| Message ID | 1443111741-4736-13-git-send-email-marcandre.lureau@redhat.com |
|---|---|
| State | New |
| Headers | show |
On 09/24/2015 10:22 AM, marcandre.lureau@redhat.com wrote: > From: Marc-André Lureau <marcandre.lureau@redhat.com> > > Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> > --- > docs/specs/vhost-user.txt | 48 +++++++++++++++++++++++++++++++++++++++++++++-- > 1 file changed, 46 insertions(+), 2 deletions(-) > @@ -140,8 +142,7 @@ Multiple queue support > > Multiple queue is treated as a protocol extension, hence the slave has to > implement protocol features first. The multiple queues feature is supported > -only when the protocol feature VHOST_USER_PROTOCOL_F_MQ (bit 0) is set: > -#define VHOST_USER_PROTOCOL_F_MQ 0 > +only when the protocol feature VHOST_USER_PROTOCOL_F_MQ (bit 0) is set. Should this hunk be in an earlier patch, > + > +Protocol features > +----------------- > + > +#define VHOST_USER_PROTOCOL_F_MQ 0 > +#define VHOST_USER_PROTOCOL_F_LOG_SHMFD 1 along with this section (of course, with just bit 0 in that patch)?
Hi ----- Original Message ----- > On 09/24/2015 10:22 AM, marcandre.lureau@redhat.com wrote: > > From: Marc-André Lureau <marcandre.lureau@redhat.com> > > > > Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> > > --- > > docs/specs/vhost-user.txt | 48 > > +++++++++++++++++++++++++++++++++++++++++++++-- > > 1 file changed, 46 insertions(+), 2 deletions(-) > > > @@ -140,8 +142,7 @@ Multiple queue support > > > > Multiple queue is treated as a protocol extension, hence the slave has to > > implement protocol features first. The multiple queues feature is > > supported > > -only when the protocol feature VHOST_USER_PROTOCOL_F_MQ (bit 0) is set: > > -#define VHOST_USER_PROTOCOL_F_MQ 0 > > +only when the protocol feature VHOST_USER_PROTOCOL_F_MQ (bit 0) is set. > > Should this hunk be in an earlier patch, The series is on top of last Michael PULL request. I just moved the define in a common section, since now they are 2 and later 3. Does that make sense? > > > + > > +Protocol features > > +----------------- > > + > > +#define VHOST_USER_PROTOCOL_F_MQ 0 > > +#define VHOST_USER_PROTOCOL_F_LOG_SHMFD 1 > > along with this section (of course, with just bit 0 in that patch)? > > -- > Eric Blake eblake redhat com +1-919-301-3266 > Libvirt virtualization library http://libvirt.org > >
On 09/24/2015 10:41 AM, Marc-André Lureau wrote: >>> -only when the protocol feature VHOST_USER_PROTOCOL_F_MQ (bit 0) is set: >>> -#define VHOST_USER_PROTOCOL_F_MQ 0 >>> +only when the protocol feature VHOST_USER_PROTOCOL_F_MQ (bit 0) is set. >> >> Should this hunk be in an earlier patch, > > The series is on top of last Michael PULL request. I just moved the define > in a common section, since now they are 2 and later 3. Does that make sense? Sure. My bad for not checking whether it was this series that introduced bit 0 vs. it being pre-existing from an earlier series.
diff --git a/docs/specs/vhost-user.txt b/docs/specs/vhost-user.txt index 4eadad1..e0292a0 100644 --- a/docs/specs/vhost-user.txt +++ b/docs/specs/vhost-user.txt @@ -115,11 +115,13 @@ the ones that do: * VHOST_GET_FEATURES * VHOST_GET_PROTOCOL_FEATURES * VHOST_GET_VRING_BASE + * VHOST_SET_LOG_BASE (if VHOST_USER_PROTOCOL_F_LOG_SHMFD) There are several messages that the master sends with file descriptors passed in the ancillary data: * VHOST_SET_MEM_TABLE + * VHOST_SET_LOG_BASE (if VHOST_USER_PROTOCOL_F_LOG_SHMFD) * VHOST_SET_LOG_FD * VHOST_SET_VRING_KICK * VHOST_SET_VRING_CALL @@ -140,8 +142,7 @@ Multiple queue support Multiple queue is treated as a protocol extension, hence the slave has to implement protocol features first. The multiple queues feature is supported -only when the protocol feature VHOST_USER_PROTOCOL_F_MQ (bit 0) is set: -#define VHOST_USER_PROTOCOL_F_MQ 0 +only when the protocol feature VHOST_USER_PROTOCOL_F_MQ (bit 0) is set. The max number of queues the slave supports can be queried with message VHOST_USER_GET_PROTOCOL_FEATURES. Master should stop when the number of @@ -152,6 +153,48 @@ queue in the sent message to identify a specified queue. One queue pair is enabled initially. More queues are enabled dynamically, by sending message VHOST_USER_SET_VRING_ENABLE. +Migration +--------- + +During live migration, the master may need to track the modifications +the slave makes to the memory mapped regions. The client should mark +the dirty pages in a log. Once it complies to this logging, it may +declare the VHOST_F_LOG_ALL vhost feature. + +All the modifications to memory pointed by vring "descriptor" should +be marked. Modifications to "used" vring should be marked if +VHOST_VRING_F_LOG is part of ring's features. + +Dirty pages are of size: +#define VHOST_LOG_PAGE 0x1000 + +The log memory fd is provided in the ancillary data of +VHOST_USER_SET_LOG_BASE message when the slave has +VHOST_USER_PROTOCOL_F_LOG_SHMFD protocol feature. + +The size of the log may be computed by using all the known guest +addresses. The log covers from address 0 to the maximum of guest +regions. In pseudo-code, to mark page at "addr" as dirty: + +page = addr / VHOST_LOG_PAGE +log[page / 8] |= 1 << page % 8 + +Use atomic operations, as the log may be concurrently manipulated. + +VHOST_USER_SET_LOG_FD is an optional message with an eventfd in +ancillary data, it may be used to inform the master that the log has +been modified. + +Once the source has finished migration, VHOST_USER_RESET_OWNER message +will be sent by the source. No further update must be done before the +destination takes over with new regions & rings. + +Protocol features +----------------- + +#define VHOST_USER_PROTOCOL_F_MQ 0 +#define VHOST_USER_PROTOCOL_F_LOG_SHMFD 1 + Message types ------------- @@ -236,6 +279,7 @@ Message types Id: 6 Equivalent ioctl: VHOST_SET_LOG_BASE Master payload: u64 + Slave payload: N/A Sets the logging base address.