[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [RFC v2 11/32] vhub: Open userfaultfd
From: |
Dr. David Alan Gilbert (git) |
Subject: |
[Qemu-devel] [RFC v2 11/32] vhub: Open userfaultfd |
Date: |
Thu, 24 Aug 2017 20:27:09 +0100 |
From: "Dr. David Alan Gilbert" <address@hidden>
Open a userfaultfd (on a postcopy_advise) and send it back in
the reply to the qemu for it to monitor.
Signed-off-by: Dr. David Alan Gilbert <address@hidden>
---
contrib/libvhost-user/libvhost-user.c | 26 +++++++++++++++++++++++---
contrib/libvhost-user/libvhost-user.h | 3 +++
2 files changed, 26 insertions(+), 3 deletions(-)
diff --git a/contrib/libvhost-user/libvhost-user.c
b/contrib/libvhost-user/libvhost-user.c
index 47884c0a15..f9b5b12b28 100644
--- a/contrib/libvhost-user/libvhost-user.c
+++ b/contrib/libvhost-user/libvhost-user.c
@@ -15,6 +15,7 @@
#include <qemu/osdep.h>
#include <sys/eventfd.h>
+#include <sys/syscall.h>
#include <linux/vhost.h>
#include "qemu/atomic.h"
@@ -773,11 +774,30 @@ vu_set_vring_enable_exec(VuDev *dev, VhostUserMsg *vmsg)
static bool
vu_set_postcopy_advise(VuDev *dev, VhostUserMsg *vmsg)
{
- /* TODO: Open ufd, pass it back in the request
- * TODO: Add addresses
- */
+ struct uffdio_api api_struct;
+
+ dev->postcopy_ufd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK);
+ /* TODO: Add addresses */
vmsg->payload.u64 = 0xcafe;
vmsg->size = sizeof(vmsg->payload.u64);
+
+ if (dev->postcopy_ufd == -1) {
+ vu_panic(dev, "Userfaultfd not available: %s", strerror(errno));
+ goto out;
+ }
+ api_struct.api = UFFD_API;
+ api_struct.features = 0;
+ if (ioctl(dev->postcopy_ufd, UFFDIO_API, &api_struct)) {
+ vu_panic(dev, "Failed UFFDIO_API: %s", strerror(errno));
+ close(dev->postcopy_ufd);
+ dev->postcopy_ufd = -1;
+ goto out;
+ }
+ /* TODO: Stash feature flags somewhere */
+out:
+ /* Return a ufd to the QEMU */
+ vmsg->fd_num = 1;
+ vmsg->fds[0] = dev->postcopy_ufd;
return true; /* = send a reply */
}
diff --git a/contrib/libvhost-user/libvhost-user.h
b/contrib/libvhost-user/libvhost-user.h
index 3987ce643d..3e8efdd919 100644
--- a/contrib/libvhost-user/libvhost-user.h
+++ b/contrib/libvhost-user/libvhost-user.h
@@ -234,6 +234,9 @@ struct VuDev {
* re-initialize */
vu_panic_cb panic;
const VuDevIface *iface;
+
+ /* Postcopy data */
+ int postcopy_ufd;
};
typedef struct VuVirtqElement {
--
2.13.5
- [Qemu-devel] [RFC v2 06/32] postcopy: use UFFDIO_ZEROPAGE only when available, (continued)
- [Qemu-devel] [RFC v2 06/32] postcopy: use UFFDIO_ZEROPAGE only when available, Dr. David Alan Gilbert (git), 2017/08/24
- [Qemu-devel] [RFC v2 07/32] postcopy: Add notifier chain, Dr. David Alan Gilbert (git), 2017/08/24
- [Qemu-devel] [RFC v2 08/32] postcopy: Add vhost-user flag for postcopy and check it, Dr. David Alan Gilbert (git), 2017/08/24
- [Qemu-devel] [RFC v2 09/32] vhost-user: Add 'VHOST_USER_POSTCOPY_ADVISE' message, Dr. David Alan Gilbert (git), 2017/08/24
- [Qemu-devel] [RFC v2 10/32] vhub: Support sending fds back to qemu, Dr. David Alan Gilbert (git), 2017/08/24
- [Qemu-devel] [RFC v2 11/32] vhub: Open userfaultfd,
Dr. David Alan Gilbert (git) <=
- [Qemu-devel] [RFC v2 12/32] postcopy: Allow registering of fd handler, Dr. David Alan Gilbert (git), 2017/08/24
- [Qemu-devel] [RFC v2 13/32] vhost+postcopy: Register shared ufd with postcopy, Dr. David Alan Gilbert (git), 2017/08/24
- [Qemu-devel] [RFC v2 14/32] vhost+postcopy: Transmit 'listen' to client, Dr. David Alan Gilbert (git), 2017/08/24
- [Qemu-devel] [RFC v2 15/32] vhost+postcopy: Register new regions with the ufd, Dr. David Alan Gilbert (git), 2017/08/24
- [Qemu-devel] [RFC v2 16/32] vhost+postcopy: Send address back to qemu, Dr. David Alan Gilbert (git), 2017/08/24