Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm fixes from Paolo Bonzini:
 "ARM:

   - Correctly clean the BSS to the PoC before allowing EL2 to access it
     on nVHE/hVHE/protected configurations

   - Propagate ownership of debug registers in protected mode after the
     rework that landed in 6.14-rc1

   - Stop pretending that we can run the protected mode without a GICv3
     being present on the host

   - Fix a use-after-free situation that can occur if a vcpu fails to
     initialise the NV shadow S2 MMU contexts

   - Always evaluate the need to arm a background timer for fully
     emulated guest timers

   - Fix the emulation of EL1 timers in the absence of FEAT_ECV

   - Correctly handle the EL2 virtual timer, specially when HCR_EL2.E2H==0

  s390:

   - move some of the guest page table (gmap) logic into KVM itself,
     inching towards the final goal of completely removing gmap from the
     non-kvm memory management code.

     As an initial set of cleanups, move some code from mm/gmap into kvm
     and start using __kvm_faultin_pfn() to fault-in pages as needed;
     but especially stop abusing page->index and page->lru to aid in the
     pgdesc conversion.

  x86:

   - Add missing check in the fix to defer starting the huge page
     recovery vhost_task

   - SRSO_USER_KERNEL_NO does not need SYNTHESIZED_F"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (31 commits)
  KVM: x86/mmu: Ensure NX huge page recovery thread is alive before waking
  KVM: remove kvm_arch_post_init_vm
  KVM: selftests: Fix spelling mistake "initally" -> "initially"
  kvm: x86: SRSO_USER_KERNEL_NO is not synthesized
  KVM: arm64: timer: Don't adjust the EL2 virtual timer offset
  KVM: arm64: timer: Correctly handle EL1 timer emulation when !FEAT_ECV
  KVM: arm64: timer: Always evaluate the need for a soft timer
  KVM: arm64: Fix nested S2 MMU structures reallocation
  KVM: arm64: Fail protected mode init if no vgic hardware is present
  KVM: arm64: Flush/sync debug state in protected mode
  KVM: s390: selftests: Streamline uc_skey test to issue iske after sske
  KVM: s390: remove the last user of page->index
  KVM: s390: move PGSTE softbits
  KVM: s390: remove useless page->index usage
  KVM: s390: move gmap_shadow_pgt_lookup() into kvm
  KVM: s390: stop using lists to keep track of used dat tables
  KVM: s390: stop using page->index for non-shadow gmaps
  KVM: s390: move some gmap shadowing functions away from mm/gmap.c
  KVM: s390: get rid of gmap_translate()
  KVM: s390: get rid of gmap_fault()
  ...

Documentation/virt/kvm/api.rst

@@ -1419,7 +1419,7 @@ fetch) is injected in the guest.
 S390:
 ^^^^^
 
-Returns -EINVAL if the VM has the KVM_VM_S390_UCONTROL flag set.
+Returns -EINVAL or -EEXIST if the VM has the KVM_VM_S390_UCONTROL flag set.
 Returns -EINVAL if called on a protected VM.
 
 4.36 KVM_SET_TSS_ADDR

arch/arm64/kvm/arch_timer.c

@@ -471,10 +471,8 @@ static void timer_emulate(struct arch_timer_context *ctx)
 
 	trace_kvm_timer_emulate(ctx, should_fire);
 
-	if (should_fire != ctx->irq.level) {
+	if (should_fire != ctx->irq.level)
 		kvm_timer_update_irq(ctx->vcpu, should_fire, ctx);
-		return;
-	}
 
 	kvm_timer_update_status(ctx, should_fire);
 
@@ -761,21 +759,6 @@ static void kvm_timer_vcpu_load_nested_switch(struct kvm_vcpu *vcpu,
 					    timer_irq(map->direct_ptimer),
 					    &arch_timer_irq_ops);
 		WARN_ON_ONCE(ret);
-
-		/*
-		 * The virtual offset behaviour is "interesting", as it
-		 * always applies when HCR_EL2.E2H==0, but only when
-		 * accessed from EL1 when HCR_EL2.E2H==1. So make sure we
-		 * track E2H when putting the HV timer in "direct" mode.
-		 */
-		if (map->direct_vtimer == vcpu_hvtimer(vcpu)) {
-			struct arch_timer_offset *offs = &map->direct_vtimer->offset;
-
-			if (vcpu_el2_e2h_is_set(vcpu))
-				offs->vcpu_offset = NULL;
-			else
-				offs->vcpu_offset = &__vcpu_sys_reg(vcpu, CNTVOFF_EL2);
-		}
 	}
 }
 
