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From: Paolo Bonzini <pbonzini@redhat.com>
To: Sean Christopherson <seanjc@google.com>,
	Jim Mattson <jmattson@google.com>
Cc: Aaron Lewis <aaronlewis@google.com>, kvm@vger.kernel.org
Subject: Re: [PATCH] KVM: x86: Fix a stall when KVM_SET_MSRS is called on the pmu counters
Date: Wed, 2 Nov 2022 18:55:06 +0100	[thread overview]
Message-ID: <67c59554-1d90-0c7c-a436-e2dd0782f4cb@redhat.com> (raw)
In-Reply-To: <Y1xbINshcICWxxfa@google.com>

On 10/29/22 00:43, Sean Christopherson wrote:
>>> Checking 'dat' doesn't restrict counter 0, it skips printing if the guest (or host)
>>> is writing '0', e.g. it would also skip the case you encountered where the host is
>>> blindly "restoring" unused MSRs.
>> The VMM is only blind because KVM_GET_MSR_INDEX_LIST poked it in the
>> eye. It would be nice to have an API that the VMM could query for the
>> list of supported MSRs.
> That should be a fairly easy bug fix, kvm_init_msr_list() can and should omit PMU
> MSRs if enable_pmu==false.

Aaron, are you going to send a patch for this?

Thanks,

Paolo


  reply	other threads:[~2022-11-02 17:56 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-10-28 13:00 [PATCH] KVM: x86: Fix a stall when KVM_SET_MSRS is called on the pmu counters Aaron Lewis
2022-10-28 16:26 ` Sean Christopherson
2022-10-28 20:47   ` Aaron Lewis
2022-10-28 21:50     ` Sean Christopherson
2022-10-28 22:01       ` Jim Mattson
2022-10-28 22:43         ` Sean Christopherson
2022-11-02 17:55           ` Paolo Bonzini [this message]
2022-11-02 23:15             ` Aaron Lewis
2022-10-29  0:34       ` Aaron Lewis

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