* [Qemu-devel] SCSI HBA auto-created for -drive if=scsi
@ 2017-01-18 17:15 Markus Armbruster
2017-01-18 17:21 ` Paolo Bonzini
0 siblings, 1 reply; 3+ messages in thread
From: Markus Armbruster @ 2017-01-18 17:15 UTC (permalink / raw)
To: qemu-devel; +Cc: Paolo Bonzini, Peter Maydell
Some boards automatically cold-plug SCSI HBAs to honor -drive if=scsi.
Which one depends on the machine:
pc*, realview-eb*, versatile*: lsi53c895a
spapr-machine: spapr-vscsi
Should we use something less thoroughly obsolete than lsi53c895a for new
machine types? Something that actually has a maintainer?
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [Qemu-devel] SCSI HBA auto-created for -drive if=scsi
2017-01-18 17:15 [Qemu-devel] SCSI HBA auto-created for -drive if=scsi Markus Armbruster
@ 2017-01-18 17:21 ` Paolo Bonzini
2017-01-18 19:37 ` Markus Armbruster
0 siblings, 1 reply; 3+ messages in thread
From: Paolo Bonzini @ 2017-01-18 17:21 UTC (permalink / raw)
To: Markus Armbruster, qemu-devel; +Cc: Peter Maydell
On 18/01/2017 18:15, Markus Armbruster wrote:
> Some boards automatically cold-plug SCSI HBAs to honor -drive if=scsi.
> Which one depends on the machine:
>
> pc*, realview-eb*, versatile*: lsi53c895a
> spapr-machine: spapr-vscsi
>
> Should we use something less thoroughly obsolete than lsi53c895a for new
> machine types? Something that actually has a maintainer?
Or just raise an error?...
Paolo
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [Qemu-devel] SCSI HBA auto-created for -drive if=scsi
2017-01-18 17:21 ` Paolo Bonzini
@ 2017-01-18 19:37 ` Markus Armbruster
0 siblings, 0 replies; 3+ messages in thread
From: Markus Armbruster @ 2017-01-18 19:37 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: qemu-devel, Peter Maydell
Paolo Bonzini <pbonzini@redhat.com> writes:
> On 18/01/2017 18:15, Markus Armbruster wrote:
>> Some boards automatically cold-plug SCSI HBAs to honor -drive if=scsi.
>> Which one depends on the machine:
>>
>> pc*, realview-eb*, versatile*: lsi53c895a
>> spapr-machine: spapr-vscsi
>>
>> Should we use something less thoroughly obsolete than lsi53c895a for new
>> machine types? Something that actually has a maintainer?
>
> Or just raise an error?...
On IRC, you remarked "there's no HBA that works reliably for all guest
OSes".
If there's really no sane default, perhaps we shouldn't provide one.
Most machine types don't. They don't error out, though, they ignore
drives with if=scsi, which leads to an "Orphaned drive without device"
warning, unless the user explicitly configures a suitable SCSI HBA.
Suitable SCSI HBAs are "am53c974", "dc390", "esp", "lsi53c810",
"lsi53c895a", "megasas", "megasas-gen2", "mptsas1068", "spapr-vscsi",
"virtio-scsi-device", but not "pvscsi", "usb-storage", "usb-bot",
"usb-uas". QEMU is weird.
This automatic creation of frontends for orphaned drives when some
"suitable" device appears is specific to if=scsi. It isn't done for any
other interface type. Again, QEMU is weird.
I'd love to ditch this special SCSI magic completely. But backward
compatibility may compel us to ditch it only for new machine types.
Opinions?
^ permalink raw reply [flat|nested] 3+ messages in thread
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2017-01-18 17:15 [Qemu-devel] SCSI HBA auto-created for -drive if=scsi Markus Armbruster
2017-01-18 17:21 ` Paolo Bonzini
2017-01-18 19:37 ` Markus Armbruster
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