@@ -976,31 +959,21 @@ void kvm_timer_sync_nested(struct kvm_vcpu *vcpu)
 	 * which allows trapping of the timer registers even with NV2.
 	 * Still, this is still worse than FEAT_NV on its own. Meh.
 	 */
-	if (!vcpu_el2_e2h_is_set(vcpu)) {
-		if (cpus_have_final_cap(ARM64_HAS_ECV))
-			return;
-
-		/*
-		 * A non-VHE guest hypervisor doesn't have any direct access
-		 * to its timers: the EL2 registers trap (and the HW is
-		 * fully emulated), while the EL0 registers access memory
-		 * despite the access being notionally direct. Boo.
-		 *
-		 * We update the hardware timer registers with the
-		 * latest value written by the guest to the VNCR page
-		 * and let the hardware take care of the rest.
-		 */
-		write_sysreg_el0(__vcpu_sys_reg(vcpu, CNTV_CTL_EL0),  SYS_CNTV_CTL);
-		write_sysreg_el0(__vcpu_sys_reg(vcpu, CNTV_CVAL_EL0), SYS_CNTV_CVAL);
-		write_sysreg_el0(__vcpu_sys_reg(vcpu, CNTP_CTL_EL0),  SYS_CNTP_CTL);
-		write_sysreg_el0(__vcpu_sys_reg(vcpu, CNTP_CVAL_EL0), SYS_CNTP_CVAL);
-	} else {
+	if (!cpus_have_final_cap(ARM64_HAS_ECV)) {
 		/*
 		 * For a VHE guest hypervisor, the EL2 state is directly
-		 * stored in the host EL1 timers, while the emulated EL0
+		 * stored in the host EL1 timers, while the emulated EL1
 		 * state is stored in the VNCR page. The latter could have
 		 * been updated behind our back, and we must reset the
 		 * emulation of the timers.
+		 *
+		 * A non-VHE guest hypervisor doesn't have any direct access
+		 * to its timers: the EL2 registers trap despite being
+		 * notionally direct (we use the EL1 HW, as for VHE), while
+		 * the EL1 registers access memory.
+		 *
+		 * In both cases, process the emulated timers on each guest
+		 * exit. Boo.
 		 */
 		struct timer_map map;
 		get_timer_map(vcpu, &map);

arch/arm64/kvm/arm.c

@@ -2290,6 +2290,19 @@ static int __init init_subsystems(void)
 		break;
 	case -ENODEV:
 	case -ENXIO:
+		/*
+		 * No VGIC? No pKVM for you.
+		 *
+		 * Protected mode assumes that VGICv3 is present, so no point
+		 * in trying to hobble along if vgic initialization fails.
+		 */
+		if (is_protected_kvm_enabled())
+			goto out;
+
+		/*
+		 * Otherwise, userspace could choose to implement a GIC for its
+		 * guest on non-cooperative hardware.
+		 */
 		vgic_present = false;
 		err = 0;
 		break;
@@ -2400,6 +2413,13 @@ static void kvm_hyp_init_symbols(void)
 	kvm_nvhe_sym(id_aa64smfr0_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64SMFR0_EL1);
 	kvm_nvhe_sym(__icache_flags) = __icache_flags;
 	kvm_nvhe_sym(kvm_arm_vmid_bits) = kvm_arm_vmid_bits;
+
+	/*
+	 * Flush entire BSS since part of its data containing init symbols is read
+	 * while the MMU is off.
+	 */
+	kvm_flush_dcache_to_poc(kvm_ksym_ref(__hyp_bss_start),
+				kvm_ksym_ref(__hyp_bss_end) - kvm_ksym_ref(__hyp_bss_start));
 }
 
 static int __init kvm_hyp_init_protection(u32 hyp_va_bits)

arch/arm64/kvm/hyp/nvhe/hyp-main.c

@@ -91,11 +91,34 @@ static void fpsimd_sve_sync(struct kvm_vcpu *vcpu)
 	*host_data_ptr(fp_owner) = FP_STATE_HOST_OWNED;
 }
 
