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From: Zenghui Yu <yuzenghui@huawei.com>
To: Marc Zyngier <maz@kernel.org>
Cc: Auger Eric <eric.auger@redhat.com>,
	<linux-arm-kernel@lists.infradead.org>,
	<kvmarm@lists.cs.columbia.edu>, <kvm@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Jason Cooper <jason@lakedaemon.net>,
	"Robert Richter" <rrichter@marvell.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	"James Morse" <james.morse@arm.com>,
	Julien Thierry <julien.thierry.kdev@gmail.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>
Subject: Re: [PATCH v5 23/23] KVM: arm64: GICv4.1: Expose HW-based SGIs in debugfs
Date: Fri, 20 Mar 2020 19:35:39 +0800	[thread overview]
Message-ID: <8d7fdb7f-7a21-da22-52a2-51ee8ac9393f@huawei.com> (raw)
In-Reply-To: <b63950513f519d9a04f9719f5aa6a2db@kernel.org>

Hi Marc,

On 2020/3/20 17:09, Marc Zyngier wrote:
> Hi Zenghui,
> 
> On 2020-03-20 04:38, Zenghui Yu wrote:
>> Hi Marc,
>>
>> On 2020/3/19 23:21, Marc Zyngier wrote:
>>> With GICv4.1, you can introspect the HW state for SGIs. You can also
>>> look at the vLPI state by peeking at the virtual pending table, but
>>> you'd need to unmap the VPE first,
>>
>> Out of curiosity, could you please point me to the "unmap the VPE"
>> requirement in the v4.1 spec? I'd like to have a look.
> 
> Sure. See IHI0069F, 5.3.19 (VMAPP GICv4.1), "Caching of virtual LPI data
> structures", and the bit that says:
> 
> "A VMAPP with {V,Alloc}=={0,1} cleans and invalidates any caching of the
> Virtual Pending Table and Virtual Configuration Table associated with the
> vPEID held in the GIC"
> 
> which is what was crucially missing from the GICv4.0 spec (it doesn't say
> when the GIC is done writing to memory).

OK. Thanks for the pointer!

> 
> Side note: it'd be good to know what the rules are for your own GICv4
> implementations, so that we can at least make sure the current code is 
> safe.

As far as I know, there will be some clean and invalidate operations
when v4.0 VPENDBASER.Valid gets programmed. But not sure about behaviors
on VMAPP (unmap), it may be a totally v4.1 stuff. I'll have a talk with
our SOC team.

But how can the current code be unsafe? Is anywhere in the current code
will peek/poke the vpt (whilst GIC continues writing things into it)?


Thanks,
Zenghui


  reply	other threads:[~2020-03-20 11:36 UTC|newest]

Thread overview: 99+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-04 20:33 [PATCH v5 00/23] irqchip/gic-v4: GICv4.1 architecture support Marc Zyngier
2020-03-04 20:33 ` [PATCH v5 01/23] irqchip/gic-v3: Use SGIs without active state if offered Marc Zyngier
2020-03-12  6:30   ` Zenghui Yu
2020-03-12  9:28     ` Marc Zyngier
2020-03-12 12:05       ` Marc Zyngier
2020-03-13  1:39         ` Zenghui Yu
2020-03-12 17:16   ` Auger Eric
2020-03-12 17:23     ` Marc Zyngier
2020-03-04 20:33 ` [PATCH v5 02/23] irqchip/gic-v4.1: Skip absent CPUs while iterating over redistributors Marc Zyngier
2020-03-16 17:10   ` Auger Eric
2020-03-04 20:33 ` [PATCH v5 03/23] irqchip/gic-v4.1: Ensure mutual exclusion between vPE affinity change and RD access Marc Zyngier
2020-03-12  6:56   ` