Commit b89456ae authored by Sean Christopherson's avatar Sean Christopherson
Browse files

KVM: nSVM: Use KVM-governed feature framework to track "vGIF enabled" 

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

Note, checking KVM's capabilities instead of the "vgif" param means that
the code isn't strictly equivalent, as vgif_enabled could have been set
if nested=false where as that the governed feature cannot.  But that's a
glorified nop as the feature/flag is consumed only by paths that are

Link: https://lore.kernel.org/r/20230815203653.519297-14-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent 59d67fc1

arch/x86/kvm/governed_features.h

+1 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 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

arch/x86/kvm/svm/nested.c

+2 −1
Original line number Diff line number Diff line
@@ -660,7 +660,8 @@ 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);

arch/x86/kvm/svm/svm.c

+1 −2
Original line number Diff line number Diff line
@@ -4273,8 +4273,7 @@ static void svm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu) 


	kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_PAUSEFILTER);

	kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_PFTHRESHOLD);



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

	kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_VGIF);



	svm->vnmi_enabled = vnmi && guest_cpuid_has(vcpu, X86_FEATURE_VNMI);

arch/x86/kvm/svm/svm.h

+3 −2
Original line number Diff line number Diff line
@@ -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)
@@ -259,7 +260,6 @@ struct vcpu_svm { 
	bool soft_int_injected;



	/* optional nested SVM features that are enabled for this guest  */

	bool vgif_enabled                 : 1;

	bool vnmi_enabled                 : 1;



	u32 ldr_reg;
@@ -485,7 +485,8 @@ 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)