diff mbox

[2/3] ppc64-softmmu: Remove unsupported FDC from config

Message ID 1425278787-10079-3-git-send-email-aik@ozlabs.ru
State New
Headers show

Commit Message

Alexey Kardashevskiy March 2, 2015, 6:46 a.m. UTC
This removes floppy disks support as it is not supported by any PPC64
system anyway as the only way to have floppy disk on such systems would
be an ISA bus and Linux kernels seems have never had such support.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---

At the moment on POWERPC platform ISA bus depends on CHRP config option
which is so unsupported that it depends on 6xx config option which is not
defined anywhere in the kernel (there is PPC_6xx instead with PPC_ prefix).
---
 default-configs/ppc64-softmmu.mak | 1 -
 1 file changed, 1 deletion(-)

Comments

David Gibson March 2, 2015, 7:07 a.m. UTC | #1
On Mon, Mar 02, 2015 at 05:46:26PM +1100, Alexey Kardashevskiy wrote:
> This removes floppy disks support as it is not supported by any PPC64
> system anyway as the only way to have floppy disk on such systems would
> be an ISA bus and Linux kernels seems have never had such support.
> 
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Alexander Graf March 9, 2015, 12:31 p.m. UTC | #2
On 02.03.15 00:46, Alexey Kardashevskiy wrote:
> This removes floppy disks support as it is not supported by any PPC64
> system anyway as the only way to have floppy disk on such systems would
> be an ISA bus and Linux kernels seems have never had such support.
> 
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>

I removed this patch from my queue again. The ppc64-softmmu target can
execute -M PReP which in turn uses the fdc.


Alex

> ---
> 
> At the moment on POWERPC platform ISA bus depends on CHRP config option
> which is so unsupported that it depends on 6xx config option which is not
> defined anywhere in the kernel (there is PPC_6xx instead with PPC_ prefix).
> ---
>  default-configs/ppc64-softmmu.mak | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/default-configs/ppc64-softmmu.mak b/default-configs/ppc64-softmmu.mak
> index 2d97bdf..53f5c73 100644
> --- a/default-configs/ppc64-softmmu.mak
> +++ b/default-configs/ppc64-softmmu.mak
> @@ -10,7 +10,6 @@ CONFIG_SERIAL=y
>  CONFIG_PARALLEL=y
>  CONFIG_I8254=y
>  CONFIG_PCKBD=y
> -CONFIG_FDC=y
>  CONFIG_I8257=y
>  CONFIG_I82374=y
>  CONFIG_OPENPIC=y
>
Alexey Kardashevskiy March 9, 2015, 2:39 p.m. UTC | #3
On 03/09/2015 11:31 PM, Alexander Graf wrote:
>
>
> On 02.03.15 00:46, Alexey Kardashevskiy wrote:
>> This removes floppy disks support as it is not supported by any PPC64
>> system anyway as the only way to have floppy disk on such systems would
>> be an ISA bus and Linux kernels seems have never had such support.
>>
>> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
>
> I removed this patch from my queue again. The ppc64-softmmu target can
> execute -M PReP which in turn uses the fdc.


Out of curiosity - do you have actual 64bit guests being able to run on 
PReP? :) Current Linux ditched its support...


>
>
> Alex
>
>> ---
>>
>> At the moment on POWERPC platform ISA bus depends on CHRP config option
>> which is so unsupported that it depends on 6xx config option which is not
>> defined anywhere in the kernel (there is PPC_6xx instead with PPC_ prefix).
>> ---
>>   default-configs/ppc64-softmmu.mak | 1 -
>>   1 file changed, 1 deletion(-)
>>
>> diff --git a/default-configs/ppc64-softmmu.mak b/default-configs/ppc64-softmmu.mak
>> index 2d97bdf..53f5c73 100644
>> --- a/default-configs/ppc64-softmmu.mak
>> +++ b/default-configs/ppc64-softmmu.mak
>> @@ -10,7 +10,6 @@ CONFIG_SERIAL=y
>>   CONFIG_PARALLEL=y
>>   CONFIG_I8254=y
>>   CONFIG_PCKBD=y
>> -CONFIG_FDC=y
>>   CONFIG_I8257=y
>>   CONFIG_I82374=y
>>   CONFIG_OPENPIC=y
>>
Alexey Kardashevskiy March 10, 2015, 3:52 a.m. UTC | #4
On 03/10/2015 01:39 AM, Alexey Kardashevskiy wrote:
> On 03/09/2015 11:31 PM, Alexander Graf wrote:
>>
>>
>> On 02.03.15 00:46, Alexey Kardashevskiy wrote:
>>> This removes floppy disks support as it is not supported by any PPC64
>>> system anyway as the only way to have floppy disk on such systems would
>>> be an ISA bus and Linux kernels seems have never had such support.
>>>
>>> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
>>
>> I removed this patch from my queue again. The ppc64-softmmu target can
>> execute -M PReP which in turn uses the fdc.
>
>
> Out of curiosity - do you have actual 64bit guests being able to run on
> PReP? :) Current Linux ditched its support...


