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

Pull kvm updates from Paolo Bonzini:
 "ARM:

   - Initial infrastructure for shadow stage-2 MMUs, as part of nested
     virtualization enablement

   - Support for userspace changes to the guest CTR_EL0 value, enabling
     (in part) migration of VMs between heterogenous hardware

   - Fixes + improvements to pKVM's FF-A proxy, adding support for v1.1
     of the protocol

   - FPSIMD/SVE support for nested, including merged trap configuration
     and exception routing

   - New command-line parameter to control the WFx trap behavior under
     KVM

   - Introduce kCFI hardening in the EL2 hypervisor

   - Fixes + cleanups for handling presence/absence of FEAT_TCRX

   - Miscellaneous fixes + documentation updates

  LoongArch:

   - Add paravirt steal time support

   - Add support for KVM_DIRTY_LOG_INITIALLY_SET

   - Add perf kvm-stat support for loongarch

  RISC-V:

   - Redirect AMO load/store access fault traps to guest

   - perf kvm stat support

   - Use guest files for IMSIC virtualization, when available

  s390:

   - Assortment of tiny fixes which are not time critical

  x86:

   - Fixes for Xen emulation

   - Add a global struct to consolidate tracking of host values, e.g.
     EFER

   - Add KVM_CAP_X86_APIC_BUS_CYCLES_NS to allow configuring the
     effective APIC bus frequency, because TDX

   - Print the name of the APICv/AVIC inhibits in the relevant
     tracepoint

   - Clean up KVM's handling of vendor specific emulation to
     consistently act on "compatible with Intel/AMD", versus checking
     for a specific vendor

   - Drop MTRR virtualization, and instead always honor guest PAT on
     CPUs that support self-snoop

   - Update to the newfangled Intel CPU FMS infrastructure

   - Don't advertise IA32_PERF_GLOBAL_OVF_CTRL as an MSR-to-be-saved, as
     it reads '0' and writes from userspace are ignored

   - Misc cleanups

  x86 - MMU:

   - Small cleanups, renames and refactoring extracted from the upcoming
     Intel TDX support

   - Don't allocate kvm_mmu_page.shadowed_translation for shadow pages
     that can't hold leafs SPTEs

   - Unconditionally drop mmu_lock when allocating TDP MMU page tables
     for eager page splitting, to avoid stalling vCPUs when splitting
     huge pages

   - Bug the VM instead of simply warning if KVM tries to split a SPTE
     that is non-present or not-huge. KVM is guaranteed to end up in a
     broken state because the callers fully expect a valid SPTE, it's
     all but dangerous to let more MMU changes happen afterwards

  x86 - AMD:

   - Make per-CPU save_area allocations NUMA-aware

   - Force sev_es_host_save_area() to be inlined to avoid calling into
     an instrumentable function from noinstr code

   - Base support for running SEV-SNP guests. API-wise, this includes a
     new KVM_X86_SNP_VM type, encrypting/measure the initial image into
     guest memory, and finalizing it before launching it. Internally,
     there are some gmem/mmu hooks needed to prepare gmem-allocated
     pages before mapping them into guest private memory ranges

     This includes basic support for attestation guest requests, enough
     to say that KVM supports the GHCB 2.0 specification

     There is no support yet for loading into the firmware those signing
     keys to be used for attestation requests, and therefore no need yet
     for the host to provide certificate data for those keys.

     To support fetching certificate data from userspace, a new KVM exit
     type will be needed to handle fetching the certificate from
     userspace.

     An attempt to define a new KVM_EXIT_COCO / KVM_EXIT_COCO_REQ_CERTS
     exit type to handle this was introduced in v1 of this patchset, but
     is still being discussed by community, so for now this patchset
     only implements a stub version of SNP Extended Guest Requests that
     does not provide certificate data

  x86 - Intel:

   - Remove an unnecessary EPT TLB flush when enabling hardware

   - Fix a series of bugs that cause KVM to fail to detect nested
     pending posted interrupts as valid wake eents for a vCPU executing
     HLT in L2 (with HLT-exiting disable by L1)

   - KVM: x86: Suppress MMIO that is triggered during task switch
     emulation

     Explicitly suppress userspace emulated MMIO exits that are
     triggered when emulating a task switch as KVM doesn't support
     userspace MMIO during complex (multi-step) emulation

     Silently ignoring the exit request can result in the
     WARN_ON_ONCE(vcpu->mmio_needed) firing if KVM exits to userspace
     for some other reason prior to purging mmio_needed

     See commit 0dc902267cb3 ("KVM: x86: Suppress pending MMIO write
     exits if emulator detects exception") for more details on KVM's
     limitations with respect to emulated MMIO during complex emulator
     flows

