | - shadow_me_mask; + shadow_me_value; } mmu->root.hpa = __pa(mmu->pae_root); } else { From a9603ae0e4ee6e7de0184801d4abe5925f43b49c Mon Sep 17 00:00:00 2001 From: Maxim Levitsky Date: Mon, 6 Jun 2022 21:08:23 +0300 Subject: [PATCH 16/34] KVM: x86: document AVIC/APICv inhibit reasons These days there are too many AVIC/APICv inhibit reasons, and it doesn't hurt to have some documentation for them. Signed-off-by: Maxim Levitsky Message-Id: <20220606180829.102503-2-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini --- arch/x86/include/asm/kvm_host.h | 59 +++++++++++++++++++++++++++++++-- 1 file changed, 57 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 3a240a64ac68f..1f9e47b895cf9 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1047,14 +1047,69 @@ struct kvm_x86_msr_filter { }; enum kvm_apicv_inhibit { + + /********************************************************************/ + /* INHIBITs that are relevant to both Intel's APICv and AMD's AVIC. */ + /********************************************************************/ + + /* + * APIC acceleration is disabled by a module parameter + * and/or not supported in hardware. + */ APICV_INHIBIT_REASON_DISABLE, + + /* + * APIC acceleration is inhibited because AutoEOI feature is + * being used by a HyperV guest. + */ APICV_INHIBIT_REASON_HYPERV, + + /* + * APIC acceleration is inhibited because the userspace didn't yet + * enable the kernel/split irqchip. + */ + APICV_INHIBIT_REASON_ABSENT, + + /* APIC acceleration is inhibited because KVM_GUESTDBG_BLOCKIRQ + * (out of band, debug measure of blocking all interrupts on this vCPU) + * was enabled, to avoid AVIC/APICv bypassing it. + */ + APICV_INHIBIT_REASON_BLOCKIRQ, + + /******************************************************/ + /* INHIBITs that are relevant only to the AMD's AVIC. */ + /******************************************************/ + + /* + * AVIC is inhibited on a vCPU because it runs a nested guest. + * + * This is needed because unlike APICv, the peers of this vCPU + * cannot use the doorbell mechanism to signal interrupts via AVIC when + * a vCPU runs nested. + */ APICV_INHIBIT_REASON_NESTED, + + /* + * On SVM, the wait for the IRQ window is implemented with pending vIRQ, + * which cannot be injected when the AVIC is enabled, thus AVIC + * is inhibited while KVM waits for IRQ window. + */ APICV_INHIBIT_REASON_IRQWIN, + + /* + * PIT (i8254) 're-inject' mode, relies on EOI intercept, + * which AVIC doesn't support for edge triggered interrupts. + */ APICV_INHIBIT_REASON_PIT_REINJ, + + /* + * AVIC is inhibited because the guest has x2apic in its CPUID. + */ APICV_INHIBIT_REASON_X2APIC, - APICV_INHIBIT_REASON_BLOCKIRQ, - APICV_INHIBIT_REASON_ABSENT, + + /* + * AVIC is disabled because SEV doesn't support it. + */ APICV_INHIBIT_REASON_SEV, }; From 3743c2f0251743b8ae968329708bbbeefff244cf Mon Sep 17 00:00:00 2001 From: Maxim Levitsky Date: Mon, 6 Jun 2022 21:08:24 +0300 Subject: [PATCH 17/34] KVM: x86: inhibit APICv/AVIC on changes to APIC ID or APIC base Neither of these settings should be changed by the guest and it is a burden to support it in the acceleration code, so just inhibit this code instead. Signed-off-by: Maxim Levitsky Message-Id: <20220606180829.102503-3-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini --- arch/x86/include/asm/kvm_host.h | 8 ++++++++ arch/x86/kvm/lapic.c | 27 +++++++++++++++++++++++---- arch/x86/kvm/svm/avic.c | 4 +++- arch/x86/kvm/vmx/vmx.c | 4 +++- 4 files changed, 37 insertions(+), 6 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 1f9e47b895cf9..9217bd6cf0d14 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1076,6 +1076,14 @@ enum kvm_apicv_inhibit { */ APICV_INHIBIT_REASON_BLOCKIRQ, + /* + * For simplicity, the APIC acceleration is inhibited + * first time either APIC ID or APIC base are changed by the guest + * from their reset values. + */ + APICV_INHIBIT_REASON_APIC_ID_MODIFIED, + APICV_INHIBIT_REASON_APIC_BASE_MODIFIED, + /******************************************************/ /* INHIBITs that are relevant only to the AMD's AVIC. */ /******************************************************/ diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index f1bdac3f5aa8a..0e68b4c937fcd 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -2039,6 +2039,19 @@ static void apic_manage_nmi_watchdog(struct kvm_lapic *apic, u32 lvt0_val) } } +static void kvm_lapic_xapic_id_updated(struct kvm_lapic *apic) +{ + struct kvm *kvm = apic->vcpu->kvm; + + if (KVM_BUG_ON(apic_x2apic_mode(apic), kvm)) + return; + + if (kvm_xapic_id(apic) == apic->vcpu->vcpu_id) + return; + + kvm_set_apicv_inhibit(apic->vcpu->kvm, APICV_INHIBIT_REASON_APIC_ID_MODIFIED); +} + static int kvm_lapic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val) { int ret = 0; @@ -2047,10 +2060,12 @@ static int kvm_lapic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val) switch (reg) { case APIC_ID: /* Local APIC ID */ - if (!apic_x2apic_mode(apic)) + if (!apic_x2apic_mode(apic)) { kvm_apic_set_xapic_id(apic, val >> 24); - else + kvm_lapic_xapic_id_updated(apic); + } else { ret = 1; + } break; case APIC_TASKPRI: @@ -2336,8 +2351,10 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value) MSR_IA32_APICBASE_BASE; if ((value & MSR_IA32_APICBASE_ENABLE) && - apic->base_address != APIC_DEFAULT_PHYS_BASE) - pr_warn_once("APIC base relocation is unsupported by KVM"); + apic->base_address != APIC_DEFAULT_PHYS_BASE) { + kvm_set_apicv_inhibit(apic->vcpu->kvm, + APICV_INHIBIT_REASON_APIC_BASE_MODIFIED); + } } void kvm_apic_update_apicv(struct kvm_vcpu *vcpu) @@ -2648,6 +2665,8 @@ static int kvm_apic_state_fixup(struct kvm_vcpu *vcpu, icr = __kvm_lapic_get_reg64(s->regs, APIC_ICR); __kvm_lapic_set_reg(s->regs, APIC_ICR2, icr >> 32); } + } else { + kvm_lapic_xapic_id_updated(vcpu->arch.apic); } return 0; diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c index 54fe03714f8a6..8dffd67f60862 100644 --- a/arch/x86/kvm/svm/avic.c +++ b/arch/x86/kvm/svm/avic.c @@ -910,7 +910,9 @@ bool avic_check_apicv_inhibit_reasons(enum kvm_apicv_inhibit reason) BIT(APICV_INHIBIT_REASON_PIT_REINJ) | BIT(APICV_INHIBIT_REASON_X2APIC) | BIT(APICV_INHIBIT_REASON_BLOCKIRQ) | - BIT(APICV_INHIBIT_REASON_SEV); + BIT(APICV_INHIBIT_REASON_SEV | + BIT(APICV_INHIBIT_REASON_APIC_ID_MODIFIED) | + BIT(APICV_INHIBIT_REASON_APIC_BASE_MODIFIED)); return supported & BIT(reason); } diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 9bd86ecccdab5..553dd2317b9cb 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -7709,7 +7709,9 @@ static bool vmx_check_apicv_inhibit_reasons(enum kvm_apicv_inhibit reason) ulong supported = BIT(APICV_INHIBIT_REASON_DISABLE) | BIT(APICV_INHIBIT_REASON_ABSENT) | BIT(APICV_INHIBIT_REASON_HYPERV) | - BIT(APICV_INHIBIT_REASON_BLOCKIRQ); + BIT(APICV_INHIBIT_REASON_BLOCKIRQ) | + BIT(APICV_INHIBIT_REASON_APIC_ID_MODIFIED) | + BIT(APICV_INHIBIT_REASON_APIC_BASE_MODIFIED); return supported & BIT(reason); } From f5f9089f76ddc882b915c5d78e4beeb48dcabd1b Mon Sep 17 00:00:00 2001 From: Maxim Levitsky Date: Mon, 6 Jun 2022 21:08:25 +0300 Subject: [PATCH 18/34] KVM: x86: SVM: remove avic's broken code that updated APIC ID AVIC is now inhibited if the guest changes the apic id, and therefore this code is no longer needed. There are several ways this code was broken, including: 1. a vCPU was only allowed to change its apic id to an apic id of an existing vCPU. 2. After such change, the vCPU whose apic id entry was overwritten, could not correctly change its own apic id, because its own entry is already overwritten. Signed-off-by: Maxim Levitsky Message-Id: <20220606180829.102503-4-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/svm/avic.c | 35 ----------------------------------- 1 file changed, 35 deletions(-) diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c index 8dffd67f60862..072e2c8cc66aa 100644 --- a/arch/x86/kvm/svm/avic.c +++ b/arch/x86/kvm/svm/avic.c @@ -508,35 +508,6 @@ static int avic_handle_ldr_update(struct kvm_vcpu *vcpu) return ret; } -static int avic_handle_apic_id_update(struct kvm_vcpu *vcpu) -{ - u64 *old, *new; - struct vcpu_svm *svm = to_svm(vcpu); - u32 id = kvm_xapic_id(vcpu->arch.apic); - - if (vcpu->vcpu_id == id) - return 0; - - old = avic_get_physical_id_entry(vcpu, vcpu->vcpu_id); - new = avic_get_physical_id_entry(vcpu, id); - if (!new || !old) - return 1; - - /* We need to move physical_id_entry to new offset */ - *new = *old; - *old = 0ULL; - to_svm(vcpu)->avic_physical_id_cache = new; - - /* - * Also update