From ca0bde28f2ed66c2229ecfb7f4bfa0defa3da4b5 Mon Sep 17 00:00:00 2001 From: Jim Mattson Date: Wed, 30 Nov 2016 12:03:46 -0800 Subject: [PATCH] kvm: nVMX: Split VMCS checks from nested_vmx_run() The checks performed on the contents of the vmcs12 are extracted from nested_vmx_run so that they can be used to validate a vmcs12 that has been restored from a checkpoint. Signed-off-by: Jim Mattson [Change prepare_vmcs02 and nested_vmx_load_cr3's last argument to u32, to match check_vmentry_postreqs. Update comments for singlestep handling. - Paolo] Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx.c | 194 ++++++++++++++++++++++++--------------------- 1 file changed, 103 insertions(+), 91 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 650f34336fada..71df7411959fe 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -10035,7 +10035,7 @@ static bool nested_cr3_valid(struct kvm_vcpu *vcpu, unsigned long val) * is assigned to entry_failure_code on failure. */ static int nested_vmx_load_cr3(struct kvm_vcpu *vcpu, unsigned long cr3, bool nested_ept, - unsigned long *entry_failure_code) + u32 *entry_failure_code) { if (cr3 != kvm_read_cr3(vcpu) || (!nested_ept && pdptrs_changed(vcpu))) { if (!nested_cr3_valid(vcpu, cr3)) { @@ -10075,7 +10075,7 @@ static int nested_vmx_load_cr3(struct kvm_vcpu *vcpu, unsigned long cr3, bool ne * is assigned to entry_failure_code on failure. */ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, - bool from_vmentry, unsigned long *entry_failure_code) + bool from_vmentry, u32 *entry_failure_code) { struct vcpu_vmx *vmx = to_vmx(vcpu); u32 exec_control; @@ -10411,68 +10411,22 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, return 0; } -/* - * nested_vmx_run() handles a nested entry, i.e., a VMLAUNCH or VMRESUME on L1 - * for running an L2 nested guest. - */ -static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) +static int check_vmentry_prereqs(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) { - struct vmcs12 *vmcs12; struct vcpu_vmx *vmx = to_vmx(vcpu); - int cpu; - struct loaded_vmcs *vmcs02; - bool ia32e; - u32 msr_entry_idx; - unsigned long exit_qualification; - - if (!nested_vmx_check_permission(vcpu)) - return 1; - - if (!nested_vmx_check_vmcs12(vcpu)) - goto out; - - vmcs12 = get_vmcs12(vcpu); - - if (enable_shadow_vmcs) - copy_shadow_to_vmcs12(vmx); - - /* - * The nested entry process starts with enforcing various prerequisites - * on vmcs12 as required by the Intel SDM, and act appropriately when - * they fail: As the SDM explains, some conditions should cause the - * instruction to fail, while others will cause the instruction to seem - * to succeed, but return an EXIT_REASON_INVALID_STATE. - * To speed up the normal (success) code path, we should avoid checking - * for misconfigurations which will anyway be caught by the processor - * when using the merged vmcs02. - */ - if (vmcs12->launch_state == launch) { - nested_vmx_failValid(vcpu, - launch ? VMXERR_VMLAUNCH_NONCLEAR_VMCS - : VMXERR_VMRESUME_NONLAUNCHED_VMCS); - goto out; - } if (vmcs12->guest_activity_state != GUEST_ACTIVITY_ACTIVE && - vmcs12->guest_activity_state != GUEST_ACTIVITY_HLT) { - nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD); - goto out; - } + vmcs12->guest_activity_state != GUEST_ACTIVITY_HLT) + return VMXERR_ENTRY_INVALID_CONTROL_FIELD; - if (nested_vmx_check_msr_bitmap_controls(vcpu, vmcs12)) { - nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD); - goto out; - } + if (nested_vmx_check_msr_bitmap_controls(vcpu, vmcs12)) + return VMXERR_ENTRY_INVALID_CONTROL_FIELD; - if (nested_vmx_check_apicv_controls(vcpu, vmcs12)) { - nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD); - goto out; - } + if (nested_vmx_check_apicv_controls(vcpu, vmcs12)) + return VMXERR_ENTRY_INVALID_CONTROL_FIELD; - if (nested_vmx_check_msr_switch_controls(vcpu, vmcs12)) { - nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD); - goto out; - } + if (nested_vmx_check_msr_switch_controls(vcpu, vmcs12)) + return VMXERR_ENTRY_INVALID_CONTROL_FIELD; if (!vmx_control_verify(vmcs12->cpu_based_vm_exec_control, vmx->nested.nested_vmx_procbased_ctls_low, @@ -10489,28 +10443,30 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) !vmx_control_verify(vmcs12->vm_entry_controls, vmx->nested.nested_vmx_entry_ctls_low, vmx->nested.nested_vmx_entry_ctls_high)) - { - nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD); - goto out; - } + return VMXERR_ENTRY_INVALID_CONTROL_FIELD; if (!nested_host_cr0_valid(vcpu, vmcs12->host_cr0) || !nested_host_cr4_valid(vcpu, vmcs12->host_cr4) || - !nested_cr3_valid(vcpu, vmcs12->host_cr3)) { - nested_vmx_failValid(vcpu, - VMXERR_ENTRY_INVALID_HOST_STATE_FIELD); - goto out; - } + !nested_cr3_valid(vcpu, vmcs12->host_cr3)) + return VMXERR_ENTRY_INVALID_HOST_STATE_FIELD; + + return 0; +} + +static int check_vmentry_postreqs(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, + u32 *exit_qual) +{ + bool ia32e; + + *exit_qual = ENTRY_FAIL_DEFAULT; if (!nested_guest_cr0_valid(vcpu, vmcs12->guest_cr0) || - !nested_guest_cr4_valid(vcpu, vmcs12->guest_cr4)) { - nested_vmx_entry_failure(vcpu, vmcs12, - EXIT_REASON_INVALID_STATE, ENTRY_FAIL_DEFAULT); + !nested_guest_cr4_valid(vcpu, vmcs12->guest_cr4)) return 1; - } - if (vmcs12->vmcs_link_pointer != -1ull) { - nested_vmx_entry_failure(vcpu, vmcs12, - EXIT_REASON_INVALID_STATE, ENTRY_FAIL_VMCS_LINK_PTR); + + if (!nested_cpu_has2(vmcs12, SECONDARY_EXEC_SHADOW_VMCS) && + vmcs12->vmcs_link_pointer != -1ull) { + *exit_qual = ENTRY_FAIL_VMCS_LINK_PTR; return 1; } @@ -10523,16 +10479,14 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) * to bit 8 (LME) if bit 31 in the CR0 field (corresponding to * CR0.PG) is 1. */ - if (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_EFER) { + if (to_vmx(vcpu)->nested.nested_run_pending && + (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_EFER)) { ia32e = (vmcs12->vm_entry_controls & VM_ENTRY_IA32E_MODE) != 0; if (!kvm_valid_efer(vcpu, vmcs12->guest_ia32_efer) || ia32e != !!(vmcs12->guest_ia32_efer & EFER_LMA) || ((vmcs12->guest_cr0 & X86_CR0_PG) && - ia32e != !!(vmcs12->guest_ia32_efer & EFER_LME))) { - nested_vmx_entry_failure(vcpu, vmcs12, - EXIT_REASON_INVALID_STATE, ENTRY_FAIL_DEFAULT); + ia32e != !!(vmcs12->guest_ia32_efer & EFER_LME))) return 1; - } } /* @@ -10546,11 +10500,75 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) VM_EXIT_HOST_ADDR_SPACE_SIZE) != 0; if (!kvm_valid_efer(vcpu, vmcs12->host_ia32_efer) || ia32e != !!