  Generic:

   - Rename the AS_UNMOVABLE flag that was introduced for KVM to
     AS_INACCESSIBLE, because the special casing needed by these pages
     is not due to just unmovability (and in fact they are only
     unmovable because the CPU cannot access them)

   - New ioctl to populate the KVM page tables in advance, which is
     useful to mitigate KVM page faults during guest boot or after live
     migration. The code will also be used by TDX, but (probably) not
     through the ioctl

   - Enable halt poll shrinking by default, as Intel found it to be a
     clear win

   - Setup empty IRQ routing when creating a VM to avoid having to
     synchronize SRCU when creating a split IRQCHIP on x86

   - Rework the sched_in/out() paths to replace kvm_arch_sched_in() with
     a flag that arch code can use for hooking both sched_in() and
     sched_out()

   - Take the vCPU @id as an "unsigned long" instead of "u32" to avoid
     truncating a bogus value from userspace, e.g. to help userspace
     detect bugs

   - Mark a vCPU as preempted if and only if it's scheduled out while in
     the KVM_RUN loop, e.g. to avoid marking it preempted and thus
     writing guest memory when retrieving guest state during live
     migration blackout

  Selftests:

   - Remove dead code in the memslot modification stress test

   - Treat "branch instructions retired" as supported on all AMD Family
     17h+ CPUs

   - Print the guest pseudo-RNG seed only when it changes, to avoid
     spamming the log for tests that create lots of VMs

   - Make the PMU counters test less flaky when counting LLC cache
     misses by doing CLFLUSH{OPT} in every loop iteration"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (227 commits)
  crypto: ccp: Add the SNP_VLEK_LOAD command
  KVM: x86/pmu: Add kvm_pmu_call() to simplify static calls of kvm_pmu_ops
  KVM: x86: Introduce kvm_x86_call() to simplify static calls of kvm_x86_ops
  KVM: x86: Replace static_call_cond() with static_call()
  KVM: SEV: Provide support for SNP_EXTENDED_GUEST_REQUEST NAE event
  x86/sev: Move sev_guest.h into common SEV header
  KVM: SEV: Provide support for SNP_GUEST_REQUEST NAE event
  KVM: x86: Suppress MMIO that is triggered during task switch emulation
  KVM: x86/mmu: Clean up make_huge_page_split_spte() definition and intro
  KVM: x86/mmu: Bug the VM if KVM tries to split a !hugepage SPTE
  KVM: selftests: x86: Add test for KVM_PRE_FAULT_MEMORY
  KVM: x86: Implement kvm_arch_vcpu_pre_fault_memory()
  KVM: x86/mmu: Make kvm_mmu_do_page_fault() return mapped level
  KVM: x86/mmu: Account pf_{fixed,emulate,spurious} in callers of "do page fault"
  KVM: x86/mmu: Bump pf_taken stat only in the "real" page fault handler
  KVM: Add KVM_PRE_FAULT_MEMORY vcpu ioctl to pre-populate guest memory
  KVM: Document KVM_PRE_FAULT_MEMORY ioctl
  mm, virt: merge AS_UNMOVABLE and AS_INACCESSIBLE
  perf kvm: Add kvm-stat for loongarch64
  LoongArch: KVM: Add PV steal time support in guest side
  ...

9 files changed, 317 insertions, 40 deletions

diff --git a/arch/arm64/include/asm/esr.h b/arch/arm64/include/asm/esr.h
index 3f482500f71f..56c148890daf 100644
--- a/arch/arm64/include/asm/esr.h
+++ b/arch/arm64/include/asm/esr.h
@@ -160,6 +160,7 @@
 #define ESR_ELx_Xs_MASK		(GENMASK_ULL(4, 0))
 
 /* ISS field definitions for exceptions taken in to Hyp */
+#define ESR_ELx_FSC_ADDRSZ	(0x00)
 #define ESR_ELx_CV		(UL(1) << 24)
 #define ESR_ELx_COND_SHIFT	(20)
 #define ESR_ELx_COND_MASK	(UL(0xF) << ESR_ELx_COND_SHIFT)
@@ -387,6 +388,11 @@
 #ifndef __ASSEMBLY__
 #include <asm/types.h>
 
+static inline unsigned long esr_brk_comment(unsigned long esr)
+{
+	return esr & ESR_ELx_BRK64_ISS_COMMENT_MASK;
+}
+
 static inline bool esr_is_data_abort(unsigned long esr)
 {
 	const unsigned long ec = ESR_ELx_EC(esr);
@@ -394,6 +400,12 @@ static inline bool esr_is_data_abort(unsigned long esr)
 	return ec == ESR_ELx_EC_DABT_LOW || ec == ESR_ELx_EC_DABT_CUR;
 }
 
