From 14200f493243f73152ea4a4b97274f0ec4fb36fa Mon Sep 17 00:00:00 2001

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

Date: Thu, 21 Jul 2022 15:38:55 +0200

Subject: [PATCH 15/32] vhost: Add SVQDescState

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

RH-MergeRequest: 108: Net Control Virtqueue shadow Support

RH-Commit: [15/27] 2e2866f22e37cace8598ff44dfcdc07fcc915d6d (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 9e87868fcaf5785c8e1490c290505fa32305ff91

Author: Eugenio Pérez <eperezma@redhat.com>

Date:   Wed Jul 20 08:59:34 2022 +0200

    vhost: Add SVQDescState

    This will allow SVQ to add context to the different queue elements.

    This patch only store the actual element, 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-shadow-virtqueue.c | 16 ++++++++--------

 hw/virtio/vhost-shadow-virtqueue.h |  8 ++++++--

 2 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c

index 3cec03d709..a08e3d4025 100644

--- a/hw/virtio/vhost-shadow-virtqueue.c

+++ b/hw/virtio/vhost-shadow-virtqueue.c

@@ -256,7 +256,7 @@ static int vhost_svq_add(VhostShadowVirtqueue *svq, const struct iovec *out_sg,

         return -EINVAL;

     }

-    svq->ring_id_maps[qemu_head] = elem;

+    svq->desc_state[qemu_head].elem = elem;

     vhost_svq_kick(svq);

     return 0;

 }

@@ -411,21 +411,21 @@ static VirtQueueElement *vhost_svq_get_buf(VhostShadowVirtqueue *svq,

         return NULL;

     }

-    if (unlikely(!svq->ring_id_maps[used_elem.id])) {

+    if (unlikely(!svq->desc_state[used_elem.id].elem)) {

         qemu_log_mask(LOG_GUEST_ERROR,

             "Device %s says index %u is used, but it was not available",

             svq->vdev->name, used_elem.id);

         return NULL;

     }

-    num = svq->ring_id_maps[used_elem.id]->in_num +

-          svq->ring_id_maps[used_elem.id]->out_num;

+    num = svq->desc_state[used_elem.id].elem->in_num +

+          svq->desc_state[used_elem.id].elem->out_num;

     last_used_chain = vhost_svq_last_desc_of_chain(svq, num, used_elem.id);

     svq->desc_next[last_used_chain] = svq->free_head;

     svq->free_head = used_elem.id;

     *len = used_elem.len;

-    return g_steal_pointer(&svq->ring_id_maps[used_elem.id]);

+    return g_steal_pointer(&svq->desc_state[used_elem.id].elem);

 }

 static void vhost_svq_flush(VhostShadowVirtqueue *svq,

@@ -595,7 +595,7 @@ void vhost_svq_start(VhostShadowVirtqueue *svq, VirtIODevice *vdev,

     memset(svq->vring.desc, 0, driver_size);

     svq->vring.used = qemu_memalign(qemu_real_host_page_size, device_size);

     memset(svq->vring.used, 0, device_size);

-    svq->ring_id_maps = g_new0(VirtQueueElement *, svq->vring.num);

+    svq->desc_state = g_new0(SVQDescState, svq->vring.num);

     svq->desc_next = g_new0(uint16_t, svq->vring.num);

     for (unsigned i = 0; i < svq->vring.num - 1; i++) {

         svq->desc_next[i] = cpu_to_le16(i + 1);

@@ -620,7 +620,7 @@ void vhost_svq_stop(VhostShadowVirtqueue *svq)

     for (unsigned i = 0; i < svq->vring.num; ++i) {

         g_autofree VirtQueueElement *elem = NULL;

-        elem = g_steal_pointer(&svq->ring_id_maps[i]);

+        elem = g_steal_pointer(&svq->desc_state[i].elem);

         if (elem) {

             virtqueue_detach_element(svq->vq, elem, 0);

         }

@@ -632,7 +632,7 @@ void vhost_svq_stop(VhostShadowVirtqueue *svq)

     }

     svq->vq = NULL;

     g_free(svq->desc_next);

-    g_free(svq->ring_id_maps);

+    g_free(svq->desc_state);

     qemu_vfree(svq->vring.desc);

     qemu_vfree(svq->vring.used);

 }

diff --git a/hw/virtio/vhost-shadow-virtqueue.h b/hw/virtio/vhost-shadow-virtqueue.h

index c132c994e9..d646c35054 100644

--- a/hw/virtio/vhost-shadow-virtqueue.h

+++ b/hw/virtio/vhost-shadow-virtqueue.h

@@ -15,6 +15,10 @@

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

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

+typedef struct SVQDescState {

+    VirtQueueElement *elem;

+} SVQDescState;

+

 /* Shadow virtqueue to relay notifications */

 typedef struct VhostShadowVirtqueue {

     /* Shadow vring */

@@ -47,8 +51,8 @@ typedef struct VhostShadowVirtqueue {

     /* IOVA mapping */

     VhostIOVATree *iova_tree;

-    /* Map for use the guest's descriptors */

-    VirtQueueElement **ring_id_maps;

+    /* SVQ vring descriptors state */

+    SVQDescState *desc_state;

     /* Next VirtQueue element that guest made available */

     VirtQueueElement *next_guest_avail_elem;

-- 

2.31.1