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authorJing Liu <jing2.liu@intel.com>2022-01-05 15:35:25 +0300
committerPaolo Bonzini <pbonzini@redhat.com>2022-01-14 21:44:33 +0300
commit61f208134a871047f1d642ed3b813f4f71e30b0e (patch)
treeabc436e9f9c01f21526833cf2b6c4948ab0d5b7b
parent548e83650a51dce0d188b9e41b1e2ca5d63597cf (diff)
downloadlinux-61f208134a871047f1d642ed3b813f4f71e30b0e.tar.xz
kvm: x86: Disable RDMSR interception of IA32_XFD_ERR
This saves one unnecessary VM-exit in guest #NM handler, given that the MSR is already restored with the guest value before the guest is resumed. Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Jing Liu <jing2.liu@intel.com> Signed-off-by: Yang Zhong <yang.zhong@intel.com> Message-Id: <20220105123532.12586-15-yang.zhong@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r--arch/x86/kvm/vmx/vmx.c6
-rw-r--r--arch/x86/kvm/vmx/vmx.h2
2 files changed, 7 insertions, 1 deletions
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 84f6904cdb6e..b8b7f5c7b3df 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -162,6 +162,7 @@ static u32 vmx_possible_passthrough_msrs[MAX_POSSIBLE_PASSTHROUGH_MSRS] = {
MSR_FS_BASE,
MSR_GS_BASE,
MSR_KERNEL_GS_BASE,
+ MSR_IA32_XFD_ERR,
#endif
MSR_IA32_SYSENTER_CS,
MSR_IA32_SYSENTER_ESP,
@@ -7288,6 +7289,11 @@ static void vmx_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
}
}
+ if (kvm_cpu_cap_has(X86_FEATURE_XFD))
+ vmx_set_intercept_for_msr(vcpu, MSR_IA32_XFD_ERR, MSR_TYPE_R,
+ !guest_cpuid_has(vcpu, X86_FEATURE_XFD));
+
+
set_cr4_guest_host_mask(vmx);
vmx_write_encls_bitmap(vcpu, NULL);
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index 18111368cf85..69dd2f85abdc 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -349,7 +349,7 @@ struct vcpu_vmx {
struct lbr_desc lbr_desc;
/* Save desired MSR intercept (read: pass-through) state */
-#define MAX_POSSIBLE_PASSTHROUGH_MSRS 13
+#define MAX_POSSIBLE_PASSTHROUGH_MSRS 14
struct {
DECLARE_BITMAP(read, MAX_POSSIBLE_PASSTHROUGH_MSRS);
DECLARE_BITMAP(write, MAX_POSSIBLE_PASSTHROUGH_MSRS);