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.
> -
> - /* 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
>