+static inline bool esr_is_cfi_brk(unsigned long esr)
+{
+	return ESR_ELx_EC(esr) == ESR_ELx_EC_BRK64 &&
+	       (esr_brk_comment(esr) & ~CFI_BRK_IMM_MASK) == CFI_BRK_IMM_BASE;
+}
+
 static inline bool esr_fsc_is_translation_fault(unsigned long esr)
 {
 	esr = esr & ESR_ELx_FSC;
diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index b2adc2c6c82a..d81cc746e0eb 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -102,7 +102,6 @@
 #define HCR_HOST_NVHE_PROTECTED_FLAGS (HCR_HOST_NVHE_FLAGS | HCR_TSC)
 #define HCR_HOST_VHE_FLAGS (HCR_RW | HCR_TGE | HCR_E2H)
 
-#define HCRX_GUEST_FLAGS (HCRX_EL2_SMPME | HCRX_EL2_TCR2En)
 #define HCRX_HOST_FLAGS (HCRX_EL2_MSCEn | HCRX_EL2_TCR2En | HCRX_EL2_EnFPM)
 
 /* TCR_EL2 Registers bits */
diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index a6330460d9e5..2181a11b9d92 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -232,6 +232,8 @@ extern void __kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu,
 					phys_addr_t start, unsigned long pages);
 extern void __kvm_tlb_flush_vmid(struct kvm_s2_mmu *mmu);
 
+extern int __kvm_tlbi_s1e2(struct kvm_s2_mmu *mmu, u64 va, u64 sys_encoding);
+
 extern void __kvm_timer_set_cntvoff(u64 cntvoff);
 
 extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);
diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index 21650e7924d4..a601a9305b10 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -11,6 +11,7 @@
 #ifndef __ARM64_KVM_EMULATE_H__
 #define __ARM64_KVM_EMULATE_H__
 
+#include <linux/bitfield.h>
 #include <linux/kvm_host.h>
 
 #include <asm/debug-monitors.h>
@@ -55,6 +56,14 @@ void kvm_emulate_nested_eret(struct kvm_vcpu *vcpu);
 int kvm_inject_nested_sync(struct kvm_vcpu *vcpu, u64 esr_el2);
 int kvm_inject_nested_irq(struct kvm_vcpu *vcpu);
 
+static inline void kvm_inject_nested_sve_trap(struct kvm_vcpu *vcpu)
+{
+	u64 esr = FIELD_PREP(ESR_ELx_EC_MASK, ESR_ELx_EC_SVE) |
+		  ESR_ELx_IL;
+
+	kvm_inject_nested_sync(vcpu, esr);
+}
+
 #if defined(__KVM_VHE_HYPERVISOR__) || defined(__KVM_NVHE_HYPERVISOR__)
 static __always_inline bool vcpu_el1_is_32bit(struct kvm_vcpu *vcpu)
 {
@@ -69,39 +78,17 @@ static __always_inline bool vcpu_el1_is_32bit(struct kvm_vcpu *vcpu)
 
 static inline void vcpu_reset_hcr(struct kvm_vcpu *vcpu)
 {
-	vcpu->arch.hcr_el2 = HCR_GUEST_FLAGS;
-	if (has_vhe() || has_hvhe())
-		vcpu->arch.hcr_el2 |= HCR_E2H;
-	if (cpus_have_final_cap(ARM64_HAS_RAS_EXTN)) {
-		/* route synchronous external abort exceptions to EL2 */
-		vcpu->arch.hcr_el2 |= HCR_TEA;
-		/* trap error record accesses */
-		vcpu->arch.hcr_el2 |= HCR_TERR;
-	}
+	if (!vcpu_has_run_once(vcpu))
+		vcpu->arch.hcr_el2 = HCR_GUEST_FLAGS;
 
-	if (cpus_have_final_cap(ARM64_HAS_STAGE2_FWB)) {
-		vcpu->arch.hcr_el2 |= HCR_FWB;
-	} else {
-		/*
-		 * For non-FWB CPUs, we trap VM ops (HCR_EL2.TVM) until M+C
-		 * get set in SCTLR_EL1 such that we can detect when the guest
-		 * MMU gets turned on and do the necessary cache maintenance
-		 * then.
-		 */
+	/*
+	 * For non-FWB CPUs, we trap VM ops (HCR_EL2.TVM) until M+C
+	 * get set in SCTLR_EL1 such that we can detect when the guest
+	 * MMU gets turned on and do the necessary cache maintenance
+	 * then.
+	 */
+	if (!cpus_have_final_cap(ARM64_HAS_STAGE2_FWB))
 		vcpu->arch.hcr_el2 |= HCR_TVM;
-	}
-
-	if (cpus_have_final_cap(ARM64_HAS_EVT) &&
-	    !cpus_have_final_cap(ARM64_MISMATCHED_CACHE_TYPE))
-		vcpu->arch.hcr_el2 |= HCR_TID4;
-	else
-		vcpu->arch.hcr_el2 |= HCR_TID2;
-
-	if (vcpu_el1_is_32bit(vcpu))
-		vcpu->arch.hcr_el2 &= ~HCR_RW;
-
-	if (kvm_has_mte(vcpu->kvm))
-		vcpu->arch.hcr_el2 |= HCR_ATA;
 }
 
