| Message ID | 20221201134227.1983-1-luzhipeng@cestc.cn (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | blockdev: add 'media=cdrom' argument to support usb cdrom emulated as cdrom | expand |
luzhipeng <luzhipeng@cestc.cn> writes: > From: zhipeng Lu <luzhipeng@cestc.cn> > > The drive interface supports media=cdrom so that the usb cdrom > can be emulated as cdrom in qemu, but libvirt deprived the drive > interface, so media=cdrom is added to the blockdev interface to > support usb cdrom emulated as cdrom > > Signed-off-by: zhipeng Lu <luzhipeng@cestc.cn> What problem are you trying to solve?
libvirt issue： https://gitlab.com/libvirt/libvirt/-/issues/261
1、start vm with usb cdrom
<disk type="file" device="cdrom">
<driver name="qemu" type="raw" discard="unmap"/>
<source file="/tmp/cdrom"/>
<target dev="sda" bus="usb"/>
<readonly/>
<address type="usb" bus="0" port="1"/>
</disk>
2、 get qemu cmdline
qemu ... -blockdev
{"driver":"file","filename":"/tmp/cdrom","node-name":"libvirt-1-storage","auto-read-only":true,"discard":"unmap"}
-blockdev
{"node-name":"libvirt-1-format","read-only":true,"discard":"unmap","driver":"raw","file":"libvirt-1-storage"}
-device
{"driver":"usb-storage","bus":"usb.0","port":"1","drive":"libvirt-1-format","id":"usb-disk0","removable":false}
3、 in vm
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 100M 1 disk
vda 252:0 0 10G 0 disk
├─vda1 252:1 0 1G 0 part /boot
└─vda2 252:2 0 9G 0 part
├─rhel-root 253:0 0 8G 0 lvm /
└─rhel-swap 253:1 0 1G 0 lvm [SWAP]
lshw -short|grep cdrom -i
No cdrom.
My patch is to solve this problem, usb cdrom emulated as cdrom.
在 2022/12/1 23:35, Markus Armbruster 写道:
> luzhipeng <luzhipeng@cestc.cn> writes:
>
>> From: zhipeng Lu <luzhipeng@cestc.cn>
>>
>> The drive interface supports media=cdrom so that the usb cdrom
>> can be emulated as cdrom in qemu, but libvirt deprived the drive
>> interface, so media=cdrom is added to the blockdev interface to
>> support usb cdrom emulated as cdrom
>>
>> Signed-off-by: zhipeng Lu <luzhipeng@cestc.cn>
>
> What problem are you trying to solve?
>
>
>
On 12/2/22 03:26, Zhipeng Lu wrote: > NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT > sda 8:0 0 100M 1 disk > vda 252:0 0 10G 0 disk > ├─vda1 252:1 0 1G 0 part /boot > └─vda2 252:2 0 9G 0 part > ├─rhel-root 253:0 0 8G 0 lvm / > └─rhel-swap 253:1 0 1G 0 lvm [SWAP] > lshw -short|grep cdrom -i > No cdrom. > > My patch is to solve this problem, usb cdrom emulated as cdrom. This is a libvirt bug, it should use usb-bot instead of usb-storage together with -blockdev. Then it can add a scsi-cd device below usb-bot. Paolo > > > 在 2022/12/1 23:35, Markus Armbruster 写道: >> luzhipeng <luzhipeng@cestc.cn> writes: >> >>> From: zhipeng Lu <luzhipeng@cestc.cn> >>> >>> The drive interface supports media=cdrom so that the usb cdrom >>> can be emulated as cdrom in qemu, but libvirt deprived the drive >>> interface, so media=cdrom is added to the blockdev interface to >>> support usb cdrom emulated as cdrom >>> >>> Signed-off-by: zhipeng Lu <luzhipeng@cestc.cn> >> >> What problem are you trying to solve? >> >> >> > > >
