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From: Marc Zyngier <marc.zyngier@arm.com>
To: Christoffer Dall <christoffer.dall@linaro.org>,
	Vladimir Murzin <vladimir.murzin@arm.com>
Cc: andre.przywara@arm.com, kvmarm@lists.cs.columbia.edu,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2 7/7] ARM: KVM: Unlock vgic-v3 support
Date: Tue, 6 Sep 2016 14:08:10 +0100	[thread overview]
Message-ID: <57CEBFBA.6060109@arm.com> (raw)
In-Reply-To: <20160905112927.GL26366@cbox>

On 05/09/16 12:29, Christoffer Dall wrote:
> On Tue, Aug 16, 2016 at 11:46:58AM +0100, Vladimir Murzin wrote:
>> It is time to get access to common version of vgic-v3.
> 
> common version?
> 
>>
>> We basically would need to tell build system how to pick it up and
>> undo KVM_ARM_VGIC_V3 guarding introduced in 4f64cb6 ("arm/arm64: KVM:
>> Only allow 64bit hosts to build VGICv3") and remove stubs. However,
>> since vgic got ITS support KVM_ARM_VGIC_V3 tend to protect a little
>> bit more than just plain vgic-v3 - this guard is used for ITS too
>> which is not supported in 32-bit world yet.  So, along with removal of
>> KVM_ARM_VGIC_V3 guard introduce the new one - KVM_ARM_VGIC_V3_ITS to
>> protect ITS related code.
> 
> I don't find this paragraph particularly helpful, I'm afraid.
> 
>>
>> The only unpleasant part is how we decide which save/restore sequence to
>> use under __vgic_save_state() - we don't have patching framework in hand
>> like arm64, so have to check runtime on every invocation.
> 
> Do static keys work on 32-bit arm?

They do. It'd be interesting to see if we could move both architectures
to use static keys for selecting the GIC backend.

	M.
-- 
Jazz is not dead. It just smells funny...

WARNING: multiple messages have this Message-ID (diff)
From: marc.zyngier@arm.com (Marc Zyngier)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 7/7] ARM: KVM: Unlock vgic-v3 support
Date: Tue, 6 Sep 2016 14:08:10 +0100	[thread overview]
Message-ID: <57CEBFBA.6060109@arm.com> (raw)
In-Reply-To: <20160905112927.GL26366@cbox>

On 05/09/16 12:29, Christoffer Dall wrote:
> On Tue, Aug 16, 2016 at 11:46:58AM +0100, Vladimir Murzin wrote:
>> It is time to get access to common version of vgic-v3.
> 
> common version?
> 
>>
>> We basically would need to tell build system how to pick it up and
>> undo KVM_ARM_VGIC_V3 guarding introduced in 4f64cb6 ("arm/arm64: KVM:
>> Only allow 64bit hosts to build VGICv3") and remove stubs. However,
>> since vgic got ITS support KVM_ARM_VGIC_V3 tend to protect a little
>> bit more than just plain vgic-v3 - this guard is used for ITS too
>> which is not supported in 32-bit world yet.  So, along with removal of
>> KVM_ARM_VGIC_V3 guard introduce the new one - KVM_ARM_VGIC_V3_ITS to
>> protect ITS related code.
> 
> I don't find this paragraph particularly helpful, I'm afraid.
> 
>>
>> The only unpleasant part is how we decide which save/restore sequence to
>> use under __vgic_save_state() - we don't have patching framework in hand
>> like arm64, so have to check runtime on every invocation.
> 
> Do static keys work on 32-bit arm?

They do. It'd be interesting to see if we could move both architectures
to use static keys for selecting the GIC backend.

	M.
-- 
Jazz is not dead. It just smells funny...

  reply	other threads:[~2016-09-06 12:59 UTC|newest]

