Merging upstream version 6.9.7.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

3 files changed, 50 insertions, 24 deletions

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 759581bb2..4471b4e08 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -666,6 +666,14 @@ static int __sev_launch_update_vmsa(struct kvm *kvm, struct kvm_vcpu *vcpu,
 	  return ret;
 
 	vcpu->arch.guest_state_protected = true;
+
+	/*
+	 * SEV-ES guest mandates LBR Virtualization to be _always_ ON. Enable it
+	 * only after setting guest_state_protected because KVM_SET_MSRS allows
+	 * dynamic toggling of LBRV (for performance reason) on write access to
+	 * MSR_IA32_DEBUGCTLMSR when guest_state_protected is not set.
+	 */
+	svm_enable_lbrv(vcpu);
 	return 0;
 }
 
@@ -2269,6 +2277,12 @@ void __init sev_hardware_setup(void)
 	if (!boot_cpu_has(X86_FEATURE_SEV_ES))
 		goto out;
 
+	if (!lbrv) {
+		WARN_ONCE(!boot_cpu_has(X86_FEATURE_LBRV),
+			  "LBRV must be present for SEV-ES support");
+		goto out;
+	}
+
 	/* Has the system been allocated ASIDs for SEV-ES? */
 	if (min_sev_asid == 1)
 		goto out;
@@ -3034,7 +3048,6 @@ static void sev_es_init_vmcb(struct vcpu_svm *svm)
 	struct kvm_vcpu *vcpu = &svm->vcpu;
 
 	svm->vmcb->control.nested_ctl |= SVM_NESTED_CTL_SEV_ES_ENABLE;
-	svm->vmcb->control.virt_ext |= LBR_CTL_ENABLE_MASK;
 
 	/*
 	 * An SEV-ES guest requires a VMSA area that is a separate from the
@@ -3086,10 +3099,6 @@ static void sev_es_init_vmcb(struct vcpu_svm *svm)
 	/* Clear intercepts on selected MSRs */
 	set_msr_interception(vcpu, svm->msrpm, MSR_EFER, 1, 1);
 	set_msr_interception(vcpu, svm->msrpm, MSR_IA32_CR_PAT, 1, 1);
-	set_msr_interception(vcpu, svm->msrpm, MSR_IA32_LASTBRANCHFROMIP, 1, 1);
-	set_msr_interception(vcpu, svm->msrpm, MSR_IA32_LASTBRANCHTOIP, 1, 1);
-	set_msr_interception(vcpu, svm->msrpm, MSR_IA32_LASTINTFROMIP, 1, 1);
-	set_msr_interception(vcpu, svm->msrpm, MSR_IA32_LASTINTTOIP, 1, 1);
 }
 
 void sev_init_vmcb(struct vcpu_svm *svm)
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 9aaf83c8d..4650153af 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -99,6 +99,7 @@ static const struct svm_direct_access_msrs {
 	{ .index = MSR_IA32_SPEC_CTRL,			.always = false },
 	{ .index = MSR_IA32_PRED_CMD,			.always = false },
 	{ .index = MSR_IA32_FLUSH_CMD,			.always = false },
+	{ .index = MSR_IA32_DEBUGCTLMSR,		.always = false },
 	{ .index = MSR_IA32_LASTBRANCHFROMIP,		.always = false },
 	{ .index = MSR_IA32_LASTBRANCHTOIP,		.always = false },
 	{ .index = MSR_IA32_LASTINTFROMIP,		.always = false },
@@ -215,7 +216,7 @@ int vgif = true;
 module_param(vgif, int, 0444);
 
 /* enable/disable LBR virtualization */
-static int lbrv = true;
+int lbrv = true;
 module_param(lbrv, int, 0444);
 
 static int tsc_scaling = true;
@@ -990,7 +991,7 @@ void svm_copy_lbrs(struct vmcb *to_vmcb, struct vmcb *from_vmcb)
 	vmcb_mark_dirty(to_vmcb, VMCB_LBR);
 }
 
-static void svm_enable_lbrv(struct kvm_vcpu *vcpu)
+void svm_enable_lbrv(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
 
@@ -1000,6 +1001,9 @@ static void svm_enable_lbrv(struct kvm_vcpu *vcpu)
 	set_msr_interception(vcpu, svm->msrpm, MSR_IA32_LASTINTFROMIP, 1, 1);
 	set_msr_interception(vcpu, svm->msrpm, MSR_IA32_LASTINTTOIP, 1, 1);
 
+	if (sev_es_guest(vcpu->kvm))
+		set_msr_interception(vcpu, svm->msrpm, MSR_IA32_DEBUGCTLMSR, 1, 1);
+
 	/* Move the LBR msrs to the vmcb02 so that the guest can see them. */
 	if (is_guest_mode(vcpu))
 		svm_copy_lbrs(svm->vmcb, svm->vmcb01.ptr);
@@ -1009,6 +1013,8 @@ static void svm_disable_lbrv(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
 
