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authorJakub Kicinski <kuba@kernel.org>2023-10-05 13:16:31 -0700
committerJakub Kicinski <kuba@kernel.org>2023-10-05 13:16:47 -0700
commit2606cf059c56bfb86d5d6bd0f41bd7eedefc8b0a (patch)
tree6bd918ad4fc55e677cc6ccb3212eab873c467c7f /arch/x86/kvm/svm/svm.c
parent49e7265fd098fdade2bbdd9331e6b914cda7fa83 (diff)
parentf291209eca5eba0b4704fa0832af57b12dbc1a02 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR. No conflicts (or adjacent changes of note). Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'arch/x86/kvm/svm/svm.c')
-rw-r--r--arch/x86/kvm/svm/svm.c43
1 files changed, 35 insertions, 8 deletions
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index f283eb47f6ac..9507df93f410 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -683,6 +683,21 @@ static int svm_hardware_enable(void)
amd_pmu_enable_virt();
+ /*
+ * If TSC_AUX virtualization is supported, TSC_AUX becomes a swap type
+ * "B" field (see sev_es_prepare_switch_to_guest()) for SEV-ES guests.
+ * Since Linux does not change the value of TSC_AUX once set, prime the
+ * TSC_AUX field now to avoid a RDMSR on every vCPU run.
+ */
+ if (boot_cpu_has(X86_FEATURE_V_TSC_AUX)) {
+ struct sev_es_save_area *hostsa;
+ u32 msr_hi;
+
+ hostsa = (struct sev_es_save_area *)(page_address(sd->save_area) + 0x400);
+
+ rdmsr(MSR_TSC_AUX, hostsa->tsc_aux, msr_hi);
+ }
+
return 0;
}
@@ -1532,7 +1547,14 @@ static void svm_prepare_switch_to_guest(struct kvm_vcpu *vcpu)
if (tsc_scaling)
__svm_write_tsc_multiplier(vcpu->arch.tsc_scaling_ratio);
- if (likely(tsc_aux_uret_slot >= 0))
+ /*
+ * TSC_AUX is always virtualized for SEV-ES guests when the feature is
+ * available. The user return MSR support is not required in this case
+ * because TSC_AUX is restored on #VMEXIT from the host save area
+ * (which has been initialized in svm_hardware_enable()).
+ */
+ if (likely(tsc_aux_uret_slot >= 0) &&
+ (!boot_cpu_has(X86_FEATURE_V_TSC_AUX) || !sev_es_guest(vcpu->kvm)))
kvm_set_user_return_msr(tsc_aux_uret_slot, svm->tsc_aux, -1ull);
svm->guest_state_loaded = true;
@@ -3087,6 +3109,16 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
break;
case MSR_TSC_AUX:
/*
+ * TSC_AUX is always virtualized for SEV-ES guests when the
+ * feature is available. The user return MSR support is not
+ * required in this case because TSC_AUX is restored on #VMEXIT
+ * from the host save area (which has been initialized in
+ * svm_hardware_enable()).
+ */
+ if (boot_cpu_has(X86_FEATURE_V_TSC_AUX) && sev_es_guest(vcpu->kvm))
+ break;
+
+ /*
* TSC_AUX is usually changed only during boot and never read
* directly. Intercept TSC_AUX instead of exposing it to the
* guest via direct_access_msrs, and switch it via user return.
@@ -4284,7 +4316,6 @@ static bool svm_has_emulated_msr(struct kvm *kvm, u32 index)
static void svm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
{
struct vcpu_svm *svm = to_svm(vcpu);
- struct kvm_cpuid_entry2 *best;
/*
* SVM doesn't provide a way to disable just XSAVES in the guest, KVM
@@ -4328,12 +4359,8 @@ static void svm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
set_msr_interception(vcpu, svm->msrpm, MSR_IA32_FLUSH_CMD, 0,
!!guest_cpuid_has(vcpu, X86_FEATURE_FLUSH_L1D));
- /* For sev guests, the memory encryption bit is not reserved in CR3. */
- if (sev_guest(vcpu->kvm)) {
- best = kvm_find_cpuid_entry(vcpu, 0x8000001F);
- if (best)
- vcpu->arch.reserved_gpa_bits &= ~(1UL << (best->ebx & 0x3f));
- }
+ if (sev_guest(vcpu->kvm))
+ sev_vcpu_after_set_cpuid(svm);
init_vmcb_after_set_cpuid(vcpu);
}