Paul suggested that there has never ever been a 64bit PReP CPU so there is 
no point in emulating it in QEMU. Or there is some reason for that?
David Gibson March 10, 2015, 3:58 a.m. UTC | #5
On Tue, Mar 10, 2015 at 02:52:48PM +1100, Alexey Kardashevskiy wrote:
> On 03/10/2015 01:39 AM, Alexey Kardashevskiy wrote:
> >On 03/09/2015 11:31 PM, Alexander Graf wrote:
> >>
> >>
> >>On 02.03.15 00:46, Alexey Kardashevskiy wrote:
> >>>This removes floppy disks support as it is not supported by any PPC64
> >>>system anyway as the only way to have floppy disk on such systems would
> >>>be an ISA bus and Linux kernels seems have never had such support.
> >>>
> >>>Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> >>
> >>I removed this patch from my queue again. The ppc64-softmmu target can
> >>execute -M PReP which in turn uses the fdc.
> >
> >
> >Out of curiosity - do you have actual 64bit guests being able to run on
> >PReP? :) Current Linux ditched its support...
> 
> 
> Paul suggested that there has never ever been a 64bit PReP CPU so there is
> no point in emulating it in QEMU. Or there is some reason for that?

IIUC, qemu-system-ppc64 (roughly speaking) emulates a superset of what
qemu-system-ppc does, not a different set of hardware.
Alexey Kardashevskiy March 10, 2015, 4:44 a.m. UTC | #6
On 03/10/2015 02:58 PM, David Gibson wrote:
> On Tue, Mar 10, 2015 at 02:52:48PM +1100, Alexey Kardashevskiy wrote:
>> On 03/10/2015 01:39 AM, Alexey Kardashevskiy wrote:
>>> On 03/09/2015 11:31 PM, Alexander Graf wrote:
>>>>
>>>>
>>>> On 02.03.15 00:46, Alexey Kardashevskiy wrote:
>>>>> This removes floppy disks support as it is not supported by any PPC64
>>>>> system anyway as the only way to have floppy disk on such systems would
>>>>> be an ISA bus and Linux kernels seems have never had such support.
>>>>>
>>>>> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
>>>>
>>>> I removed this patch from my queue again. The ppc64-softmmu target can
>>>> execute -M PReP which in turn uses the fdc.
>>>
>>>
>>> Out of curiosity - do you have actual 64bit guests being able to run on
>>> PReP? :) Current Linux ditched its support...
>>
>>
>> Paul suggested that there has never ever been a 64bit PReP CPU so there is
>> no point in emulating it in QEMU. Or there is some reason for that?
>
> IIUC, qemu-system-ppc64 (roughly speaking) emulates a superset of what
> qemu-system-ppc does, not a different set of hardware.

Well, default-configs/ppc-softmmu.mak does not include 
default-configs/ppc64-softmmu.mak or vice versa so I would say these are 
pretty independent and I would simply remove CONFIG_PREP* from 
default-configs/ppc64-softmmu.mak.
Alexander Graf March 10, 2015, 5:38 a.m. UTC | #7
> Am 09.03.2015 um 23:44 schrieb Alexey Kardashevskiy <aik@ozlabs.ru>:
> 
>> On 03/10/2015 02:58 PM, David Gibson wrote:
>>> On Tue, Mar 10, 2015 at 02:52:48PM +1100, Alexey Kardashevskiy wrote:
>>>> On 03/10/2015 01:39 AM, Alexey Kardashevskiy wrote:
>>>>> On 03/09/2015 11:31 PM, Alexander Graf wrote:
>>>>> 
>>>>> 
>>>>>> On 02.03.15 00:46, Alexey Kardashevskiy wrote:
>>>>>> This removes floppy disks support as it is not supported by any PPC64
>>>>>> system anyway as the only way to have floppy disk on such systems would
>>>>>> be an ISA bus and Linux kernels seems have never had such support.
>>>>>> 
>>>>>> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
>>>>> 
>>>>> I removed this patch from my queue again. The ppc64-softmmu target can
>>>>> execute -M PReP which in turn uses the fdc.
>>>> 
>>>> 
>>>> Out of curiosity - do you have actual 64bit guests being able to run on
>>>> PReP? :) Current Linux ditched its support...
>>> 
>>> 
>>> Paul suggested that there has never ever been a 64bit PReP CPU so there is
>>> no point in emulating it in QEMU. Or there is some reason for that?
>> 
>> IIUC, qemu-system-ppc64 (roughly speaking) emulates a superset of what
>> qemu-system-ppc does, not a different set of hardware.
> 
> Well, default-configs/ppc-softmmu.mak does not include default-configs/ppc64-softmmu.mak or vice versa so I would say these are pretty independent and I would simply remove CONFIG_PREP* from default-configs/ppc64-softmmu.mak.

