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

Pull x86 kvm updates from Paolo Bonzini:
 "x86:

   - KVM currently invalidates the entirety of the page tables, not just
     those for the memslot being touched, when a memslot is moved or
     deleted.

     This does not traditionally have particularly noticeable overhead,
     but Intel's TDX will require the guest to re-accept private pages
     if they are dropped from the secure EPT, which is a non starter.

     Actually, the only reason why this is not already being done is a
     bug which was never fully investigated and caused VM instability
     with assigned GeForce GPUs, so allow userspace to opt into the new
     behavior.

   - Advertise AVX10.1 to userspace (effectively prep work for the
     "real" AVX10 functionality that is on the horizon)

   - Rework common MSR handling code to suppress errors on userspace
     accesses to unsupported-but-advertised MSRs

     This will allow removing (almost?) all of KVM's exemptions for
     userspace access to MSRs that shouldn't exist based on the vCPU
     model (the actual cleanup is non-trivial future work)

   - Rework KVM's handling of x2APIC ICR, again, because AMD (x2AVIC)
     splits the 64-bit value into the legacy ICR and ICR2 storage,
     whereas Intel (APICv) stores the entire 64-bit value at the ICR
     offset

   - Fix a bug where KVM would fail to exit to userspace if one was
     triggered by a fastpath exit handler

   - Add fastpath handling of HLT VM-Exit to expedite re-entering the
     guest when there's already a pending wake event at the time of the
     exit

   - Fix a WARN caused by RSM entering a nested guest from SMM with
     invalid guest state, by forcing the vCPU out of guest mode prior to
     signalling SHUTDOWN (the SHUTDOWN hits the VM altogether, not the
     nested guest)

   - Overhaul the "unprotect and retry" logic to more precisely identify
     cases where retrying is actually helpful, and to harden all retry
     paths against putting the guest into an infinite retry loop

   - Add support for yielding, e.g. to honor NEED_RESCHED, when zapping
     rmaps in the shadow MMU

   - Refactor pieces of the shadow MMU related to aging SPTEs in
     prepartion for adding multi generation LRU support in KVM

   - Don't stuff the RSB after VM-Exit when RETPOLINE=y and AutoIBRS is
     enabled, i.e. when the CPU has already flushed the RSB

   - Trace the per-CPU host save area as a VMCB pointer to improve
     readability and cleanup the retrieval of the SEV-ES host save area

   - Remove unnecessary accounting of temporary nested VMCB related
     allocations

   - Set FINAL/PAGE in the page fault error code for EPT violations if
     and only if the GVA is valid. If the GVA is NOT valid, there is no
     guest-side page table walk and so stuffing paging related metadata
     is nonsensical

   - Fix a bug where KVM would incorrectly synthesize a nested VM-Exit
     instead of emulating posted interrupt delivery to L2

   - Add a lockdep assertion to detect unsafe accesses of vmcs12
     structures

   - Harden eVMCS loading against an impossible NULL pointer deref
     (really truly should be impossible)

   - Minor SGX fix and a cleanup

   - Misc cleanups

  Generic:

   - Register KVM's cpuhp and syscore callbacks when enabling
     virtualization in hardware, as the sole purpose of said callbacks
     is to disable and re-enable virtualization as needed

   - Enable virtualization when KVM is loaded, not right before the
     first VM is created

     Together with the previous change, this simplifies a lot the logic
     of the callbacks, because their very existence implies
     virtualization is enabled

   - Fix a bug that results in KVM prematurely exiting to userspace for
     coalesced MMIO/PIO in many cases, clean up the related code, and
     add a testcase

   - Fix a bug in kvm_clear_guest() where it would trigger a buffer
     overflow _if_ the gpa+len crosses a page boundary, which thankfully
     is guaranteed to not happen in the current code base. Add WARNs in
     more helpers that read/write guest memory to detect similar bugs

  Selftests:

   - Fix a goof that caused some Hyper-V tests to be skipped when run on
     bare metal, i.e. NOT in a VM

   - Add a regression test for KVM's handling of SHUTDOWN for an SEV-ES
     guest

   - Explicitly include one-off assets in .gitignore. Past Sean was
     completely wrong about not being able to detect missing .gitignore
     entries

   - Verify userspace single-stepping works when KVM happens to handle a
     VM-Exit in its fastpath