 static inline unsigned long *vcpu_hcr(struct kvm_vcpu *vcpu)
@@ -660,4 +647,50 @@ static __always_inline void kvm_reset_cptr_el2(struct kvm_vcpu *vcpu)
 
 	kvm_write_cptr_el2(val);
 }
+
+/*
+ * Returns a 'sanitised' view of CPTR_EL2, translating from nVHE to the VHE
+ * format if E2H isn't set.
+ */
+static inline u64 vcpu_sanitised_cptr_el2(const struct kvm_vcpu *vcpu)
+{
+	u64 cptr = __vcpu_sys_reg(vcpu, CPTR_EL2);
+
+	if (!vcpu_el2_e2h_is_set(vcpu))
+		cptr = translate_cptr_el2_to_cpacr_el1(cptr);
+
+	return cptr;
+}
+
+static inline bool ____cptr_xen_trap_enabled(const struct kvm_vcpu *vcpu,
+					     unsigned int xen)
+{
+	switch (xen) {
+	case 0b00:
+	case 0b10:
+		return true;
+	case 0b01:
+		return vcpu_el2_tge_is_set(vcpu) && !vcpu_is_el2(vcpu);
+	case 0b11:
+	default:
+		return false;
+	}
+}
+
+#define __guest_hyp_cptr_xen_trap_enabled(vcpu, xen)				\
+	(!vcpu_has_nv(vcpu) ? false :						\
+	 ____cptr_xen_trap_enabled(vcpu,					\
+				   SYS_FIELD_GET(CPACR_ELx, xen,		\
+						 vcpu_sanitised_cptr_el2(vcpu))))
+
+static inline bool guest_hyp_fpsimd_traps_enabled(const struct kvm_vcpu *vcpu)
+{
+	return __guest_hyp_cptr_xen_trap_enabled(vcpu, FPEN);
+}
+
+static inline bool guest_hyp_sve_traps_enabled(const struct kvm_vcpu *vcpu)
+{
+	return __guest_hyp_cptr_xen_trap_enabled(vcpu, ZEN);
+}
+
 #endif /* __ARM64_KVM_EMULATE_H__ */
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 36b8e97bf49e..a33f5996ca9f 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -189,6 +189,33 @@ struct kvm_s2_mmu {
 	uint64_t split_page_chunk_size;
 
 	struct kvm_arch *arch;
+
+	/*
+	 * For a shadow stage-2 MMU, the virtual vttbr used by the
+	 * host to parse the guest S2.
+	 * This either contains:
+	 * - the virtual VTTBR programmed by the guest hypervisor with
+         *   CnP cleared
+	 * - The value 1 (VMID=0, BADDR=0, CnP=1) if invalid
+	 *
+	 * We also cache the full VTCR which gets used for TLB invalidation,
+	 * taking the ARM ARM's "Any of the bits in VTCR_EL2 are permitted
+	 * to be cached in a TLB" to the letter.
+	 */
+	u64	tlb_vttbr;
+	u64	tlb_vtcr;
+
+	/*
+	 * true when this represents a nested context where virtual
+	 * HCR_EL2.VM == 1
+	 */
+	bool	nested_stage2_enabled;
+
+	/*
+	 *  0: Nobody is currently using this, check vttbr for validity
+	 * >0: Somebody is actively using this.
+	 */
+	atomic_t refcnt;
 };
 
 struct kvm_arch_memory_slot {
@@ -256,6 +283,14 @@ struct kvm_arch {
 	 */
 	u64 fgu[__NR_FGT_GROUP_IDS__];
 
+	/*
+	 * Stage 2 paging state for VMs with nested S2 using a virtual
+	 * VMID.
+	 */
+	struct kvm_s2_mmu *nested_mmus;
+	size_t nested_mmus_size;
+	int nested_mmus_next;
+
 	/* Interrupt controller */
 	struct vgic_dist	vgic;
 
