Hi On Tue, Aug 29, 2017 at 5:09 PM, Michael S. Tsirkin <[email protected]> wrote: > On Tue, Aug 29, 2017 at 05:04:34PM +0200, Marc-André Lureau wrote: >> Hi >> >> On Tue, Aug 29, 2017 at 5:01 PM, Michael S. Tsirkin <[email protected]> wrote: >> > On Tue, Aug 29, 2017 at 04:48:04PM +0200, Marc-André Lureau wrote: >> >> This is the same workaround as commit 523b018dde3b765, which was lost >> >> with libvhost-user transition in commit e10e798c85c2331. >> >> >> >> Signed-off-by: Marc-André Lureau <[email protected]> >> >> --- >> >> contrib/libvhost-user/libvhost-user.h | 5 +++++ >> >> contrib/libvhost-user/libvhost-user.c | 13 +++++++++++++ >> >> 2 files changed, 18 insertions(+) >> >> >> >> diff --git a/contrib/libvhost-user/libvhost-user.h >> >> b/contrib/libvhost-user/libvhost-user.h >> >> index 53ef222c0b..aca71717c1 100644 >> >> --- a/contrib/libvhost-user/libvhost-user.h >> >> +++ b/contrib/libvhost-user/libvhost-user.h >> >> @@ -132,6 +132,7 @@ typedef void (*vu_set_features_cb) (VuDev *dev, >> >> uint64_t features); >> >> typedef int (*vu_process_msg_cb) (VuDev *dev, VhostUserMsg *vmsg, >> >> int *do_reply); >> >> typedef void (*vu_queue_set_started_cb) (VuDev *dev, int qidx, bool >> >> started); >> >> +typedef bool (*vu_queue_resume_to_used_cb) (VuDev *dev, int qidx); >> >> >> >> typedef struct VuDevIface { >> >> /* called by VHOST_USER_GET_FEATURES to get the features bitmask */ >> >> @@ -148,6 +149,10 @@ typedef struct VuDevIface { >> >> vu_process_msg_cb process_msg; >> >> /* tells when queues can be processed */ >> >> vu_queue_set_started_cb queue_set_started; >> >> + /* If the queue must be resumed to vring.used->idx. */ >> >> + /* This can help to support resuming on unmanaged exit/crash when >> >> + * the slave/driver processes elements in order. */ >> >> + vu_queue_resume_to_used_cb queue_resume_to_used; >> >> } VuDevIface; >> >> >> >> typedef void (*vu_queue_handler_cb) (VuDev *dev, int qidx); >> > >> > Let's consider: this is only safe if queue is processed in order. >> > So I think that would be a better name for the field. >> > >> That's what the comment say already :) >> >> Which name do you suggest? vu_queue_is_processed_in_order? > > Something like this. > >> Does that >> imply it should always resume? > > Not sure I understand the question.
If a "queue_is_processed_in_order", does that imply libvhost-user should always resume it based on used_idx? I think it does, but the correlation is less obvious than explicitly saying "resume_to_used". -- Marc-André Lureau
