From: Paolo Bonzini <pbonzini@redhat.com>
To: Jim Mattson <jmattson@google.com>
Cc: kvm@vger.kernel.org, Like Xu <like.xu.linux@gmail.com>
Subject: Re: [PATCH kvm-unit-tests] pmu: fix conditions for emulation test
Date: Tue, 16 Nov 2021 19:03:06 +0100 [thread overview]
Message-ID: <ea98ccf5-059b-11b3-e071-a46bad687699@redhat.com> (raw)
In-Reply-To: <CALMp9eSy7-ziFeOrz+zsdBPOC7AqULYRSrP1kKSMWkFwrmzy8w@mail.gmail.com>
On 11/16/21 18:49, Jim Mattson wrote:
> Thanks for fixing this. By the way, one of the reasons that we don't
> expose a virtual PMU to more customers is the conflict with the NMI
> watchdog. We aren't willing to give up the NMI watchdog on the host,
> and we don't really want to report a reduced number of general purpose
> counters to the guest. (On AMD, we *can't* report a reduced number of
> counters to the guest; the architectural specification doesn't allow
> it.)
FWIW we also generally use the PMU emulation only for debugging of guest
performance issues.
> We can't be the only ones running with the NMI watchdog enabled. How
> do others deal with this? Is there any hope of suspending the NMI
> watchdog while in VMX non-root mode (or guest mode on AMD)?
Like, what do you think?
Paolo
>> This also hid a typo for the force_emulation_prefix module parameter,
>> which is part of the kvm module rather than the kvm_intel module,
>> so fix that.
>>
>> Reported-by: Like Xu <like.xu.linux@gmail.com>
>> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> Reviewed-by: Jim Mattson <jmattson@google.com>
>
next prev parent reply other threads:[~2021-11-16 18:03 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-16 10:50 [PATCH kvm-unit-tests] pmu: fix conditions for emulation test Paolo Bonzini
2021-11-16 17:49 ` Jim Mattson
2021-11-16 18:03 ` Paolo Bonzini [this message]
2021-11-16 20:00 ` Jim Mattson
2021-11-17 2:49 ` Like Xu
2022-02-12 23:45 ` Jim Mattson
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