@@ -327,11 +362,11 @@ struct kvm_arch {
 	 * Atomic access to multiple idregs are guarded by kvm_arch.config_lock.
 	 */
 #define IDREG_IDX(id)		(((sys_reg_CRm(id) - 1) << 3) | sys_reg_Op2(id))
-#define IDX_IDREG(idx)		sys_reg(3, 0, 0, ((idx) >> 3) + 1, (idx) & Op2_mask)
-#define IDREG(kvm, id)		((kvm)->arch.id_regs[IDREG_IDX(id)])
 #define KVM_ARM_ID_REG_NUM	(IDREG_IDX(sys_reg(3, 0, 0, 7, 7)) + 1)
 	u64 id_regs[KVM_ARM_ID_REG_NUM];
 
+	u64 ctr_el0;
+
 	/* Masks for VNCR-baked sysregs */
 	struct kvm_sysreg_masks	*sysreg_masks;
 
@@ -423,6 +458,7 @@ enum vcpu_sysreg {
 	MDCR_EL2,	/* Monitor Debug Configuration Register (EL2) */
 	CPTR_EL2,	/* Architectural Feature Trap Register (EL2) */
 	HACR_EL2,	/* Hypervisor Auxiliary Control Register */
+	ZCR_EL2,	/* SVE Control Register (EL2) */
 	TTBR0_EL2,	/* Translation Table Base Register 0 (EL2) */
 	TTBR1_EL2,	/* Translation Table Base Register 1 (EL2) */
 	TCR_EL2,	/* Translation Control Register (EL2) */
@@ -867,6 +903,9 @@ struct kvm_vcpu_arch {
 
 #define vcpu_sve_max_vq(vcpu)	sve_vq_from_vl((vcpu)->arch.sve_max_vl)
 
+#define vcpu_sve_zcr_elx(vcpu)						\
+	(unlikely(is_hyp_ctxt(vcpu)) ? ZCR_EL2 : ZCR_EL1)
+
 #define vcpu_sve_state_size(vcpu) ({					\
 	size_t __size_ret;						\
 	unsigned int __vcpu_vq;						\
@@ -991,6 +1030,7 @@ static inline bool __vcpu_read_sys_reg_from_cpu(int reg, u64 *val)
 	case DACR32_EL2:	*val = read_sysreg_s(SYS_DACR32_EL2);	break;
 	case IFSR32_EL2:	*val = read_sysreg_s(SYS_IFSR32_EL2);	break;
 	case DBGVCR32_EL2:	*val = read_sysreg_s(SYS_DBGVCR32_EL2);	break;
+	case ZCR_EL1:		*val = read_sysreg_s(SYS_ZCR_EL12);	break;
 	default:		return false;
 	}
 
@@ -1036,6 +1076,7 @@ static inline bool __vcpu_write_sys_reg_to_cpu(u64 val, int reg)
 	case DACR32_EL2:	write_sysreg_s(val, SYS_DACR32_EL2);	break;
 	case IFSR32_EL2:	write_sysreg_s(val, SYS_IFSR32_EL2);	break;
 	case DBGVCR32_EL2:	write_sysreg_s(val, SYS_DBGVCR32_EL2);	break;
+	case ZCR_EL1:		write_sysreg_s(val, SYS_ZCR_EL12);	break;
 	default:		return false;
 	}
 
@@ -1145,7 +1186,7 @@ int __init populate_nv_trap_config(void);
 bool lock_all_vcpus(struct kvm *kvm);
 void unlock_all_vcpus(struct kvm *kvm);
 
-void kvm_init_sysreg(struct kvm_vcpu *);
+void kvm_calculate_traps(struct kvm_vcpu *vcpu);
 
 /* MMIO helpers */
 void kvm_mmio_write_buf(void *buf, unsigned int len, unsigned long data);
@@ -1248,7 +1289,6 @@ static inline bool kvm_system_needs_idmapped_vectors(void)
 }
 
 static inline void kvm_arch_sync_events(struct kvm *kvm) {}
-static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
 
 void kvm_arm_init_debug(void);
 void kvm_arm_vcpu_init_debug(struct kvm_vcpu *vcpu);
@@ -1306,6 +1346,7 @@ void kvm_vcpu_load_vhe(struct kvm_vcpu *vcpu);
 void kvm_vcpu_put_vhe(struct kvm_vcpu *vcpu);
 
 int __init kvm_set_ipa_limit(void);
+u32 kvm_get_pa_bits(struct kvm *kvm);
 
