On 06/28/2017 09:00 PM, Dr. David Alan Gilbert (git) wrote:
From: "Dr. David Alan Gilbert" <[email protected]>
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 <[email protected]>
---
contrib/libvhost-user/libvhost-user.c | 23 +++++++++++++++++++++++
contrib/libvhost-user/libvhost-user.h | 1 +
hw/virtio/vhost-user.c | 1 +
3 files changed, 25 insertions(+)
diff --git a/contrib/libvhost-user/libvhost-user.c
b/contrib/libvhost-user/libvhost-user.c
index d37052b7b0..c1716d1a62 100644
--- a/contrib/libvhost-user/libvhost-user.c
+++ b/contrib/libvhost-user/libvhost-user.c
@@ -68,6 +68,7 @@ vu_request_to_string(int req)
REQ(VHOST_USER_INPUT_GET_CONFIG),
REQ(VHOST_USER_POSTCOPY_ADVISE),
REQ(VHOST_USER_POSTCOPY_LISTEN),
+ REQ(VHOST_USER_POSTCOPY_END),
REQ(VHOST_USER_MAX),
};
#undef REQ
@@ -889,6 +890,26 @@ vu_set_postcopy_listen(VuDev *dev, VhostUserMsg *vmsg)
return false;
}
+
+static bool
+vu_set_postcopy_end(VuDev *dev, VhostUserMsg *vmsg)
+{
+ fprintf(stderr, "%s: Entry\n", __func__);
+ dev->postcopy_listening = false;
+ if (dev->postcopy_ufd > 0) {
+ close(dev->postcopy_ufd);
+ dev->postcopy_ufd = -1;
+ fprintf(stderr, "%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;
+ fprintf(stderr, "%s: exit\n", __func__);
+ return true;
+}
+
It is what reply-ack is done for, so to avoid code duplication,
maybe Qemu could set VHOST_USER_NEED_REPLY_MASK bit when reply-ack
feature is supported.
I'm wondering if we shouldn't consider adding reply-ack feature support
to libvhost-user, and make postcopy support to depend on this feature.
Cheers,
Maxime
