Linux Virtualization - Jun 2009 - [PATCHv3 12/13] qemu: virtio save/load bindings

Implement bindings for virtio save/load. Use them in virtio pci.

Signed-off-by: Michael S. Tsirkin <mst at redhat.com>
---
 hw/virtio-pci.c |   49 ++++++++++++++++++++++++++++++++++++++++++++++++-
 hw/virtio.c     |   31 ++++++++++++++-----------------
 hw/virtio.h     |    4 ++++
 3 files changed, 66 insertions(+), 18 deletions(-)

diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c
index 294f4c7..589fbb1 100644
--- a/hw/virtio-pci.c
+++ b/hw/virtio-pci.c
@@ -105,6 +105,48 @@ static void virtio_pci_notify(void *opaque, uint16_t
vector)
         qemu_set_irq(proxy->pci_dev.irq[0], proxy->vdev->isr & 1);
 }
 
+static void virtio_pci_save_config(void * opaque, QEMUFile *f)
+{
+    VirtIOPCIProxy *proxy = opaque;
+    pci_device_save(&proxy->pci_dev, f);
+    msix_save(&proxy->pci_dev, f);
+    if (msix_present(&proxy->pci_dev))
+        qemu_put_be16(f, proxy->vdev->config_vector);
+}
+
+static void virtio_pci_save_queue(void * opaque, int n, QEMUFile *f)
+{
+    VirtIOPCIProxy *proxy = opaque;
+    if (msix_present(&proxy->pci_dev))
+        qemu_put_be16(f, virtio_queue_vector(proxy->vdev, n));
+}
+
+static int virtio_pci_load_config(void * opaque, QEMUFile *f)
+{
+    VirtIOPCIProxy *proxy = opaque;
+    int ret;
+    ret = pci_device_load(&proxy->pci_dev, f);
+    if (ret)
+        return ret;
+    ret = msix_load(&proxy->pci_dev, f);
+    if (ret)
+        return ret;
+    if (msix_present(&proxy->pci_dev))
+        qemu_get_be16s(f, &proxy->vdev->config_vector);
+    return 0;
+}
+
+static int virtio_pci_load_queue(void * opaque, int n, QEMUFile *f)
+{
+    VirtIOPCIProxy *proxy = opaque;
+    uint16_t vector;
+    if (!msix_present(&proxy->pci_dev))
+        return 0;
+    qemu_get_be16s(f, &vector);
+    virtio_queue_set_vector(proxy->vdev, n, vector);
+    return 0;
+}
+
 static void virtio_pci_reset(void *opaque)
 {
     VirtIOPCIProxy *proxy = opaque;
@@ -317,7 +359,12 @@ static void virtio_write_config(PCIDevice *pci_dev,
uint32_t address,
 }
 
 static const VirtIOBindings virtio_pci_bindings = {
-    .notify = virtio_pci_notify
+    .notify = virtio_pci_notify,
+    .save_config = virtio_pci_save_config,
+    .load_config = virtio_pci_load_config,
+    .save_config = virtio_pci_save_config,
+    .save_queue = virtio_pci_save_queue,
+    .load_queue = virtio_pci_load_queue,
 };
 
 static void virtio_init_pci(VirtIOPCIProxy *proxy, VirtIODevice *vdev,
diff --git a/hw/virtio.c b/hw/virtio.c
index 63ffcff..b773dff 100644
--- a/hw/virtio.c
+++ b/hw/virtio.c
@@ -568,9 +568,8 @@ void virtio_save(VirtIODevice *vdev, QEMUFile *f)
 {
     int i;
 
-    /* FIXME: load/save binding.  */
-    //pci_device_save(&vdev->pci_dev, f);
-    //msix_save(&vdev->pci_dev, f);
+    if (vdev->binding->save_config)
+        vdev->binding->save_config(vdev->binding_opaque, f);
 
     qemu_put_8s(f, &vdev->status);
     qemu_put_8s(f, &vdev->isr);
@@ -596,19 +595,20 @@ void virtio_save(VirtIODevice *vdev, QEMUFile *f)
         qemu_put_be32(f, vdev->vq[i].vring.num);
         qemu_put_be64(f, vdev->vq[i].pa);
         qemu_put_be16s(f, &vdev->vq[i].last_avail_idx);
-        if (vdev->nvectors)
-            qemu_put_be16s(f, &vdev->vq[i].vector);
+        if (vdev->binding->save_queue)
+            vdev->binding->save_queue(vdev->binding_opaque, i, f);
     }
 }
 
 int virtio_load(VirtIODevice *vdev, QEMUFile *f)
 {
-    int num, i;
+    int num, i, ret;
 
-    /* FIXME: load/save binding.  */
-    //pci_device_load(&vdev->pci_dev, f);
-    //r = msix_load(&vdev->pci_dev, f);
-    //pci_resize_io_region(&vdev->pci_dev, 1,
msix_bar_size(&vdev->pci_dev));
+    if (vdev->binding->load_config) {
+        ret = vdev->binding->load_config(vdev->binding_opaque, f);
+        if (ret)
+            return ret;
+    }
 
     qemu_get_8s(f, &vdev->status);
     qemu_get_8s(f, &vdev->isr);
@@ -617,10 +617,6 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f)
     vdev->config_len = qemu_get_be32(f);
     qemu_get_buffer(f, vdev->config, vdev->config_len);
 
-    if (vdev->nvectors) {
-        qemu_get_be16s(f, &vdev->config_vector);
-        //msix_vector_use(&vdev->pci_dev, vdev->config_vector);
-    }
     num = qemu_get_be32(f);
 
     for (i = 0; i < num; i++) {
@@ -631,9 +627,10 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f)
         if (vdev->vq[i].pa) {
             virtqueue_init(&vdev->vq[i]);
         }
-        if (vdev->nvectors) {
-            qemu_get_be16s(f, &vdev->vq[i].vector);
-            //msix_vector_use(&vdev->pci_dev, vdev->config_vector);
+        if (vdev->binding->load_queue) {
+            ret = vdev->binding->load_queue(vdev->binding_opaque, i,
f);
+            if (ret)
+                return ret;
         }
     }
 
diff --git a/hw/virtio.h b/hw/virtio.h
index 04a3c3d..ce05517 100644
--- a/hw/virtio.h
+++ b/hw/virtio.h
@@ -72,6 +72,10 @@ typedef struct VirtQueueElement
 
 typedef struct {
     void (*notify)(void * opaque, uint16_t vector);
+    void (*save_config)(void * opaque, QEMUFile *f);
+    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);
 } VirtIOBindings;
 
 #define VIRTIO_PCI_QUEUE_MAX 16
-- 
1.6.3.1.56.g79e1.dirty

duplicated save config.
> diff --git a/hw/virtio.h b/hw/virtio.h
> index 04a3c3d..ce05517 100644
> --- a/hw/virtio.h
> +++ b/hw/virtio.h
> @@ -72,6 +72,10 @@ typedef struct VirtQueueElement
>  
>  typedef struct {
>      void (*notify)(void * opaque, uint16_t vector);
> +    void (*save_config)(void * opaque, QEMUFile *f);
> +    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);
>  } VirtIOBindings;
>  
So, what's the overall effect on a virtual machine that gets migrated,
of a certain device not implementing one of those functions? Will it work?
Will it break?

On Tue, Jun 09, 2009 at 02:45:54PM -0300, Glauber Costa
wrote:
> duplicated save config.
Good catch. Fixed.

-- 
MST