virtio-pci: fix bus master work around on load

Commit c81131db15dd1844d0db1d51f3cd7a105cfd2cf3
detects old guests by comparing virtio and
PCI status. It attempts to do this on load,
as well, but load_config callback in a binding
is invoked too early and so the virtio status
isn't set yet.

We could add yet another callback to the
binding, to invoke after load, but it
seems easier to reuse the existing vmstate
callback.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Alexander Graf <agraf@suse.de>
(cherry picked from commit 89c473fd82daf7dddad8162a683bcd0ef671ecda)

diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c
index 3911b09b07eec7b0d8fcacde17caab07f68dd241..d40ac230ee24dcc5d8b95e97ad93ae747953922d 100644 (file)
--- a/hw/virtio-pci.c
+++ b/hw/virtio-pci.c
@@ -160,13 +160,6 @@ static int virtio_pci_load_config(void * opaque, QEMUFile *f)
     if (proxy->vdev->config_vector != VIRTIO_NO_VECTOR) {
         return msix_vector_use(&proxy->pci_dev, proxy->vdev->config_vector);
     }
-
-    /* Try to find out if the guest has bus master disabled, but is
-       in ready state. Then we have a buggy guest OS. */
-    if ((proxy->vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) &&
-        !(proxy->pci_dev.config[PCI_COMMAND] & PCI_COMMAND_MASTER)) {
-        proxy->flags |= VIRTIO_PCI_FLAG_BUS_MASTER_BUG;
-    }
     return 0;
 }
 
@@ -651,6 +644,12 @@ static void virtio_pci_vmstate_change(void *opaque, bool running)
     VirtIOPCIProxy *proxy = opaque;
 
     if (running) {
+        /* Try to find out if the guest has bus master disabled, but is
+           in ready state. Then we have a buggy guest OS. */
+        if ((proxy->vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) &&
+            !(proxy->pci_dev.config[PCI_COMMAND] & PCI_COMMAND_MASTER)) {
+            proxy->flags |= VIRTIO_PCI_FLAG_BUS_MASTER_BUG;
+        }
         virtio_pci_start_ioeventfd(proxy);
     } else {
         virtio_pci_stop_ioeventfd(proxy);

diff --git a/hw/virtio.h b/hw/virtio.h
index 31d16e1c317acf2e211d30b9bb0828193cfaa0fd..d1fb8a0f5c7f52ede115cce1b780f05ca367c430 100644 (file)
--- a/hw/virtio.h
+++ b/hw/virtio.h
@@ -92,6 +92,7 @@ typedef struct {
     void (*save_queue)(void * opaque, int n, QEMUFile *f);
     int (*load_config)(void * opaque, QEMUFile *f);
     int (*load_queue)(void * opaque, int n, QEMUFile *f);
+    int (*load_done)(void * opaque, QEMUFile *f);
     unsigned (*get_features)(void * opaque);
     bool (*query_guest_notifiers)(void * opaque);
     int (*set_guest_notifiers)(void * opaque, bool assigned);