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authorStefan Hajnoczi <stefanha@redhat.com>2019-06-26 08:48:13 +0100
committerMichael S. Tsirkin <mst@redhat.com>2019-07-04 17:00:32 -0400
commit6f5fd837889814e57a4bb473bf80ce08e355a12d (patch)
tree94a9980f0db7259a68621d91d65cc5a83477663d /contrib/libvhost-user/libvhost-user.h
parentdb68f4ff06cbe0517ed0d9b5634f6cddaed2547c (diff)
downloadqemu-6f5fd837889814e57a4bb473bf80ce08e355a12d.zip
libvhost-user: support many virtqueues
Currently libvhost-user is hardcoded to at most 8 virtqueues. The device backend should decide the number of virtqueues, not libvhost-user. This is important for multiqueue device backends where the guest driver needs an accurate number of virtqueues. This change breaks libvhost-user and libvhost-user-glib API stability. There is no stability guarantee yet, so make this change now and update all in-tree library users. This patch touches up vhost-user-blk, vhost-user-gpu, vhost-user-input, vhost-user-scsi, and vhost-user-bridge. If the device has a fixed number of queues that exact number is used. Otherwise the previous default of 8 virtqueues is used. vu_init() and vug_init() can now fail if malloc() returns NULL. I considered aborting with an error in libvhost-user but it should be safe to instantiate new vhost-user instances at runtime without risk of terminating the process. Therefore callers need to handle the vu_init() failure now. vhost-user-blk and vhost-user-scsi duplicate virtqueue index checks that are already performed by libvhost-user. This code would need to be modified to use max_queues but remove it completely instead since it's redundant. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <20190626074815.19994-3-stefanha@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'contrib/libvhost-user/libvhost-user.h')
-rw-r--r--contrib/libvhost-user/libvhost-user.h10
1 files changed, 7 insertions, 3 deletions
diff --git a/contrib/libvhost-user/libvhost-user.h b/contrib/libvhost-user/libvhost-user.h
index 3b888ff0a5..46b600799b 100644
--- a/contrib/libvhost-user/libvhost-user.h
+++ b/contrib/libvhost-user/libvhost-user.h
@@ -25,7 +25,6 @@
#define VHOST_USER_F_PROTOCOL_FEATURES 30
#define VHOST_LOG_PAGE 4096
-#define VHOST_MAX_NR_VIRTQUEUE 8
#define VIRTQUEUE_MAX_SIZE 1024
#define VHOST_MEMORY_MAX_NREGIONS 8
@@ -353,7 +352,7 @@ struct VuDev {
int sock;
uint32_t nregions;
VuDevRegion regions[VHOST_MEMORY_MAX_NREGIONS];
- VuVirtq vq[VHOST_MAX_NR_VIRTQUEUE];
+ VuVirtq *vq;
VuDevInflightInfo inflight_info;
int log_call_fd;
int slave_fd;
@@ -362,6 +361,7 @@ struct VuDev {
uint64_t features;
uint64_t protocol_features;
bool broken;
+ uint16_t max_queues;
/* @set_watch: add or update the given fd to the watch set,
* call cb when condition is met */
@@ -391,6 +391,7 @@ typedef struct VuVirtqElement {
/**
* vu_init:
* @dev: a VuDev context
+ * @max_queues: maximum number of virtqueues
* @socket: the socket connected to vhost-user master
* @panic: a panic callback
* @set_watch: a set_watch callback
@@ -398,8 +399,11 @@ typedef struct VuVirtqElement {
* @iface: a VuDevIface structure with vhost-user device callbacks
*
* Intializes a VuDev vhost-user context.
+ *
+ * Returns: true on success, false on failure.
**/
-void vu_init(VuDev *dev,
+bool vu_init(VuDev *dev,
+ uint16_t max_queues,
int socket,
vu_panic_cb panic,
vu_set_watch_cb set_watch,