kvm.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Paolo Bonzini <pbonzini@redhat.com>
To: Suleiman Souhlal <suleiman@google.com>
Cc: rkrcmar@redhat.com, Thomas Gleixner <tglx@linutronix.de>,
	John Stultz <john.stultz@linaro.org>,
	sboyd@kernel.org, Linux Kernel <linux-kernel@vger.kernel.org>,
	kvm@vger.kernel.org, Suleiman Souhlal <ssouhlal@freebsd.org>,
	tfiga@chromium.org, Vitaly Kuznetsov <vkuznets@redhat.com>
Subject: Re: [RFC v2 2/2] x86/kvmclock: Introduce kvm-hostclock clocksource.
Date: Tue, 15 Oct 2019 10:59:05 +0200	[thread overview]
Message-ID: <b98fcfc6-2759-7293-b3b5-0282830c9379@redhat.com> (raw)
In-Reply-To: <CABCjUKAsO9bOW9-VW1gk0O_U=9V6Zhft8LjpcqXVbDVTvWJ5Hw@mail.gmail.com>

On 15/10/19 10:39, Suleiman Souhlal wrote:
> I think we have that already (pvtk->flags).
> I'll change the if statement above to use pvtk instead of pv_timekeeper.

Of course, thanks.

>>> +kvm_hostclock_init(void)
>>> +{
>>> +     unsigned long pa;
>>> +
>>> +     pa = __pa(&pv_timekeeper);
>>> +     wrmsrl(MSR_KVM_TIMEKEEPER_EN, pa);
>>
>>
>> As Vitaly said, a new CPUID bit must be defined in
>> Documentation/virt/kvm/cpuid.txt, and used here.  Also please make bit 0
>> an enable bit.
> 
> I think I might not be able to move the enable bit to 0 because we
> need the generation count (pvclock_timekeeper.gen) to be the first
> word of the struct due to the way we copy the data to userspace,
> similarly to how kvm_setup_pvclock_page() does it.

I mean bit 0 of the MSR.

Thanks,

Paolo

  reply	other threads:[~2019-10-15  8:59 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-10  7:30 [RFC v2 0/2] kvm: Use host timekeeping in guest Suleiman Souhlal
2019-10-10  7:30 ` [RFC v2 1/2] kvm: Mechanism to copy host timekeeping parameters into guest Suleiman Souhlal
2019-10-10  8:31   ` Vitaly Kuznetsov
2019-10-10 10:50   ` Paolo Bonzini
2019-10-10  7:30 ` [RFC v2 2/2] x86/kvmclock: Introduce kvm-hostclock clocksource Suleiman Souhlal
2019-10-10  8:37   ` Vitaly Kuznetsov
2019-10-10 10:55   ` Paolo Bonzini
2019-10-15  8:39     ` Suleiman Souhlal
2019-10-15  8:59       ` Paolo Bonzini [this message]
2019-10-10 10:39 ` [RFC v2 0/2] kvm: Use host timekeeping in guest Roman Kagan
2019-10-11 18:50   ` Konrad Rzeszutek Wilk
2019-10-15  5:08   ` Suleiman Souhlal
2019-10-10 10:43 ` Paolo Bonzini

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=b98fcfc6-2759-7293-b3b5-0282830c9379@redhat.com \
    --to=pbonzini@redhat.com \
    --cc=john.stultz@linaro.org \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=rkrcmar@redhat.com \
    --cc=sboyd@kernel.org \
    --cc=ssouhlal@freebsd.org \
    --cc=suleiman@google.com \
    --cc=tfiga@chromium.org \
    --cc=tglx@linutronix.de \
    --cc=vkuznets@redhat.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;
as well as URLs for NNTP newsgroup(s).