[PATCH 11/12] KVM: nSVM: Use KVM-governed feature framework to track "vGIF enabled"

From: Sean Christopherson
Date: Fri Feb 17 2023 - 18:11:52 EST


Track "virtual GIF exposed to L1" via a governed feature flag instead of
using a dedicated bit/flag in vcpu_svm.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/governed_features.h | 1 +
arch/x86/kvm/svm/nested.c | 3 ++-
arch/x86/kvm/svm/svm.c | 3 ++-
arch/x86/kvm/svm/svm.h | 7 +++----
4 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kvm/governed_features.h b/arch/x86/kvm/governed_features.h
index 93c7d840e546..b49fdabb88c4 100644
--- a/arch/x86/kvm/governed_features.h
+++ b/arch/x86/kvm/governed_features.h
@@ -13,6 +13,7 @@ KVM_GOVERNED_X86_FEATURE(V_VMSAVE_VMLOAD)
KVM_GOVERNED_X86_FEATURE(LBRV)
KVM_GOVERNED_X86_FEATURE(PAUSEFILTER)
KVM_GOVERNED_X86_FEATURE(PFTHRESHOLD)
+KVM_GOVERNED_X86_FEATURE(VGIF)

#undef KVM_GOVERNED_X86_FEATURE
#undef KVM_GOVERNED_FEATURE
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index c38f17ba818e..c73c2acaf4c0 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -648,7 +648,8 @@ static void nested_vmcb02_prepare_control(struct vcpu_svm *svm,
* exit_int_info, exit_int_info_err, next_rip, insn_len, insn_bytes.
*/

- if (svm->vgif_enabled && (svm->nested.ctl.int_ctl & V_GIF_ENABLE_MASK))
+ if (guest_can_use(vcpu, X86_FEATURE_VGIF) &&
+ (svm->nested.ctl.int_ctl & V_GIF_ENABLE_MASK))
int_ctl_vmcb12_bits |= (V_GIF_MASK | V_GIF_ENABLE_MASK);
else
int_ctl_vmcb01_bits |= (V_GIF_MASK | V_GIF_ENABLE_MASK);
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index b18bd0b33942..11068e8eb969 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4163,7 +4163,8 @@ static void svm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
if (kvm_cpu_cap_has(X86_FEATURE_PFTHRESHOLD))
kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_PFTHRESHOLD);

- svm->vgif_enabled = vgif && guest_cpuid_has(vcpu, X86_FEATURE_VGIF);
+ if (vgif)
+ kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_VGIF);

svm_recalc_instruction_intercepts(vcpu, svm);

diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index c05eea319d28..be5419975694 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -22,6 +22,7 @@
#include <asm/svm.h>
#include <asm/sev-common.h>

+#include "cpuid.h"
#include "kvm_cache_regs.h"

#define __sme_page_pa(x) __sme_set(page_to_pfn(x) << PAGE_SHIFT)
@@ -257,9 +258,6 @@ struct vcpu_svm {
unsigned long soft_int_next_rip;
bool soft_int_injected;

- /* optional nested SVM features that are enabled for this guest */
- bool vgif_enabled : 1;
-
u32 ldr_reg;
u32 dfr_reg;
struct page *avic_backing_page;
@@ -484,7 +482,8 @@ static inline bool svm_is_intercept(struct vcpu_svm *svm, int bit)

static inline bool nested_vgif_enabled(struct vcpu_svm *svm)
{
- return svm->vgif_enabled && (svm->nested.ctl.int_ctl & V_GIF_ENABLE_MASK);
+ return guest_can_use(&svm->vcpu, X86_FEATURE_VGIF) &&
+ (svm->nested.ctl.int_ctl & V_GIF_ENABLE_MASK);
}

static inline struct vmcb *get_vgif_vmcb(struct vcpu_svm *svm)
--
2.39.2.637.g21b0678d19-goog