[Qemu-devel] [PATCH v1 18/37] vhost-user: send guest physical address of virtqueues to the slave

[Wei Wang <wei.w.wang@intel.com>]

In the vhost-pci case, the slave needs the master side guest physical
address, rather than the qemu virtual address.

Signed-off-by: Wei Wang <wei.w.wang@intel.com>
---
 hw/virtio/vhost.c         | 61 ++++++++++++++++++++++++++++++++---------------
 include/hw/virtio/vhost.h |  2 ++
 2 files changed, 44 insertions(+), 19 deletions(-)

diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index f7f7023..df04375 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -26,6 +26,7 @@
 #include "hw/virtio/virtio-bus.h"
 #include "hw/virtio/virtio-access.h"
 #include "migration/migration.h"
+#include "hw/virtio/vhost-user.h"
 
 /* enabled until disconnected backend stabilizes */
 #define _VHOST_DEBUG 1
@@ -858,6 +859,12 @@ static int vhost_virtqueue_set_vring_endian_legacy(struct vhost_dev *dev,
     return -errno;
 }
 
+bool vhost_pci_enabled(struct vhost_dev *dev)
+{
+    return ((dev->protocol_features &
+            (1ULL << VHOST_USER_PROTOCOL_F_VHOST_PCI)) != 0);
+}
+
 static int vhost_virtqueue_start(struct vhost_dev *dev,
                                 struct VirtIODevice *vdev,
                                 struct vhost_virtqueue *vq,
@@ -901,26 +908,40 @@ static int vhost_virtqueue_start(struct vhost_dev *dev,
         }
     }
 
-    vq->desc_size = s = l = virtio_queue_get_desc_size(vdev, idx);
     vq->desc_phys = a = virtio_queue_get_desc_addr(vdev, idx);
-    vq->desc = cpu_physical_memory_map(a, &l, 0);
-    if (!vq->desc || l != s) {
-        r = -ENOMEM;
-        goto fail_alloc_desc;
+    if (vhost_pci_enabled(dev)) {
+        vq->desc = (void *)a;
+    } else {
+        vq->desc_size = s = l = virtio_queue_get_desc_size(vdev, idx);
+        vq->desc = cpu_physical_memory_map(a, &l, 0);
+        if (!vq->desc || l != s) {
+            r = -ENOMEM;
+            goto fail_alloc_desc;
+        }
     }
+
     vq->avail_size = s = l = virtio_queue_get_avail_size(vdev, idx);
     vq->avail_phys = a = virtio_queue_get_avail_addr(vdev, idx);
-    vq->avail = cpu_physical_memory_map(a, &l, 0);
-    if (!vq->avail || l != s) {
-        r = -ENOMEM;
-        goto fail_alloc_avail;
+    if (vhost_pci_enabled(dev)) {
+        vq->avail = (void *)a;
+    } else {
+        vq->avail = cpu_physical_memory_map(a, &l, 0);
+        if (!vq->avail || l != s) {
+            r = -ENOMEM;
+            goto fail_alloc_avail;
+        }
     }
+
     vq->used_size = s = l = virtio_queue_get_used_size(vdev, idx);
     vq->used_phys = a = virtio_queue_get_used_addr(vdev, idx);
-    vq->used = cpu_physical_memory_map(a, &l, 1);
-    if (!vq->used || l != s) {
-        r = -ENOMEM;
-        goto fail_alloc_used;
+    if (vhost_pci_enabled(dev)) {
+        vq->used = (void *)a;
+    } else {
+        vq->used = cpu_physical_memory_map(a, &l, 1);
+        if (!vq->used || l != s) {
+            r = -ENOMEM;
+            goto fail_alloc_used;
+        }
     }
 
     r = vhost_virtqueue_set_addr(dev, vq, vhost_vq_index, dev->log_enabled);
@@ -1003,12 +1024,14 @@ static void vhost_virtqueue_stop(struct vhost_dev *dev,
                                                 vhost_vq_index);
     }
 
-    cpu_physical_memory_unmap(vq->used, virtio_queue_get_used_size(vdev, idx),
-                              1, virtio_queue_get_used_size(vdev, idx));
-    cpu_physical_memory_unmap(vq->avail, virtio_queue_get_avail_size(vdev, idx),
-                              0, virtio_queue_get_avail_size(vdev, idx));
-    cpu_physical_memory_unmap(vq->desc, virtio_queue_get_desc_size(vdev, idx),
-                              0, virtio_queue_get_desc_size(vdev, idx));
+    if (!vhost_pci_enabled(dev)) {
+        cpu_physical_memory_unmap(vq->used, virtio_queue_get_used_size(vdev, idx),
+                                  1, virtio_queue_get_used_size(vdev, idx));
+        cpu_physical_memory_unmap(vq->avail, virtio_queue_get_avail_size(vdev, idx),
+                                  0, virtio_queue_get_avail_size(vdev, idx));
+        cpu_physical_memory_unmap(vq->desc, virtio_queue_get_desc_size(vdev, idx),
+                                  0, virtio_queue_get_desc_size(vdev, idx));
+    }
 }
 
 static void vhost_eventfd_add(MemoryListener *listener,
diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
index 9cf32e2..9955e07 100644
--- a/include/hw/virtio/vhost.h
+++ b/include/hw/virtio/vhost.h
@@ -92,4 +92,6 @@ bool vhost_has_free_slot(void);
 int vhost_net_set_backend(struct vhost_dev *hdev,
                           struct vhost_vring_file *file);
 
+bool vhost_pci_enabled(struct vhost_dev *dev);
+
 #endif
-- 
2.7.4