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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.