[PATCH 1/6] KVM: X86: Reset vcpu->arch.cpuid_nent to 0 if SET_CPUID fails

[Xiaoyao Li]

It needs to invalidate CPUID configruations if usersapce provides
illegal input.

Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
---
 arch/x86/kvm/cpuid.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index cd708b0b460a..2f1a9650b7f2 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -210,6 +210,8 @@ int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
 	kvm_apic_set_version(vcpu);
 	kvm_x86_ops.cpuid_update(vcpu);
 	r = kvm_update_cpuid(vcpu);
+	if (r)
+		vcpu->arch.cpuid_nent = 0;
 
 out:
 	vfree(cpuid_entries);
@@ -233,6 +235,8 @@ int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
 	kvm_apic_set_version(vcpu);
 	kvm_x86_ops.cpuid_update(vcpu);
 	r = kvm_update_cpuid(vcpu);
+	if (r)
+		vcpu->arch.cpuid_nent = 0;
 out:
 	return r;
 }
-- 
2.18.2