 #define __KVM_HAVE_ARCH_VM_ALLOC
 struct kvm *kvm_arch_alloc_vm(void);
@@ -1355,6 +1396,24 @@ static inline void kvm_hyp_reserve(void) { }
 void kvm_arm_vcpu_power_off(struct kvm_vcpu *vcpu);
 bool kvm_arm_vcpu_stopped(struct kvm_vcpu *vcpu);
 
+static inline u64 *__vm_id_reg(struct kvm_arch *ka, u32 reg)
+{
+	switch (reg) {
+	case sys_reg(3, 0, 0, 1, 0) ... sys_reg(3, 0, 0, 7, 7):
+		return &ka->id_regs[IDREG_IDX(reg)];
+	case SYS_CTR_EL0:
+		return &ka->ctr_el0;
+	default:
+		WARN_ON_ONCE(1);
+		return NULL;
+	}
+}
+
+#define kvm_read_vm_id_reg(kvm, reg)					\
+	({ u64 __val = *__vm_id_reg(&(kvm)->arch, reg); __val; })
+
+void kvm_set_vm_id_reg(struct kvm *kvm, u32 reg, u64 val);
+
 #define __expand_field_sign_unsigned(id, fld, val)			\
 	((u64)SYS_FIELD_VALUE(id, fld, val))
 
@@ -1371,7 +1430,7 @@ bool kvm_arm_vcpu_stopped(struct kvm_vcpu *vcpu);
 
 #define get_idreg_field_unsigned(kvm, id, fld)				\
 	({								\
-		u64 __val = IDREG((kvm), SYS_##id);			\
+		u64 __val = kvm_read_vm_id_reg((kvm), SYS_##id);	\
 		FIELD_GET(id##_##fld##_MASK, __val);			\
 	})
 
diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h
index b05bceca3385..c838309e4ec4 100644
--- a/arch/arm64/include/asm/kvm_hyp.h
+++ b/arch/arm64/include/asm/kvm_hyp.h
@@ -124,8 +124,8 @@ void __noreturn __hyp_do_panic(struct kvm_cpu_context *host_ctxt, u64 spsr,
 #endif
 
 #ifdef __KVM_NVHE_HYPERVISOR__
-void __pkvm_init_switch_pgd(phys_addr_t phys, unsigned long size,
-			    phys_addr_t pgd, void *sp, void *cont_fn);
+void __pkvm_init_switch_pgd(phys_addr_t pgd, unsigned long sp,
+		void (*fn)(void));
 int __pkvm_init(phys_addr_t phys, unsigned long size, unsigned long nr_cpus,
 		unsigned long *per_cpu_base, u32 hyp_va_bits);
 void __noreturn __host_enter(struct kvm_cpu_context *host_ctxt);
diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index d5e48d870461..216ca424bb16 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -98,6 +98,7 @@ alternative_cb_end
 #include <asm/mmu_context.h>
 #include <asm/kvm_emulate.h>
 #include <asm/kvm_host.h>
+#include <asm/kvm_nested.h>
 
 void kvm_update_va_mask(struct alt_instr *alt,
 			__le32 *origptr, __le32 *updptr, int nr_inst);
@@ -165,6 +166,10 @@ int create_hyp_exec_mappings(phys_addr_t phys_addr, size_t size,
 int create_hyp_stack(phys_addr_t phys_addr, unsigned long *haddr);
 void __init free_hyp_pgds(void);
 
+void kvm_stage2_unmap_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size);
+void kvm_stage2_flush_range(struct kvm_s2_mmu *mmu, phys_addr_t addr, phys_addr_t end);
+void kvm_stage2_wp_range(struct kvm_s2_mmu *mmu, phys_addr_t addr, phys_addr_t end);
+
 void stage2_unmap_vm(struct kvm *kvm);
 int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu, unsigned long type);
 void kvm_uninit_stage2_mmu(struct kvm *kvm);
@@ -326,5 +331,26 @@ static inline struct kvm *kvm_s2_mmu_to_kvm(struct kvm_s2_mmu *mmu)
 {
 	return container_of(mmu->arch, struct kvm, arch);
 }
+
+static inline u64 get_vmid(u64 vttbr)
+{
+	return (vttbr & VTTBR_VMID_MASK(kvm_get_vmid_bits())) >>
+		VTTBR_VMID_SHIFT;
+}
+
+static inline bool kvm_s2_mmu_valid(struct kvm_s2_mmu *mmu)
+{
+	return !(mmu->tlb_vttbr & VTTBR_CNP_BIT);
+}
+
+static inline bool kvm_is_nested_s2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu)
+{
+	/*
+	 * Be careful, mmu may not be fully initialised so do look at
+	 * *any* of its fields.
+	 */
+	return &kvm->arch.mmu != mmu;
+}
+
 #endif /* __ASSEMBLY__ */
 #endif /* __ARM64_KVM_MMU_H__ */
diff --git a/arch/arm64/include/asm/kvm_nested.h b/arch/arm64/include/asm/kvm_nested.h
index 5e0ab0596246..5b06c31035a2 100644
--- a/arch/arm64/include/asm/kvm_nested.h
+++ b/arch/arm64/include/asm/kvm_nested.h
@@ -5,6 +5,7 @@
 #include <linux/bitfield.h>
 #include <linux/kvm_host.h>
 #include <asm/kvm_emulate.h>
+#include <asm/kvm_pgtable.h>
 