the guest physical APIC ID in the logical - * APIC ID table entry if already setup the LDR. - */ - if (svm->ldr_reg) - avic_handle_ldr_update(vcpu); - - return 0; -} - static void avic_handle_dfr_update(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm = to_svm(vcpu); @@ -555,10 +526,6 @@ static int avic_unaccel_trap_write(struct kvm_vcpu *vcpu) AVIC_UNACCEL_ACCESS_OFFSET_MASK; switch (offset) { - case APIC_ID: - if (avic_handle_apic_id_update(vcpu)) - return 0; - break; case APIC_LDR: if (avic_handle_ldr_update(vcpu)) return 0; @@ -650,8 +617,6 @@ int avic_init_vcpu(struct vcpu_svm *svm) void avic_apicv_post_state_restore(struct kvm_vcpu *vcpu) { - if (avic_handle_apic_id_update(vcpu) != 0) - return; avic_handle_dfr_update(vcpu); avic_handle_ldr_update(vcpu); } From 603ccef42ce9f07840cf4c0448f3261413460b07 Mon Sep 17 00:00:00 2001 From: Maxim Levitsky Date: Mon, 6 Jun 2022 21:08:26 +0300 Subject: [PATCH 19/34] KVM: x86: SVM: fix avic_kick_target_vcpus_fast MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit There are two issues in avic_kick_target_vcpus_fast 1. It is legal to issue an IPI request with APIC_DEST_NOSHORT and a physical destination of 0xFF (or 0xFFFFFFFF in case of x2apic), which must be treated as a broadcast destination. Fix this by explicitly checking for it. Also don’t use ‘index’ in this case as it gives no new information. 2. It is legal to issue a logical IPI request to more than one target. Index field only provides index in physical id table of first such target and therefore can't be used before we are sure that only a single target was addressed. Instead, parse the ICRL/ICRH, double check that a unicast interrupt was requested, and use that info to figure out the physical id of the target vCPU. At that point there is no need to use the index field as well. In addition to fixing the above issues, also skip the call to kvm_apic_match_dest. It is possible to do this now, because now as long as AVIC is not inhibited, it is guaranteed that none of the vCPUs changed their apic id from its default value. This fixes boot of windows guest with AVIC enabled because it uses IPI with 0xFF destination and no destination shorthand. Fixes: 7223fd2d5338 ("KVM: SVM: Use target APIC ID to complete AVIC IRQs when possible") Cc: stable@vger.kernel.org Signed-off-by: Maxim Levitsky Message-Id: <20220606180829.102503-5-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/svm/avic.c | 105 ++++++++++++++++++++++++++-------------- 1 file changed, 69 insertions(+), 36 deletions(-) diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c index 072e2c8cc66aa..5d98ac575dedc 100644 --- a/arch/x86/kvm/svm/avic.c +++ b/arch/x86/kvm/svm/avic.c @@ -291,58 +291,91 @@ void avic_ring_doorbell(struct kvm_vcpu *vcpu) static int avic_kick_target_vcpus_fast(struct kvm *kvm, struct kvm_lapic *source, u32 icrl, u32 icrh, u32 index) { - u32 dest, apic_id; - struct kvm_vcpu *vcpu; + u32 l1_physical_id, dest; + struct kvm_vcpu *target_vcpu; int dest_mode = icrl & APIC_DEST_MASK; int shorthand = icrl & APIC_SHORT_MASK; struct kvm_svm *kvm_svm = to_kvm_svm(kvm); - u32 *avic_logical_id_table = page_address(kvm_svm->avic_logical_id_table_page); if (shorthand != APIC_DEST_NOSHORT) return -EINVAL; - /* - * The AVIC incomplete IPI #vmexit info provides index into - * the physical APIC ID table, which can be used to derive - * guest physical APIC ID. - */ + if (apic_x2apic_mode(source)) + dest = icrh; + else + dest = GET_APIC_DEST_FIELD(icrh); + if (dest_mode == APIC_DEST_PHYSICAL) { - apic_id = index; + /* broadcast destination, use slow path */ + if (apic_x2apic_mode(source) && dest == X2APIC_BROADCAST) + return -EINVAL; + if (!apic_x2apic_mode(source) && dest == APIC_BROADCAST) + return -EINVAL; + + l1_physical_id = dest; + + if (WARN_ON_ONCE(l1_physical_id != index)) + return -EINVAL; + } else { - if (!apic_x2apic_mode(source)) { - /* For xAPIC logical mode, the index is for logical APIC table. */ - apic_id = avic_logical_id_table[index] & 0x1ff; + u32 bitmap, cluster; + int logid_index; + + if (apic_x2apic_mode(source)) { + /* 16 bit dest mask, 16 bit cluster id */ + bitmap = dest & 0xFFFF0000; + cluster = (dest >> 16) << 4; + } else if (kvm_lapic_get_reg(source, APIC_DFR) == APIC_DFR_FLAT) { + /* 8 bit dest mask*/ + bitmap = dest; + cluster = 0; } else { - return -EINVAL; + /* 4 bit desk mask, 4 bit cluster id */ + bitmap = dest & 0xF; + cluster = (dest >> 4) << 2; } - } - /* - * Assuming vcpu ID is the same as physical apic ID, - * and use it to retrieve the target vCPU. - */ - vcpu = kvm_get_vcpu_by_id(kvm, apic_id); - if (!vcpu) - return -EINVAL; + if (unlikely(!bitmap)) + /* guest bug: nobody to send the logical interrupt to */ + return 0; - if (apic_x2apic_mode(vcpu->arch.apic)) - dest = icrh; - else - dest = GET_APIC_DEST_FIELD(icrh); + if (!is_power_of_2(bitmap)) + /* multiple logical destinations, use slow path */ + return -EINVAL; - /* - * Try matching the destination APIC ID with the vCPU. - */ - if (kvm_apic_match_dest(vcpu, source, shorthand, dest, dest_mode)) { - vcpu->arch.apic->irr_pending = true; - svm_complete_interrupt_delivery(vcpu, - icrl & APIC_MODE_MASK, - icrl & APIC_INT_LEVELTRIG, - icrl & APIC_VECTOR_MASK); - return 0; + logid_index = cluster + __ffs(bitmap); + + if (apic_x2apic_mode(source)) { + l1_physical_id = logid_index; + } else { + u32 *avic_logical_id_table = + page_address(kvm_svm->avic_logical_id_table_page); + + u32 logid_entry = avic_logical_id_table[logid_index]; + + if (WARN_ON_ONCE(index != logid_index)) + return -EINVAL; + + /* guest bug: non existing/reserved logical destination */ + if (unlikely(!(logid_entry & AVIC_LOGICAL_ID_ENTRY_VALID_MASK))) + return 0; + + l1_physical_id = logid_entry & + AVIC_LOGICAL_ID_ENTRY_GUEST_PHYSICAL_ID_MASK; + } } - return -EINVAL; + target_vcpu = kvm_get_vcpu_by_id(kvm, l1_physical_id); + if (unlikely(!target_vcpu)) + /* guest bug: non existing vCPU is a target of this IPI*/ + return 0; + + target_vcpu->arch.apic->irr_pending = true; + svm_complete_interrupt_delivery(target_vcpu, + icrl & APIC_MODE_MASK, + icrl & APIC_INT_LEVELTRIG, + icrl & APIC_VECTOR_MASK); + return 0; } static void avic_kick_target_vcpus(struct kvm *kvm, struct kvm_lapic *source, From 66c768d30e64e1280520f34dbef83419f55f3459 Mon Sep 17 00:00:00 2001 From: Maxim Levitsky Date: Mon, 6 Jun 2022 21:08:27 +0300 Subject: [PATCH 20/34] KVM: x86: disable preemption while updating apicv inhibition Currently nothing prevents preemption in kvm_vcpu_update_apicv. On SVM, If the preemption happens after we update the vcpu->arch.apicv_active, the preemption itself will 'update' the inhibition since the AVIC will be first disabled on vCPU unload and then enabled, when the current task is loaded again. Then we will try to update it again, which will lead to a warning in __avic_vcpu_load, that the AVIC is already enabled. Fix this by disabling preemption in this code. Signed-off-by: Maxim Levitsky Message-Id: <20220606180829.102503-6-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/x86.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 03fbfbbec460f..158b2e135efce 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -9850,6 +9850,7 @@ void kvm_vcpu_update_apicv(struct kvm_vcpu *vcpu) return; down_read(&vcpu->kvm->arch.apicv_update_lock); + preempt_disable(); activate = kvm_vcpu_apicv_activated(vcpu); @@ -9870,6 +9871,7 @@ void kvm_vcpu_update_apicv(struct kvm_vcpu *vcpu) kvm_make_request(KVM_REQ_EVENT, vcpu); out: + preempt_enable(); up_read(&vcpu->kvm->arch.apicv_update_lock); } EXPORT_SYMBOL_GPL(kvm_vcpu_update_apicv); From 18869f26df1a11ed11031dfb7392bc7d774062e8 Mon Sep 17 00:00:00 2001 From: Maxim Levitsky Date: Mon, 6 Jun 2022 21:08:28 +0300 Subject: [PATCH 21/34] KVM: x86: disable preemption around the call to kvm_arch_vcpu_{un|}blocking On SVM, if preemption happens right after the call to finish_rcuwait but before call to kvm_arch_vcpu_unblocking on SVM/AVIC, it itself will re-enable AVIC, and then we will try to re-enable it again in kvm_arch_vcpu_unblocking which will lead to a warning in __avic_vcpu_load. The same problem can happen if the vCPU is preempted right after the call to kvm_arch_vcpu_blocking but before the call to prepare_to_rcuwait and in this case, we will end up with AVIC enabled during sleep - Ooops. Signed-off-by: Maxim Levitsky Message-Id: <20220606180829.102503-7-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini --- virt/kvm/kvm_main.