From 6f5fd837889814e57a4bb473bf80ce08e355a12d Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Wed, 26 Jun 2019 08:48:13 +0100 Subject: libvhost-user: support many virtqueues MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Marc-André Lureau Message-Id: <20190626074815.19994-3-stefanha@redhat.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- contrib/libvhost-user/libvhost-user.h | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) (limited to 'contrib/libvhost-user/libvhost-user.h') 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, -- cgit 1.4.1