From: Jon Kohler <jon@nutanix.com>
To: Sean Christopherson <seanjc@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] KVM: x86: Use cpu_feature_enabled() for PKU instead of #ifdef
Date: Fri, 2 Jun 2023 15:51:31 +0000 [thread overview]
Message-ID: <C8324338-FC07-454E-9A5A-1785141FEAB3@nutanix.com> (raw)
In-Reply-To: <20230602010550.785722-1-seanjc@google.com>
> On Jun 1, 2023, at 9:05 PM, Sean Christopherson <seanjc@google.com> wrote:
>
> Replace an #ifdef on CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS with a
> cpu_feature_enabled() check on X86_FEATURE_PKU. The macro magic of
> DISABLED_MASK_BIT_SET() means that cpu_feature_enabled() provides the
> same end result (no code generated) when PKU is disabled by Kconfig.
>
> No functional change intended.
>
> Cc: Jon Kohler <jon@nutanix.com>
> Signed-off-by: Sean Christopherson <seanjc@google.com>
> ---
> arch/x86/kvm/x86.c | 8 ++------
> 1 file changed, 2 insertions(+), 6 deletions(-)
>
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index ceb7c5e9cf9e..eed1f0629023 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -1017,13 +1017,11 @@ void kvm_load_guest_xsave_state(struct kvm_vcpu *vcpu)
> wrmsrl(MSR_IA32_XSS, vcpu->arch.ia32_xss);
> }
>
> -#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
> - if (static_cpu_has(X86_FEATURE_PKU) &&
> + if (cpu_feature_enabled(X86_FEATURE_PKU) &&
> vcpu->arch.pkru != vcpu->arch.host_pkru &&
> ((vcpu->arch.xcr0 & XFEATURE_MASK_PKRU) ||
> kvm_is_cr4_bit_set(vcpu, X86_CR4_PKE)))
> write_pkru(vcpu->arch.pkru);
> -#endif /* CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS */
> }
> EXPORT_SYMBOL_GPL(kvm_load_guest_xsave_state);
>
> @@ -1032,15 +1030,13 @@ void kvm_load_host_xsave_state(struct kvm_vcpu *vcpu)
> if (vcpu->arch.guest_state_protected)
> return;
>
> -#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
> - if (static_cpu_has(X86_FEATURE_PKU) &&
> + if (cpu_feature_enabled(X86_FEATURE_PKU) &&
> ((vcpu->arch.xcr0 & XFEATURE_MASK_PKRU) ||
> kvm_is_cr4_bit_set(vcpu, X86_CR4_PKE))) {
> vcpu->arch.pkru = rdpkru();
> if (vcpu->arch.pkru != vcpu->arch.host_pkru)
> write_pkru(vcpu->arch.host_pkru);
> }
> -#endif /* CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS */
>
> if (kvm_is_cr4_bit_set(vcpu, X86_CR4_OSXSAVE)) {
>
>
> base-commit: a053a0e4a9f8c52f3acf8a9d2520c4bf39077a7e
> --
> 2.41.0.rc2.161.g9c6817b8e7-goog
>
Thanks for the cleanup!
Reviewed-by: Jon Kohler <jon@nutanix.com>
next prev parent reply other threads:[~2023-06-02 15:51 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-02 1:05 [PATCH] KVM: x86: Use cpu_feature_enabled() for PKU instead of #ifdef Sean Christopherson
2023-06-02 15:51 ` Jon Kohler [this message]
2023-06-02 18:30 ` Jim Mattson
2023-06-02 20:58 ` Mingwei Zhang
2023-06-02 21:49 ` Sean Christopherson
2023-06-07 0:53 ` Sean Christopherson
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