Re: [Qemu-block] [Qemu-devel] [PATCH v2 for-2.4 3/3] hw/arm/virt: Make block devices default to virtio
Peter Maydell writes: > On 25 June 2015 at 08:40, Markus Armbruster wrote: >> Peter Maydell writes: >> >>> Now we have virtio-pci, we can make the virt board's default block >>> device type be IF_VIRTIO. This allows users to use simplified >>> command lines that don't have to explicitly create virtio-pci-blk >>> devices; the -hda &c very short options now also work. >>> >>> This means we also need to set no_cdrom to avoid getting a >>> default cdrom device -- this is needed because the virtio-blk >>> device will fail if it is connected to a block backend with >>> no media, which is what the default cdrom device typically is. >>> Providing a cdrom with media via -cdrom will still work. >> >> It'll create a virtio-blk device with non-removable medium, won't it? > > Yes, I think so. Mostly I cared that -cdrom won't make qemu die with a > confusing error. > > (Without no_cdrom, qemu dies even if you don't say -cdrom, because > of the default empty drive.) Instead of "will still work", I'd like to see something like "will succeed, but silently create a device with non-removable medium, which is probably not what you want, but the best we can do now". >>> The command line will be changed to include 'if=none', as the >> >> will have to be changed > > Yes. > > -- PMM
Re: [Qemu-block] [Qemu-devel] [PATCH v2 for-2.4 3/3] hw/arm/virt: Make block devices default to virtio
On 25 June 2015 at 08:40, Markus Armbruster wrote: > Peter Maydell writes: > >> Now we have virtio-pci, we can make the virt board's default block >> device type be IF_VIRTIO. This allows users to use simplified >> command lines that don't have to explicitly create virtio-pci-blk >> devices; the -hda &c very short options now also work. >> >> This means we also need to set no_cdrom to avoid getting a >> default cdrom device -- this is needed because the virtio-blk >> device will fail if it is connected to a block backend with >> no media, which is what the default cdrom device typically is. >> Providing a cdrom with media via -cdrom will still work. > > It'll create a virtio-blk device with non-removable medium, won't it? Yes, I think so. Mostly I cared that -cdrom won't make qemu die with a confusing error. (Without no_cdrom, qemu dies even if you don't say -cdrom, because of the default empty drive.) >> The command line will be changed to include 'if=none', as the > > will have to be changed Yes. -- PMM
Re: [Qemu-block] [Qemu-devel] [PATCH v2 for-2.4 3/3] hw/arm/virt: Make block devices default to virtio
Peter Maydell writes:
> Now we have virtio-pci, we can make the virt board's default block
> device type be IF_VIRTIO. This allows users to use simplified
> command lines that don't have to explicitly create virtio-pci-blk
> devices; the -hda &c very short options now also work.
>
> This means we also need to set no_cdrom to avoid getting a
> default cdrom device -- this is needed because the virtio-blk
> device will fail if it is connected to a block backend with
> no media, which is what the default cdrom device typically is.
> Providing a cdrom with media via -cdrom will still work.
It'll create a virtio-blk device with non-removable medium, won't it?
> Note that this change means that some command lines which used
> to work (by accident) will stop working. Where a drive was connected
> manually to a device but without 'if=none' being specified, we
> used to treat this as an IDE drive, which we would then not autoplug
> because the board doesn't support IDE. Now we will treat it as a
> virtio disk and autoplug it, which means the attempt to use the
> drive manually will fail:
> qemu-system-arm: -drive file=img.qcow2,id=foo: Drive 'foo' is already
> in use because it has been automatically connected to another device
> (did you need 'if=none' in the drive options?)
> The command line will be changed to include 'if=none', as the
will have to be changed
> error message suggests.
>
> Signed-off-by: Peter Maydell
> ---
> hw/arm/virt.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
> index f1e85c8..7e643ba 100644
> --- a/hw/arm/virt.c
> +++ b/hw/arm/virt.c
> @@ -966,6 +966,8 @@ static void virt_class_init(ObjectClass *oc, void *data)
> mc->init = machvirt_init;
> mc->max_cpus = 8;
> mc->has_dynamic_sysbus = true;
> +mc->block_default_type = IF_VIRTIO;
> +mc->no_cdrom = 1;
> }
>
> static const TypeInfo machvirt_info = {
