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

Pull kvm fixes from Paolo Bonzini:
 "Two small fixes, one of which was being worked around in selftests"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86: Retry page fault if MMU reload is pending and root has no sp
  KVM: selftests: vmx_pmu_msrs_test: Drop tests mangling guest visible CPUIDs
  KVM: x86: Drop guest CPUID check for host initiated writes to MSR_IA32_PERF_CAPABILITIES

Author: torvalds

arch/x86/kvm/mmu/mmu.c

@@ -3987,7 +3987,21 @@ static bool kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault,
 static bool is_page_fault_stale(struct kvm_vcpu *vcpu,
 				struct kvm_page_fault *fault, int mmu_seq)
 {
-	if (is_obsolete_sp(vcpu->kvm, to_shadow_page(vcpu->arch.mmu->root_hpa)))
+	struct kvm_mmu_page *sp = to_shadow_page(vcpu->arch.mmu->root_hpa);
+
+	/* Special roots, e.g. pae_root, are not backed by shadow pages. */
+	if (sp && is_obsolete_sp(vcpu->kvm, sp))
+		return true;
+
+	/*
+	 * Roots without an associated shadow page are considered invalid if
+	 * there is a pending request to free obsolete roots.  The request is
+	 * only a hint that the current root _may_ be obsolete and needs to be
+	 * reloaded, e.g. if the guest frees a PGD that KVM is tracking as a
+	 * previous root, then __kvm_mmu_prepare_zap_page() signals all vCPUs
+	 * to reload even if no vCPU is actively using the root.
+	 */
+	if (!sp && kvm_test_request(KVM_REQ_MMU_RELOAD, vcpu))
 		return true;
 
 	return fault->slot &&

arch/x86/kvm/x86.c

@@ -3413,7 +3413,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 
 		if (!msr_info->host_initiated)
 			return 1;
-		if (guest_cpuid_has(vcpu, X86_FEATURE_PDCM) && kvm_get_msr_feature(&msr_ent))
+		if (kvm_get_msr_feature(&msr_ent))
 			return 1;
 		if (data & ~msr_ent.data)
 			return 1;

tools/testing/selftests/kvm/x86_64/vmx_pmu_msrs_test.c

@@ -110,22 +110,5 @@ int main(int argc, char *argv[])
 	ret = _vcpu_set_msr(vm, 0, MSR_IA32_PERF_CAPABILITIES, PMU_CAP_LBR_FMT);
 	TEST_ASSERT(ret == 0, "Bad PERF_CAPABILITIES didn't fail.");
 
-	/* testcase 4, set capabilities when we don't have PDCM bit */
-	entry_1_0->ecx &= ~X86_FEATURE_PDCM;
-	vcpu_set_cpuid(vm, VCPU_ID, cpuid);
-	ret = _vcpu_set_msr(vm, 0, MSR_IA32_PERF_CAPABILITIES, host_cap.capabilities);
-	TEST_ASSERT(ret == 0, "Bad PERF_CAPABILITIES didn't fail.");
-
-	/* testcase 5, set capabilities when we don't have PMU version bits */
-	entry_1_0->ecx |= X86_FEATURE_PDCM;
-	eax.split.version_id = 0;
-	entry_1_0->ecx = eax.full;
-	vcpu_set_cpuid(vm, VCPU_ID, cpuid);
-	ret = _vcpu_set_msr(vm, 0, MSR_IA32_PERF_CAPABILITIES, PMU_CAP_FW_WRITES);
-	TEST_ASSERT(ret == 0, "Bad PERF_CAPABILITIES didn't fail.");
-
-	vcpu_set_msr(vm, 0, MSR_IA32_PERF_CAPABILITIES, 0);
-	ASSERT_EQ(vcpu_get_msr(vm, VCPU_ID, MSR_IA32_PERF_CAPABILITIES), 0);
-
 	kvm_vm_free(vm);
 }