[Qemu-devel] [PATCH 0/6][RFC] AArch64 support for Versatile Express using KVM

[Qemu-devel] [PATCH 0/6][RFC] AArch64 support for Versatile Express using KVM

[Mian M. Hamayun]

This patch series implements KVM support in QEMU for the ARMv8 Cortex 
A57 CPU.
It depends on the previously submitted AArch64 Preparation Patchset V4, 
and uses
as a base, the existing Versatile Express machine model and the already
available KVM in-kernel GIC support.

As a reference, KVM Tool and the AArch64 bootwrapper were used, as well as
public documentation from ARM. The following work has been tested with SMP
capabilities, under ARMv8 Fast Models and the Foundation model (Open 
Embedded
userspace with an emulated MMC).

The work has been sponsored by Huawei, and developed in collaboration with
Huawei Technologies Duesseldorf GmbH, European Research Center Munich (ERC).
A working tree of this implementation is available on the "kvm-aarch64" 
branch
of the following github repository.

https://github.com/virtualopensystems/qemu.git

Summary of Patches:

[PATCH 1/6] Added aarch64 configure support and default
[PATCH 2/6] Added KVM Headers from KVM Tool
[PATCH 3/6] Added Aarch64 CPU Initialization, Get and Put Registers
[PATCH 4/6] Added the Versatile Express Machine Model for A57
[PATCH 5/6] Added Boot Support for Aarch64 Processor.
[PATCH 6/6] Added SMP for Aarch64 Processors.

Re: [Qemu-devel] [PATCH 0/6][RFC] AArch64 support for Versatile Express using KVM

[Peter Maydell]

On 28 June 2013 13:20, Mian M. Hamayun <m.hamayun@virtualopensystems.com> wrote:
> This patch series implements KVM support in QEMU for the ARMv8 Cortex
> A57 CPU.
> It depends on the previously submitted AArch64 Preparation Patchset V4,
> and uses
> as a base, the existing Versatile Express machine model and the already
> available KVM in-kernel GIC support.

This rather overlaps with a bunch of work John Rigby has already done
(though not yet published to the mailing lists):

https://git.linaro.org/gitweb?p=people/pmaydell/qemu-aarch64.git;a=shortlog;h=refs/heads/kvm-aarch64-wip

so now we need to reconcile the two trees. If you'd let us know
you were doing this a bit earlier we could probably have
coordinated something...

thanks
-- PMM

Re: [Qemu-devel] [PATCH 0/6][RFC] AArch64 support for Versatile Express using KVM

[Andreas Färber]

Am 28.06.2013 14:44, schrieb Peter Maydell:
> On 28 June 2013 13:20, Mian M. Hamayun <m.hamayun@virtualopensystems.com> wrote:
>> This patch series implements KVM support in QEMU for the ARMv8 Cortex
>> A57 CPU.
>> It depends on the previously submitted AArch64 Preparation Patchset V4,
>> and uses
>> as a base, the existing Versatile Express machine model and the already
>> available KVM in-kernel GIC support.
> 
> This rather overlaps with a bunch of work John Rigby has already done
> (though not yet published to the mailing lists):
> 
> https://git.linaro.org/gitweb?p=people/pmaydell/qemu-aarch64.git;a=shortlog;h=refs/heads/kvm-aarch64-wip
> 
> so now we need to reconcile the two trees. If you'd let us know
> you were doing this a bit earlier we could probably have
> coordinated something...

I had been looking into that tree myself, and apart from John's
Linux'ish "ARM: " prefixes rather than our usual "target-arm: " (part of
which you forgot to fix before sending a PULL), I am really opposed to
copying A15MPCore_priv for A57. I plan to post a cleanup for the A9
version the weekend, now that we have a more elaborate hw/ directory
structure for headers.

Also I would really prefer to have the is_aarch64() helper operate on
ARMCPU rather than CPUARMState. QOM cast removal is underway to make
that more efficient.

Is there a 32-bit aarch64 register in ARMv8 to be accessed by TCG? If
not, the field should be in ARMCPU and a bool rather than uint32_t.

Regards,
Andreas

P.S. This cover letter got submitted separate from the actual patches so
that they are not marked RFC - please use --subject-prefix="RFC" or the
like and suggest to indicate there against which tree it is.

-- 
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg

Re: [Qemu-devel] [PATCH 0/6][RFC] AArch64 support for Versatile Express using KVM

[Peter Maydell]

On 28 June 2013 14:04, Andreas Färber <afaerber@suse.de> wrote:
> I had been looking into that tree myself, and apart from John's
> Linux'ish "ARM: " prefixes rather than our usual "target-arm: " (part of
> which you forgot to fix before sending a PULL), I am really opposed to
> copying A15MPCore_priv for A57.