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 44c47670447aa..a49df8988cd6a 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -3328,9 +3328,11 @@ bool kvm_vcpu_block(struct kvm_vcpu *vcpu) vcpu->stat.generic.blocking = 1; + preempt_disable(); kvm_arch_vcpu_blocking(vcpu); - prepare_to_rcuwait(wait); + preempt_enable(); + for (;;) { set_current_state(TASK_INTERRUPTIBLE); @@ -3340,9 +3342,11 @@ bool kvm_vcpu_block(struct kvm_vcpu *vcpu) waited = true; schedule(); } - finish_rcuwait(wait); + preempt_disable(); + finish_rcuwait(wait); kvm_arch_vcpu_unblocking(vcpu); + preempt_enable(); vcpu->stat.generic.blocking = 0; From ba8ec273240a7a67819b5957c8d06a267ec54db7 Mon Sep 17 00:00:00 2001 From: Maxim Levitsky Date: Mon, 6 Jun 2022 21:08:29 +0300 Subject: [PATCH 22/34] KVM: x86: SVM: drop preempt-safe wrappers for avic_vcpu_load/put Now that these functions are always called with preemption disabled, remove the preempt_disable()/preempt_enable() pair inside them. No functional change intended. Signed-off-by: Maxim Levitsky Message-Id: <20220606180829.102503-8-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/svm/avic.c | 27 ++++----------------------- arch/x86/kvm/svm/svm.c | 4 ++-- arch/x86/kvm/svm/svm.h | 4 ++-- 3 files changed, 8 insertions(+), 27 deletions(-) diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c index 5d98ac575dedc..5542d8959e114 100644 --- a/arch/x86/kvm/svm/avic.c +++ b/arch/x86/kvm/svm/avic.c @@ -946,7 +946,7 @@ avic_update_iommu_vcpu_affinity(struct kvm_vcpu *vcpu, int cpu, bool r) return ret; } -void __avic_vcpu_load(struct kvm_vcpu *vcpu, int cpu) +void avic_vcpu_load(struct kvm_vcpu *vcpu, int cpu) { u64 entry; int h_physical_id = kvm_cpu_get_apicid(cpu); @@ -978,7 +978,7 @@ void __avic_vcpu_load(struct kvm_vcpu *vcpu, int cpu) avic_update_iommu_vcpu_affinity(vcpu, h_physical_id, true); } -void __avic_vcpu_put(struct kvm_vcpu *vcpu) +void avic_vcpu_put(struct kvm_vcpu *vcpu) { u64 entry; struct vcpu_svm *svm = to_svm(vcpu); @@ -997,25 +997,6 @@ void __avic_vcpu_put(struct kvm_vcpu *vcpu) WRITE_ONCE(*(svm->avic_physical_id_cache), entry); } -static void avic_vcpu_load(struct kvm_vcpu *vcpu) -{ - int cpu = get_cpu(); - - WARN_ON(cpu != vcpu->cpu); - - __avic_vcpu_load(vcpu, cpu); - - put_cpu(); -} - -static void avic_vcpu_put(struct kvm_vcpu *vcpu) -{ - preempt_disable(); - - __avic_vcpu_put(vcpu); - - preempt_enable(); -} void avic_refresh_apicv_exec_ctrl(struct kvm_vcpu *vcpu) { @@ -1042,7 +1023,7 @@ void avic_refresh_apicv_exec_ctrl(struct kvm_vcpu *vcpu) vmcb_mark_dirty(vmcb, VMCB_AVIC); if (activated) - avic_vcpu_load(vcpu); + avic_vcpu_load(vcpu, vcpu->cpu); else avic_vcpu_put(vcpu); @@ -1075,5 +1056,5 @@ void avic_vcpu_unblocking(struct kvm_vcpu *vcpu) if (!kvm_vcpu_apicv_active(vcpu)) return; - avic_vcpu_load(vcpu); + avic_vcpu_load(vcpu, vcpu->cpu); } diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 1dc02cdf69602..1ac66fbceaa1d 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -1400,13 +1400,13 @@ static void svm_vcpu_load(struct kvm_vcpu *vcpu, int cpu) indirect_branch_prediction_barrier(); } if (kvm_vcpu_apicv_active(vcpu)) - __avic_vcpu_load(vcpu, cpu); + avic_vcpu_load(vcpu, cpu); } static void svm_vcpu_put(struct kvm_vcpu *vcpu) { if (kvm_vcpu_apicv_active(vcpu)) - __avic_vcpu_put(vcpu); + avic_vcpu_put(vcpu); svm_prepare_host_switch(vcpu); diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index 500348c1cb350..1bddd336a27e0 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -610,8 +610,8 @@ void avic_init_vmcb(struct vcpu_svm *svm, struct vmcb *vmcb); int avic_incomplete_ipi_interception(struct kvm_vcpu *vcpu); int avic_unaccelerated_access_interception(struct kvm_vcpu *vcpu); int avic_init_vcpu(struct vcpu_svm *svm); -void __avic_vcpu_load(struct kvm_vcpu *vcpu, int cpu); -void __avic_vcpu_put(struct kvm_vcpu *vcpu); +void avic_vcpu_load(struct kvm_vcpu *vcpu, int cpu); +void avic_vcpu_put(struct kvm_vcpu *vcpu); void avic_apicv_post_state_restore(struct kvm_vcpu *vcpu); void avic_set_virtual_apic_mode(struct kvm_vcpu *vcpu); void avic_refresh_apicv_exec_ctrl(struct kvm_vcpu *vcpu); From e3cdaab5ff022874e65df80ae8b8382ccc0a4fe0 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Tue, 31 May 2022 13:57:32 -0400 Subject: [PATCH 23/34] KVM: x86: SVM: fix nested PAUSE filtering when L0 intercepts PAUSE Commit 74fd41ed16fd ("KVM: x86: nSVM: support PAUSE filtering when L0 doesn't intercept PAUSE") introduced passthrough support for nested pause filtering, (when the host doesn't intercept PAUSE) (either disabled with kvm module param, or disabled with '-overcommit cpu-pm=on') Before this commit, L1 KVM didn't intercept PAUSE at all; afterwards, the feature was exposed as supported by KVM cpuid unconditionally, thus if L1 could try to use it even when the L0 KVM can't really support it. In this case the fallback caused KVM to intercept each PAUSE instruction; in some cases, such intercept can slow down the nested guest so much that it can fail to boot. Instead, before the problematic commit KVM was already setting both thresholds to 0 in vmcb02, but after the first userspace VM exit shrink_ple_window was called and would reset the pause_filter_count to the default value. To fix this, change the fallback strategy - ignore the guest threshold values, but use/update the host threshold values unless the guest specifically requests disabling PAUSE filtering (either simple or advanced). Also fix a minor bug: on nested VM exit, when PAUSE filter counter were copied back to vmcb01, a dirty bit was not set. Thanks a lot to Suravee Suthikulpanit for debugging this! Fixes: 74fd41ed16fd ("KVM: x86: nSVM: support PAUSE filtering when L0 doesn't intercept PAUSE") Reported-by: Suravee Suthikulpanit Tested-by: Suravee Suthikulpanit Co-developed-by: Maxim Levitsky Message-Id: <20220518072709.730031-1-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/svm/nested.c | 39 +++++++++++++++++++++------------------ arch/x86/kvm/svm/svm.c | 4 ++-- 2 files changed, 23 insertions(+), 20 deletions(-) diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index 3361258640a27..ba7cd26f438fc 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -616,6 +616,8 @@ static void nested_vmcb02_prepare_control(struct vcpu_svm *svm) struct kvm_vcpu *vcpu = &svm->vcpu; struct vmcb *vmcb01 = svm->vmcb01.ptr; struct vmcb *vmcb02 = svm->nested.vmcb02.ptr; + u32 pause_count12; + u32 pause_thresh12; /* * Filled at exit: exit_code, exit_code_hi, exit_info_1, exit_info_2, @@ -671,27 +673,25 @@ static void nested_vmcb02_prepare_control(struct vcpu_svm *svm) if (!nested_vmcb_needs_vls_intercept(svm)) vmcb02->control.virt_ext |= VIRTUAL_VMLOAD_VMSAVE_ENABLE_MASK; + pause_count12 = svm->pause_filter_enabled ? svm->nested.ctl.pause_filter_count : 0; + pause_thresh12 = svm->pause_threshold_enabled ? svm->nested.ctl.pause_filter_thresh : 0; if (kvm_pause_in_guest(svm->vcpu.kvm)) { - /* use guest values since host doesn't use them */ - vmcb02->control.pause_filter_count = - svm->pause_filter_enabled ? - svm->nested.ctl.pause_filter_count : 0; + /* use guest values since host doesn't intercept PAUSE */ + vmcb02->control.pause_filter_count = pause_count12; + vmcb02->control.pause_filter_thresh = pause_thresh12; - vmcb02->control.pause_filter_thresh = - svm->pause_threshold_enabled ? - svm->nested.ctl.pause_filter_thresh : 0; - - } else if (!vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_PAUSE)) { - /* use host values when guest doesn't use them */ + } else { + /* start from host values otherwise */ vmcb02->control.pause_filter_count = vmcb01->control.pause_filter_count; vmcb02->control.pause_filter_thresh = vmcb01->control.pause_filter_thresh; - } else { - /* - * Intercept every PAUSE otherwise and - * ignore both host and guest values - */ - vmcb02->control.pause_filter_count = 0; - vmcb02->control.pause_filter_thresh = 0; + + /* ... but ensure filtering is disabled if so requested. */ + if (vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_PAUSE)) { + if (!pause_count12) + vmcb02->control.pause_filter_count = 0; + if (!pause_thresh12) + vmcb02->control.pause_filter_thresh = 0; + } } nested_svm_transition_tlb_flush(vcpu); @@ -951,8 +951,11 @@ int nested_svm_vmexit(struct vcpu_svm *svm) vmcb12->control.event_inj = svm->nested.ctl.event_inj; vmcb12->control.event_inj_err = svm->nested.ctl.event_inj_err; - if (!kvm_pause_in_guest(vcpu->kvm) && vmcb02->control.pause_filter_count) + if (!kvm_pause_in_guest(vcpu->kvm)) { vmcb01->control.pause_filter_count = vmcb02->control.pause_filter_count; + vmcb_mark_dirty(vmcb01, VMCB_INTERCEPTS); + + } nested_svm_copy_common_state(svm->nested.vmcb02.ptr, svm->vmcb01.ptr); diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 1ac66fbceaa1d..87da90360bc76 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -921,7 +921,7 @@ static void grow_ple_window(struct kvm_vcpu *vcpu) struct vmcb_control_area *control = &svm->vmcb->control; int old = control->pause_filter_count; - if (kvm_pause_in_guest(vcpu->kvm) || !old) + if (kvm_pause_in_guest(vcpu->kvm)) return; control->pause_filter_count = __grow_ple_window(old, @@ -942,7 +942,7 @@ static void shrink_ple_window(struct kvm_vcpu *vcpu) struct vmcb_control_area *control = &svm->vmcb->control; int old = control->pause_filter_count; - if (kvm_pause_in_guest(vcpu->kvm) || !old) + if (kvm_pause_in_guest(vcpu->kvm)) return; control->pause_filter_count = From 4ee602e78d706e740a48be9b6ddb239df4a113b5 Mon Sep 17 00:00:00 2001 From: David Matlack Date: Fri, 20 May 2022 23:32:39 +0000 Subject: [PATCH 24/34] KVM: selftests: Replace x86_page_size with PG_LEVEL_XX x86_page_size is an enum used to communicate the desired page size with which to map a range of memory. Under the hood they just encode the desired level at which to map the page. This ends up being clunky in a few ways: - The name suggests it encodes the size of the page rather than the level. - In other places in x86_64/processor.c we just use a raw int to encode the level. Simplify this by adopting the kernel style of PG_LEVEL_XX enums and pass around raw ints when referring to the level. This makes the code easier to understand since these macros are very common in KVM MMU code. Signed-off-by: David Matlack Message-Id: <20220520233249.3776001-2-dmatlack@google.com> Signed-off-by: Paolo Bonzini --- .../selftests/kvm/include/x86_64/processor.h | 18 +++++++---- .../selftests/kvm/lib/x86_64/processor.c | 31 +++++++++---------- .../selftests/kvm/max_guest_memory_test.c | 2 +- .../selftests/kvm/x86_64/mmu_role_test.c | 2 +- 4 files changed, 29 insertions(+), 24 deletions(-) diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h index d0d51adec76eb..273c70e91647d 100644 --- a/tools/testing/selftests/kvm/include/x86_64/processor.h +++ b/tools/testing/selftests/kvm/include/x86_64/processor.h @@ -482,13 +482,19 @@ void vcpu_set_hv_cpuid(struct kvm_vm *vm, uint32_t vcpuid); struct kvm_cpuid2 *vcpu_get_supported_hv_cpuid(struct kvm_vm *vm, uint32_t vcpuid); void vm_xsave_req_perm(int bit); -enum x86_page_size { - X86_PAGE_SIZE_4K = 0, - X86_PAGE_SIZE_2M, - X86_PAGE_SIZE_1G, +enum pg_level { + PG_LEVEL_NONE, + PG_LEVEL_4K, + PG_LEVEL_2M, + PG_LEVEL_1G, + PG_LEVEL_512G, + PG_LEVEL_NUM }; -void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, - enum x86_page_size page_size); + +#define PG_LEVEL_SHIFT(_level) ((_level - 1) * 9 + 12) +#define PG_LEVEL_SIZE(_level) (1ull << PG_LEVEL_SHIFT(_level)) + +void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, int level); /* * Basic CPU control in CR0 diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c index 33ea5e9955d9b..ead7011ee8f61 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c @@ -158,7 +158,7 @@ static void *virt_get_pte(struct kvm_vm *vm, uint64_t pt_pfn, uint64_t vaddr, int level) { uint64_t *page_table = addr_gpa2hva(vm, pt_pfn << vm->page_shift); - int index = vaddr >> (vm->page_shift + level * 9) & 0x1ffu; + int index = (vaddr >> PG_LEVEL_SHIFT(level)) & 0x1ffu; return &page_table[index]; } @@ -167,14 +167,14 @@ static uint64_t *virt_create_upper_pte(struct kvm_vm *vm, uint64_t pt_pfn, uint64_t vaddr, uint64_t paddr, - int level, - enum x86_page_size page_size) + int current_level, + int target_level) { - uint64_t *pte = virt_get_pte(vm, pt_pfn, vaddr, level); + uint64_t *pte = virt_get_pte(vm, pt_pfn, vaddr, current_level); if (!(*pte & PTE_PRESENT_MASK)) { *pte = PTE_PRESENT_MASK | PTE_WRITABLE_MASK; - if (level == page_size) + if (current_level == target_level) *pte |= PTE_LARGE_MASK | (paddr & PHYSICAL_PAGE_MASK); else *pte |= vm_alloc_page_table(vm) & PHYSICAL_PAGE_MASK; @@ -184,20 +184,19 @@ static uint64_t *virt_create_upper_pte(struct kvm_vm *vm, * a hugepage at this level, and that there isn't a hugepage at * this level. */ - TEST_ASSERT(level != page_size, + TEST_ASSERT(current_level != target_level, "Cannot create hugepage at level: %u, vaddr: 0x%lx\n", - page_size, vaddr); + current_level, vaddr); TEST_ASSERT(!(*pte & PTE_LARGE_MASK), "Cannot create page table at level: %u, vaddr: 0x%lx\n", - level, vaddr); + current_level, vaddr); } return pte; } -void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, - enum x86_page_size page_size) +void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, int level) { - const uint64_t pg_size = 1ull << ((page_size * 9) + 12); + const uint64_t pg_size = PG_LEVEL_SIZE(level); uint64_t *pml4e, *pdpe, *pde; uint64_t *pte; @@ -222,20 +221,20 @@ void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, * early if a hugepage was created. */ pml4e = virt_create_upper_pte(vm, vm->pgd >> vm->page_shift, - vaddr, paddr, 3, page_size); + vaddr, paddr, PG_LEVEL_512G, level); if (*pml4e & PTE_LARGE_MASK) return; - pdpe = virt_create_upper_pte(vm, PTE_GET_PFN(*pml4e), vaddr, paddr, 2, page_size); + pdpe = virt_create_upper_pte(vm, PTE_GET_PFN(*pml4e), vaddr, paddr, PG_LEVEL_1G, level); if (*pdpe & PTE_LARGE_MASK) return; - pde = virt_create_upper_pte(vm, PTE_GET_PFN(*pdpe), vaddr, paddr, 1, page_size); + pde = virt_create_upper_pte(vm, PTE_GET_PFN(*pdpe), vaddr, paddr, PG_LEVEL_2M, level); if (*pde & PTE_LARGE_MASK) return; /* Fill in page table entry. */ - pte = virt_get_pte(vm, PTE_GET_PFN(*pde), vaddr, 0); + pte = virt_get_pte(vm, PTE_GET_PFN(*pde), vaddr, PG_LEVEL_4K); TEST_ASSERT(!(*pte & PTE_PRESENT_MASK), "PTE already present for 4k page at vaddr: 0x%lx\n", vaddr); *pte = PTE_PRESENT_MASK | PTE_WRITABLE_MASK | (paddr & PHYSICAL_PAGE_MASK); @@ -243,7 +242,7 @@ void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, void virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr) { - __virt_pg_map(vm, vaddr, paddr, X86_PAGE_SIZE_4K); + __virt_pg_map(vm, vaddr, paddr, PG_LEVEL_4K); } static uint64_t *_vm_get_page_table_entry(struct kvm_vm *vm, int vcpuid, diff --git a/tools/testing/selftests/kvm/max_guest_memory_test.c b/tools/testing/selftests/kvm/max_guest_memory_test.c index 3875c4b23a04f..15f046e19cb2c 100644 --- a/tools/testing/selftests/kvm/max_guest_memory_test.c +++ b/tools/testing/selftests/kvm/max_guest_memory_test.c @@ -244,7 +244,7 @@ int main(int argc, char *argv[]) #ifdef __x86_64__ /* Identity map memory in the guest using 1gb pages. */ for (i = 0; i < slot_size; i += size_1gb) - __virt_pg_map(vm, gpa + i, gpa + i, X86_PAGE_SIZE_1G); + __virt_pg_map(vm, gpa + i, gpa + i, PG_LEVEL_1G); #else for (i = 0; i < slot_size; i += vm_get_page_size(vm)) virt_pg_map(vm, gpa + i, gpa + i); diff --git a/tools/testing/selftests/kvm/x86_64/mmu_role_test.c b/tools/testing/selftests/kvm/x86_64/mmu_role_test.c index da2325fcad87b..bdecd532f9356 100644 --- a/tools/testing/selftests/kvm/x86_64/mmu_role_test.c +++ b/tools/testing/selftests/kvm/x86_64/mmu_role_test.c @@ -35,7 +35,7 @@ static void mmu_role_test(u32 *cpuid_reg, u32 evil_cpuid_val) run = vcpu_state(vm, VCPU_ID); /* Map 1gb page without a backing memlot. */ - __virt_pg_map(vm, MMIO_GPA, MMIO_GPA, X86_PAGE_SIZE_1G); + __virt_pg_map(vm, MMIO_GPA, MMIO_GPA, PG_LEVEL_1G); r = _vcpu_run(vm, VCPU_ID); From c5a0ccec4cb4edde8e5b7e369dbe4d169b111e42 Mon Sep 17 00:00:00 2001 From: David Matlack Date: Fri, 20 May 2022 23:32:40 +0000 Subject: [PATCH 25/34] KVM: selftests: Add option to create 2M and 1G EPT mappings The current EPT mapping code in the selftests only supports mapping 4K pages. This commit extends that support with an option to map at 2M or 1G. This will be used in a future commit to create large page mappings to test eager page splitting. No functional change intended. Signed-off-by: David Matlack Message-Id: <20220520233249.3776001-3-dmatlack@google.com> Signed-off-by: Paolo Bonzini --- tools/testing/selftests/kvm/lib/x86_64/vmx.c | 110 ++++++++++--------- 1 file changed, 60 insertions(+), 50 deletions(-) diff --git a/tools/testing/selftests/kvm/lib/x86_64/vmx.c b/tools/testing/selftests/kvm/lib/x86_64/vmx.c index d089d8b850b5c..fdc1e6deb9229 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/vmx.c +++ b/tools/testing/selftests/kvm/lib/x86_64/vmx.c @@ -392,80 +392,90 @@ void nested_vmx_check_supported(void) } } -void nested_pg_map(struct