Subject: Re: [PATCH V4 09/11] KVM: x86: Disable Intel Processor Trace when
 VMXON in L1 guest
To: Jim Mattson <jmattson@google.com>,
        Luwei Kang <luwei.kang@intel.com>
Cc: kvm list <kvm@vger.kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>,
        "H . Peter Anvin" <hpa@zytor.com>,
        the arch/x86 maintainers <x86@kernel.org>,
        =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= <rkrcmar@redhat.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Joerg Roedel <joro@8bytes.org>
References: <1512937857-10477-1-git-send-email-luwei.kang@intel.com>
 <1512937857-10477-10-git-send-email-luwei.kang@intel.com>
 <CALMp9eT63cMpJYBLP=9nSApP+=kwyht-XiDamHd6APfXr269Bg@mail.gmail.com>
From: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <69b9277e-e547-95e9-f220-958549f45ec1@redhat.com>
Date: Tue, 9 Jan 2018 22:39:51 +0100
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On 09/01/2018 21:16, Jim Mattson wrote:
> This doesn't look right to me. pt_disable_intercept_for_msr calls
> either vmx_disable_intercept_for_msr or vmx_enable_intercept_for_msr,
> both of which only change vmx_msr_bitmap_legacy
> and vmx_msr_bitmap_longmode. Neither of these MSR permission bitmaps is
> likely to be the one in use by L1 (which is more likely to be using the
> mode-appropriate x2apic or x2apic_apicv bitmap). Moreover, these changes
> affect all of the VMs that are using those MSR permission bitmaps.

Yeah, I replied this morning with something like this, on the thread
about removing the longmode bitmaps.

Paolo