linux-kernel - Re: [PATCH v14 02/11] KVM: x86/pmu: Set up IA32_PERF

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 2 Feb 2021 12:48:10 +0100
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     Like Xu <like.xu@...ux.intel.com>,
        Sean Christopherson <seanjc@...gle.com>
Cc:     Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>, ak@...ux.intel.com,
        wei.w.wang@...el.com, kan.liang@...el.com,
        alex.shi@...ux.alibaba.com, kvm@...r.kernel.org, x86@...nel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v14 02/11] KVM: x86/pmu: Set up IA32_PERF_CAPABILITIES if
 PDCM bit is available

On 01/02/21 06:10, Like Xu wrote:
> 
> -	if (guest_cpuid_has(vcpu, X86_FEATURE_PDCM))
> -		vcpu->arch.perf_capabilities = vmx_get_perf_capabilities();

Why remove this "if"?

>  	pmu->nr_arch_gp_counters = min_t(int, eax.split.num_counters, >  					 x86_pmu.num_counters_gp);
> @@ -405,6 +402,8 @@ static void intel_pmu_init(struct kvm_vcpu *vcpu)
>  		pmu->fixed_counters[i].idx = i + INTEL_PMC_IDX_FIXED;
>  		pmu->fixed_counters[i].current_config = 0;
>  	}
> +
> +	vcpu->arch.perf_capabilities = 0;

Paolo