Convention so far has been that ppc64 includes ppc includes ppcemb. I don't see why we should break that assumption.

However I do agree that we should probably reflect it with includes in the mak files.


Alex

> 
> 
> -- 
> Alexey
Alexey Kardashevskiy March 10, 2015, 9:20 a.m. UTC | #8
On 03/10/2015 04:38 PM, Alexander Graf wrote:
>
>
>
>> Am 09.03.2015 um 23:44 schrieb Alexey Kardashevskiy <aik@ozlabs.ru>:
>>
>>> On 03/10/2015 02:58 PM, David Gibson wrote:
>>>> On Tue, Mar 10, 2015 at 02:52:48PM +1100, Alexey Kardashevskiy wrote:
>>>>> On 03/10/2015 01:39 AM, Alexey Kardashevskiy wrote:
>>>>>> On 03/09/2015 11:31 PM, Alexander Graf wrote:
>>>>>>
>>>>>>
>>>>>>> On 02.03.15 00:46, Alexey Kardashevskiy wrote:
>>>>>>> This removes floppy disks support as it is not supported by any PPC64
>>>>>>> system anyway as the only way to have floppy disk on such systems would
>>>>>>> be an ISA bus and Linux kernels seems have never had such support.
>>>>>>>
>>>>>>> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
>>>>>>
>>>>>> I removed this patch from my queue again. The ppc64-softmmu target can
>>>>>> execute -M PReP which in turn uses the fdc.
>>>>>
>>>>>
>>>>> Out of curiosity - do you have actual 64bit guests being able to run on
>>>>> PReP? :) Current Linux ditched its support...
>>>>
>>>>
>>>> Paul suggested that there has never ever been a 64bit PReP CPU so there is
>>>> no point in emulating it in QEMU. Or there is some reason for that?
>>>
>>> IIUC, qemu-system-ppc64 (roughly speaking) emulates a superset of what
>>> qemu-system-ppc does, not a different set of hardware.
>>
>> Well, default-configs/ppc-softmmu.mak does not include default-configs/ppc64-softmmu.mak or vice versa so I would say these are pretty independent and I would simply remove CONFIG_PREP* from default-configs/ppc64-softmmu.mak.
>
> Convention so far has been that ppc64 includes ppc includes ppcemb. I don't see why we should break that assumption.



[aik@vpl2 ~]$ ./qemu-system-ppc64 -device help 2>&1 | grep fdc
name "isa-fdc", bus ISA
name "sysbus-fdc", bus System


afaik there is no way to get "fdc" working with qemu-system-ppc64 but 
"-device help" suggests there is a way and libvirt thinks (the original 
request came from there) it can add floppy disk. If later we use "-fda" 
with QEMU, it will warn about "Orphaned drive" as there is no fdc device. 
Ok, I can be sneakier and add "-device i82378" but I wonder if there is a 
PPC64 guest with FDC driver enabled. When I try to enable it in the current 
upstream (or anything since 2010), it needs ISA which depends on CHRP 
(about to be ditched, and PReP is ditched already) which depends on 6xx 
which is not defined at all (PPC_6xx is but not 6xx).

So if you know how to get working floppy disk with qemu-system-ppc64, that 
would help me a lot in rejecting requests from libvirt folks :) Thanks :)