+	KVM_BUG_ON(sev_es_guest(vcpu->kvm), vcpu->kvm);
+
 	svm->vmcb->control.virt_ext &= ~LBR_CTL_ENABLE_MASK;
 	set_msr_interception(vcpu, svm->msrpm, MSR_IA32_LASTBRANCHFROMIP, 0, 0);
 	set_msr_interception(vcpu, svm->msrpm, MSR_IA32_LASTBRANCHTOIP, 0, 0);
@@ -3843,16 +3849,27 @@ static void svm_enable_nmi_window(struct kvm_vcpu *vcpu)
 	struct vcpu_svm *svm = to_svm(vcpu);
 
 	/*
-	 * KVM should never request an NMI window when vNMI is enabled, as KVM
-	 * allows at most one to-be-injected NMI and one pending NMI, i.e. if
-	 * two NMIs arrive simultaneously, KVM will inject one and set
-	 * V_NMI_PENDING for the other.  WARN, but continue with the standard
-	 * single-step approach to try and salvage the pending NMI.
+	 * If NMIs are outright masked, i.e. the vCPU is already handling an
+	 * NMI, and KVM has not yet intercepted an IRET, then there is nothing
+	 * more to do at this time as KVM has already enabled IRET intercepts.
+	 * If KVM has already intercepted IRET, then single-step over the IRET,
+	 * as NMIs aren't architecturally unmasked until the IRET completes.
+	 *
+	 * If vNMI is enabled, KVM should never request an NMI window if NMIs
+	 * are masked, as KVM allows at most one to-be-injected NMI and one
+	 * pending NMI.  If two NMIs arrive simultaneously, KVM will inject one
+	 * NMI and set V_NMI_PENDING for the other, but if and only if NMIs are
+	 * unmasked.  KVM _will_ request an NMI window in some situations, e.g.
+	 * if the vCPU is in an STI shadow or if GIF=0, KVM can't immediately
+	 * inject the NMI.  In those situations, KVM needs to single-step over
+	 * the STI shadow or intercept STGI.
 	 */
-	WARN_ON_ONCE(is_vnmi_enabled(svm));
+	if (svm_get_nmi_mask(vcpu)) {
+		WARN_ON_ONCE(is_vnmi_enabled(svm));
 
-	if (svm_get_nmi_mask(vcpu) && !svm->awaiting_iret_completion)
-		return; /* IRET will cause a vm exit */
+		if (!svm->awaiting_iret_completion)
+			return; /* IRET will cause a vm exit */
+	}
 
 	/*
 	 * SEV-ES guests are responsible for signaling when a vCPU is ready to
@@ -5249,6 +5266,12 @@ static __init int svm_hardware_setup(void)
 
 	nrips = nrips && boot_cpu_has(X86_FEATURE_NRIPS);
 
+	if (lbrv) {
+		if (!boot_cpu_has(X86_FEATURE_LBRV))
+			lbrv = false;
+		else
+			pr_info("LBR virtualization supported\n");
+	}
 	/*
 	 * Note, SEV setup consumes npt_enabled and enable_mmio_caching (which
 	 * may be modified by svm_adjust_mmio_mask()), as well as nrips.
@@ -5302,14 +5325,6 @@ static __init int svm_hardware_setup(void)
 		svm_x86_ops.set_vnmi_pending = NULL;
 	}
 
-
-	if (lbrv) {
-		if (!boot_cpu_has(X86_FEATURE_LBRV))
-			lbrv = false;
-		else
-			pr_info("LBR virtualization supported\n");
-	}
-
 	if (!enable_pmu)
 		pr_info("PMU virtualization is disabled\n");
 
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 33878efde..2ed3015e0 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -30,7 +30,7 @@
 #define	IOPM_SIZE PAGE_SIZE * 3
 #define	MSRPM_SIZE PAGE_SIZE * 2
 
-#define MAX_DIRECT_ACCESS_MSRS	47
+#define MAX_DIRECT_ACCESS_MSRS	48
 #define MSRPM_OFFSETS	32
 extern u32 msrpm_offsets[MSRPM_OFFSETS] __read_mostly;
 extern bool npt_enabled;
@@ -39,6 +39,7 @@ extern int vgif;
 extern bool intercept_smi;
 extern bool x2avic_enabled;
 extern bool vnmi;
+extern int lbrv;
 
 /*
  * Clean bits in VMCB.
@@ -543,6 +544,7 @@ u32 *svm_vcpu_alloc_msrpm(void);
 void svm_vcpu_init_msrpm(struct kvm_vcpu *vcpu, u32 *msrpm);
 void svm_vcpu_free_msrpm(u32 *msrpm);
 void svm_copy_lbrs(struct vmcb *to_vmcb, struct vmcb *from_vmcb);
+void svm_enable_lbrv(struct kvm_vcpu *vcpu);
 void svm_update_lbrv(struct kvm_vcpu *vcpu);
 
 int svm_set_efer(struct kvm_vcpu *vcpu, u64 efer);