KVM: x86: Move supported EFER bits to kvm_caps

Supported EFER bits naturally fits into kvm_caps because it gets
recomputed during vendor initialization (e.g. to account for EFER.SVME
being allowed/disallowed based on nested being enabled/disabled). Move
efer_supported_bits into kvm_caps as supported_efer_bits (for naming
consistency).

As the bitmask is now globally visible as part of kvm_caps, there's
little use for helpers to enable/disable specific bits, so drop them and
open-code updates to kvm_caps.supported_efer_bits.

No functional change intended.

Suggested-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Nikolay Borisov <nik.borisov@suse.com>
Signed-off-by: Yosry Ahmed <yosry@kernel.org>
Link: https://patch.msgid.link/20260713181020.2735367-6-yosry@kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>

4 files changed, 12 insertions, 26 deletions

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 974a506538aa..6077f4e00d79 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -272,6 +272,8 @@ struct kvm_caps {
 	u64 supported_xss;
 	u64 supported_perf_cap;
 
+	u64 supported_efer_bits;
+
 	u64 supported_quirks;
 	u64 inapplicable_quirks;
 };
diff --git a/arch/x86/kvm/msrs.c b/arch/x86/kvm/msrs.c
index 8e33b87b5e8f..66fa7140d65d 100644
--- a/arch/x86/kvm/msrs.c
+++ b/arch/x86/kvm/msrs.c
@@ -19,8 +19,6 @@ bool __read_mostly report_ignored_msrs = true;
 module_param(report_ignored_msrs, bool, 0644);
 EXPORT_SYMBOL_FOR_KVM_INTERNAL(report_ignored_msrs);
 
-static u64 __read_mostly efer_supported_bits;
-
 #define MAX_IO_MSRS 256
 
 struct msr_bitmap_range {
@@ -605,7 +603,7 @@ static bool __kvm_valid_efer(struct kvm_vcpu *vcpu, u64 efer)
 }
 bool kvm_valid_efer(struct kvm_vcpu *vcpu, u64 efer)
 {
-	if (efer & ~efer_supported_bits)
+	if (efer & ~kvm_caps.supported_efer_bits)
 		return false;
 
 	return __kvm_valid_efer(vcpu, efer);
@@ -618,7 +616,7 @@ static int set_efer(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 	u64 efer = msr_info->data;
 	int r;
 
-	if (efer & ~efer_supported_bits)
+	if (efer & ~kvm_caps.supported_efer_bits)
 		return 1;
 
 	if (!msr_info->host_initiated) {
@@ -649,19 +647,6 @@ static int set_efer(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 	return 0;
 }
 
-void kvm_init_efer_bits(void)
-{
-	/* Enable syscall by default because its emulated by KVM */
-	efer_supported_bits = (u64)EFER_SCE;
-}
-EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_init_efer_bits);
-
-void kvm_enable_efer_bits(u64 mask)
-{
-	efer_supported_bits |= mask;
-}
-EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_enable_efer_bits);
-
 bool kvm_msr_allowed(struct kvm_vcpu *vcpu, u32 index, u32 type)
 {
 	struct kvm_x86_msr_filter *msr_filter;
diff --git a/arch/x86/kvm/msrs.h b/arch/x86/kvm/msrs.h
index 1f772e171758..7cc182a15b3b 100644
--- a/arch/x86/kvm/msrs.h
+++ b/arch/x86/kvm/msrs.h
@@ -58,8 +58,6 @@ int kvm_get_set_one_reg(struct kvm_vcpu *vcpu, unsigned int ioctl,
 int kvm_get_reg_list(struct kvm_vcpu *vcpu,
 		     struct kvm_reg_list __user *user_list);
 
-void kvm_init_efer_bits(void);
-void kvm_enable_efer_bits(u64);
 bool kvm_valid_efer(struct kvm_vcpu *vcpu, u64 efer);
 int kvm_emulate_msr_read(struct kvm_vcpu *vcpu, u32 index, u64 *data);
 int kvm_emulate_msr_write(struct kvm_vcpu *vcpu, u32 index, u64 data);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index cf5fa038ff17..dfaf80efec4b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6910,24 +6910,25 @@ EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_setup_xss_caps);
 
 static void kvm_setup_efer_caps(void)
 {
-	kvm_init_efer_bits();
+	/* Enable syscall by default because its emulated by KVM */
+	kvm_caps.supported_efer_bits = (u64)EFER_SCE;
 
 	if (kvm_cpu_cap_has(X86_FEATURE_LM))
-		kvm_enable_efer_bits(EFER_LME | EFER_LMA);
+		kvm_caps.supported_efer_bits |= (EFER_LME | EFER_LMA);
 
 	if (kvm_cpu_cap_has(X86_FEATURE_NX))
-		kvm_enable_efer_bits(EFER_NX);
+		kvm_caps.supported_efer_bits |= EFER_NX;
 
 	if (kvm_cpu_cap_has(X86_FEATURE_FXSR_OPT))
-		kvm_enable_efer_bits(EFER_FFXSR);
+		kvm_caps.supported_efer_bits |= EFER_FFXSR;
 
 	if (kvm_cpu_cap_has(X86_FEATURE_AUTOIBRS))
-		kvm_enable_efer_bits(EFER_AUTOIBRS);
+		kvm_caps.supported_efer_bits |= EFER_AUTOIBRS;
 
 	if (kvm_cpu_cap_has(X86_FEATURE_SVM)) {
-		kvm_enable_efer_bits(EFER_SVME);
+		kvm_caps.supported_efer_bits |= EFER_SVME;
 		if (!boot_cpu_has(X86_FEATURE_EFER_LMSLE_MBZ))
-			kvm_enable_efer_bits(EFER_LMSLE);
+			kvm_caps.supported_efer_bits |= EFER_LMSLE;
 	}
 }