On 6/24/2020 2:20 AM, Jim Mattson wrote:
On Tue, Jun 23, 2020 at 4:58 AM Xiaoyao Li <xiaoyao.li@xxxxxxxxx> wrote:
It needs to invalidate CPUID configruations if usersapce provides
Nits: configurations, userspace
oh, I'll fix it.
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 8a294f9747aa..1d13bad42bf9 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -207,6 +207,8 @@ 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;
kvfree(cpuid_entries);
out:
@@ -230,6 +232,8 @@ 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
What if vcpu->arch.cpuid_nent was greater than 0 before the ioctl in question?
Nice catch!
If considering it, then we have to restore the old CPUID configuration.
So how about making it simpler to just add one line of comment in API doc:
If KVM_SET_CPUID{2} fails, the old valid configuration is cleared as a
side effect.
