virtio-balloon: don't hardcode config size value

Use sizeof(strucy virtio_balloon_config) instead.

Signed-off-by Luiz capitulino <[email protected]>

---

I have no idea which queue this should go through...

 hw/virtio/virtio-balloon.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

hw/virtio/virtio-balloon.c +4 -4

index d9754db..a470a0b 100644
@@ -263,7 +263,7 @@ static void virtio_balloon_get_config(VirtIODevice *vdev, uint8_t *config_data)
     config.num_pages = cpu_to_le32(dev->num_pages);
     config.actual = cpu_to_le32(dev->actual);
 
-    memcpy(config_data, &config, 8);
+    memcpy(config_data, &config, sizeof(struct virtio_balloon_config));
 }
 
 static void virtio_balloon_set_config(VirtIODevice *vdev,

@@ -272,7 +272,7 @@ static void virtio_balloon_set_config(VirtIODevice *vdev,
     VirtIOBalloon *dev = VIRTIO_BALLOON(vdev);
     struct virtio_balloon_config config;
     uint32_t oldactual = dev->actual;
-    memcpy(&config, config_data, 8);
+    memcpy(&config, config_data, sizeof(struct virtio_balloon_config));
     dev->actual = le32_to_cpu(config.actual);
     if (dev->actual != oldactual) {
         qemu_balloon_changed(ram_size -

@@ -343,7 +343,8 @@ static void virtio_balloon_device_realize(DeviceState *dev, Error **errp)
     VirtIOBalloon *s = VIRTIO_BALLOON(dev);
     int ret;
 
-    virtio_init(vdev, "virtio-balloon", VIRTIO_ID_BALLOON, 8);
+    virtio_init(vdev, "virtio-balloon", VIRTIO_ID_BALLOON,
+                sizeof(struct virtio_balloon_config));
 
     ret = qemu_add_balloon_handler(virtio_balloon_to_target,
                                    virtio_balloon_stat, s);
--

1.8.1.4

Quoted 8 lines · Luiz Capitulino

Use sizeof(strucy virtio_balloon_config) instead.

hw/virtio/virtio-balloon.c +0 -0

@@ -263,7 +263,7 @@ static void virtio_balloon_get_config(VirtIODevice *vdev, uint8_t *config_data)
     config.num_pages = cpu_to_le32(dev->num_pages);
     config.actual = cpu_to_le32(dev->actual);
 

hw/virtio/virtio-balloon.c static void virtio_balloon_get_config(VirtIODevice *vdev, uint8_t *config_data) · line 266

Quoted 2 lines

hw/virtio/virtio-balloon.c +1 -1

-    memcpy(config_data, &config, 8);
+    memcpy(config_data, &config, sizeof(struct virtio_balloon_config));

I'm not sure any of those is better than another.

This is a published guest <=> host interface, the config _must_ be 8 bytes long and must contain 2 4-byte words in it.

We may use assert(sizeof(struct virtio_balloon_config) == 8) somewhere, but to my taste it is a bit overkill. No?

Thanks,

/mjt

Quoted 8 lines · Luiz Capitulino

Use sizeof(strucy virtio_balloon_config) instead.

hw/virtio/virtio-balloon.c +0 -0

@@ -263,7 +263,7 @@ static void virtio_balloon_get_config(VirtIODevice *vdev, uint8_t *config_data)
     config.num_pages = cpu_to_le32(dev->num_pages);
     config.actual = cpu_to_le32(dev->actual);
 

hw/virtio/virtio-balloon.c static void virtio_balloon_get_config(VirtIODevice *vdev, uint8_t *config_data) · line 266

Quoted 2 lines

hw/virtio/virtio-balloon.c +1 -1

-    memcpy(config_data, &config, 8);
+    memcpy(config_data, &config, sizeof(struct virtio_balloon_config));

I'm not sure any of those is better than another.

This is a published guest <=> host interface, the config _must_ be 8 bytes long and must contain 2 4-byte words in it.

We may use assert(sizeof(struct virtio_balloon_config) == 8) somewhere, but to my taste it is a bit overkill. No?

Thanks,

/mjt

Use sizeof(strucy virtio_balloon_config) instead.

Quoted 1 line · Luiz Capitulino

Use sizeof(strucy virtio_balloon_config) instead.

Thanks, applied to the trivial patches queue (with the spelling fix).