   - Misc cleanups"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (127 commits)
  Documentation: KVM: fix warning in "make htmldocs"
  s390: Enable KVM_S390_UCONTROL config in debug_defconfig
  selftests: kvm: s390: Add VM run test case
  KVM: SVM: let alternatives handle the cases when RSB filling is required
  KVM: VMX: Set PFERR_GUEST_{FINAL,PAGE}_MASK if and only if the GVA is valid
  KVM: x86/mmu: Use KVM_PAGES_PER_HPAGE() instead of an open coded equivalent
  KVM: x86/mmu: Add KVM_RMAP_MANY to replace open coded '1' and '1ul' literals
  KVM: x86/mmu: Fold mmu_spte_age() into kvm_rmap_age_gfn_range()
  KVM: x86/mmu: Morph kvm_handle_gfn_range() into an aging specific helper
  KVM: x86/mmu: Honor NEED_RESCHED when zapping rmaps and blocking is allowed
  KVM: x86/mmu: Add a helper to walk and zap rmaps for a memslot
  KVM: x86/mmu: Plumb a @can_yield parameter into __walk_slot_rmaps()
  KVM: x86/mmu: Move walk_slot_rmaps() up near for_each_slot_rmap_range()
  KVM: x86/mmu: WARN on MMIO cache hit when emulating write-protected gfn
  KVM: x86/mmu: Detect if unprotect will do anything based on invalid_list
  KVM: x86/mmu: Subsume kvm_mmu_unprotect_page() into the and_retry() version
  KVM: x86: Rename reexecute_instruction()=>kvm_unprotect_and_retry_on_failure()
  KVM: x86: Update retry protection fields when forcing retry on emulation failure
  KVM: x86: Apply retry protection to "unprotect on failure" path
  KVM: x86: Check EMULTYPE_WRITE_PF_TO_SP before unprotecting gfn
  ...

1 files changed, 96 insertions, 38 deletions

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 2392a7ef254d..a8e7bc04d9bf 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -981,7 +981,7 @@ static u32 nested_vmx_load_msr(struct kvm_vcpu *vcpu, u64 gpa, u32 count)
 				__func__, i, e.index, e.reserved);
 			goto fail;
 		}
-		if (kvm_set_msr(vcpu, e.index, e.value)) {
+		if (kvm_set_msr_with_filter(vcpu, e.index, e.value)) {
 			pr_debug_ratelimited(
 				"%s cannot write MSR (%u, 0x%x, 0x%llx)\n",
 				__func__, i, e.index, e.value);
@@ -1017,7 +1017,7 @@ static bool nested_vmx_get_vmexit_msr_value(struct kvm_vcpu *vcpu,
 		}
 	}
 
-	if (kvm_get_msr(vcpu, msr_index, data)) {
+	if (kvm_get_msr_with_filter(vcpu, msr_index, data)) {
 		pr_debug_ratelimited("%s cannot read MSR (0x%x)\n", __func__,
 			msr_index);
 		return false;
@@ -1112,9 +1112,9 @@ static void prepare_vmx_msr_autostore_list(struct kvm_vcpu *vcpu,
 			/*
 			 * Emulated VMEntry does not fail here.  Instead a less
 			 * accurate value will be returned by
-			 * nested_vmx_get_vmexit_msr_value() using kvm_get_msr()
-			 * instead of reading the value from the vmcs02 VMExit
-			 * MSR-store area.
+			 * nested_vmx_get_vmexit_msr_value() by reading KVM's
+			 * internal MSR state instead of reading the value from
+			 * the vmcs02 VMExit MSR-store area.
 			 */
 			pr_warn_ratelimited(
 				"Not enough msr entries in msr_autostore.  Can't add msr %x\n",
@@ -1251,21 +1251,32 @@ static bool is_bitwise_subset(u64 superset, u64 subset, u64 mask)
 
 static int vmx_restore_vmx_basic(struct vcpu_vmx *vmx, u64 data)
 {
-	const u64 feature_and_reserved =
-		/* feature (except bit 48; see below) */
-		BIT_ULL(49) | BIT_ULL(54) | BIT_ULL(55) |
-		/* reserved */
-		BIT_ULL(31) | GENMASK_ULL(47, 45) | GENMASK_ULL(63, 56);
+	const u64 feature_bits = VMX_BASIC_DUAL_MONITOR_TREATMENT |
+				 VMX_BASIC_INOUT |
+				 VMX_BASIC_TRUE_CTLS;
+
+	const u64 reserved_bits = GENMASK_ULL(63, 56) |
+				  GENMASK_ULL(47, 45) |
+				  BIT_ULL(31);
+
 	u64 vmx_basic = vmcs_config.nested.basic;
 
-	if (!is_bitwise_subset(vmx_basic, data, feature_and_reserved))
+	BUILD_BUG_ON(feature_bits & reserved_bits);
+
+	/*
+	 * Except for 32BIT_PHYS_ADDR_ONLY, which is an anti-feature bit (has
+	 * inverted polarity), the incoming value must not set feature bits or
+	 * reserved bits that aren't allowed/supported by KVM.  Fields, i.e.
+	 * multi-bit values, are explicitly checked below.
+	 */
+	if (!is_bitwise_subset(vmx_basic, data, feature_bits | reserved_bits))
 		return -EINVAL;
 