+static void flush_debug_state(struct pkvm_hyp_vcpu *hyp_vcpu)
+{
+	struct kvm_vcpu *host_vcpu = hyp_vcpu->host_vcpu;
+
+	hyp_vcpu->vcpu.arch.debug_owner = host_vcpu->arch.debug_owner;
+
+	if (kvm_guest_owns_debug_regs(&hyp_vcpu->vcpu))
+		hyp_vcpu->vcpu.arch.vcpu_debug_state = host_vcpu->arch.vcpu_debug_state;
+	else if (kvm_host_owns_debug_regs(&hyp_vcpu->vcpu))
+		hyp_vcpu->vcpu.arch.external_debug_state = host_vcpu->arch.external_debug_state;
+}
+
+static void sync_debug_state(struct pkvm_hyp_vcpu *hyp_vcpu)
+{
+	struct kvm_vcpu *host_vcpu = hyp_vcpu->host_vcpu;
+
+	if (kvm_guest_owns_debug_regs(&hyp_vcpu->vcpu))
+		host_vcpu->arch.vcpu_debug_state = hyp_vcpu->vcpu.arch.vcpu_debug_state;
+	else if (kvm_host_owns_debug_regs(&hyp_vcpu->vcpu))
+		host_vcpu->arch.external_debug_state = hyp_vcpu->vcpu.arch.external_debug_state;
+}
+
 static void flush_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu)
 {
 	struct kvm_vcpu *host_vcpu = hyp_vcpu->host_vcpu;
 
 	fpsimd_sve_flush();
+	flush_debug_state(hyp_vcpu);
 
 	hyp_vcpu->vcpu.arch.ctxt	= host_vcpu->arch.ctxt;
 
@@ -123,6 +146,7 @@ static void sync_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu)
 	unsigned int i;
 
 	fpsimd_sve_sync(&hyp_vcpu->vcpu);
+	sync_debug_state(hyp_vcpu);
 
 	host_vcpu->arch.ctxt		= hyp_vcpu->vcpu.arch.ctxt;
 

arch/arm64/kvm/nested.c

@@ -67,26 +67,27 @@ int kvm_vcpu_init_nested(struct kvm_vcpu *vcpu)
 	if (!tmp)
 		return -ENOMEM;
 
+	swap(kvm->arch.nested_mmus, tmp);
+
 	/*
 	 * If we went through a realocation, adjust the MMU back-pointers in
 	 * the previously initialised kvm_pgtable structures.
 	 */
 	if (kvm->arch.nested_mmus != tmp)
 		for (int i = 0; i < kvm->arch.nested_mmus_size; i++)
-			tmp[i].pgt->mmu = &tmp[i];
+			kvm->arch.nested_mmus[i].pgt->mmu = &kvm->arch.nested_mmus[i];
 
 	for (int i = kvm->arch.nested_mmus_size; !ret && i < num_mmus; i++)
-		ret = init_nested_s2_mmu(kvm, &tmp[i]);
+		ret = init_nested_s2_mmu(kvm, &kvm->arch.nested_mmus[i]);
 
 	if (ret) {
 		for (int i = kvm->arch.nested_mmus_size; i < num_mmus; i++)
-			kvm_free_stage2_pgd(&tmp[i]);
+			kvm_free_stage2_pgd(&kvm->arch.nested_mmus[i]);
 
 		return ret;
 	}
 
 	kvm->arch.nested_mmus_size = num_mmus;
-	kvm->arch.nested_mmus = tmp;
 
 	return 0;
 }

arch/arm64/kvm/sys_regs.c

@@ -1452,6 +1452,16 @@ static bool access_arch_timer(struct kvm_vcpu *vcpu,
 	return true;
 }
 
+static bool access_hv_timer(struct kvm_vcpu *vcpu,
+			    struct sys_reg_params *p,
+			    const struct sys_reg_desc *r)
+{
+	if (!vcpu_el2_e2h_is_set(vcpu))
+		return undef_access(vcpu, p, r);
+
+	return access_arch_timer(vcpu, p, r);
+}
+
 static s64 kvm_arm64_ftr_safe_value(u32 id, const struct arm64_ftr_bits *ftrp,
 				    s64 new, s64 cur)
 {
@@ -3103,9 +3113,9 @@ static const struct sys_reg_desc sys_reg_descs[] = {
 	EL2_REG(CNTHP_CTL_EL2, access_arch_timer, reset_val, 0),
 	EL2_REG(CNTHP_CVAL_EL2, access_arch_timer, reset_val, 0),
 
-	{ SYS_DESC(SYS_CNTHV_TVAL_EL2), access_arch_timer },
-	EL2_REG(CNTHV_CTL_EL2, access_arch_timer, reset_val, 0),
-	EL2_REG(CNTHV_CVAL_EL2, access_arch_timer, reset_val, 0),
+	{ SYS_DESC(SYS_CNTHV_TVAL_EL2), access_hv_timer },
+	EL2_REG(CNTHV_CTL_EL2, access_hv_timer, reset_val, 0),
+	EL2_REG(CNTHV_CVAL_EL2, access_hv_timer, reset_val, 0),
 