(vmcs12->host_ia32_efer & EFER_LMA) || - ia32e != !!(vmcs12->host_ia32_efer & EFER_LME)) { - nested_vmx_entry_failure(vcpu, vmcs12, - EXIT_REASON_INVALID_STATE, ENTRY_FAIL_DEFAULT); + ia32e != !!(vmcs12->host_ia32_efer & EFER_LME)) return 1; - } + } + + return 0; +} + +/* + * nested_vmx_run() handles a nested entry, i.e., a VMLAUNCH or VMRESUME on L1 + * for running an L2 nested guest. + */ +static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) +{ + struct vmcs12 *vmcs12; + struct vcpu_vmx *vmx = to_vmx(vcpu); + int cpu; + struct loaded_vmcs *vmcs02; + u32 msr_entry_idx; + u32 exit_qual; + int ret; + + if (!nested_vmx_check_permission(vcpu)) + return 1; + + if (!nested_vmx_check_vmcs12(vcpu)) + goto out; + + vmcs12 = get_vmcs12(vcpu); + + if (enable_shadow_vmcs) + copy_shadow_to_vmcs12(vmx); + + /* + * The nested entry process starts with enforcing various prerequisites + * on vmcs12 as required by the Intel SDM, and act appropriately when + * they fail: As the SDM explains, some conditions should cause the + * instruction to fail, while others will cause the instruction to seem + * to succeed, but return an EXIT_REASON_INVALID_STATE. + * To speed up the normal (success) code path, we should avoid checking + * for misconfigurations which will anyway be caught by the processor + * when using the merged vmcs02. + */ + if (vmcs12->launch_state == launch) { + nested_vmx_failValid(vcpu, + launch ? VMXERR_VMLAUNCH_NONCLEAR_VMCS + : VMXERR_VMRESUME_NONLAUNCHED_VMCS); + goto out; + } + + ret = check_vmentry_prereqs(vcpu, vmcs12); + if (ret) { + nested_vmx_failValid(vcpu, ret); + goto out; + } + + /* + * After this point, the trap flag no longer triggers a singlestep trap + * on the vm entry instructions; don't call kvm_skip_emulated_instruction. + * This is not 100% correct; for performance reasons, we delegate most + * of the checks on host state to the processor. If those fail, + * the singlestep trap is missed. + */ + skip_emulated_instruction(vcpu); + + ret = check_vmentry_postreqs(vcpu, vmcs12, &exit_qual); + if (ret) { + nested_vmx_entry_failure(vcpu, vmcs12, + EXIT_REASON_INVALID_STATE, exit_qual); + return 1; } /* @@ -10562,12 +10580,6 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) if (!vmcs02) return -ENOMEM; - /* - * After this point, the trap flag no longer triggers a singlestep trap - * on the vm entry instructions. Don't call - * kvm_skip_emulated_instruction. - */ - skip_emulated_instruction(vcpu); enter_guest_mode(vcpu); if (!(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_DEBUG_CONTROLS)) @@ -10582,11 +10594,11 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) vmx_segment_cache_clear(vmx); - if (prepare_vmcs02(vcpu, vmcs12, true, &exit_qualification)) { + if (prepare_vmcs02(vcpu, vmcs12, true, &exit_qual)) { leave_guest_mode(vcpu); vmx_load_vmcs01(vcpu); nested_vmx_entry_failure(vcpu, vmcs12, - EXIT_REASON_INVALID_STATE, exit_qualification); + EXIT_REASON_INVALID_STATE, exit_qual); return 1; } @@ -10937,7 +10949,7 @@ static void load_vmcs12_host_state(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) { struct kvm_segment seg; - unsigned long entry_failure_code; + u32 entry_failure_code; if (vmcs12->vm_exit_controls & VM_EXIT_LOAD_IA32_EFER) vcpu->arch.efer = vmcs12->host_ia32_efer;