vmx_pages *vmx, struct kvm_vm *vm, - uint64_t nested_paddr, uint64_t paddr) +static void nested_create_pte(struct kvm_vm *vm, + struct eptPageTableEntry *pte, + uint64_t nested_paddr, + uint64_t paddr, + int current_level, + int target_level) +{ + if (!pte->readable) { + pte->writable = true; + pte->readable = true; + pte->executable = true; + pte->page_size = (current_level == target_level); + if (pte->page_size) + pte->address = paddr >> vm->page_shift; + else + pte->address = vm_alloc_page_table(vm) >> vm->page_shift; + } else { + /* + * Entry already present. Assert that the caller doesn't want + * a hugepage at this level, and that there isn't a hugepage at + * this level. + */ + TEST_ASSERT(current_level != target_level, + "Cannot create hugepage at level: %u, nested_paddr: 0x%lx\n", + current_level, nested_paddr); + TEST_ASSERT(!pte->page_size, + "Cannot create page table at level: %u, nested_paddr: 0x%lx\n", + current_level, nested_paddr); + } +} + + +void __nested_pg_map(struct vmx_pages *vmx, struct kvm_vm *vm, + uint64_t nested_paddr, uint64_t paddr, int target_level) { - uint16_t index[4]; - struct eptPageTableEntry *pml4e; + const uint64_t page_size = PG_LEVEL_SIZE(target_level); + struct eptPageTableEntry *pt = vmx->eptp_hva, *pte; + uint16_t index; TEST_ASSERT(vm->mode == VM_MODE_PXXV48_4K, "Attempt to use " "unknown or unsupported guest mode, mode: 0x%x", vm->mode); - TEST_ASSERT((nested_paddr % vm->page_size) == 0, + TEST_ASSERT((nested_paddr % page_size) == 0, "Nested physical address not on page boundary,\n" - " nested_paddr: 0x%lx vm->page_size: 0x%x", - nested_paddr, vm->page_size); + " nested_paddr: 0x%lx page_size: 0x%lx", + nested_paddr, page_size); TEST_ASSERT((nested_paddr >> vm->page_shift) <= vm->max_gfn, "Physical address beyond beyond maximum supported,\n" " nested_paddr: 0x%lx vm->max_gfn: 0x%lx vm->page_size: 0x%x", paddr, vm->max_gfn, vm->page_size); - TEST_ASSERT((paddr % vm->page_size) == 0, + TEST_ASSERT((paddr % page_size) == 0, "Physical address not on page boundary,\n" - " paddr: 0x%lx vm->page_size: 0x%x", - paddr, vm->page_size); + " paddr: 0x%lx page_size: 0x%lx", + paddr, page_size); TEST_ASSERT((paddr >> vm->page_shift) <= vm->max_gfn, "Physical address beyond beyond maximum supported,\n" " paddr: 0x%lx vm->max_gfn: 0x%lx vm->page_size: 0x%x", paddr, vm->max_gfn, vm->page_size); - index[0] = (nested_paddr >> 12) & 0x1ffu; - index[1] = (nested_paddr >> 21) & 0x1ffu; - index[2] = (nested_paddr >> 30) & 0x1ffu; - index[3] = (nested_paddr >> 39) & 0x1ffu; - - /* Allocate page directory pointer table if not present. */ - pml4e = vmx->eptp_hva; - if (!pml4e[index[3]].readable) { - pml4e[index[3]].address = vm_alloc_page_table(vm) >> vm->page_shift; - pml4e[index[3]].writable = true; - pml4e[index[3]].readable = true; - pml4e[index[3]].executable = true; - } + for (int level = PG_LEVEL_512G; level >= PG_LEVEL_4K; level--) { + index = (nested_paddr >> PG_LEVEL_SHIFT(level)) & 0x1ffu; + pte = &pt[index]; - /* Allocate page directory table if not present. */ - struct eptPageTableEntry *pdpe; - pdpe = addr_gpa2hva(vm, pml4e[index[3]].address * vm->page_size); - if (!pdpe[index[2]].readable) { - pdpe[index[2]].address = vm_alloc_page_table(vm) >> vm->page_shift; - pdpe[index[2]].writable = true; - pdpe[index[2]].readable = true; - pdpe[index[2]].executable = true; - } + nested_create_pte(vm, pte, nested_paddr, paddr, level, target_level); - /* Allocate page table if not present. */ - struct eptPageTableEntry *pde; - pde = addr_gpa2hva(vm, pdpe[index[2]].address * vm->page_size); - if (!pde[index[1]].readable) { - pde[index[1]].address = vm_alloc_page_table(vm) >> vm->page_shift; - pde[index[1]].writable = true; - pde[index[1]].readable = true; - pde[index[1]].executable = true; - } + if (pte->page_size) + break; - /* Fill in page table entry. */ - struct eptPageTableEntry *pte; - pte = addr_gpa2hva(vm, pde[index[1]].address * vm->page_size); - pte[index[0]].address = paddr >> vm->page_shift; - pte[index[0]].writable = true; - pte[index[0]].readable = true; - pte[index[0]].executable = true; + pt = addr_gpa2hva(vm, pte->address * vm->page_size); + } /* * For now mark these as accessed and dirty because the only * testcase we have needs that. Can be reconsidered later. */ - pte[index[0]].accessed = true; - pte[index[0]].dirty = true; + pte->accessed = true; + pte->dirty = true; + +} + +void nested_pg_map(struct vmx_pages *vmx, struct kvm_vm *vm, + uint64_t nested_paddr, uint64_t paddr) +{ + __nested_pg_map(vmx, vm, nested_paddr, paddr, PG_LEVEL_4K); } /* From b8ca01ea19068b54938ebb4ebc06814a89dee8ea Mon Sep 17 00:00:00 2001 From: David Matlack Date: Fri, 20 May 2022 23:32:41 +0000 Subject: [PATCH 26/34] KVM: selftests: Drop stale function parameter comment for nested_map() nested_map() does not take a parameter named eptp_memslot. Drop the comment referring to it. Reviewed-by: Peter Xu Signed-off-by: David Matlack Message-Id: <20220520233249.3776001-4-dmatlack@google.com> Signed-off-by: Paolo Bonzini --- tools/testing/selftests/kvm/lib/x86_64/vmx.c | 1 - 1 file changed, 1 deletion(-) diff --git a/tools/testing/selftests/kvm/lib/x86_64/vmx.c b/tools/testing/selftests/kvm/lib/x86_64/vmx.c index fdc1e6deb9229..baeaa35de1139 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/vmx.c +++ b/tools/testing/selftests/kvm/lib/x86_64/vmx.c @@ -486,7 +486,6 @@ void nested_pg_map(struct vmx_pages *vmx, struct kvm_vm *vm, * nested_paddr - Nested guest physical address to map * paddr - VM Physical Address * size - The size of the range to map - * eptp_memslot - Memory region slot for new virtual translation tables * * Output Args: None * From ce690e9c17d27486af879defc506679cbbb14777 Mon Sep 17 00:00:00 2001 From: David Matlack Date: Fri, 20 May 2022 23:32:42 +0000 Subject: [PATCH 27/34] KVM: selftests: Refactor nested_map() to specify target level Refactor nested_map() to specify that it explicityl wants 4K mappings (the existing behavior) and push the implementation down into __nested_map(), which can be used in subsequent commits to create huge page mappings. No function change intended. Reviewed-by: Peter Xu Signed-off-by: David Matlack Message-Id: <20220520233249.3776001-5-dmatlack@google.com> Signed-off-by: Paolo Bonzini --- tools/testing/selftests/kvm/lib/x86_64/vmx.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/tools/testing/selftests/kvm/lib/x86_64/vmx.c b/tools/testing/selftests/kvm/lib/x86_64/vmx.c index baeaa35de1139..b8cfe4914a3aa 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/vmx.c +++ b/tools/testing/selftests/kvm/lib/x86_64/vmx.c @@ -486,6 +486,7 @@ void nested_pg_map(struct vmx_pages *vmx, struct kvm_vm *vm, * nested_paddr - Nested guest physical address to map * paddr - VM Physical Address * size - The size of the range to map + * level - The level at which to map the range * * Output Args: None * @@ -494,22 +495,29 @@ void nested_pg_map(struct vmx_pages *vmx, struct kvm_vm *vm, * Within the VM given by vm, creates a nested guest translation for the * page range starting at nested_paddr to the page range starting at paddr. */ -void nested_map(struct vmx_pages *vmx, struct kvm_vm *vm, - uint64_t nested_paddr, uint64_t paddr, uint64_t size) +void __nested_map(struct vmx_pages *vmx, struct kvm_vm *vm, + uint64_t nested_paddr, uint64_t paddr, uint64_t size, + int level) { - size_t page_size = vm->page_size; + size_t page_size = PG_LEVEL_SIZE(level); size_t npages = size / page_size; TEST_ASSERT(nested_paddr + size > nested_paddr, "Vaddr overflow"); TEST_ASSERT(paddr + size > paddr, "Paddr overflow"); while (npages--) { - nested_pg_map(vmx, vm, nested_paddr, paddr); + __nested_pg_map(vmx, vm, nested_paddr, paddr, level); nested_paddr += page_size; paddr += page_size; } } +void nested_map(struct vmx_pages *vmx, struct kvm_vm *vm, + uint64_t nested_paddr, uint64_t paddr, uint64_t size) +{ + __nested_map(vmx, vm, nested_paddr, paddr, size, PG_LEVEL_4K); +} + /* Prepare an identity extended page table that maps all the * physical pages in VM. */ From b6c086d04c0a1ba356145cdba5b46bd6cea2b9bd Mon Sep 17 00:00:00 2001 From: David Matlack Date: Fri, 20 May 2022 23:32:43 +0000 Subject: [PATCH 28/34] KVM: selftests: Move VMX_EPT_VPID_CAP_AD_BITS to vmx.h This is a VMX-related macro so move it to vmx.h. While here, open code the mask like the rest of the VMX bitmask macros. No functional change intended. Reviewed-by: Peter Xu Signed-off-by: David Matlack Message-Id: <20220520233249.3776001-6-dmatlack@google.com> Signed-off-by: Paolo Bonzini --- tools/testing/selftests/kvm/include/x86_64/processor.h | 3 --- tools/testing/selftests/kvm/include/x86_64/vmx.h | 2 ++ 2 files changed, 2 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h index 273c70e91647d..d78f97f502b5c 100644 --- a/tools/testing/selftests/kvm/include/x86_64/processor.h +++ b/tools/testing/selftests/kvm/include/x86_64/processor.h @@ -511,9 +511,6 @@ void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, int level) #define X86_CR0_CD (1UL<<30) /* Cache Disable */ #define X86_CR0_PG (1UL<<31) /* Paging */ -/* VMX_EPT_VPID_CAP bits */ -#define VMX_EPT_VPID_CAP_AD_BITS (1ULL << 21) - #define XSTATE_XTILE_CFG_BIT 17 #define XSTATE_XTILE_DATA_BIT 18 diff --git a/tools/testing/selftests/kvm/include/x86_64/vmx.h b/tools/testing/selftests/kvm/include/x86_64/vmx.h index 583ceb0d14574..3b1794baa97cb 100644 --- a/tools/testing/selftests/kvm/include/x86_64/vmx.h +++ b/tools/testing/selftests/kvm/include/x86_64/vmx.h @@ -96,6 +96,8 @@ #define VMX_MISC_PREEMPTION_TIMER_RATE_MASK 0x0000001f #define VMX_MISC_SAVE_EFER_LMA 0x00000020 +#define VMX_EPT_VPID_CAP_AD_BITS 0x00200000 + #define EXIT_REASON_FAILED_VMENTRY 0x80000000 #define EXIT_REASON_EXCEPTION_NMI 0 #define EXIT_REASON_EXTERNAL_INTERRUPT 1 From c363d95986b1b930947305e2372665141721d15f Mon Sep 17 00:00:00 2001 From: David Matlack Date: Fri, 20 May 2022 23:32:44 +0000 Subject: [PATCH 29/34] KVM: selftests: Add a helper to check EPT/VPID capabilities Create a small helper function to check if a given EPT/VPID capability is supported. This will be re-used in a follow-up commit to check for 1G page support. No functional change intended. Reviewed-by: Peter Xu Signed-off-by: David Matlack Message-Id: <20220520233249.3776001-7-dmatlack@google.com> Signed-off-by: Paolo Bonzini --- tools/testing/selftests/kvm/lib/x86_64/vmx.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/kvm/lib/x86_64/vmx.c b/tools/testing/selftests/kvm/lib/x86_64/vmx.c index b8cfe4914a3aa..5bf1691794557 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/vmx.c +++ b/tools/testing/selftests/kvm/lib/x86_64/vmx.c @@ -198,6 +198,11 @@ bool load_vmcs(struct vmx_pages *vmx) return true; } +static bool ept_vpid_cap_supported(uint64_t mask) +{ + return rdmsr(MSR_IA32_VMX_EPT_VPID_CAP) & mask; +} + /* * Initialize the control fields to the most basic settings possible. */ @@ -215,7 +220,7 @@ static inline void init_vmcs_control_fields(struct vmx_pages *vmx) struct eptPageTablePointer eptp = { .memory_type = VMX_BASIC_MEM_TYPE_WB, .page_walk_length = 3, /* + 1 */ - .ad_enabled = !!(rdmsr(MSR_IA32_VMX_EPT_VPID_CAP) & VMX_EPT_VPID_CAP_AD_BITS), + .ad_enabled = ept_vpid_cap_supported(VMX_EPT_VPID_CAP_AD_BITS), .address = vmx->eptp_gpa >> PAGE_SHIFT_4K, }; From acf57736e755ba5c467fc6fa85e4a0750cc36150 Mon Sep 17 00:00:00 2001 From: David Matlack Date: Fri, 20 May 2022 23:32:45 +0000 Subject: [PATCH 30/34] KVM: selftests: Drop unnecessary rule for STATIC_LIBS Drop the "all: $(STATIC_LIBS)" rule. The KVM selftests already depend on $(STATIC_LIBS), so there is no reason to have an extra "all" rule. Suggested-by: Peter Xu Signed-off-by: David Matlack Message-Id: <20220520233249.3776001-8-dmatlack@google.com> Signed-off-by: Paolo Bonzini --- tools/testing/selftests/kvm/Makefile | 1 - 1 file changed, 1 deletion(-) diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index 81470a99ed1c0..e7d65e04b16a9 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -192,7 +192,6 @@ $(OUTPUT)/libkvm.a: $(LIBKVM_OBJS) $(AR) crs $@ $^ x := $(shell mkdir -p $(sort $(dir $(TEST_GEN_PROGS)))) -all: $(STATIC_LIBS) $(TEST_GEN_PROGS): $(STATIC_LIBS) cscope: include_paths = $(LINUX_TOOL_INCLUDE) $(LINUX_HDR_PATH) include lib .. From cdc979dae265cc77a035b736f78f58e4c7309bb2 Mon Sep 17 00:00:00 2001 From: David Matlack Date: Fri, 20 May 2022 23:32:46 +0000 Subject: [PATCH 31/34] KVM: selftests: Link selftests directly with lib object files The linker does obey strong/weak symbols when linking static libraries, it simply resolves an undefined symbol to the first-encountered symbol. This means that defining __weak arch-generic functions and then defining arch-specific strong functions to override them in libkvm will not always work. More specifically, if we have: lib/generic.c: void __weak foo(void) { pr_info("weak\n"); } void bar(void) { foo(); } lib/x86_64/arch.c: void foo(void) { pr_info("strong\n"); } And a selftest that calls bar(), it will print "weak". Now if you make generic.o explicitly depend on arch.o (e.g. add function to arch.c that is called directly from generic.c) it will print "strong". In other words, it seems that the linker is free to throw out arch.o when linking because generic.o does not explicitly depend on it, which causes the linker to lose the strong symbol. One solution is to link libkvm.a with --whole-archive so that the linker doesn't throw away object files it thinks are unnecessary. However that is a bit difficult to plumb since we are using the common selftests makefile rules. An easier solution is to drop libkvm.a just link selftests with all the .o files that were originally in libkvm.a. Reviewed-by: Peter Xu Signed-off-by: David Matlack Message-Id: <20220520233249.3776001-9-dmatlack@google.com> Signed-off-by: Paolo Bonzini --- tools/testing/selftests/kvm/Makefile | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index e7d65e04b16a9..804bf927618a1 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -173,12 +173,13 @@ LDFLAGS += -pthread $(no-pie-option) $(pgste-option) # $(TEST_GEN_PROGS) starts with $(OUTPUT)/ include ../lib.mk -STATIC_LIBS := $(OUTPUT)/libkvm.a LIBKVM_C := $(filter %.c,$(LIBKVM)) LIBKVM_S := $(filter %.S,$(LIBKVM)) LIBKVM_C_OBJ := $(patsubst %.c, $(OUTPUT)/%.o, $(LIBKVM_C)) LIBKVM_S_OBJ := $(patsubst %.S, $(OUTPUT)/%.o, $(LIBKVM_S)) -EXTRA_CLEAN += $(LIBKVM_C_OBJ) $(LIBKVM_S_OBJ) $(STATIC_LIBS) cscope.* +LIBKVM_OBJS = $(LIBKVM_C_OBJ) $(LIBKVM_S_OBJ) + +EXTRA_CLEAN += $(LIBKVM_OBJS) cscope.* x := $(shell mkdir -p $(sort $(dir $(LIBKVM_C_OBJ) $(LIBKVM_S_OBJ)))) $(LIBKVM_C_OBJ): $(OUTPUT)/%.o: %.c @@ -187,12 +188,8 @@ $(LIBKVM_C_OBJ): $(OUTPUT)/%.o: %.c $(LIBKVM_S_OBJ): $(OUTPUT)/%.o: %.S $(CC) $(CFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c $< -o $@ -LIBKVM_OBJS = $(LIBKVM_C_OBJ) $(LIBKVM_S_OBJ) -$(OUTPUT)/libkvm.a: $(LIBKVM_OBJS) - $(AR) crs $@ $^ - x := $(shell mkdir -p $(sort $(dir $(TEST_GEN_PROGS)))) -$(TEST_GEN_PROGS): $(STATIC_LIBS) +$(TEST_GEN_PROGS): $(LIBKVM_OBJS) cscope: include_paths = $(LINUX_TOOL_INCLUDE) $(LINUX_HDR_PATH) include lib .. cscope: From cf97d5e99f69f876dc310ea21b5f97c3a493a18a Mon Sep 17 00:00:00 2001 From: David Matlack Date: Fri, 20 May 2022 23:32:47 +0000 Subject: [PATCH 32/34] KVM: selftests: Clean up LIBKVM files in Makefile Break up the long lines for LIBKVM and alphabetize each architecture. This makes reading the Makefile easier, and will make reading diffs to LIBKVM easier. No functional change intended. Reviewed-by: Peter Xu Signed-off-by: David Matlack Message-Id: <20220520233249.3776001-10-dmatlack@google.com> Signed-off-by: Paolo Bonzini --- tools/testing/selftests/kvm/Makefile | 36 ++++++++++++++++++++++++---- 1 file changed, 31 insertions(+), 5 deletions(-) diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index 804bf927618a1..14566c0a330d4 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -37,11 +37,37 @@ ifeq ($(ARCH),riscv) UNAME_M := riscv endif -LIBKVM = lib/assert.c lib/elf.c lib/io.c lib/kvm_util.c lib/rbtree.c lib/sparsebit.c lib/test_util.c lib/guest_modes.c lib/perf_test_util.c -LIBKVM_x86_64 = lib/x86_64/apic.c lib/x86_64/processor.c lib/x86_64/vmx.c lib/x86_64/svm.c lib/x86_64/ucall.c lib/x86_64/handlers.S -LIBKVM_aarch64 = lib/aarch64/processor.c lib/aarch64/ucall.c lib/aarch64/handlers.S lib/aarch64/spinlock.c lib/aarch64/gic.c lib/aarch64/gic_v3.c lib/aarch64/vgic.c -LIBKVM_s390x = lib/s390x/processor.c lib/s390x/ucall.c lib/s390x/diag318_test_handler.c -LIBKVM_riscv = lib/riscv/processor.c lib/riscv/ucall.c +LIBKVM += lib/assert.c +LIBKVM += lib/elf.c +LIBKVM += lib/guest_modes.c +LIBKVM += lib/io.c +LIBKVM += lib/kvm_util.c +LIBKVM += lib/perf_test_util.c +LIBKVM += lib/rbtree.c +LIBKVM += lib/sparsebit.c +LIBKVM += lib/test_util.c + +LIBKVM_x86_64 += lib/x86_64/apic.c +LIBKVM_x86_64 += lib/x86_64/handlers.S +LIBKVM_x86_64 += lib/x86_64/processor.c +LIBKVM_x86_64 += lib/x86_64/svm.c +LIBKVM_x86_64 += lib/x86_64/ucall.c +LIBKVM_x86_64 += lib/x86_64/vmx.c + +LIBKVM_aarch64 += lib/aarch64/gic.c +LIBKVM_aarch64 += lib/aarch64/gic_v3.c +LIBKVM_aarch64 += lib/aarch64/handlers.S +LIBKVM_aarch64 += lib/aarch64/processor.c +LIBKVM_aarch64 += lib/aarch64/spinlock.c +LIBKVM_aarch64 += lib/aarch64/ucall.c +LIBKVM_aarch64 += lib/aarch64/vgic.c + +LIBKVM_s390x += lib/s390x/diag318_test_handler.c +LIBKVM_s390x += lib/s390x/processor.c +LIBKVM_s390x += lib/s390x/ucall.c + +LIBKVM_riscv += lib/riscv/processor.c +LIBKVM_riscv += lib/riscv/ucall.c TEST_GEN_PROGS_x86_64 = x86_64/cpuid_test TEST_GEN_PROGS_x86_64 += x86_64/cr4_cpuid_sync_test From 71d489661904fcc3ec31b343acd5c0dac84b5410 Mon Sep 17 00:00:00 2001 From: David Matlack Date: Fri, 20 May 2022 23:32:48 +0000 Subject: [PATCH 33/34] KVM: selftests: Add option to run dirty_log_perf_test vCPUs in L2 Add an option to dirty_log_perf_test that configures the vCPUs to run in L2 instead of L1. This makes it possible to benchmark the dirty logging performance of nested virtualization, which is particularly interesting because KVM must shadow L1's EPT/NPT tables. For now this support only works on x86_64 CPUs with VMX. Otherwise passing -n results in the test being skipped. Signed-off-by: David Matlack Message-Id: <20220520233249.3776001-11-dmatlack@google.com> Signed-off-by: Paolo Bonzini --- tools/testing/selftests/kvm/Makefile | 1 + .../selftests/kvm/dirty_log_perf_test.c | 10 +- .../selftests/kvm/include/perf_test_util.h | 9 ++ .../selftests/kvm/include/x86_64/processor.h | 4 + .../selftests/kvm/include/x86_64/vmx.h | 4 + .../selftests/kvm/lib/perf_test_util.c | 35 +++++- .../selftests/kvm/lib/x86_64/perf_test_util.c | 112 ++++++++++++++++++ tools/testing/selftests/kvm/lib/x86_64/vmx.c | 15 +++ 8 files changed, 182 insertions(+), 8 deletions(-) create mode 100644 tools/testing/selftests/kvm/lib/x86_64/perf_test_util.c diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index 14566c0a330d4..22423c871ed61 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -49,6 +49,7 @@ LIBKVM += lib/test_util.c LIBKVM_x86_64 += lib/x86_64/apic.c LIBKVM_x86_64 += lib/x86_64/handlers.S +LIBKVM_x86_64 += lib/x86_64/perf_test_util.c LIBKVM_x86_64 += lib/x86_64/processor.c LIBKVM_x86_64 += lib/x86_64/svm.c LIBKVM_x86_64 += lib/x86_64/ucall.c diff --git a/tools/testing/selftests/kvm/dirty_log_perf_test.c b/tools/testing/selftests/kvm/dirty_log_perf_test.c index 7b47ae4f952e6..d60a34cdfaee1 100644 --- a/tools/testing/selftests/kvm/dirty_log_perf_test.c +++ b/tools/testing/selftests/kvm/dirty_log_perf_test.c @@ -336,8 +336,8 @@ static void run_test(enum vm_guest_mode mode, void *arg) static void help(char *name) { puts(""); - printf("usage: %s [-h] [-i iterations] [-p offset] [-g]" - "[-m mode] [-b vcpu bytes] [-v vcpus] [-o] [-s mem type]" + printf("usage: %s [-h] [-i iterations] [-p offset] [-g] " + "[-m mode] [-n] [-b vcpu bytes] [-v vcpus] [-o] [-s mem type]" "[-x memslots]\n", name); puts(""); printf(" -i: specify iteration counts (default: %"PRIu64")\n", @@ -351,6 +351,7 @@ static void help(char *name) printf(" -p: specify guest physical test memory offset\n" " Warning: a low offset can conflict with the loaded test code.\n"); guest_modes_help(); + printf(" -n: Run the vCPUs in nested mode (L2)\n"); printf(" -b: specify the size of the memory region which should be\n" " dirtied by each vCPU. e.g. 10M or 3G.\n" " (default: 1G)\n"); @@ -387,7 +388,7 @@ int main(int argc, char *argv[]) guest_modes_append_default(); - while ((opt = getopt(argc, argv, "ghi:p:m:b:f:v:os:x:")) != -1) { + while ((opt = getopt(argc, argv, "ghi:p:m:nb:f:v:os:x:")) != -1) { switch (opt) { case 'g': dirty_log_manual_caps = 0; @@ -401,6 +402,9 @@ int main(int argc, char *argv[]) case 'm': guest_modes_cmdline(optarg); break; + case 'n': + perf_test_args.nested = true; + break; case 'b': guest_percpu_mem_size = parse_size(optarg); break; diff --git a/tools/testing/selftests/kvm/include/perf_test_util.h b/tools/testing/selftests/kvm/include/perf_test_util.h index a86f953d8d365..d822cb670f1cd 100644 --- a/tools/testing/selftests/kvm/include/perf_test_util.h +++ b/tools/testing/selftests/kvm/include/perf_test_util.h @@ -30,10 +30,15 @@ struct perf_test_vcpu_args { struct perf_test_args { struct kvm_vm *vm; + /* The starting address and size of the guest test region. */ uint64_t gpa; + uint64_t size; uint64_t guest_page_size; int wr_fract; + /* Run vCPUs in L2 instead of L1, if the architecture supports it. */ + bool nested; + struct perf_test_vcpu_args vcpu_args[KVM_MAX_VCPUS]; }; @@ -49,5 +54,9 @@ void perf_test_set_wr_fract(struct kvm_vm *vm, int wr_fract); void perf_test_start_vcpu_threads(int vcpus, void (*vcpu_fn)(struct perf_test_vcpu_args *)); void perf_test_join_vcpu_threads(int vcpus); +void perf_test_guest_code(uint32_t vcpu_id); + +uint64_t perf_test_nested_pages(int nr_vcpus); +void perf_test_setup_nested(struct kvm_vm *vm, int nr_vcpus); #endif /* SELFTEST_KVM_PERF_TEST_UTIL_H */ diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h index d78f97f502b5c..6ce185449259f 100644 --- a/tools/testing/selftests/kvm/include/x86_64/processor.h +++ b/tools/testing/selftests/kvm/include/x86_64/processor.h @@ -494,6 +494,10 @@ enum pg_level { #define PG_LEVEL_SHIFT(_level) ((_level - 1) * 9 + 12) #define PG_LEVEL_SIZE(_level) (1ull << PG_LEVEL_SHIFT(_level)) +#define PG_SIZE_4K PG_LEVEL_SIZE(PG_LEVEL_4K) +#define PG_SIZE_2M PG_LEVEL_SIZE(PG_LEVEL_2M) +#define PG_SIZE_1G PG_LEVEL_SIZE(PG_LEVEL_1G) + void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, int level); /* diff --git a/tools/testing/selftests/kvm/include/x86_64/vmx.h b/tools/testing/selftests/kvm/include/x86_64/vmx.h index 3b1794baa97cb..cc3604f8f1d3c 100644 --- a/tools/testing/selftests/kvm/include/x86_64/vmx.h +++ b/tools/testing/selftests/kvm/include/x86_64/vmx.h @@ -96,6 +96,7 @@ #define VMX_MISC_PREEMPTION_TIMER_RATE_MASK 0x0000001f #define VMX_MISC_SAVE_EFER_LMA 0x00000020 +#define VMX_EPT_VPID_CAP_1G_PAGES 0x00020000 #define VMX_EPT_VPID_CAP_AD_BITS 0x00200000 #define EXIT_REASON_FAILED_VMENTRY 0x80000000 @@ -608,6 +609,7 @@ bool load_vmcs(struct vmx_pages *vmx); bool nested_vmx_supported(void); void nested_vmx_check_supported(void); +bool ept_1g_pages_supported(void); void nested_pg_map(struct vmx_pages *vmx, struct kvm_vm *vm, uint64_t nested_paddr, uint64_t paddr); @@ -615,6 +617,8 @@ void nested_map(struct vmx_pages *vmx, struct kvm_vm *vm, uint64_t nested_paddr, uint64_t paddr, uint64_t size); void nested_map_memslot(struct vmx_pages *vmx, struct kvm_vm *vm, uint32_t memslot); +void nested_identity_map_1g(struct vmx_pages *vmx, struct kvm_vm *vm, + uint64_t addr, uint64_t size); void prepare_eptp(struct vmx_pages *vmx, struct kvm_vm *vm, uint32_t eptp_memslot); void prepare_virtualize_apic_accesses(struct vmx_pages *vmx, struct kvm_vm *vm); diff --git a/tools/testing/selftests/kvm/lib/perf_test_util.c b/tools/testing/selftests/kvm/lib/perf_test_util.c index 722df3a28791c..b2ff2cee2e51c 100644 --- a/tools/testing/selftests/kvm/lib/perf_test_util.c +++ b/tools/testing/selftests/kvm/lib/perf_test_util.c @@ -40,7 +40,7 @@ static bool all_vcpu_threads_running; * Continuously write to the first 8 bytes of each page in the * specified region. */ -static void guest_code(uint32_t vcpu_id) +void perf_test_guest_code(uint32_t vcpu_id) { struct perf_test_args *pta = &perf_test_args; struct perf_test_vcpu_args *vcpu_args = &pta->vcpu_args[vcpu_id]; @@ -108,7 +108,7 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int vcpus, { struct perf_test_args *pta = &perf_test_args; struct kvm_vm *vm; - uint64_t guest_num_pages; + uint64_t guest_num_pages, slot0_pages = DEFAULT_GUEST_PHY_PAGES; uint64_t backing_src_pagesz = get_backing_src_pagesz(backing_src); int i; @@ -134,13 +134,20 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int vcpus, "Guest memory cannot be evenly divided into %d slots.", slots); + /* + * If using nested, allocate extra pages for the nested page tables and + * in-memory data structures. + */ + if (pta->nested) + slot0_pages += perf_test_nested_pages(vcpus); + /* * Pass guest_num_pages to populate the page tables for test memory. * The memory is also added to memslot 0, but that's a benign side * effect as KVM allows aliasing HVAs in meslots. */ - vm = vm_create_with_vcpus(mode, vcpus, DEFAULT_GUEST_PHY_PAGES, - guest_num_pages, 0, guest_code, NULL); + vm = vm_create_with_vcpus(mode, vcpus, slot0_pages, guest_num_pages, 0, + perf_test_guest_code, NULL); pta->vm = vm; @@ -161,7 +168,9 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int vcpus, /* Align to 1M (segment size) */ pta->gpa = align_down(pta->gpa, 1 << 20); #endif - pr_info("guest physical test memory offset: 0x%lx\n", pta->gpa); + pta->size = guest_num_pages * pta->guest_page_size; + pr_info("guest physical test memory: [0x%lx, 0x%lx)\n", + pta->gpa, pta->gpa + pta->size); /* Add extra memory slots for testing */ for (i = 0; i < slots; i++) { @@ -178,6 +187,11 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int vcpus, perf_test_setup_vcpus(vm, vcpus, vcpu_memory_bytes, partition_vcpu_memory_access); + if (pta->nested) { + pr_info("Configuring vCPUs to run in L2 (nested).