All of lore.kernel.org
 help / color / mirror / Atom feed
From: Paolo Bonzini <pbonzini@redhat.com>
To: Roman Kagan <rkagan@virtuozzo.com>,
	"Denis V. Lunev" <den@openvz.org>,
	virtualization@lists.linux-foundation.org, qemu-devel@nongnu.org,
	Andrey Smetanin <asmetanin@virtuozzo.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	"K. Y. Srinivasan" <kys@microsoft.com>,
	Gleb Natapov <gleb@kernel.org>
Subject: Re: [Qemu-devel] [PATCH 2/2] kvm/x86: Hyper-V kvm exit
Date: Fri, 9 Oct 2015 16:57:33 +0200	[thread overview]
Message-ID: <5617D5DD.7050701@redhat.com> (raw)
In-Reply-To: <20151009145358.GT27239@rkaganb.sw.ru>



On 09/10/2015 16:53, Roman Kagan wrote:
>> > Why is this exit necessary?
> The guest writes to synic-related MSRs and that should take "immediate"
> effect.
> 
> E.g. it may decide to disable or relocate the message page by writing to
> SIMP MSR.  The host is then supposed to stop accessing the old message
> page before the vCPU proceeds to the next instruction.  Hence the exit,
> to allow the userspace to react accordingly before reentering the guest.

Ok, thanks!

Paolo

WARNING: multiple messages have this Message-ID (diff)
From: Paolo Bonzini <pbonzini@redhat.com>
To: Roman Kagan <rkagan@virtuozzo.com>,
	"Denis V. Lunev" <den@openvz.org>,
	virtualization@lists.linux-foundation.org, qemu-devel@nongnu.org,
	Andrey Smetanin <asmetanin@virtuozzo.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	"K. Y. Srinivasan" <kys@microsoft.com>,
	Gleb Natapov <gleb@kernel.org>
Subject: Re: [PATCH 2/2] kvm/x86: Hyper-V kvm exit
Date: Fri, 9 Oct 2015 16:57:33 +0200	[thread overview]
Message-ID: <5617D5DD.7050701@redhat.com> (raw)
In-Reply-To: <20151009145358.GT27239@rkaganb.sw.ru>



On 09/10/2015 16:53, Roman Kagan wrote:
>> > Why is this exit necessary?
> The guest writes to synic-related MSRs and that should take "immediate"
> effect.
> 
> E.g. it may decide to disable or relocate the message page by writing to
> SIMP MSR.  The host is then supposed to stop accessing the old message
> page before the vCPU proceeds to the next instruction.  Hence the exit,
> to allow the userspace to react accordingly before reentering the guest.

Ok, thanks!

Paolo

  reply	other threads:[~2015-10-09 14:57 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-10-09 13:39 [Qemu-devel] [PATCH 0/2] Hyper-V synthetic interrupt controller Denis V. Lunev
2015-10-09 13:39 ` Denis V. Lunev
2015-10-09 13:39 ` [Qemu-devel] [PATCH 1/2] kvm/x86: " Denis V. Lunev
2015-10-09 13:39   ` Denis V. Lunev
2015-10-09 14:42   ` [Qemu-devel] " Paolo Bonzini
2015-10-09 14:42     ` Paolo Bonzini
2015-10-09 15:53     ` [Qemu-devel] " Roman Kagan
2015-10-09 15:58       ` Paolo Bonzini
2015-10-09 15:58         ` Paolo Bonzini
2015-10-09 15:53     ` Roman Kagan
2015-10-12  7:54     ` [Qemu-devel] " Christian Borntraeger
2015-10-12  7:54       ` Christian Borntraeger
2015-10-12  8:48       ` [Qemu-devel] " Cornelia Huck
2015-10-12  8:48         ` Cornelia Huck
2015-10-12  8:58         ` [Qemu-devel] " Paolo Bonzini
2015-10-12  8:58           ` Paolo Bonzini
2015-10-12 11:05           ` Roman Kagan
2015-10-12 11:05           ` [Qemu-devel] " Roman Kagan
2015-10-09 13:39 ` [Qemu-devel] [PATCH 2/2] kvm/x86: Hyper-V kvm exit Denis V. Lunev
2015-10-09 13:39   ` Denis V. Lunev
2015-10-09 14:41   ` [Qemu-devel] " Paolo Bonzini
2015-10-09 14:41     ` Paolo Bonzini
2015-10-09 14:53     ` [Qemu-devel] " Roman Kagan
2015-10-09 14:57       ` Paolo Bonzini [this message]
2015-10-09 14:57         ` Paolo Bonzini
2015-10-09 14:53     ` Roman Kagan
2015-10-12 13:42   ` [Qemu-devel] " Eric Blake
2015-10-12 13:42     ` Eric Blake
2015-10-12 13:44     ` Eric Blake
2015-10-12 13:44       ` Eric Blake
2015-10-12 13:46     ` Paolo Bonzini
2015-10-12 13:46       ` Paolo Bonzini
2015-10-12 13:46     ` Denis V. Lunev
2015-10-12 13:46       ` Denis V. Lunev
2015-10-12 22:21       ` KY Srinivasan
2015-10-12 22:21         ` KY Srinivasan
2015-10-12 13:52     ` Roman Kagan
2015-10-12 13:52       ` Roman Kagan

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=5617D5DD.7050701@redhat.com \
    --to=pbonzini@redhat.com \
    --cc=asmetanin@virtuozzo.com \
    --cc=den@openvz.org \
    --cc=gleb@kernel.org \
    --cc=kys@microsoft.com \
    --cc=qemu-devel@nongnu.org \
    --cc=rkagan@virtuozzo.com \
    --cc=virtualization@lists.linux-foundation.org \
    --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 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.