KVM: x86: Create mask for guest CR4 reserved bits in kvm_update_cpuid()

Instead of creating the mask for guest CR4 reserved bits in kvm_valid_cr4(),
do it in kvm_update_cpuid() so that it can be reused instead of creating it
each time kvm_valid_cr4() is called.
Suggested-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NKrish Sadhukhan <krish.sadhukhan@oracle.com>
Message-Id: <1594168797-29444-2-git-send-email-krish.sadhukhan@oracle.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

arch/x86/include/asm/kvm_host.h

@@ -545,6 +545,7 @@ struct kvm_vcpu_arch {
 	unsigned long cr3;
 	unsigned long cr4;
 	unsigned long cr4_guest_owned_bits;
+	unsigned long cr4_guest_rsvd_bits;
 	unsigned long cr8;
 	u32 host_pkru;
 	u32 pkru;

arch/x86/kvm/cpuid.c

@@ -128,6 +128,8 @@ int kvm_update_cpuid(struct kvm_vcpu *vcpu)
 	kvm_mmu_reset_context(vcpu);
 
 	kvm_pmu_refresh(vcpu);
+	vcpu->arch.cr4_guest_rsvd_bits =
+	    __cr4_reserved_bits(guest_cpuid_has, vcpu);
 	return 0;
 }
 

arch/x86/kvm/x86.c

@@ -955,33 +955,12 @@ int kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr)
 }
 EXPORT_SYMBOL_GPL(kvm_set_xcr);
 
-#define __cr4_reserved_bits(__cpu_has, __c)		\
-({							\
-	u64 __reserved_bits = CR4_RESERVED_BITS;	\
-							\
-	if (!__cpu_has(__c, X86_FEATURE_XSAVE))		\
-		__reserved_bits |= X86_CR4_OSXSAVE;	\
-	if (!__cpu_has(__c, X86_FEATURE_SMEP))		\
-		__reserved_bits |= X86_CR4_SMEP;	\
-	if (!__cpu_has(__c, X86_FEATURE_SMAP))		\
-		__reserved_bits |= X86_CR4_SMAP;	\
-	if (!__cpu_has(__c, X86_FEATURE_FSGSBASE))	\
-		__reserved_bits |= X86_CR4_FSGSBASE;	\
-	if (!__cpu_has(__c, X86_FEATURE_PKU))		\
-		__reserved_bits |= X86_CR4_PKE;		\
-	if (!__cpu_has(__c, X86_FEATURE_LA57))		\
-		__reserved_bits |= X86_CR4_LA57;	\
-	if (!__cpu_has(__c, X86_FEATURE_UMIP))		\
-		__reserved_bits |= X86_CR4_UMIP;	\
-	__reserved_bits;				\
-})
-
 static int kvm_valid_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
 {
 	if (cr4 & cr4_reserved_bits)
 		return -EINVAL;
 
-	if (cr4 & __cr4_reserved_bits(guest_cpuid_has, vcpu))
+	if (cr4 & vcpu->arch.cr4_guest_rsvd_bits)
 		return -EINVAL;
 
 	return 0;

arch/x86/kvm/x86.h

@@ -373,4 +373,25 @@ bool kvm_vcpu_exit_request(struct kvm_vcpu *vcpu);
 
 #define  KVM_MSR_RET_INVALID  2
 
+#define __cr4_reserved_bits(__cpu_has, __c)             \
+({                                                      \
+	u64 __reserved_bits = CR4_RESERVED_BITS;        \
+                                                        \
+	if (!__cpu_has(__c, X86_FEATURE_XSAVE))         \
+		__reserved_bits |= X86_CR4_OSXSAVE;     \
+	if (!__cpu_has(__c, X86_FEATURE_SMEP))          \
+		__reserved_bits |= X86_CR4_SMEP;        \
+	if (!__cpu_has(__c, X86_FEATURE_SMAP))          \
+		__reserved_bits |= X86_CR4_SMAP;        \
+	if (!__cpu_has(__c, X86_FEATURE_FSGSBASE))      \
+		__reserved_bits |= X86_CR4_FSGSBASE;    \
+	if (!__cpu_has(__c, X86_FEATURE_PKU))           \
+		__reserved_bits |= X86_CR4_PKE;         \
+	if (!__cpu_has(__c, X86_FEATURE_LA57))          \
+		__reserved_bits |= X86_CR4_LA57;        \
+	if (!__cpu_has(__c, X86_FEATURE_UMIP))          \
+		__reserved_bits |= X86_CR4_UMIP;        \
+	__reserved_bits;                                \
+})
+
 #endif