On 7/3/2020 3:02 AM, Sean Christopherson wrote:
On Thu, Jul 02, 2020 at 11:54:03AM -0700, Sean Christopherson wrote:
On Tue, Jun 23, 2020 at 07:58:11PM +0800, Xiaoyao Li wrote:
As handling of bits other leaf 1 added over time, kvm_update_cpuid()
should not return directly if leaf 1 is absent, but should go on
updateing other CPUID leaves.
Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
This should probably be marked for stable.
---
arch/x86/kvm/cpuid.c | 23 +++++++++++------------
1 file changed, 11 insertions(+), 12 deletions(-)
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 1d13bad42bf9..0164dac95ef5 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -60,22 +60,21 @@ int kvm_update_cpuid(struct kvm_vcpu *vcpu)
struct kvm_lapic *apic = vcpu->arch.apic;
best = kvm_find_cpuid_entry(vcpu, 1, 0);
- if (!best)
- return 0;
Rather than wrap the existing code, what about throwing it in a separate
helper? That generates an easier to read diff and also has the nice
property of getting 'apic' out of the common code.
Hrm, that'd be overkill once the apic code is moved in a few patches.
What if you keep the cpuid updates wrapped (as in this patch), but then
do
if (best && apic) {
}
for the apic path? That'll minimize churn for code that is disappearing,
e.g. will make future git archaeologists happy :-).
Sure. I'll do it in next version.
-
- /* Update OSXSAVE bit */
- if (boot_cpu_has(X86_FEATURE_XSAVE) && best->function == 0x1)
- cpuid_entry_change(best, X86_FEATURE_OSXSAVE,
+ if (best) {
+ /* Update OSXSAVE bit */
+ if (boot_cpu_has(X86_FEATURE_XSAVE))
+ cpuid_entry_change(best, X86_FEATURE_OSXSAVE,
kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE));
- cpuid_entry_change(best, X86_FEATURE_APIC,
+ cpuid_entry_change(best, X86_FEATURE_APIC,
vcpu->arch.apic_base & MSR_IA32_APICBASE_ENABLE);
- if (apic) {
- if (cpuid_entry_has(best, X86_FEATURE_TSC_DEADLINE_TIMER))
- apic->lapic_timer.timer_mode_mask = 3 << 17;
- else
- apic->lapic_timer.timer_mode_mask = 1 << 17;
+ if (apic) {
+ if (cpuid_entry_has(best, X86_FEATURE_TSC_DEADLINE_TIMER))
+ apic->lapic_timer.timer_mode_mask = 3 << 17;
+ else
+ apic->lapic_timer.timer_mode_mask = 1 << 17;
+ }
}
best = kvm_find_cpuid_entry(vcpu, 7, 0);
--
2.18.2