Could you give the detail qemu cmdline about usb-bot? 在 2022/12/2 17:40, Paolo Bonzini 写道: > On 12/2/22 03:26, Zhipeng Lu wrote: >> NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT >> sda 8:0 0 100M 1 disk >> vda 252:0 0 10G 0 disk >> ├─vda1 252:1 0 1G 0 part /boot >> └─vda2 252:2 0 9G 0 part >> ├─rhel-root 253:0 0 8G 0 lvm / >> └─rhel-swap 253:1 0 1G 0 lvm [SWAP] >> lshw -short|grep cdrom -i >> No cdrom. >> >> My patch is to solve this problem, usb cdrom emulated as cdrom. > > This is a libvirt bug, it should use usb-bot instead of usb-storage > together with -blockdev. Then it can add a scsi-cd device below usb-bot. > > Paolo > >> >> >> 在 2022/12/1 23:35, Markus Armbruster 写道: >>> luzhipeng <luzhipeng@cestc.cn> writes: >>> >>>> From: zhipeng Lu <luzhipeng@cestc.cn> >>>> >>>> The drive interface supports media=cdrom so that the usb cdrom >>>> can be emulated as cdrom in qemu, but libvirt deprived the drive >>>> interface, so media=cdrom is added to the blockdev interface to >>>> support usb cdrom emulated as cdrom >>>> >>>> Signed-off-by: zhipeng Lu <luzhipeng@cestc.cn> >>> >>> What problem are you trying to solve? >>> >>> >>> >> >> >> > > >
It should be like this:
-device usb-bot,id=bot0
-device scsi-{cd,hd},bus=bot0.0,drive=drive0
Libvirt has the code to generate the options for SCSI controllers, but
usb-bot only allows one disk attached to it so it's easier to make it a
<drive> element.
Paolo
Il sab 3 dic 2022, 13:52 Zhipeng Lu <luzhipeng@cestc.cn> ha scritto:
> Could you give the detail qemu cmdline about usb-bot?
>
> 在 2022/12/2 17:40, Paolo Bonzini 写道:
> > On 12/2/22 03:26, Zhipeng Lu wrote:
> >> NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
> >> sda 8:0 0 100M 1 disk
> >> vda 252:0 0 10G 0 disk
> >> ├─vda1 252:1 0 1G 0 part /boot
> >> └─vda2 252:2 0 9G 0 part
> >> ├─rhel-root 253:0 0 8G 0 lvm /
> >> └─rhel-swap 253:1 0 1G 0 lvm [SWAP]
> >> lshw -short|grep cdrom -i
> >> No cdrom.
> >>
> >> My patch is to solve this problem, usb cdrom emulated as cdrom.
> >
> > This is a libvirt bug, it should use usb-bot instead of usb-storage
> > together with -blockdev. Then it can add a scsi-cd device below usb-bot.
> >
> > Paolo
> >
> >>
> >>
> >> 在 2022/12/1 23:35, Markus Armbruster 写道:
> >>> luzhipeng <luzhipeng@cestc.cn> writes:
> >>>
> >>>> From: zhipeng Lu <luzhipeng@cestc.cn>
> >>>>
> >>>> The drive interface supports media=cdrom so that the usb cdrom
> >>>> can be emulated as cdrom in qemu, but libvirt deprived the drive
> >>>> interface, so media=cdrom is added to the blockdev interface to
> >>>> support usb cdrom emulated as cdrom
> >>>>
> >>>> Signed-off-by: zhipeng Lu <luzhipeng@cestc.cn>
> >>>
> >>> What problem are you trying to solve?
> >>>
> >>>
> >>>
> >>
> >>
> >>
> >
> >
> >
>
>
>
Thanks.
-device usb-bot,id=bot0
-device scsi-{cd,hd},bus=bot0.0,drive=drive0
Qemu implements virtio scsi to emulate scsi controller, but if the
virtual machine(for example windows guest os) don't install the virtio
scsi driver, it don't work
i need the function: emulate cdrom in guest, support hotplug and unplug,
not depend on virtio driver
have a better idea?