 static inline bool vcpu_has_nv(const struct kvm_vcpu *vcpu)
 {
@@ -32,7 +33,7 @@ static inline u64 translate_tcr_el2_to_tcr_el1(u64 tcr)
 
 static inline u64 translate_cptr_el2_to_cpacr_el1(u64 cptr_el2)
 {
-	u64 cpacr_el1 = 0;
+	u64 cpacr_el1 = CPACR_ELx_RES1;
 
 	if (cptr_el2 & CPTR_EL2_TTA)
 		cpacr_el1 |= CPACR_ELx_TTA;
@@ -41,6 +42,8 @@ static inline u64 translate_cptr_el2_to_cpacr_el1(u64 cptr_el2)
 	if (!(cptr_el2 & CPTR_EL2_TZ))
 		cpacr_el1 |= CPACR_ELx_ZEN;
 
+	cpacr_el1 |= cptr_el2 & (CPTR_EL2_TCPAC | CPTR_EL2_TAM);
+
 	return cpacr_el1;
 }
 
@@ -61,6 +64,125 @@ static inline u64 translate_ttbr0_el2_to_ttbr0_el1(u64 ttbr0)
 }
 
 extern bool forward_smc_trap(struct kvm_vcpu *vcpu);
+extern void kvm_init_nested(struct kvm *kvm);
+extern int kvm_vcpu_init_nested(struct kvm_vcpu *vcpu);
+extern void kvm_init_nested_s2_mmu(struct kvm_s2_mmu *mmu);
+extern struct kvm_s2_mmu *lookup_s2_mmu(struct kvm_vcpu *vcpu);
+
+union tlbi_info;
+
+extern void kvm_s2_mmu_iterate_by_vmid(struct kvm *kvm, u16 vmid,
+				       const union tlbi_info *info,
+				       void (*)(struct kvm_s2_mmu *,
+						const union tlbi_info *));
+extern void kvm_vcpu_load_hw_mmu(struct kvm_vcpu *vcpu);
+extern void kvm_vcpu_put_hw_mmu(struct kvm_vcpu *vcpu);
+
+struct kvm_s2_trans {
+	phys_addr_t output;
+	unsigned long block_size;
+	bool writable;
+	bool readable;
+	int level;
+	u32 esr;
+	u64 upper_attr;
+};
+
+static inline phys_addr_t kvm_s2_trans_output(struct kvm_s2_trans *trans)
+{
+	return trans->output;
+}
+
+static inline unsigned long kvm_s2_trans_size(struct kvm_s2_trans *trans)
+{
+	return trans->block_size;
+}
+
+static inline u32 kvm_s2_trans_esr(struct kvm_s2_trans *trans)
+{
+	return trans->esr;
+}
+
+static inline bool kvm_s2_trans_readable(struct kvm_s2_trans *trans)
+{
+	return trans->readable;
+}
+
+static inline bool kvm_s2_trans_writable(struct kvm_s2_trans *trans)
+{
+	return trans->writable;
+}
+
+static inline bool kvm_s2_trans_executable(struct kvm_s2_trans *trans)
+{
+	return !(trans->upper_attr & BIT(54));
+}
+
+extern int kvm_walk_nested_s2(struct kvm_vcpu *vcpu, phys_addr_t gipa,
+			      struct kvm_s2_trans *result);
+extern int kvm_s2_handle_perm_fault(struct kvm_vcpu *vcpu,
+				    struct kvm_s2_trans *trans);
+extern int kvm_inject_s2_fault(struct kvm_vcpu *vcpu, u64 esr_el2);
+extern void kvm_nested_s2_wp(struct kvm *kvm);
+extern void kvm_nested_s2_unmap(struct kvm *kvm);
+extern void kvm_nested_s2_flush(struct kvm *kvm);
+
+unsigned long compute_tlb_inval_range(struct kvm_s2_mmu *mmu, u64 val);
+
+static inline bool kvm_supported_tlbi_s1e1_op(struct kvm_vcpu *vpcu, u32 instr)
+{
+	struct kvm *kvm = vpcu->kvm;
+	u8 CRm = sys_reg_CRm(instr);
+
+	if (!(sys_reg_Op0(instr) == TLBI_Op0 &&
+	      sys_reg_Op1(instr) == TLBI_Op1_EL1))
+		return false;
+
+	if (!(sys_reg_CRn(instr) == TLBI_CRn_XS ||
+	      (sys_reg_CRn(instr) == TLBI_CRn_nXS &&
+	       kvm_has_feat(kvm, ID_AA64ISAR1_EL1, XS, IMP))))
+		return false;
+
+	if (CRm == TLBI_CRm_nROS &&
+	    !kvm_has_feat(kvm, ID_AA64ISAR0_EL1, TLB, OS))
+		return false;
+
+	if ((CRm == TLBI_CRm_RIS || CRm == TLBI_CRm_ROS ||
+	     CRm == TLBI_CRm_RNS) &&
+	    !kvm_has_feat(kvm, ID_AA64ISAR0_EL1, TLB, RANGE))
+		return false;
+
+	return true;
+}
+
+static inline bool kvm_supported_tlbi_s1e2_op(struct kvm_vcpu *vpcu, u32 instr)
+{
+	struct kvm *kvm = vpcu->kvm;
+	u8 CRm = sys_reg_CRm(instr);
+
+	if (!(sys_reg_Op0(instr) == TLBI_Op0 &&
+	      sys_reg_Op1(instr) == TLBI_Op1_EL2))
+		return false;
+
+	if (!(sys_reg_CRn(instr) == TLBI_CRn_XS ||
+	      (sys_reg_CRn(instr) == TLBI_CRn_nXS &&
+	       kvm_has_feat(kvm, ID_AA64ISAR1_EL1, XS, IMP))))
+		return false;
+
+	if (CRm == TLBI_CRm_IPAIS || CRm == TLBI_CRm_IPAONS)
+		return false;
+
+	if (CRm == TLBI_CRm_nROS &&
+	    !kvm_has_feat(kvm, ID_AA64ISAR0_EL1, TLB, OS))
+		return false;
+
+	if ((CRm == TLBI_CRm_RIS || CRm == TLBI_CRm_ROS ||
+	     CRm == TLBI_CRm_RNS) &&
+	    !kvm_has_feat(kvm, ID_AA64ISAR0_EL1, TLB, RANGE))
+		return false;
+
+	return true;
+}
 
