From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

Date: Mon, 27 Jan 2020 19:01:00 +0000

Subject: [PATCH] virtiofsd: Start queue threads

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Start a thread for each queue when we get notified it's been started.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

fix by:

Signed-off-by: Jun Piao <piaojun@huawei.com>

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

(cherry picked from commit e4c55a3c144493b436e40031e2eed61a84eca47b)

---

 tools/virtiofsd/fuse_virtio.c | 89 +++++++++++++++++++++++++++++++++++

 1 file changed, 89 insertions(+)

diff --git a/tools/virtiofsd/fuse_virtio.c b/tools/virtiofsd/fuse_virtio.c

index 4819e56568..2a94bb3cca 100644

--- a/tools/virtiofsd/fuse_virtio.c

+++ b/tools/virtiofsd/fuse_virtio.c

@@ -11,6 +11,7 @@

  * See the file COPYING.LIB

  */

+#include "qemu/osdep.h"

 #include "fuse_virtio.h"

 #include "fuse_i.h"

 #include "standard-headers/linux/fuse.h"

@@ -30,6 +31,15 @@

 #include "contrib/libvhost-user/libvhost-user.h"

+struct fv_QueueInfo {

+    pthread_t thread;

+    struct fv_VuDev *virtio_dev;

+

+    /* Our queue index, corresponds to array position */

+    int qidx;

+    int kick_fd;

+};

+

 /*

  * We pass the dev element into libvhost-user

  * and then use it to get back to the outer

@@ -38,6 +48,13 @@

 struct fv_VuDev {

     VuDev dev;

     struct fuse_session *se;

+

+    /*

+     * The following pair of fields are only accessed in the main

+     * virtio_loop

+     */

+    size_t nqueues;

+    struct fv_QueueInfo **qi;

 };

 /* From spec */

@@ -83,6 +100,75 @@ static void fv_panic(VuDev *dev, const char *err)

     exit(EXIT_FAILURE);

 }

+static void *fv_queue_thread(void *opaque)

+{

+    struct fv_QueueInfo *qi = opaque;

+    fuse_log(FUSE_LOG_INFO, "%s: Start for queue %d kick_fd %d\n", __func__,

+             qi->qidx, qi->kick_fd);

+    while (1) {

+        /* TODO */

+    }

+

+    return NULL;

+}

+

+/* Callback from libvhost-user on start or stop of a queue */

+static void fv_queue_set_started(VuDev *dev, int qidx, bool started)

+{

+    struct fv_VuDev *vud = container_of(dev, struct fv_VuDev, dev);

+    struct fv_QueueInfo *ourqi;

+

+    fuse_log(FUSE_LOG_INFO, "%s: qidx=%d started=%d\n", __func__, qidx,

+             started);

+    assert(qidx >= 0);

+

+    /*

+     * Ignore additional request queues for now.  passthrough_ll.c must be

+     * audited for thread-safety issues first.  It was written with a

+     * well-behaved client in mind and may not protect against all types of

+     * races yet.

+     */

+    if (qidx > 1) {

+        fuse_log(FUSE_LOG_ERR,

+                 "%s: multiple request queues not yet implemented, please only "

+                 "configure 1 request queue\n",

+                 __func__);

+        exit(EXIT_FAILURE);

+    }

+

+    if (started) {

+        /* Fire up a thread to watch this queue */

+        if (qidx >= vud->nqueues) {

+            vud->qi = realloc(vud->qi, (qidx + 1) * sizeof(vud->qi[0]));

+            assert(vud->qi);

+            memset(vud->qi + vud->nqueues, 0,

+                   sizeof(vud->qi[0]) * (1 + (qidx - vud->nqueues)));

+            vud->nqueues = qidx + 1;

+        }

+        if (!vud->qi[qidx]) {

+            vud->qi[qidx] = calloc(sizeof(struct fv_QueueInfo), 1);

+            assert(vud->qi[qidx]);

+            vud->qi[qidx]->virtio_dev = vud;

+            vud->qi[qidx]->qidx = qidx;

+        } else {

+            /* Shouldn't have been started */

+            assert(vud->qi[qidx]->kick_fd == -1);

+        }

+        ourqi = vud->qi[qidx];

+        ourqi->kick_fd = dev->vq[qidx].kick_fd;

+        if (pthread_create(&ourqi->thread, NULL, fv_queue_thread, ourqi)) {

+            fuse_log(FUSE_LOG_ERR, "%s: Failed to create thread for queue %d\n",

+                     __func__, qidx);

+            assert(0);

+        }

+    } else {

+        /* TODO: Kill the thread */

+        assert(qidx < vud->nqueues);

+        ourqi = vud->qi[qidx];

+        ourqi->kick_fd = -1;

+    }

+}

+

 static bool fv_queue_order(VuDev *dev, int qidx)

 {

     return false;

@@ -92,6 +178,9 @@ static const VuDevIface fv_iface = {

     .get_features = fv_get_features,

     .set_features = fv_set_features,

+    /* Don't need process message, we've not got any at vhost-user level */

+    .queue_set_started = fv_queue_set_started,

+

     .queue_is_processed_in_order = fv_queue_order,

 };