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Re: [Qemu-devel] [RFC PATCH] hw/arm/virt: Added preliminary GICv3 suppor
From: |
Eric Auger |
Subject: |
Re: [Qemu-devel] [RFC PATCH] hw/arm/virt: Added preliminary GICv3 support for kvm mode |
Date: |
Tue, 19 May 2015 14:50:44 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 |
Dear all,
On 05/15/2015 08:42 AM, Pavel Fedin wrote:
> Hello!
>
>> Added -M virt,gicversion=2,3 property to configure GICv2 or GICv3.
>> GICv3 save/restore is not supported as vgic-v3-emul.c is yet to support
>> them.
>>
>> Signed-off-by: Ashok Kumar <address@hidden>
>
> I also work on this, just not published yet. Some notes about your version:
> 1. May be there should be hw/intc/arm_gicv3_kvm.c file created for GICv3? As
> far as i can
> see, save/restore code should differ a lot.
> 2. kvm_arch_irqchip_create() should probe only for type we want to get. It
> has to be
> passed there somehow from the virt machine initializer.
After a closer look, kvm_arch_irqchip_create is called here with test
mode = true. With that option, at kernel level, we only check the kvm
device registered its ops and do not go further (see
kvm_ioctl_create_device in kvm_main.c): typically the gic kvm_device is
not created at that stage. So if my understanding is correct, that piece
of code only should & does check either GICv2 or GICV3 was seen in the
host dt and accordingly registered. I think Ashok
kvm_arch_irqchip_create code is good here. Actual device creation is
handled in the device itself with test mode = false.
Do you share this understanding?
Best Regards
Eric
And, if we want GICv3, then upon
> failure it should return error, not zero. This is because when
> kvm_arch_irqchip_create()
> returns zero, a fallback code is used, which will create GICv2.
> 3. Perhaps you should base your work on these patch sets:
> https://lists.gnu.org/archive/html/qemu-devel/2015-05/msg00941.html
> https://lists.gnu.org/archive/html/qemu-devel/2015-05/msg01505.html
>
> I added Shlomo to cc because he might also be interested.
>
> Kind regards,
> Pavel Fedin
> Expert Engineer
> Samsung Electronics Research center Russia
>
>
>
Re: [Qemu-devel] [RFC PATCH] hw/arm/virt: Added preliminary GICv3 support for kvm mode, Eric Auger, 2015/05/19
Re: [Qemu-devel] [RFC PATCH] hw/arm/virt: Added preliminary GICv3 support for kvm mode, Eric Auger, 2015/05/18