linux-kernel - Re: [PATCH v14 07/13] KVM: VMX: Emulate reads and writes to CET MSRs

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Date:   Thu, 28 Jan 2021 18:45:08 +0100
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     Yang Weijiang <weijiang.yang@...el.com>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org, sean.j.christopherson@...el.com,
        jmattson@...gle.com
Cc:     yu.c.zhang@...ux.intel.com
Subject: Re: [PATCH v14 07/13] KVM: VMX: Emulate reads and writes to CET MSRs

On 06/11/20 02:16, Yang Weijiang wrote:
> 
> +static bool cet_is_ssp_msr_accessible(struct kvm_vcpu *vcpu,
> +				      struct msr_data *msr)
> +{
> +	u64 mask;
> +
> +	if (!kvm_cet_supported())
> +		return false;
> +
> +	if (msr->host_initiated)
> +		return true;
> +
> +	if (!guest_cpuid_has(vcpu, X86_FEATURE_SHSTK))
> +		return false;
> +
> +	if (msr->index == MSR_IA32_INT_SSP_TAB)
> +		return false;

Shouldn't this return true?

Paolo

> +	mask = (msr->index == MSR_IA32_PL3_SSP) ? XFEATURE_MASK_CET_USER :
> +						  XFEATURE_MASK_CET_KERNEL;
> +	return !!(vcpu->arch.guest_supported_xss & mask);
> +}