[PATCH v3 1/8] KVM: x86: Add kvm_permitted_xcr0()

[Aaron Lewis <aaronlewis@xxxxxxxxxx>]

Add the helper, kvm_permitted_xcr0(), to make it easier to filter
the supported XCR0 before using it.

No functional changes intended.

Signed-off-by: Aaron Lewis <aaronlewis@xxxxxxxxxx>
---
 arch/x86/kvm/cpuid.c | 7 ++++++-
 arch/x86/kvm/cpuid.h | 1 +
 arch/x86/kvm/x86.c   | 4 +---
 3 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 8f8edeaf8177..e1165c196970 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -60,6 +60,11 @@ u32 xstate_required_size(u64 xstate_bv, bool compacted)
 	return ret;
 }
 
+u64 kvm_permitted_xcr0(void)
+{
+	return kvm_caps.supported_xcr0 & xstate_get_guest_group_perm();
+}
+
 /*
  * This one is tied to SSB in the user API, and not
  * visible in /proc/cpuinfo.
@@ -981,7 +986,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
 		entry->eax = entry->ebx = entry->ecx = 0;
 		break;
 	case 0xd: {
-		u64 permitted_xcr0 = kvm_caps.supported_xcr0 & xstate_get_guest_group_perm();
+		u64 permitted_xcr0 = kvm_permitted_xcr0();
 		u64 permitted_xss = kvm_caps.supported_xss;
 
 		entry->eax &= permitted_xcr0;
diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h
index b1658c0de847..224c25e02748 100644
--- a/arch/x86/kvm/cpuid.h
+++ b/arch/x86/kvm/cpuid.h
@@ -33,6 +33,7 @@ bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx,
 	       u32 *ecx, u32 *edx, bool exact_only);
 
 u32 xstate_required_size(u64 xstate_bv, bool compacted);
+u64 kvm_permitted_xcr0(void);
 
 int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu);
 u64 kvm_vcpu_reserved_gpa_bits_raw(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index f706621c35b8..596b234fc100 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4519,9 +4519,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 			r = 0;
 		break;
 	case KVM_CAP_XSAVE2: {
-		u64 guest_perm = xstate_get_guest_group_perm();
-
-		r = xstate_required_size(kvm_caps.supported_xcr0 & guest_perm, false);
+		r = xstate_required_size(kvm_permitted_xcr0(), false);
 		if (r < sizeof(struct kvm_xsave))
 			r = sizeof(struct kvm_xsave);
 		break;
-- 
2.39.2.637.g21b0678d19-goog