Commit e3563584 authored by Binbin Wu's avatar Binbin Wu Committed by Zhiquan Li
Browse files

KVM: x86: Use KVM-governed feature framework to track "LAM enabled" 

mainline inclusion
from mainline-v6.8-rc1
commit 183bdd161c2b773a62f01d1c030f5a3a5b7c33b5
category: feature
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I94GWL
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=183bdd161c2b773a62f01d1c030f5a3a5b7c33b5



--------------------------------

Use the governed feature framework to track if Linear Address Masking (LAM)
is "enabled", i.e. if LAM can be used by the guest.

Using the framework to avoid the relative expensive call guest_cpuid_has()
during cr3 and vmexit handling paths for LAM.

No functional change intended.

Intel-SIG: commit 183bdd161c2b KVM: x86: Use KVM-governed feature
framework to track "LAM enabled"
Backport KVM Linear Address Masking (LAM) support.

Signed-off-by: default avatarBinbin Wu <binbin.wu@linux.intel.com>
Tested-by: default avatarXuelian Guo <xuelian.guo@intel.com>
Link: https://lore.kernel.org/r/20230913124227.12574-14-binbin.wu@linux.intel.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
[ Zhiquan Li: amend commit log ]
Signed-off-by: default avatarZhiquan Li <zhiquan1.li@intel.com>
parent ce5c6600

arch/x86/kvm/cpuid.h

+1 −2
Original line number Diff line number Diff line
@@ -275,8 +275,7 @@ static __always_inline bool guest_can_use(struct kvm_vcpu *vcpu, 


static inline bool kvm_vcpu_is_legal_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)

{

	if (kvm_cpu_cap_has(X86_FEATURE_LAM) &&

	    guest_cpuid_has(vcpu, X86_FEATURE_LAM))

	if (guest_can_use(vcpu, X86_FEATURE_LAM))

		cr3 &= ~(X86_CR3_LAM_U48 | X86_CR3_LAM_U57);



	return kvm_vcpu_is_legal_gpa(vcpu, cr3);

arch/x86/kvm/governed_features.h

+1 −0
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ KVM_GOVERNED_X86_FEATURE(PAUSEFILTER) 
KVM_GOVERNED_X86_FEATURE(PFTHRESHOLD)

KVM_GOVERNED_X86_FEATURE(VGIF)

KVM_GOVERNED_X86_FEATURE(VNMI)

KVM_GOVERNED_X86_FEATURE(LAM)



#undef KVM_GOVERNED_X86_FEATURE

#undef KVM_GOVERNED_FEATURE

arch/x86/kvm/mmu.h

+1 −2
Original line number Diff line number Diff line
@@ -148,8 +148,7 @@ static inline unsigned long kvm_get_active_pcid(struct kvm_vcpu *vcpu) 


static inline unsigned long kvm_get_active_cr3_lam_bits(struct kvm_vcpu *vcpu)

{

	if (!kvm_cpu_cap_has(X86_FEATURE_LAM) ||

	    !guest_cpuid_has(vcpu, X86_FEATURE_LAM))

	if (!guest_can_use(vcpu, X86_FEATURE_LAM))

		return 0;



	return kvm_read_cr3(vcpu) & (X86_CR3_LAM_U48 | X86_CR3_LAM_U57);

arch/x86/kvm/vmx/vmx.c

+1 −0
Original line number Diff line number Diff line
@@ -7775,6 +7775,7 @@ static void vmx_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu) 
		kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_XSAVES);



	kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_VMX);

	kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_LAM);



	vmx_setup_uret_msrs(vmx);