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Re: [Qemu-devel] [PATCH v3 24/29] vhost-user: Add VHOST_USER_POSTCOPY_EN
From: |
Dr. David Alan Gilbert |
Subject: |
Re: [Qemu-devel] [PATCH v3 24/29] vhost-user: Add VHOST_USER_POSTCOPY_END message |
Date: |
Tue, 27 Feb 2018 10:09:34 +0000 |
User-agent: |
Mutt/1.9.2 (2017-12-15) |
* Michael S. Tsirkin (address@hidden) wrote:
> On Fri, Feb 16, 2018 at 01:16:20PM +0000, Dr. David Alan Gilbert (git) wrote:
> > From: "Dr. David Alan Gilbert" <address@hidden>
> >
> > This message is sent just before the end of postcopy to get the
> > client to stop using userfault since we wont respond to any more
> > requests. It should close userfaultfd so that any other pages
> > get mapped to the backing file automatically by the kernel, since
> > at this point we know we've received everything.
> >
> > Signed-off-by: Dr. David Alan Gilbert <address@hidden>
> > Reviewed-by: Peter Xu <address@hidden>
> > ---
> > contrib/libvhost-user/libvhost-user.c | 23 +++++++++++++++++++++++
> > contrib/libvhost-user/libvhost-user.h | 1 +
> > docs/interop/vhost-user.txt | 8 ++++++++
> > hw/virtio/vhost-user.c | 1 +
> > 4 files changed, 33 insertions(+)
> >
> > diff --git a/contrib/libvhost-user/libvhost-user.c
> > b/contrib/libvhost-user/libvhost-user.c
> > index 1b224af706..1f988ab787 100644
> > --- a/contrib/libvhost-user/libvhost-user.c
> > +++ b/contrib/libvhost-user/libvhost-user.c
> > @@ -99,6 +99,7 @@ vu_request_to_string(unsigned int req)
> > REQ(VHOST_USER_SET_CONFIG),
> > REQ(VHOST_USER_POSTCOPY_ADVISE),
> > REQ(VHOST_USER_POSTCOPY_LISTEN),
> > + REQ(VHOST_USER_POSTCOPY_END),
> > REQ(VHOST_USER_MAX),
> > };
> > #undef REQ
> > @@ -1095,6 +1096,26 @@ vu_set_postcopy_listen(VuDev *dev, VhostUserMsg
> > *vmsg)
> > vmsg->payload.u64 = 0; /* Success */
> > return true;
> > }
> > +
> > +static bool
> > +vu_set_postcopy_end(VuDev *dev, VhostUserMsg *vmsg)
> > +{
> > + DPRINT("%s: Entry\n", __func__);
> > + dev->postcopy_listening = false;
> > + if (dev->postcopy_ufd > 0) {
> > + close(dev->postcopy_ufd);
> > + dev->postcopy_ufd = -1;
> > + DPRINT("%s: Done close\n", __func__);
> > + }
> > +
> > + vmsg->fd_num = 0;
> > + vmsg->payload.u64 = 0;
> > + vmsg->size = sizeof(vmsg->payload.u64);
> > + vmsg->flags = VHOST_USER_VERSION | VHOST_USER_REPLY_MASK;
> > + DPRINT("%s: exit\n", __func__);
> > + return true;
> > +}
> > +
> > static bool
> > vu_process_message(VuDev *dev, VhostUserMsg *vmsg)
> > {
> > @@ -1170,6 +1191,8 @@ vu_process_message(VuDev *dev, VhostUserMsg *vmsg)
> > return vu_set_postcopy_advise(dev, vmsg);
> > case VHOST_USER_POSTCOPY_LISTEN:
> > return vu_set_postcopy_listen(dev, vmsg);
> > + case VHOST_USER_POSTCOPY_END:
> > + return vu_set_postcopy_end(dev, vmsg);
> > default:
> > vmsg_close_fds(vmsg);
> > vu_panic(dev, "Unhandled request: %d", vmsg->request);
> > diff --git a/contrib/libvhost-user/libvhost-user.h
> > b/contrib/libvhost-user/libvhost-user.h
> > index fcba53c3c3..9696b89f6e 100644
> > --- a/contrib/libvhost-user/libvhost-user.h
> > +++ b/contrib/libvhost-user/libvhost-user.h
> > @@ -84,6 +84,7 @@ typedef enum VhostUserRequest {
> > VHOST_USER_SET_CONFIG = 25,
> > VHOST_USER_POSTCOPY_ADVISE = 26,
> > VHOST_USER_POSTCOPY_LISTEN = 27,
> > + VHOST_USER_POSTCOPY_END = 28,
> > VHOST_USER_MAX
> > } VhostUserRequest;
> >
> > diff --git a/docs/interop/vhost-user.txt b/docs/interop/vhost-user.txt
> > index 5bbcab2cc4..4bf7d8ef99 100644
> > --- a/docs/interop/vhost-user.txt
> > +++ b/docs/interop/vhost-user.txt
> > @@ -697,6 +697,14 @@ Master message types
> >
> > Master advises slave that a transition to postcopy mode has happened.