 	{ SYS_DESC(SYS_CNTKCTL_EL12), access_cntkctl_el12 },
 

arch/s390/include/asm/gmap.h

@@ -23,7 +23,6 @@
 /**
  * struct gmap_struct - guest address space
  * @list: list head for the mm->context gmap list
- * @crst_list: list of all crst tables used in the guest address space
  * @mm: pointer to the parent mm_struct
  * @guest_to_host: radix tree with guest to host address translation
  * @host_to_guest: radix tree with pointer to segment table entries
@@ -35,7 +34,6 @@
  * @guest_handle: protected virtual machine handle for the ultravisor
  * @host_to_rmap: radix tree with gmap_rmap lists
  * @children: list of shadow gmap structures
- * @pt_list: list of all page tables used in the shadow guest address space
  * @shadow_lock: spinlock to protect the shadow gmap list
  * @parent: pointer to the parent gmap for shadow guest address spaces
  * @orig_asce: ASCE for which the shadow page table has been created
@@ -45,7 +43,6 @@
  */
 struct gmap {
 	struct list_head list;
-	struct list_head crst_list;
 	struct mm_struct *mm;
 	struct radix_tree_root guest_to_host;
 	struct radix_tree_root host_to_guest;
@@ -61,7 +58,6 @@ struct gmap {
 	/* Additional data for shadow guest address spaces */
 	struct radix_tree_root host_to_rmap;
 	struct list_head children;
-	struct list_head pt_list;
 	spinlock_t shadow_lock;
 	struct gmap *parent;
 	unsigned long orig_asce;
@@ -106,23 +102,21 @@ struct gmap *gmap_create(struct mm_struct *mm, unsigned long limit);
 void gmap_remove(struct gmap *gmap);
 struct gmap *gmap_get(struct gmap *gmap);
 void gmap_put(struct gmap *gmap);
+void gmap_free(struct gmap *gmap);
+struct gmap *gmap_alloc(unsigned long limit);
 
 int gmap_map_segment(struct gmap *gmap, unsigned long from,
 		     unsigned long to, unsigned long len);
 int gmap_unmap_segment(struct gmap *gmap, unsigned long to, unsigned long len);
 unsigned long __gmap_translate(struct gmap *, unsigned long gaddr);
-unsigned long gmap_translate(struct gmap *, unsigned long gaddr);
 int __gmap_link(struct gmap *gmap, unsigned long gaddr, unsigned long vmaddr);
-int gmap_fault(struct gmap *, unsigned long gaddr, unsigned int fault_flags);
 void gmap_discard(struct gmap *, unsigned long from, unsigned long to);
 void __gmap_zap(struct gmap *, unsigned long gaddr);
 void gmap_unlink(struct mm_struct *, unsigned long *table, unsigned long vmaddr);
 
 int gmap_read_table(struct gmap *gmap, unsigned long gaddr, unsigned long *val);
 
-struct gmap *gmap_shadow(struct gmap *parent, unsigned long asce,
-			 int edat_level);
-int gmap_shadow_valid(struct gmap *sg, unsigned long asce, int edat_level);
+void gmap_unshadow(struct gmap *sg);
 int gmap_shadow_r2t(struct gmap *sg, unsigned long saddr, unsigned long r2t,
 		    int fake);
 int gmap_shadow_r3t(struct gmap *sg, unsigned long saddr, unsigned long r3t,
@@ -131,24 +125,22 @@ int gmap_shadow_sgt(struct gmap *sg, unsigned long saddr, unsigned long sgt,
 		    int fake);
 int gmap_shadow_pgt(struct gmap *sg, unsigned long saddr, unsigned long pgt,
 		    int fake);
-int gmap_shadow_pgt_lookup(struct gmap *sg, unsigned long saddr,
-			   unsigned long *pgt, int *dat_protection, int *fake);
 int gmap_shadow_page(struct gmap *sg, unsigned long saddr, pte_t pte);
 
 void gmap_register_pte_notifier(struct gmap_notifier *);
 void gmap_unregister_pte_notifier(struct gmap_notifier *);
 
