linux-kernel - Re: [PATCH v2 38/49] KVM: x86: Initialize guest cpu

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Date: Thu, 20 Jun 2024 10:24:55 +0800
From: "Yang, Weijiang" <weijiang.yang@...el.com>
To: Sean Christopherson <seanjc@...gle.com>
CC: Vitaly Kuznetsov <vkuznets@...hat.com>, Paolo Bonzini
	<pbonzini@...hat.com>, <kvm@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
	Hou Wenlong <houwenlong.hwl@...group.com>, Kechen Lu <kechenl@...dia.com>,
	Oliver Upton <oliver.upton@...ux.dev>, Maxim Levitsky <mlevitsk@...hat.com>,
	Binbin Wu <binbin.wu@...ux.intel.com>, Robert Hoo
	<robert.hoo.linux@...il.com>
Subject: Re: [PATCH v2 38/49] KVM: x86: Initialize guest cpu_caps based on
 guest CPUID

On 5/18/2024 1:39 AM, Sean Christopherson wrote:

[...]

>   
> -static __always_inline void guest_cpu_cap_check_and_set(struct kvm_vcpu *vcpu,
> -							unsigned int x86_feature)
> +static __always_inline void guest_cpu_cap_clear(struct kvm_vcpu *vcpu,
> +						unsigned int x86_feature)
>   {
> -	if (kvm_cpu_cap_has(x86_feature) && guest_cpuid_has(vcpu, x86_feature))
> +	unsigned int x86_leaf = __feature_leaf(x86_feature);
> +
> +	reverse_cpuid_check(x86_leaf);

Unnecessary reverse_cpuid_check()  same as in previous patch.

> +	vcpu->arch.cpu_caps[x86_leaf] &= ~__feature_bit(x86_feature);
> +}
> +
>
[...]