KVM: x86: Add a helper to query whether or not a vCPU has ever run

Add a helper to query if a vCPU has run so that KVM doesn't have to open
code the check on last_vmentry_cpu being set to a magic value.

No functional change intended.

Suggested-by: Xiaoyao Li <xiaoyao.li@intel.com>
Cc: Like Xu <like.xu.linux@gmail.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Link: https://lore.kernel.org/r/20230311004618.920745-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 9583a11..b736ddb 100644 (file)
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -420,7 +420,7 @@ static int kvm_set_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 *e2,
         * KVM_SET_CPUID{,2} again. To support this legacy behavior, check
         * whether the supplied CPUID data is equal to what's already set.
         */
-       if (vcpu->arch.last_vmentry_cpu != -1) {
+       if (kvm_vcpu_has_run(vcpu)) {
                r = kvm_cpuid_check_equal(vcpu, e2, nent);
                if (r)
                        return r;

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 144c5a0..8ced487 100644 (file)
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -5393,7 +5393,7 @@ void kvm_mmu_after_set_cpuid(struct kvm_vcpu *vcpu)
         * Changing guest CPUID after KVM_RUN is forbidden, see the comment in
         * kvm_arch_vcpu_ioctl().
         */
-       KVM_BUG_ON(vcpu->arch.last_vmentry_cpu != -1, vcpu->kvm);
+       KVM_BUG_ON(kvm_vcpu_has_run(vcpu), vcpu->kvm);
 }
 
 void kvm_mmu_reset_context(struct kvm_vcpu *vcpu)

diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index a8167b4..754190a 100644 (file)
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -83,6 +83,11 @@ static inline unsigned int __shrink_ple_window(unsigned int val,
 void kvm_service_local_tlb_flush_requests(struct kvm_vcpu *vcpu);
 int kvm_check_nested_events(struct kvm_vcpu *vcpu);
 
+static inline bool kvm_vcpu_has_run(struct kvm_vcpu *vcpu)
+{
+       return vcpu->arch.last_vmentry_cpu != -1;
+}
+
 static inline bool kvm_is_exception_pending(struct kvm_vcpu *vcpu)
 {
        return vcpu->arch.exception.pending ||