 	/*
 	 * KVM does not emulate a version of VMX that constrains physical
 	 * addresses of VMX structures (e.g. VMCS) to 32-bits.
 	 */
-	if (data & BIT_ULL(48))
+	if (data & VMX_BASIC_32BIT_PHYS_ADDR_ONLY)
 		return -EINVAL;
 
 	if (vmx_basic_vmcs_revision_id(vmx_basic) !=
@@ -1334,16 +1345,29 @@ vmx_restore_control_msr(struct vcpu_vmx *vmx, u32 msr_index, u64 data)
 
 static int vmx_restore_vmx_misc(struct vcpu_vmx *vmx, u64 data)
 {
-	const u64 feature_and_reserved_bits =
-		/* feature */
-		BIT_ULL(5) | GENMASK_ULL(8, 6) | BIT_ULL(14) | BIT_ULL(15) |
-		BIT_ULL(28) | BIT_ULL(29) | BIT_ULL(30) |
-		/* reserved */
-		GENMASK_ULL(13, 9) | BIT_ULL(31);
+	const u64 feature_bits = VMX_MISC_SAVE_EFER_LMA |
+				 VMX_MISC_ACTIVITY_HLT |
+				 VMX_MISC_ACTIVITY_SHUTDOWN |
+				 VMX_MISC_ACTIVITY_WAIT_SIPI |
+				 VMX_MISC_INTEL_PT |
+				 VMX_MISC_RDMSR_IN_SMM |
+				 VMX_MISC_VMWRITE_SHADOW_RO_FIELDS |
+				 VMX_MISC_VMXOFF_BLOCK_SMI |
+				 VMX_MISC_ZERO_LEN_INS;
+
+	const u64 reserved_bits = BIT_ULL(31) | GENMASK_ULL(13, 9);
+
 	u64 vmx_misc = vmx_control_msr(vmcs_config.nested.misc_low,
 				       vmcs_config.nested.misc_high);
 
-	if (!is_bitwise_subset(vmx_misc, data, feature_and_reserved_bits))
+	BUILD_BUG_ON(feature_bits & reserved_bits);
+
+	/*
+	 * The incoming value must not set feature bits or reserved bits that
+	 * aren't allowed/supported by KVM.  Fields, i.e. multi-bit values, are
+	 * explicitly checked below.
+	 */
+	if (!is_bitwise_subset(vmx_misc, data, feature_bits | reserved_bits))
 		return -EINVAL;
 
 	if ((vmx->nested.msrs.pinbased_ctls_high &
@@ -2317,10 +2341,12 @@ static void prepare_vmcs02_early(struct vcpu_vmx *vmx, struct loaded_vmcs *vmcs0
 
 	/* Posted interrupts setting is only taken from vmcs12.  */
 	vmx->nested.pi_pending = false;
-	if (nested_cpu_has_posted_intr(vmcs12))
+	if (nested_cpu_has_posted_intr(vmcs12)) {
 		vmx->nested.posted_intr_nv = vmcs12->posted_intr_nv;
-	else
+	} else {
+		vmx->nested.posted_intr_nv = -1;
 		exec_control &= ~PIN_BASED_POSTED_INTR;
+	}
 	pin_controls_set(vmx, exec_control);
 
 	/*
@@ -2470,6 +2496,7 @@ static void prepare_vmcs02_rare(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12)
 
 	if (!hv_evmcs || !(hv_evmcs->hv_clean_fields &
 			   HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_GRP2)) {
+
 		vmcs_write16(GUEST_ES_SELECTOR, vmcs12->guest_es_selector);
 		vmcs_write16(GUEST_CS_SELECTOR, vmcs12->guest_cs_selector);
 		vmcs_write16(GUEST_SS_SELECTOR, vmcs12->guest_ss_selector);
@@ -2507,7 +2534,7 @@ static void prepare_vmcs02_rare(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12)
 		vmcs_writel(GUEST_GDTR_BASE, vmcs12->guest_gdtr_base);
 		vmcs_writel(GUEST_IDTR_BASE, vmcs12->guest_idtr_base);
 
