virtio: finalize features before using devicerel-1.16.1

Under the standard of Virtio 1.0, the initialization process of the
device must first write sub-features back to device before
using device, such as finding vqs.

There are four places using vp_find_vq().

1. virtio-blk.pci:    put the code of finalizing features in front of using device
2. virtio-blk.mmio:   put the code of finalizing features in front of using device
3. virtio-scsi.pci:   is ok
4. virtio-scsi.mmio:  add the code of finalizing features before vp_find_vq()

Link: https://www.mail-archive.com/qemu-devel@nongnu.org/msg920776.html
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20221114035818.109511-3-xuanzhuo@linux.alibaba.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

2 files changed, 26 insertions, 9 deletions

diff --git a/src/hw/virtio-blk.c b/src/hw/virtio-blk.c
index ce3265e..e087fe4 100644
--- a/src/hw/virtio-blk.c
+++ b/src/hw/virtio-blk.c
@@ -151,10 +151,6 @@ init_virtio_blk(void *data)
     vdrive->drive.cntl_id = pci->bdf;
 
     vp_init_simple(&vdrive->vp, pci);
-    if (vp_find_vq(&vdrive->vp, 0, &vdrive->vq) < 0 ) {
-        dprintf(1, "fail to find vq for virtio-blk %pP\n", pci);
-        goto fail;
-    }
 
     if (vdrive->vp.use_modern) {
         struct vp_device *vp = &vdrive->vp;
@@ -212,7 +208,14 @@ init_virtio_blk(void *data)
             vp_read(&vp->device, struct virtio_blk_config, heads);
         vdrive->drive.pchs.sector =
             vp_read(&vp->device, struct virtio_blk_config, sectors);
-    } else {
+    }
+
+    if (vp_find_vq(&vdrive->vp, 0, &vdrive->vq) < 0 ) {
+        dprintf(1, "fail to find vq for virtio-blk %pP\n", pci);
+        goto fail;
+    }
+
+    if (!vdrive->vp.use_modern) {
         struct virtio_blk_config cfg;
         vp_get_legacy(&vdrive->vp, 0, &cfg, sizeof(cfg));
 
@@ -272,10 +275,6 @@ init_virtio_blk_mmio(void *mmio)
     vdrive->drive.cntl_id = (u32)mmio;
 
     vp_init_mmio(&vdrive->vp, mmio);
-    if (vp_find_vq(&vdrive->vp, 0, &vdrive->vq) < 0 ) {
-        dprintf(1, "fail to find vq for virtio-blk-mmio %p\n", mmio);
-        goto fail;
-    }
 
     struct vp_device *vp = &vdrive->vp;
     u64 features = vp_get_features(vp);
@@ -294,6 +293,11 @@ init_virtio_blk_mmio(void *mmio)
         goto fail;
     }
 
+    if (vp_find_vq(&vdrive->vp, 0, &vdrive->vq) < 0 ) {
+        dprintf(1, "fail to find vq for virtio-blk-mmio %p\n", mmio);
+        goto fail;
+    }
+
     if (features & max_segment_size)
         vdrive->drive.max_segment_size =
             vp_read(&vp->device, struct virtio_blk_config, size_max);
diff --git a/src/hw/virtio-scsi.c b/src/hw/virtio-scsi.c
index 369c981..79bda0b 100644
--- a/src/hw/virtio-scsi.c
+++ b/src/hw/virtio-scsi.c
@@ -239,6 +239,19 @@ init_virtio_scsi_mmio(void *mmio)
     vp_init_mmio(vp, mmio);
     u8 status = VIRTIO_CONFIG_S_ACKNOWLEDGE | VIRTIO_CONFIG_S_DRIVER;
 
+    u64 features = vp_get_features(vp);
+    u64 version1 = 1ull << VIRTIO_F_VERSION_1;
+    if (features & version1) {
+        u64 iommu_platform = 1ull << VIRTIO_F_IOMMU_PLATFORM;
+
+        vp_set_features(vp, features & (version1 | iommu_platform));
+        vp_set_status(vp, VIRTIO_CONFIG_S_FEATURES_OK);
+        if (!(vp_get_status(vp) & VIRTIO_CONFIG_S_FEATURES_OK)) {
+            dprintf(1, "device didn't accept features: %pP\n", mmio);
+            goto fail;
+        }
+    }
+
     if (vp_find_vq(vp, 2, &vq) < 0 ) {
         dprintf(1, "fail to find vq for virtio-scsi-mmio %p\n", mmio);
         goto fail;