From c33bc0b7f2b5cfa330a6d89d60ee94de129c65c1 Mon Sep 17 00:00:00 2001

From: =?UTF-8?q?Eugenio=20P=C3=A9rez?= <eperezma@redhat.com>

Date: Thu, 21 Jul 2022 16:05:38 +0200

Subject: [PATCH 23/32] vdpa: manual forward CVQ buffers

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RH-Author: Eugenio Pérez <eperezma@redhat.com>

RH-MergeRequest: 108: Net Control Virtqueue shadow Support

RH-Commit: [23/27] ce128d5152be7eebf87e186eb8b58c2ed95aff6d (eperezmartin/qemu-kvm)

RH-Bugzilla: 1939363

RH-Acked-by: Stefano Garzarella <sgarzare@redhat.com>

RH-Acked-by: Cindy Lu <lulu@redhat.com>

RH-Acked-by: Laurent Vivier <lvivier@redhat.com>

Bugzilla: https://bugzilla.redhat.com/1939363

Upstream Status: git://git.qemu.org/qemu.git

commit bd907ae4b00ebedad5e586af05ea3d6490318d45

Author: Eugenio Pérez <eperezma@redhat.com>

Date:   Wed Jul 20 08:59:42 2022 +0200

    vdpa: manual forward CVQ buffers

    Do a simple forwarding of CVQ buffers, the same work SVQ could do but

    through callbacks. No functional change intended.

    Signed-off-by: Eugenio Pérez <eperezma@redhat.com>

    Reviewed-by: Michael S. Tsirkin <mst@redhat.com>

    Signed-off-by: Jason Wang <jasowang@redhat.com>

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>

---

 hw/virtio/vhost-vdpa.c         |  3 +-

 include/hw/virtio/vhost-vdpa.h |  3 ++

 net/vhost-vdpa.c               | 58 ++++++++++++++++++++++++++++++++++

 3 files changed, 63 insertions(+), 1 deletion(-)

diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c

index 14b02fe079..49effe5462 100644

--- a/hw/virtio/vhost-vdpa.c

+++ b/hw/virtio/vhost-vdpa.c

@@ -417,7 +417,8 @@ static int vhost_vdpa_init_svq(struct vhost_dev *hdev, struct vhost_vdpa *v,

     for (unsigned n = 0; n < hdev->nvqs; ++n) {

         g_autoptr(VhostShadowVirtqueue) svq;

-        svq = vhost_svq_new(v->iova_tree, NULL, NULL);

+        svq = vhost_svq_new(v->iova_tree, v->shadow_vq_ops,

+                            v->shadow_vq_ops_opaque);

         if (unlikely(!svq)) {

             error_setg(errp, "Cannot create svq %u", n);

             return -1;

diff --git a/include/hw/virtio/vhost-vdpa.h b/include/hw/virtio/vhost-vdpa.h

index 7214eb47dc..1111d85643 100644

--- a/include/hw/virtio/vhost-vdpa.h

+++ b/include/hw/virtio/vhost-vdpa.h

@@ -15,6 +15,7 @@

 #include <gmodule.h>

 #include "hw/virtio/vhost-iova-tree.h"

+#include "hw/virtio/vhost-shadow-virtqueue.h"

 #include "hw/virtio/virtio.h"

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

@@ -35,6 +36,8 @@ typedef struct vhost_vdpa {

     /* IOVA mapping used by the Shadow Virtqueue */

     VhostIOVATree *iova_tree;

     GPtrArray *shadow_vqs;

+    const VhostShadowVirtqueueOps *shadow_vq_ops;

+    void *shadow_vq_ops_opaque;

     struct vhost_dev *dev;

     VhostVDPAHostNotifier notifier[VIRTIO_QUEUE_MAX];

 } VhostVDPA;

diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c

index df1e69ee72..2e3b6b10d8 100644

--- a/net/vhost-vdpa.c

+++ b/net/vhost-vdpa.c

@@ -11,11 +11,14 @@

 #include "qemu/osdep.h"

 #include "clients.h"

+#include "hw/virtio/virtio-net.h"

 #include "net/vhost_net.h"

 #include "net/vhost-vdpa.h"

 #include "hw/virtio/vhost-vdpa.h"

 #include "qemu/config-file.h"

 #include "qemu/error-report.h"

+#include "qemu/log.h"

+#include "qemu/memalign.h"

 #include "qemu/option.h"

 #include "qapi/error.h"

 #include <linux/vhost.h>

@@ -187,6 +190,57 @@ static NetClientInfo net_vhost_vdpa_info = {

         .check_peer_type = vhost_vdpa_check_peer_type,

 };

+/**

+ * Forward buffer for the moment.

+ */

+static int vhost_vdpa_net_handle_ctrl_avail(VhostShadowVirtqueue *svq,

+                                            VirtQueueElement *elem,

+                                            void *opaque)

+{

+    unsigned int n = elem->out_num + elem->in_num;

+    g_autofree struct iovec *dev_buffers = g_new(struct iovec, n);

+    size_t in_len, dev_written;

+    virtio_net_ctrl_ack status = VIRTIO_NET_ERR;

+    int r;

+

+    memcpy(dev_buffers, elem->out_sg, elem->out_num);

+    memcpy(dev_buffers + elem->out_num, elem->in_sg, elem->in_num);

+

+    r = vhost_svq_add(svq, &dev_buffers[0], elem->out_num, &dev_buffers[1],

+                      elem->in_num, elem);

+    if (unlikely(r != 0)) {

+        if (unlikely(r == -ENOSPC)) {

+            qemu_log_mask(LOG_GUEST_ERROR, "%s: No space on device queue\n",

+                          __func__);

+        }

+        goto out;

+    }

+

+    /*

+     * We can poll here since we've had BQL from the time we sent the

+     * descriptor. Also, we need to take the answer before SVQ pulls by itself,

+     * when BQL is released

+     */

+    dev_written = vhost_svq_poll(svq);

+    if (unlikely(dev_written < sizeof(status))) {

+        error_report("Insufficient written data (%zu)", dev_written);

+    }

+

+out:

+    in_len = iov_from_buf(elem->in_sg, elem->in_num, 0, &status,

+                          sizeof(status));

+    if (unlikely(in_len < sizeof(status))) {

+        error_report("Bad device CVQ written length");

+    }

+    vhost_svq_push_elem(svq, elem, MIN(in_len, sizeof(status)));

+    g_free(elem);

+    return r;

+}

+

+static const VhostShadowVirtqueueOps vhost_vdpa_net_svq_ops = {

+    .avail_handler = vhost_vdpa_net_handle_ctrl_avail,

+};

+

 static NetClientState *net_vhost_vdpa_init(NetClientState *peer,

                                            const char *device,

                                            const char *name,

@@ -211,6 +265,10 @@ static NetClientState *net_vhost_vdpa_init(NetClientState *peer,

     s->vhost_vdpa.device_fd = vdpa_device_fd;

     s->vhost_vdpa.index = queue_pair_index;

+    if (!is_datapath) {

+        s->vhost_vdpa.shadow_vq_ops = &vhost_vdpa_net_svq_ops;

+        s->vhost_vdpa.shadow_vq_ops_opaque = s;

+    }

     ret = vhost_vdpa_add(nc, (void *)&s->vhost_vdpa, queue_pair_index, nvqs);

     if (ret) {

         qemu_del_net_client(nc);

-- 

2.31.1