Re: [PATCH v1 2/5] virtio-mem: Check that "memaddr" is multiples of the block size

[Pankaj Gupta]

> The spec requires us to set the "addr" in guest physical address space to
> multiples of the block size. In some cases, this is not the case right
> now: For example, when starting a VM with 4 GiB boot memory and a
> virtio-mem device with a block size of 2 GiB, "memaddr" will be
> auto-assigned to 0x14000 / 5 GiB.
>
> We'll try to improve auto-assignment for memory devices next, to avoid
> bailing out in case memory device code selects a bad address.
>
> Note: The Linux driver doesn't support such big block sizes yet.
>
> Cc: "Michael S. Tsirkin" 
> Cc: Wei Yang 
> Cc: Dr. David Alan Gilbert 
> Cc: Igor Mammedov 
> Cc: Pankaj Gupta 
> Signed-off-by: David Hildenbrand 
> ---
>  hw/virtio/virtio-mem.c | 5 +
>  1 file changed, 5 insertions(+)
>
> diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c
> index 58098686ee..716eddd792 100644
> --- a/hw/virtio/virtio-mem.c
> +++ b/hw/virtio/virtio-mem.c
> @@ -515,6 +515,11 @@ static void virtio_mem_device_realize(DeviceState *dev, 
> Error **errp)
> ")", VIRTIO_MEM_REQUESTED_SIZE_PROP,
> VIRTIO_MEM_BLOCK_SIZE_PROP, vmem->block_size);
>  return;
> +} else if (!QEMU_IS_ALIGNED(vmem->addr, vmem->block_size)) {
> +error_setg(errp, "'%s' property has to be multiples of '%s' (0x%" 
> PRIx64
> +   ")", VIRTIO_MEM_ADDR_PROP, VIRTIO_MEM_BLOCK_SIZE_PROP,
> +   vmem->block_size);
> +return;
>  } else if (!QEMU_IS_ALIGNED(memory_region_size(&vmem->memdev->mr),
>  vmem->block_size)) {
>  error_setg(errp, "'%s' property memdev size has to be multiples of"
> --
> 2.26.2

Reviewed-by: Pankaj Gupta 

[PATCH v1 2/5] virtio-mem: Check that "memaddr" is multiples of the block size

[David Hildenbrand]

The spec requires us to set the "addr" in guest physical address space to
multiples of the block size. In some cases, this is not the case right
now: For example, when starting a VM with 4 GiB boot memory and a
virtio-mem device with a block size of 2 GiB, "memaddr" will be
auto-assigned to 0x14000 / 5 GiB.

We'll try to improve auto-assignment for memory devices next, to avoid
bailing out in case memory device code selects a bad address.

Note: The Linux driver doesn't support such big block sizes yet.

Cc: "Michael S. Tsirkin" 
Cc: Wei Yang 
Cc: Dr. David Alan Gilbert 
Cc: Igor Mammedov 
Cc: Pankaj Gupta 
Signed-off-by: David Hildenbrand 
---
 hw/virtio/virtio-mem.c | 5 +
 1 file changed, 5 insertions(+)

diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c
index 58098686ee..716eddd792 100644
--- a/hw/virtio/virtio-mem.c
+++ b/hw/virtio/virtio-mem.c
@@ -515,6 +515,11 @@ static void virtio_mem_device_realize(DeviceState *dev, 
Error **errp)
")", VIRTIO_MEM_REQUESTED_SIZE_PROP,
VIRTIO_MEM_BLOCK_SIZE_PROP, vmem->block_size);
 return;
+} else if (!QEMU_IS_ALIGNED(vmem->addr, vmem->block_size)) {
+error_setg(errp, "'%s' property has to be multiples of '%s' (0x%" 
PRIx64
+   ")", VIRTIO_MEM_ADDR_PROP, VIRTIO_MEM_BLOCK_SIZE_PROP,
+   vmem->block_size);
+return;
 } else if (!QEMU_IS_ALIGNED(memory_region_size(&vmem->memdev->mr),
 vmem->block_size)) {
 error_setg(errp, "'%s' property memdev size has to be multiples of"
-- 
2.26.2