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Message-ID: <4123eb60-d89a-9112-dd7e-1a7627a0fc70@redhat.com>
Date: Wed, 8 Jul 2020 14:41:33 +0200
From: Paolo Bonzini <pbonzini@...hat.com>
To: Xiaoyao Li <xiaoyao.li@...el.com>,
Sean Christopherson <sean.j.christopherson@...el.com>,
Jim Mattson <jmattson@...gle.com>
Cc: kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
linux-doc@...r.kernel.org, Jonathan Corbet <corbet@....net>,
Vitaly Kuznetsov <vkuznets@...hat.com>,
Wanpeng Li <wanpengli@...cent.com>,
Joerg Roedel <joro@...tes.org>
Subject: Re: [PATCH v3 4/8] KVM: X86: Split kvm_update_cpuid()
On 08/07/20 14:33, Xiaoyao Li wrote:
> On 7/8/2020 8:06 PM, Paolo Bonzini wrote:
>> On 08/07/20 08:50, Xiaoyao Li wrote:
>>> Split the part of updating vcpu model out of kvm_update_cpuid(), and put
>>> it into a new kvm_update_vcpu_model(). So it's more clear that
>>> kvm_update_cpuid() is to update guest CPUID settings, while
>>> kvm_update_vcpu_model() is to update vcpu model (settings) based on the
>>> updated CPUID settings.
>>>
>>> Signed-off-by: Xiaoyao Li <xiaoyao.li@...el.com>
>>
>> I would prefer to keep the kvm_update_cpuid name for what you called
>> kvm_update_vcpu_model(), and rename the rest to
>> kvm_update_cpuid_runtime().
>
> But there is no CPUID being updated in kvm_update_cpuid(), after
> kvm_update_cpuid_runtime() is split out. This is confusing, IMO.
Then what about kvm_vcpu_after_set_cpuid()? It's the "model" that is
not clear.
Thanks,
Paolo
>> Paolo
>>
>>> ---
>>> arch/x86/kvm/cpuid.c | 38 ++++++++++++++++++++++++--------------
>>> arch/x86/kvm/cpuid.h | 1 +
>>> arch/x86/kvm/x86.c | 1 +
>>> 3 files changed, 26 insertions(+), 14 deletions(-)
>>>
>>> diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
>>> index a825878b7f84..001f5a94880e 100644
>>> --- a/arch/x86/kvm/cpuid.c
>>> +++ b/arch/x86/kvm/cpuid.c
>>> @@ -76,7 +76,6 @@ static int kvm_check_cpuid(struct kvm_vcpu *vcpu)
>>> void kvm_update_cpuid(struct kvm_vcpu *vcpu)
>>> {
>>> struct kvm_cpuid_entry2 *best;
>>> - struct kvm_lapic *apic = vcpu->arch.apic;
>>> best = kvm_find_cpuid_entry(vcpu, 1, 0);
>>> if (best) {
>>> @@ -89,26 +88,14 @@ void kvm_update_cpuid(struct kvm_vcpu *vcpu)
>>> vcpu->arch.apic_base & MSR_IA32_APICBASE_ENABLE);
>>> }
>>> - if (best && 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);
>>> if (best && boot_cpu_has(X86_FEATURE_PKU) && best->function ==
>>> 0x7)
>>> cpuid_entry_change(best, X86_FEATURE_OSPKE,
>>> kvm_read_cr4_bits(vcpu, X86_CR4_PKE));
>>> best = kvm_find_cpuid_entry(vcpu, 0xD, 0);
>>> - if (!best) {
>>> - vcpu->arch.guest_supported_xcr0 = 0;
>>> - } else {
>>> - vcpu->arch.guest_supported_xcr0 =
>>> - (best->eax | ((u64)best->edx << 32)) & supported_xcr0;
>>> + if (best)
>>> best->ebx = xstate_required_size(vcpu->arch.xcr0, false);
>>> - }
>>> best = kvm_find_cpuid_entry(vcpu, 0xD, 1);
>>> if (best && (cpuid_entry_has(best, X86_FEATURE_XSAVES) ||
>>> @@ -127,6 +114,27 @@ void kvm_update_cpuid(struct kvm_vcpu *vcpu)
>>> vcpu->arch.ia32_misc_enable_msr &
>>> MSR_IA32_MISC_ENABLE_MWAIT);
>>> }
>>> +}
>>> +
>>> +void kvm_update_vcpu_model(struct kvm_vcpu *vcpu)
>>> +{
>>> + struct kvm_lapic *apic = vcpu->arch.apic;
>>> + struct kvm_cpuid_entry2 *best;
>>> +
>>> + best = kvm_find_cpuid_entry(vcpu, 1, 0);
>>> + if (best && 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, 0xD, 0);
>>> + if (!best)
>>> + vcpu->arch.guest_supported_xcr0 = 0;
>>> + else
>>> + vcpu->arch.guest_supported_xcr0 =
>>> + (best->eax | ((u64)best->edx << 32)) & supported_xcr0;
>>> /* Note, maxphyaddr must be updated before tdp_level. */
>>> vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu);
>>> @@ -218,6 +226,7 @@ int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
>>> kvm_apic_set_version(vcpu);
>>> kvm_x86_ops.cpuid_update(vcpu);
>>> kvm_update_cpuid(vcpu);
>>> + kvm_update_vcpu_model(vcpu);
>>> kvfree(cpuid_entries);
>>> out:
>>> @@ -247,6 +256,7 @@ int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
>>> kvm_apic_set_version(vcpu);
>>> kvm_x86_ops.cpuid_update(vcpu);
>>> kvm_update_cpuid(vcpu);
>>> + kvm_update_vcpu_model(vcpu);
>>> out:
>>> return r;
>>> }
>>> diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h
>>> index f136de1debad..45e3643e2fba 100644
>>> --- a/arch/x86/kvm/cpuid.h
>>> +++ b/arch/x86/kvm/cpuid.h
>>> @@ -10,6 +10,7 @@ extern u32 kvm_cpu_caps[NCAPINTS] __read_mostly;
>>> void kvm_set_cpu_caps(void);
>>> void kvm_update_cpuid(struct kvm_vcpu *vcpu);
>>> +void kvm_update_vcpu_model(struct kvm_vcpu *vcpu);
>>> struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
>>> u32 function, u32 index);
>>> int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
>>> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
>>> index 09ee54f5e385..6f376392e6e6 100644
>>> --- a/arch/x86/kvm/x86.c
>>> +++ b/arch/x86/kvm/x86.c
>>> @@ -8184,6 +8184,7 @@ static void enter_smm(struct kvm_vcpu *vcpu)
>>> #endif
>>> kvm_update_cpuid(vcpu);
>>> + kvm_update_vcpu_model(vcpu);
>>> kvm_mmu_reset_context(vcpu);
>>> }
>>>
>>
>
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