\n"); + perf_test_setup_nested(vm, vcpus); + } + ucall_init(vm, NULL); /* Export the shared variables to the guest. */ @@ -198,6 +212,17 @@ void perf_test_set_wr_fract(struct kvm_vm *vm, int wr_fract) sync_global_to_guest(vm, perf_test_args); } +uint64_t __weak perf_test_nested_pages(int nr_vcpus) +{ + return 0; +} + +void __weak perf_test_setup_nested(struct kvm_vm *vm, int nr_vcpus) +{ + pr_info("%s() not support on this architecture, skipping.\n", __func__); + exit(KSFT_SKIP); +} + static void *vcpu_thread_main(void *data) { struct vcpu_thread *vcpu = data; diff --git a/tools/testing/selftests/kvm/lib/x86_64/perf_test_util.c b/tools/testing/selftests/kvm/lib/x86_64/perf_test_util.c new file mode 100644 index 0000000000000..e258524435a06 --- /dev/null +++ b/tools/testing/selftests/kvm/lib/x86_64/perf_test_util.c @@ -0,0 +1,112 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * x86_64-specific extensions to perf_test_util.c. + * + * Copyright (C) 2022, Google, Inc. + */ +#include +#include +#include +#include + +#include "test_util.h" +#include "kvm_util.h" +#include "perf_test_util.h" +#include "../kvm_util_internal.h" +#include "processor.h" +#include "vmx.h" + +void perf_test_l2_guest_code(uint64_t vcpu_id) +{ + perf_test_guest_code(vcpu_id); + vmcall(); +} + +extern char perf_test_l2_guest_entry[]; +__asm__( +"perf_test_l2_guest_entry:" +" mov (%rsp), %rdi;" +" call perf_test_l2_guest_code;" +" ud2;" +); + +static void perf_test_l1_guest_code(struct vmx_pages *vmx, uint64_t vcpu_id) +{ +#define L2_GUEST_STACK_SIZE 64 + unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE]; + unsigned long *rsp; + + GUEST_ASSERT(vmx->vmcs_gpa); + GUEST_ASSERT(prepare_for_vmx_operation(vmx)); + GUEST_ASSERT(load_vmcs(vmx)); + GUEST_ASSERT(ept_1g_pages_supported()); + + rsp = &l2_guest_stack[L2_GUEST_STACK_SIZE - 1]; + *rsp = vcpu_id; + prepare_vmcs(vmx, perf_test_l2_guest_entry, rsp); + + GUEST_ASSERT(!vmlaunch()); + GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL); + GUEST_DONE(); +} + +uint64_t perf_test_nested_pages(int nr_vcpus) +{ + /* + * 513 page tables is enough to identity-map 256 TiB of L2 with 1G + * pages and 4-level paging, plus a few pages per-vCPU for data + * structures such as the VMCS. + */ + return 513 + 10 * nr_vcpus; +} + +void perf_test_setup_ept(struct vmx_pages *vmx, struct kvm_vm *vm) +{ + uint64_t start, end; + + prepare_eptp(vmx, vm, 0); + + /* + * Identity map the first 4G and the test region with 1G pages so that + * KVM can shadow the EPT12 with the maximum huge page size supported + * by the backing source. + */ + nested_identity_map_1g(vmx, vm, 0, 0x100000000ULL); + + start = align_down(perf_test_args.gpa, PG_SIZE_1G); + end = align_up(perf_test_args.gpa + perf_test_args.size, PG_SIZE_1G); + nested_identity_map_1g(vmx, vm, start, end - start); +} + +void perf_test_setup_nested(struct kvm_vm *vm, int nr_vcpus) +{ + struct vmx_pages *vmx, *vmx0 = NULL; + struct kvm_regs regs; + vm_vaddr_t vmx_gva; + int vcpu_id; + + nested_vmx_check_supported(); + + for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) { + vmx = vcpu_alloc_vmx(vm, &vmx_gva); + + if (vcpu_id == 0) { + perf_test_setup_ept(vmx, vm); + vmx0 = vmx; + } else { + /* Share the same EPT table across all vCPUs. */ + vmx->eptp = vmx0->eptp; + vmx->eptp_hva = vmx0->eptp_hva; + vmx->eptp_gpa = vmx0->eptp_gpa; + } + + /* + * Override the vCPU to run perf_test_l1_guest_code() which will + * bounce it into L2 before calling perf_test_guest_code(). + */ + vcpu_regs_get(vm, vcpu_id, ®s); + regs.rip = (unsigned long) perf_test_l1_guest_code; + vcpu_regs_set(vm, vcpu_id, ®s); + vcpu_args_set(vm, vcpu_id, 2, vmx_gva, vcpu_id); + } +} diff --git a/tools/testing/selftests/kvm/lib/x86_64/vmx.c b/tools/testing/selftests/kvm/lib/x86_64/vmx.c index 5bf1691794557..b77a01d0a2713 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/vmx.c +++ b/tools/testing/selftests/kvm/lib/x86_64/vmx.c @@ -203,6 +203,11 @@ static bool ept_vpid_cap_supported(uint64_t mask) return rdmsr(MSR_IA32_VMX_EPT_VPID_CAP) & mask; } +bool ept_1g_pages_supported(void) +{ + return ept_vpid_cap_supported(VMX_EPT_VPID_CAP_1G_PAGES); +} + /* * Initialize the control fields to the most basic settings possible. */ @@ -439,6 +444,9 @@ void __nested_pg_map(struct vmx_pages *vmx, struct kvm_vm *vm, TEST_ASSERT(vm->mode == VM_MODE_PXXV48_4K, "Attempt to use " "unknown or unsupported guest mode, mode: 0x%x", vm->mode); + TEST_ASSERT((nested_paddr >> 48) == 0, + "Nested physical address 0x%lx requires 5-level paging", + nested_paddr); TEST_ASSERT((nested_paddr % page_size) == 0, "Nested physical address not on page boundary,\n" " nested_paddr: 0x%lx page_size: 0x%lx", @@ -547,6 +555,13 @@ void nested_map_memslot(struct vmx_pages *vmx, struct kvm_vm *vm, } } +/* Identity map a region with 1GiB Pages. */ +void nested_identity_map_1g(struct vmx_pages *vmx, struct kvm_vm *vm, + uint64_t addr, uint64_t size) +{ + __nested_map(vmx, vm, addr, addr, size, PG_LEVEL_1G); +} + void prepare_eptp(struct vmx_pages *vmx, struct kvm_vm *vm, uint32_t eptp_memslot) { From e0f3f46e42064a51573914766897b4ab95d943e3 Mon Sep 17 00:00:00 2001 From: David Matlack Date: Fri, 20 May 2022 23:32:49 +0000 Subject: [PATCH 34/34] KVM: selftests: Restrict test region to 48-bit physical addresses when using nested The selftests nested code only supports 4-level paging at the moment. This means it cannot map nested guest physical addresses with more than 48 bits. Allow perf_test_util nested mode to work on hosts with more than 48 physical addresses by restricting the guest test region to 48-bits. While here, opportunistically fix an off-by-one error when dealing with vm_get_max_gfn(). perf_test_util.c was treating this as the maximum number of GFNs, rather than the maximum allowed GFN. This didn't result in any correctness issues, but it did end up shifting the test region down slightly when using huge pages. Suggested-by: Sean Christopherson Signed-off-by: David Matlack Message-Id: <20220520233249.3776001-12-dmatlack@google.com> Signed-off-by: Paolo Bonzini --- .../testing/selftests/kvm/lib/perf_test_util.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/kvm/lib/perf_test_util.c b/tools/testing/selftests/kvm/lib/perf_test_util.c index b2ff2cee2e51c..f989ff91f022a 100644 --- a/tools/testing/selftests/kvm/lib/perf_test_util.c +++ b/tools/testing/selftests/kvm/lib/perf_test_util.c @@ -110,6 +110,7 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int vcpus, struct kvm_vm *vm; uint64_t guest_num_pages, slot0_pages = DEFAULT_GUEST_PHY_PAGES; uint64_t backing_src_pagesz = get_backing_src_pagesz(backing_src); + uint64_t region_end_gfn; int i; pr_info("Testing guest mode: %s\n", vm_guest_mode_string(mode)); @@ -151,18 +152,29 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int vcpus, pta->vm = vm; + /* Put the test region at the top guest physical memory. */ + region_end_gfn = vm_get_max_gfn(vm) + 1; + +#ifdef __x86_64__ + /* + * When running vCPUs in L2, restrict the test region to 48 bits to + * avoid needing 5-level page tables to identity map L2. + */ + if (pta->nested) + region_end_gfn = min(region_end_gfn, (1UL << 48) / pta->guest_page_size); +#endif /* * If there should be more memory in the guest test region than there * can be pages in the guest, it will definitely cause problems. */ - TEST_ASSERT(guest_num_pages < vm_get_max_gfn(vm), + TEST_ASSERT(guest_num_pages < region_end_gfn, "Requested more guest memory than address space allows.\n" " guest pages: %" PRIx64 " max gfn: %" PRIx64 " vcpus: %d wss: %" PRIx64 "]\n", - guest_num_pages, vm_get_max_gfn(vm), vcpus, + guest_num_pages, region_end_gfn - 1, vcpus, vcpu_memory_bytes); - pta->gpa = (vm_get_max_gfn(vm) - guest_num_pages) * pta->guest_page_size; + pta->gpa = (region_end_gfn - guest_num_pages) * pta->guest_page_size; pta->gpa = align_down(pta->gpa, backing_src_pagesz); #ifdef __s390x__ /* Align to 1M (segment size) */