Thread overview: 74+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-08-16 10:46 [PATCH v2 0/7] ARM: KVM: Support for vgic-v3 Vladimir Murzin
2016-08-16 10:46 ` Vladimir Murzin
2016-08-16 10:46 ` [PATCH v2 1/7] arm64: KVM: Move GIC accessors to arch_gicv3.h Vladimir Murzin
2016-08-16 10:46   ` Vladimir Murzin
2016-09-05 11:28   ` Christoffer Dall
2016-09-05 11:28     ` Christoffer Dall
2016-09-06 12:33     ` Vladimir Murzin
2016-09-06 12:33       ` Vladimir Murzin
2016-08-16 10:46 ` [PATCH v2 2/7] arm64: KVM: Move vgic-v3 save/restore to virt/kvm/arm/hyp Vladimir Murzin
2016-08-16 10:46   ` Vladimir Murzin
2016-08-16 10:46 ` [PATCH v2 3/7] KVM: arm: vgic-new: improve compatibility with 32-bit Vladimir Murzin
2016-08-16 10:46   ` Vladimir Murzin
2016-09-05 11:29   ` Christoffer Dall
2016-09-05 11:29     ` Christoffer Dall
2016-09-06 12:41     ` Vladimir Murzin
2016-09-06 12:41       ` Vladimir Murzin
2016-09-06 13:22       ` Christoffer Dall
2016-09-06 13:22         ` Christoffer Dall
2016-09-06 13:54         ` Vladimir Murzin
2016-09-06 13:54           ` Vladimir Murzin
2016-09-06 16:31           ` Christoffer Dall
2016-09-06 16:31             ` Christoffer Dall
2016-09-07  9:06             ` Vladimir Murzin
2016-09-07  9:06               ` Vladimir Murzin
2016-09-07  9:43               ` Christoffer Dall
2016-09-07  9:43                 ` Christoffer Dall
2016-08-16 10:46 ` [PATCH v2 4/7] ARM: update MPIDR accessors macro Vladimir Murzin
2016-08-16 10:46   ` Vladimir Murzin
2016-09-05 11:29   ` Christoffer Dall
2016-09-05 11:29     ` Christoffer Dall
2016-09-06 12:42     ` Vladimir Murzin
2016-09-06 12:42       ` Vladimir Murzin
2016-08-16 10:46 ` [PATCH v2 5/7] ARM: move system register accessors to asm/cp15.h Vladimir Murzin
2016-08-16 10:46   ` Vladimir Murzin
2016-09-05 11:29   ` Christoffer Dall
2016-09-05 11:29     ` Christoffer Dall
2016-09-06 13:05     ` Vladimir Murzin
2016-09-06 13:05       ` Vladimir Murzin
2016-09-06 16:34       ` Christoffer Dall
2016-09-06 16:34         ` Christoffer Dall
2016-08-16 10:46 ` [PATCH v2 6/7] ARM: KVM: Get ready to use vgic-v3 Vladimir Murzin
2016-08-16 10:46   ` Vladimir Murzin
2016-09-05 11:29   ` Christoffer Dall
2016-09-05 11:29     ` Christoffer Dall
2016-09-06 13:12     ` Vladimir Murzin
2016-09-06 13:12       ` Vladimir Murzin
2016-09-06 16:49       ` Christoffer Dall
2016-09-06 16:49         ` Christoffer Dall
2016-08-16 10:46 ` [PATCH v2 7/7] ARM: KVM: Unlock vgic-v3 support Vladimir Murzin
2016-08-16 10:46   ` Vladimir Murzin
2016-09-05 11:29   ` Christoffer Dall
2016-09-05 11:29     ` Christoffer Dall
2016-09-06 13:08     ` Marc Zyngier [this message]
2016-09-06 13:08       ` Marc Zyngier
2016-09-06 13:18     ` Vladimir Murzin
2016-09-06 13:18       ` Vladimir Murzin
2016-09-06 16:52       ` Christoffer Dall
2016-09-06 16:52         ` Christoffer Dall
2016-09-06 13:23     ` Vladimir Murzin
2016-09-06 13:23       ` Vladimir Murzin
2016-09-06 16:55       ` Christoffer Dall
2016-09-06 16:55         ` Christoffer Dall
2016-09-07 10:48         ` Vladimir Murzin
2016-09-07 10:48           ` Vladimir Murzin
2016-09-07 12:58           ` Christoffer Dall
2016-09-07 12:58             ` Christoffer Dall
2016-09-07 14:20             ` Peter Maydell
2016-09-07 14:20               ` Peter Maydell
2016-09-07 14:47               ` Christoffer Dall
2016-09-07 14:47                 ` Christoffer Dall
2016-09-05 11:28 ` [PATCH v2 0/7] ARM: KVM: Support for vgic-v3 Christoffer Dall
2016-09-05 11:28   ` Christoffer Dall
2016-09-06 12:32   ` Vladimir Murzin
2016-09-06 12:32     ` Vladimir Murzin

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