-int gmap_mprotect_notify(struct gmap *, unsigned long start,
-			 unsigned long len, int prot);
+int gmap_protect_one(struct gmap *gmap, unsigned long gaddr, int prot, unsigned long bits);
 
 void gmap_sync_dirty_log_pmd(struct gmap *gmap, unsigned long dirty_bitmap[4],
 			     unsigned long gaddr, unsigned long vmaddr);
 int s390_disable_cow_sharing(void);
-void s390_unlist_old_asce(struct gmap *gmap);
 int s390_replace_asce(struct gmap *gmap);
 void s390_uv_destroy_pfns(unsigned long count, unsigned long *pfns);
 int __s390_uv_destroy_range(struct mm_struct *mm, unsigned long start,
 			    unsigned long end, bool interruptible);
+int kvm_s390_wiggle_split_folio(struct mm_struct *mm, struct folio *folio, bool split);
+unsigned long *gmap_table_walk(struct gmap *gmap, unsigned long gaddr, int level);
 
 /**
  * s390_uv_destroy_range - Destroy a range of pages in the given mm.

arch/s390/include/asm/kvm_host.h

@@ -30,6 +30,8 @@
 #define KVM_S390_ESCA_CPU_SLOTS 248
 #define KVM_MAX_VCPUS 255
 
+#define KVM_INTERNAL_MEM_SLOTS 1
+
 /*
  * These seem to be used for allocating ->chip in the routing table, which we
  * don't use. 1 is as small as we can get to reduce the needed memory. If we
@@ -931,12 +933,14 @@ struct sie_page2 {
 	u8 reserved928[0x1000 - 0x928];			/* 0x0928 */
 };
 
+struct vsie_page;
+
 struct kvm_s390_vsie {
 	struct mutex mutex;
 	struct radix_tree_root addr_to_page;
 	int page_count;
 	int next;
-	struct page *pages[KVM_MAX_VCPUS];
+	struct vsie_page *pages[KVM_MAX_VCPUS];
 };
 
 struct kvm_s390_gisa_iam {

arch/s390/include/asm/pgtable.h

@@ -420,9 +420,10 @@ void setup_protection_map(void);
 #define PGSTE_HC_BIT	0x0020000000000000UL
 #define PGSTE_GR_BIT	0x0004000000000000UL
 #define PGSTE_GC_BIT	0x0002000000000000UL
-#define PGSTE_UC_BIT	0x0000800000000000UL	/* user dirty (migration) */
-#define PGSTE_IN_BIT	0x0000400000000000UL	/* IPTE notify bit */
-#define PGSTE_VSIE_BIT	0x0000200000000000UL	/* ref'd in a shadow table */
+#define PGSTE_ST2_MASK	0x0000ffff00000000UL
+#define PGSTE_UC_BIT	0x0000000000008000UL	/* user dirty (migration) */
+#define PGSTE_IN_BIT	0x0000000000004000UL	/* IPTE notify bit */
+#define PGSTE_VSIE_BIT	0x0000000000002000UL	/* ref'd in a shadow table */
 
 /* Guest Page State used for virtualization */
 #define _PGSTE_GPS_ZERO			0x0000000080000000UL
@@ -2007,4 +2008,18 @@ extern void s390_reset_cmma(struct mm_struct *mm);
 #define pmd_pgtable(pmd) \
 	((pgtable_t)__va(pmd_val(pmd) & -sizeof(pte_t)*PTRS_PER_PTE))
 
+static inline unsigned long gmap_pgste_get_pgt_addr(unsigned long *pgt)
+{
+	unsigned long *pgstes, res;
+
+	pgstes = pgt + _PAGE_ENTRIES;
+
+	res = (pgstes[0] & PGSTE_ST2_MASK) << 16;
+	res |= pgstes[1] & PGSTE_ST2_MASK;
+	res |= (pgstes[2] & PGSTE_ST2_MASK) >> 16;
+	res |= (pgstes[3] & PGSTE_ST2_MASK) >> 32;
+
+	return res;
+}
+
 #endif /* _S390_PAGE_H */

arch/s390/include/asm/uv.h

@@ -628,12 +628,12 @@ static inline int is_prot_virt_host(void)
 }
 
 int uv_pin_shared(unsigned long paddr);
-int gmap_make_secure(struct gmap *gmap, unsigned long gaddr, void *uvcb);
-int gmap_destroy_page(struct gmap *gmap, unsigned long gaddr);
 int uv_destroy_folio(struct folio *folio);
 int uv_destroy_pte(pte_t pte);
 int uv_convert_from_secure_pte(pte_t pte);
-int gmap_convert_to_secure(struct gmap *gmap, unsigned long gaddr);
+int make_folio_secure(struct folio *folio, struct uv_cb_header *uvcb);
+int uv_convert_from_secure(unsigned long paddr);
+int uv_convert_from_secure_folio(struct folio *folio);
 
 void setup_uv(void);