 int kvm_init_nv_sysregs(struct kvm *kvm);
 
@@ -76,4 +198,11 @@ static inline bool kvm_auth_eretax(struct kvm_vcpu *vcpu, u64 *elr)
 }
 #endif
 
+#define KVM_NV_GUEST_MAP_SZ	(KVM_PGTABLE_PROT_SW1 | KVM_PGTABLE_PROT_SW0)
+
+static inline u64 kvm_encode_nested_level(struct kvm_s2_trans *trans)
+{
+	return FIELD_PREP(KVM_NV_GUEST_MAP_SZ, trans->level);
+}
+
 #endif /* __ARM64_KVM_NESTED_H */
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index 1b6e436dbb55..4a9ea103817e 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -654,6 +654,23 @@
 #define OP_AT_S12E0W	sys_insn(AT_Op0, 4, AT_CRn, 8, 7)
 
 /* TLBI instructions */
+#define TLBI_Op0	1
+
+#define TLBI_Op1_EL1	0	/* Accessible from EL1 or higher */
+#define TLBI_Op1_EL2	4	/* Accessible from EL2 or higher */
+
+#define TLBI_CRn_XS	8	/* Extra Slow (the common one) */
+#define TLBI_CRn_nXS	9	/* not Extra Slow (which nobody uses)*/
+
+#define TLBI_CRm_IPAIS	0	/* S2 Inner-Shareable */
+#define TLBI_CRm_nROS	1	/* non-Range, Outer-Sharable */
+#define TLBI_CRm_RIS	2	/* Range, Inner-Sharable */
+#define TLBI_CRm_nRIS	3	/* non-Range, Inner-Sharable */
+#define TLBI_CRm_IPAONS	4	/* S2 Outer and Non-Shareable */
+#define TLBI_CRm_ROS	5	/* Range, Outer-Sharable */
+#define TLBI_CRm_RNS	6	/* Range, Non-Sharable */
+#define TLBI_CRm_nRNS	7	/* non-Range, Non-Sharable */
+
 #define OP_TLBI_VMALLE1OS		sys_insn(1, 0, 8, 1, 0)
 #define OP_TLBI_VAE1OS			sys_insn(1, 0, 8, 1, 1)
 #define OP_TLBI_ASIDE1OS		sys_insn(1, 0, 8, 1, 2)