-		vmx->segment_cache.bitmask = 0;
+		vmx_segment_cache_clear(vmx);
 	}
 
 	if (!hv_evmcs || !(hv_evmcs->hv_clean_fields &
@@ -4284,11 +4311,52 @@ static int vmx_check_nested_events(struct kvm_vcpu *vcpu)
 	}
 
 	if (kvm_cpu_has_interrupt(vcpu) && !vmx_interrupt_blocked(vcpu)) {
+		int irq;
+
 		if (block_nested_events)
 			return -EBUSY;
 		if (!nested_exit_on_intr(vcpu))
 			goto no_vmexit;
-		nested_vmx_vmexit(vcpu, EXIT_REASON_EXTERNAL_INTERRUPT, 0, 0);
+
+		if (!nested_exit_intr_ack_set(vcpu)) {
+			nested_vmx_vmexit(vcpu, EXIT_REASON_EXTERNAL_INTERRUPT, 0, 0);
+			return 0;
+		}
+
+		irq = kvm_cpu_get_extint(vcpu);
+		if (irq != -1) {
+			nested_vmx_vmexit(vcpu, EXIT_REASON_EXTERNAL_INTERRUPT,
+					  INTR_INFO_VALID_MASK | INTR_TYPE_EXT_INTR | irq, 0);
+			return 0;
+		}
+
+		irq = kvm_apic_has_interrupt(vcpu);
+		if (WARN_ON_ONCE(irq < 0))
+			goto no_vmexit;
+
+		/*
+		 * If the IRQ is L2's PI notification vector, process posted
+		 * interrupts for L2 instead of injecting VM-Exit, as the
+		 * detection/morphing architecturally occurs when the IRQ is
+		 * delivered to the CPU.  Note, only interrupts that are routed
+		 * through the local APIC trigger posted interrupt processing,
+		 * and enabling posted interrupts requires ACK-on-exit.
+		 */
+		if (irq == vmx->nested.posted_intr_nv) {
+			vmx->nested.pi_pending = true;
+			kvm_apic_clear_irr(vcpu, irq);
+			goto no_vmexit;
+		}
+
+		nested_vmx_vmexit(vcpu, EXIT_REASON_EXTERNAL_INTERRUPT,
+				  INTR_INFO_VALID_MASK | INTR_TYPE_EXT_INTR | irq, 0);
+
+		/*
+		 * ACK the interrupt _after_ emulating VM-Exit, as the IRQ must
+		 * be marked as in-service in vmcs01.GUEST_INTERRUPT_STATUS.SVI
+		 * if APICv is active.
+		 */
+		kvm_apic_ack_interrupt(vcpu, irq);
 		return 0;
 	}
 
@@ -4806,7 +4874,7 @@ static void nested_vmx_restore_host_state(struct kvm_vcpu *vcpu)
 				goto vmabort;
 			}
 
-			if (kvm_set_msr(vcpu, h.index, h.value)) {
+			if (kvm_set_msr_with_filter(vcpu, h.index, h.value)) {
 				pr_debug_ratelimited(
 					"%s WRMSR failed (%u, 0x%x, 0x%llx)\n",
 					__func__, j, h.index, h.value);
@@ -4969,14 +5037,6 @@ void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 vm_exit_reason,
 	vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
 
 	if (likely(!vmx->fail)) {
-		if ((u16)vm_exit_reason == EXIT_REASON_EXTERNAL_INTERRUPT &&
-		    nested_exit_intr_ack_set(vcpu)) {
-			int irq = kvm_cpu_get_interrupt(vcpu);
-			WARN_ON(irq < 0);
-			vmcs12->vm_exit_intr_info = irq |
-				INTR_INFO_VALID_MASK | INTR_TYPE_EXT_INTR;
-		}
-
 		if (vm_exit_reason != -1)
 			trace_kvm_nested_vmexit_inject(vmcs12->vm_exit_reason,
 						       vmcs12->exit_qualification,
@@ -7051,7 +7111,7 @@ static void nested_vmx_setup_misc_data(struct vmcs_config *vmcs_conf,
 {
 	msrs->misc_low = (u32)vmcs_conf->misc & VMX_MISC_SAVE_EFER_LMA;
 	msrs->misc_low |=
-		MSR_IA32_VMX_MISC_VMWRITE_SHADOW_RO_FIELDS |
+		VMX_MISC_VMWRITE_SHADOW_RO_FIELDS |
 		VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE |
 		VMX_MISC_ACTIVITY_HLT |
 		VMX_MISC_ACTIVITY_WAIT_SIPI;
@@ -7066,12 +7126,10 @@ static void nested_vmx_setup_basic(struct nested_vmx_msrs *msrs)
 	 * guest, and the VMCS structure we give it - not about the
 	 * VMX support of the underlying hardware.
 	 */
-	msrs->basic =
-		VMCS12_REVISION |
-		VMX_BASIC_TRUE_CTLS |
-		((u64)VMCS12_SIZE << VMX_BASIC_VMCS_SIZE_SHIFT) |
-		(VMX_BASIC_MEM_TYPE_WB << VMX_BASIC_MEM_TYPE_SHIFT);
+	msrs->basic = vmx_basic_encode_vmcs_info(VMCS12_REVISION, VMCS12_SIZE,
+						 X86_MEMTYPE_WB);
 
+	msrs->basic |= VMX_BASIC_TRUE_CTLS;
 	if (cpu_has_vmx_basic_inout())
 		msrs->basic |= VMX_BASIC_INOUT;
 }