> >
> > + * VHOST_USER_POSTCOPY_END
> > + Id: 28
> > + Slave payload: u64
> > +
> > + Master advises that postcopy migration has now completed. The
> > + slave must disable the userfaultfd. The response is an
> > acknowledgement
> > + only.
> > +
> > Slave message types
> > -------------------
> >
>
> Which protocol feature enables this message?
VHOST_USER_PROTOCOL_F_PAGEFAULT - if you have that,
AND postcopy-ram is enabled
AND postcopy mode is entered
you'll get VHOST_USER_POSTCOPY_LISTEN and sometime later
VHOST_USER_POSTCOPY_END.
Dave
> > diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
> > index 74807091a0..cf7923b25f 100644
> > --- a/hw/virtio/vhost-user.c
> > +++ b/hw/virtio/vhost-user.c
> > @@ -78,6 +78,7 @@ typedef enum VhostUserRequest {
> > VHOST_USER_SET_CONFIG = 25,
> > VHOST_USER_POSTCOPY_ADVISE = 26,
> > VHOST_USER_POSTCOPY_LISTEN = 27,
> > + VHOST_USER_POSTCOPY_END = 28,
> > VHOST_USER_MAX
> > } VhostUserRequest;
> >
> > --
> > 2.14.3
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK
- [Qemu-devel] [PATCH v3 21/29] vhost+postcopy: Add vhost waker, (continued)
- [Qemu-devel] [PATCH v3 21/29] vhost+postcopy: Add vhost waker, Dr. David Alan Gilbert (git), 2018/02/16
- [Qemu-devel] [PATCH v3 22/29] vhost+postcopy: Call wakeups, Dr. David Alan Gilbert (git), 2018/02/16
- [Qemu-devel] [PATCH v3 19/29] postcopy: wake shared, Dr. David Alan Gilbert (git), 2018/02/16
- [Qemu-devel] [PATCH v3 25/29] vhost+postcopy: Wire up POSTCOPY_END notify, Dr. David Alan Gilbert (git), 2018/02/16
- [Qemu-devel] [PATCH v3 26/29] vhost: Huge page align and merge, Dr. David Alan Gilbert (git), 2018/02/16
- [Qemu-devel] [PATCH v3 27/29] postcopy: Allow shared memory, Dr. David Alan Gilbert (git), 2018/02/16
- [Qemu-devel] [PATCH v3 28/29] libvhost-user: Claim support for postcopy, Dr. David Alan Gilbert (git), 2018/02/16
- [Qemu-devel] [PATCH v3 23/29] libvhost-user: mprotect & madvises for postcopy, Dr. David Alan Gilbert (git), 2018/02/16
- [Qemu-devel] [PATCH v3 24/29] vhost-user: Add VHOST_USER_POSTCOPY_END message, Dr. David Alan Gilbert (git), 2018/02/16
- [Qemu-devel] [PATCH v3 29/29] postcopy shared docs, Dr. David Alan Gilbert (git), 2018/02/16
- Re: [Qemu-devel] [PATCH v3 00/29] postcopy+vhost-user/shared ram, Michael S. Tsirkin, 2018/02/27