在 2022/12/7 16:39, Paolo Bonzini 写道:
> It should be like this:
>
> -device usb-bot,id=bot0
> -device scsi-{cd,hd},bus=bot0.0,drive=drive0
>
> Libvirt has the code to generate the options for SCSI controllers, but
> usb-bot only allows one disk attached to it so it's easier to make it a
> <drive> element.
>
> Paolo
>
> Il sab 3 dic 2022, 13:52 Zhipeng Lu <luzhipeng@cestc.cn
> <mailto:luzhipeng@cestc.cn>> ha scritto:
>
> Could you give the detail qemu cmdline about usb-bot?
>
> 在 2022/12/2 17:40, Paolo Bonzini 写道:
> > On 12/2/22 03:26, Zhipeng Lu wrote:
> >> NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
> >> sda 8:0 0 100M 1 disk
> >> vda 252:0 0 10G 0 disk
> >> ├─vda1 252:1 0 1G 0 part /boot
> >> └─vda2 252:2 0 9G 0 part
> >> ├─rhel-root 253:0 0 8G 0 lvm /
> >> └─rhel-swap 253:1 0 1G 0 lvm [SWAP]
> >> lshw -short|grep cdrom -i
> >> No cdrom.
> >>
> >> My patch is to solve this problem, usb cdrom emulated as cdrom.
> >
> > This is a libvirt bug, it should use usb-bot instead of usb-storage
> > together with -blockdev. Then it can add a scsi-cd device below
> usb-bot.
> >
> > Paolo
> >
> >>
> >>
> >> 在 2022/12/1 23:35, Markus Armbruster 写道:
> >>> luzhipeng <luzhipeng@cestc.cn <mailto:luzhipeng@cestc.cn>> writes:
> >>>
> >>>> From: zhipeng Lu <luzhipeng@cestc.cn <mailto:luzhipeng@cestc.cn>>
> >>>>
> >>>> The drive interface supports media=cdrom so that the usb cdrom
> >>>> can be emulated as cdrom in qemu, but libvirt deprived the drive
> >>>> interface, so media=cdrom is added to the blockdev interface to
> >>>> support usb cdrom emulated as cdrom
> >>>>
> >>>> Signed-off-by: zhipeng Lu <luzhipeng@cestc.cn
> <mailto:luzhipeng@cestc.cn>>
> >>>
> >>> What problem are you trying to solve?
> >>>
> >>>
> >>>
> >>
> >>
> >>
> >
> >
> >
>
>
On 12/9/22 03:28, Zhipeng Lu wrote: > Thanks. > > -device usb-bot,id=bot0 > -device scsi-{cd,hd},bus=bot0.0,drive=drive0 > > Qemu implements virtio scsi to emulate scsi controller, but if the > virtual machine(for example windows guest os) don't install the virtio > scsi driver, it don't work > i need the function: emulate cdrom in guest, support hotplug and unplug, > not depend on virtio driver usb-bot *is* a SCSI controller and it does not require drivers in the guest. It is not very high-performance, but as you say it has hotplug functionality via USB. Paolo
diff --git a/block.c b/block.c index a18f052374..d194e3039e 100644 --- a/block.c +++ b/block.c @@ -3787,6 +3787,7 @@ static BlockDriverState *bdrv_open_inherit(const char *filename, Error *local_err = NULL; QDict *snapshot_options = NULL; int snapshot_flags = 0; + int media = 0; assert(!child_class || !flags); assert(!child_class == !parent); @@ -3906,6 +3907,12 @@ static BlockDriverState *bdrv_open_inherit(const char *filename, qdict_del(bs->options, "backing"); qdict_del(options, "backing"); } + if (!g_strcmp0(qdict_get_try_str(options, "media"), "cdrom")) { + media = 1; + qdict_del(bs->explicit_options, "media"); + qdict_del(bs->options, "media"); + qdict_del(options, "media"); + } /* Open