> However I do agree that we should probably reflect it with includes in the mak files.
>
>
> Alex
>
>>
>>
>> --
>> Alexey
Alexander Graf March 11, 2015, 11:27 a.m. UTC | #9
On 10.03.15 04:20, Alexey Kardashevskiy wrote:
> On 03/10/2015 04:38 PM, Alexander Graf wrote:
>>
>>
>>
>>> Am 09.03.2015 um 23:44 schrieb Alexey Kardashevskiy <aik@ozlabs.ru>:
>>>
>>>> On 03/10/2015 02:58 PM, David Gibson wrote:
>>>>> On Tue, Mar 10, 2015 at 02:52:48PM +1100, Alexey Kardashevskiy wrote:
>>>>>> On 03/10/2015 01:39 AM, Alexey Kardashevskiy wrote:
>>>>>>> On 03/09/2015 11:31 PM, Alexander Graf wrote:
>>>>>>>
>>>>>>>
>>>>>>>> On 02.03.15 00:46, Alexey Kardashevskiy wrote:
>>>>>>>> This removes floppy disks support as it is not supported by any
>>>>>>>> PPC64
>>>>>>>> system anyway as the only way to have floppy disk on such
>>>>>>>> systems would
>>>>>>>> be an ISA bus and Linux kernels seems have never had such support.
>>>>>>>>
>>>>>>>> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
>>>>>>>
>>>>>>> I removed this patch from my queue again. The ppc64-softmmu
>>>>>>> target can
>>>>>>> execute -M PReP which in turn uses the fdc.
>>>>>>
>>>>>>
>>>>>> Out of curiosity - do you have actual 64bit guests being able to
>>>>>> run on
>>>>>> PReP? :) Current Linux ditched its support...
>>>>>
>>>>>
>>>>> Paul suggested that there has never ever been a 64bit PReP CPU so
>>>>> there is
>>>>> no point in emulating it in QEMU. Or there is some reason for that?
>>>>
>>>> IIUC, qemu-system-ppc64 (roughly speaking) emulates a superset of what
>>>> qemu-system-ppc does, not a different set of hardware.
>>>
>>> Well, default-configs/ppc-softmmu.mak does not include
>>> default-configs/ppc64-softmmu.mak or vice versa so I would say these
>>> are pretty independent and I would simply remove CONFIG_PREP* from
>>> default-configs/ppc64-softmmu.mak.
>>
>> Convention so far has been that ppc64 includes ppc includes ppcemb. I
>> don't see why we should break that assumption.
> 
> 
> 
> [aik@vpl2 ~]$ ./qemu-system-ppc64 -device help 2>&1 | grep fdc
> name "isa-fdc", bus ISA
> name "sysbus-fdc", bus System
> 
> 
> afaik there is no way to get "fdc" working with qemu-system-ppc64 but

It might work with -M prep, but definitely not any of the others. The
same holds true for qemu-system-ppc. There also only -M prep supports an
ISA bus, all the other machines don't.

> "-device help" suggests there is a way and libvirt thinks (the original
> request came from there) it can add floppy disk. If later we use "-fda"
> with QEMU, it will warn about "Orphaned drive" as there is no fdc
> device. Ok, I can be sneakier and add "-device i82378" but I wonder if
> there is a PPC64 guest with FDC driver enabled. When I try to enable it
> in the current upstream (or anything since 2010), it needs ISA which
> depends on CHRP (about to be ditched, and PReP is ditched already) which
> depends on 6xx which is not defined at all (PPC_6xx is but not 6xx).

The fact that we have an fdc in the "device bucket" doesn't mean that
that particular device can ever be instantiated. We don't have an ISA
bus, so we can't really ;).

> So if you know how to get working floppy disk with qemu-system-ppc64,
> that would help me a lot in rejecting requests from libvirt folks :)
> Thanks :)

I don't think you want floppy disk emulation on -M pseries at all. In
fact, you only ever want floppy disk emulation on x86. So I'd recommend
to change the logic in libvirt accordingly and just hard code floppy
emulation to x86 (and if alpha or some other weird architecture needs it
later as well, have them extend the list).


Alex
Maciej W. Rozycki March 23, 2015, 7:18 p.m. UTC | #10
On Wed, 11 Mar 2015, Alexander Graf wrote:

> > So if you know how to get working floppy disk with qemu-system-ppc64,
> > that would help me a lot in rejecting requests from libvirt folks :)
> > Thanks :)
> 
> I don't think you want floppy disk emulation on -M pseries at all. In
> fact, you only ever want floppy disk emulation on x86. So I'd recommend
> to change the logic in libvirt accordingly and just hard code floppy
> emulation to x86 (and if alpha or some other weird architecture needs it
> later as well, have them extend the list).

 For the record: the MIPS Malta board that we support also has direct PC 
FDD support.  The real board has a SMSC FDC37M817 super I/O controller 
chip wired to Intel 82371EB (PIIX4E) south bridge's LPC interface and a 
suitable IDC header for a FDD data cable soldered onto the PCB as well.  
So it's not only x86 that can make use of floppy disk emulation.  Note 
that there's no real ISA (no slots) on the Malta board, only the LPC and 
PIIX4E on-chip stuff.

  Maciej
diff mbox

Patch

diff --git a/default-configs/ppc64-softmmu.mak b/default-configs/ppc64-softmmu.mak
index 2d97bdf..53f5c73 100644
--- a/default-configs/ppc64-softmmu.mak
+++ b/default-configs/ppc64-softmmu.mak
@@ -10,7 +10,6 @@  CONFIG_SERIAL=y
 CONFIG_PARALLEL=y
 CONFIG_I8254=y
 CONFIG_PCKBD=y
-CONFIG_FDC=y
 CONFIG_I8257=y
 CONFIG_I82374=y
 CONFIG_OPENPIC=y