From: "Mi, Dapeng" <dapeng1.mi@linux.intel.com>
To: Jim Mattson <jmattson@google.com>
Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: [PATCH v4 3/3] KVM: selftests: Test behavior of KVM_X86_DISABLE_EXITS_APERFMPERF
Date: Wed, 11 Jun 2025 09:47:04 +0800 [thread overview]
Message-ID: <2e32978a-25c4-45a9-bdff-3097bb3abcdd@linux.intel.com> (raw)
In-Reply-To: <CALMp9eSS09bzdUs2JPnaQKM6ALWjxJNqWTsNYM5LOnSJjyRanQ@mail.gmail.com>
On 6/11/2025 12:59 AM, Jim Mattson wrote:
> On Tue, Jun 10, 2025 at 1:42 AM Mi, Dapeng <dapeng1.mi@linux.intel.com> wrote:
>>
>> On 5/31/2025 2:52 AM, Jim Mattson wrote:
>>> For a VCPU thread pinned to a single LPU, verify that interleaved host
>>> and guest reads of IA32_[AM]PERF return strictly increasing values when
>>> APERFMPERF exiting is disabled.
>> Should we consider the possible overflow case of these 2 MSRs although it
>> could be extremely rare? Thanks.
> Unless someone moves the MSRs forward, at current frequencies, the
> machine will have to be up for more than 100 years. I'll be long dead
> by then.
😂
>
> Note that frequency invariant scheduling doesn't accommodate overflow
> either. If the MSRs overflow, frequency invariant scheduling is
> disabled.
Agree.
next prev parent reply other threads:[~2025-06-11 1:47 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-05-30 18:52 [PATCH v4 0/3] KVM: x86: Provide a capability to disable APERF/MPERF read intercepts Jim Mattson
2025-05-30 18:52 ` [PATCH v4 1/3] KVM: x86: Replace growing set of *_in_guest bools with a u64 Jim Mattson
2025-06-24 21:25 ` Sean Christopherson
2025-06-24 22:34 ` Jim Mattson
2025-05-30 18:52 ` [PATCH v4 2/3] KVM: x86: Provide a capability to disable APERF/MPERF read intercepts Jim Mattson
2025-06-24 21:35 ` Sean Christopherson
2025-06-24 22:37 ` Jim Mattson
2025-06-24 23:31 ` Sean Christopherson
2025-06-25 0:11 ` Jim Mattson
2025-05-30 18:52 ` [PATCH v4 3/3] KVM: selftests: Test behavior of KVM_X86_DISABLE_EXITS_APERFMPERF Jim Mattson
2025-06-10 8:42 ` Mi, Dapeng
2025-06-10 16:59 ` Jim Mattson
2025-06-11 1:47 ` Mi, Dapeng [this message]
2025-06-24 22:24 ` Sean Christopherson
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=2e32978a-25c4-45a9-bdff-3097bb3abcdd@linux.intel.com \
--to=dapeng1.mi@linux.intel.com \
--cc=jmattson@google.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=pbonzini@redhat.com \
--cc=seanjc@google.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®