I agree that just copying A15 is wrong (among other things, we
should be modelling the hardware, not just "this seems to make
KVM not barf"). That's one of the reasons I hadn't sent the patch
set out yet.

> Also I would really prefer to have the is_aarch64() helper operate on
> ARMCPU rather than CPUARMState. QOM cast removal is underway to make
> that more efficient.
>
> Is there a 32-bit aarch64 register in ARMv8 to be accessed by TCG? If
> not, the field should be in ARMCPU and a bool rather than uint32_t.

This also needs looking at, yes.

-- PMM

Re: [Qemu-devel] [PATCH 0/6][RFC] AArch64 support for Versatile Express using KVM

[Mian M. Hamayun]

At the time we started working on AArch64, we were not certain that our 
implementation would be published in near future. Now that this is 
cleared up we are more than happy to coordinate together.
> On 28 June 2013 14:04, Andreas Färber <afaerber@suse.de> wrote:
>> I had been looking into that tree myself, and apart from John's
>> Linux'ish "ARM: " prefixes rather than our usual "target-arm: " (part of
>> which you forgot to fix before sending a PULL), I am really opposed to
>> copying A15MPCore_priv for A57.
> I agree that just copying A15 is wrong (among other things, we
> should be modelling the hardware, not just "this seems to make
> KVM not barf"). That's one of the reasons I hadn't sent the patch
> set out yet.
>
Initially we thought about this aspect too, but in order to get started, 
we made the choice to continue using the already available A15 part as 
is. Obviously this is an RFC patch series and we would like to have your 
opinion on how we can proceed from here, based on the working solution 
that we have now, although we may have some differences from the real 
hardware.
>> Also I would really prefer to have the is_aarch64() helper operate on
>> ARMCPU rather than CPUARMState. QOM cast removal is underway to make
>> that more efficient.
>>
>> Is there a 32-bit aarch64 register in ARMv8 to be accessed by TCG? If
>> not, the field should be in ARMCPU and a bool rather than uint32_t.
> This also needs looking at, yes.
>
> -- PMM
--
Hamayun

Re: [Qemu-devel] [PATCH 0/6][RFC] AArch64 support for Versatile Express using KVM

[Andreas Färber]

Alex,

Am 28.06.2013 15:04, schrieb Andreas Färber:
> Am 28.06.2013 14:44, schrieb Peter Maydell:
>> On 28 June 2013 13:20, Mian M. Hamayun <m.hamayun@virtualopensystems.com> wrote:
>>> This patch series implements KVM support in QEMU for the ARMv8 Cortex
>>> A57 CPU.
>>> It depends on the previously submitted AArch64 Preparation Patchset V4,
>>> and uses
>>> as a base, the existing Versatile Express machine model and the already
>>> available KVM in-kernel GIC support.
>>
>> This rather overlaps with a bunch of work John Rigby has already done
>> (though not yet published to the mailing lists):
>>
>> https://git.linaro.org/gitweb?p=people/pmaydell/qemu-aarch64.git;a=shortlog;h=refs/heads/kvm-aarch64-wip
>>
>> so now we need to reconcile the two trees. If you'd let us know
>> you were doing this a bit earlier we could probably have
>> coordinated something...
> 
> I had been looking into that tree myself, and apart from John's
> Linux'ish "ARM: " prefixes rather than our usual "target-arm: " (part of
> which you forgot to fix before sending a PULL), I am really opposed to
> copying A15MPCore_priv for A57. I plan to post a cleanup for the A9
> version the weekend, now that we have a more elaborate hw/ directory
> structure for headers.
> 
> Also I would really prefer to have the is_aarch64() helper operate on
> ARMCPU rather than CPUARMState. QOM cast removal is underway to make
> that more efficient.
> 
> Is there a 32-bit aarch64 register in ARMv8 to be accessed by TCG? If
> not, the field should be in ARMCPU and a bool rather than uint32_t.

Care to comment on the latter?

Regards,
Andreas

-- 
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg

Re: [Qemu-devel] [PATCH 0/6][RFC] AArch64 support for Versatile Express using KVM

[Peter Maydell]

On 2 September 2013 10:46, Andreas Färber <afaerber@suse.de> wrote:
> Am 28.06.2013 15:04, schrieb Andreas Färber:
>> Is there a 32-bit aarch64 register in ARMv8 to be accessed by TCG? If
>> not, the field should be in ARMCPU and a bool rather than uint32_t.
>
> Care to comment on the latter?

I don't suppose the usermode emulation touches it, but the
architectural state corresponding to that 'aarch64' field is the
PSTATE nRW bit. I don't think this bit is directly accessible via
a register access though (other PSTATE bits may be).

thanks
-- PMM