image file without format layer. This BlockBackend is only used for * probing, the block drivers will do their own bdrv_open_child() for the @@ -4033,7 +4040,9 @@ static BlockDriverState *bdrv_open_inherit(const char *filename, bdrv_unref(bs); bs = snapshot_bs; } - + if (bs && media) { + bs->media_cd = true; + } return bs; fail: diff --git a/block/block-backend.c b/block/block-backend.c index d98a96ff37..1760079a67 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -72,6 +72,7 @@ struct BlockBackend { uint64_t perm; uint64_t shared_perm; bool disable_perm; + bool media_cd; bool allow_aio_context_change; bool allow_write_beyond_eof; @@ -2634,3 +2635,20 @@ int blk_make_empty(BlockBackend *blk, Error **errp) return bdrv_make_empty(blk->root, errp); } + +bool blk_is_cdrom(BlockBackend *blk) +{ + if (!blk) { + return false; + } + return blk->media_cd; + +} + +void blk_set_cdrom(BlockBackend *blk) +{ + if (!blk) { + return ; + } + blk->media_cd = true; +} diff --git a/hw/core/qdev-properties-system.c b/hw/core/qdev-properties-system.c index a91f60567a..99df29ccb8 100644 --- a/hw/core/qdev-properties-system.c +++ b/hw/core/qdev-properties-system.c @@ -149,6 +149,9 @@ static void set_drive_helper(Object *obj, Visitor *v, const char *name, if (ret < 0) { goto fail; } + if (bs->media_cd) { + blk_set_cdrom(blk); + } } } if (!blk) { diff --git a/hw/scsi/scsi-bus.c b/hw/scsi/scsi-bus.c index ceceafb2cd..bc2bbdc823 100644 --- a/hw/scsi/scsi-bus.c +++ b/hw/scsi/scsi-bus.c @@ -321,7 +321,9 @@ SCSIDevice *scsi_bus_legacy_add_drive(SCSIBus *bus, BlockBackend *blk, driver = "scsi-generic"; } else { dinfo = blk_legacy_dinfo(blk); - if (dinfo && dinfo->media_cd) { + if ((dinfo && dinfo->media_cd)) { + driver = "scsi-cd"; + } else if (blk_is_cdrom(blk)) { driver = "scsi-cd"; } else { driver = "scsi-hd"; diff --git a/include/block/block_int-common.h b/include/block/block_int-common.h index 31ae91e56e..04a814ab1b 100644 --- a/include/block/block_int-common.h +++ b/include/block/block_int-common.h @@ -1023,6 +1023,7 @@ struct BlockDriverState { bool probed; /* if true, format was probed rather than specified */ bool force_share; /* if true, always allow all shared permissions */ bool implicit; /* if true, this filter node was automatically inserted */ + bool media_cd; BlockDriver *drv; /* NULL means no media */ void *opaque; diff --git a/include/sysemu/block-backend-global-state.h b/include/sysemu/block-backend-global-state.h index 6858e39cb6..108dfad283 100644 --- a/include/sysemu/block-backend-global-state.h +++ b/include/sysemu/block-backend-global-state.h @@ -71,6 +71,8 @@ void blk_set_on_error(BlockBackend *blk, BlockdevOnError on_read_error, BlockdevOnError on_write_error); bool blk_supports_write_perm(BlockBackend *blk); bool blk_is_sg(BlockBackend *blk); +bool blk_is_cdrom(BlockBackend *blk); +void blk_set_cdrom(BlockBackend *blk); void blk_set_enable_write_cache(BlockBackend *blk, bool wce); int blk_get_flags(BlockBackend *blk); bool blk_op_is_blocked(BlockBackend *blk, BlockOpType op, Error **errp);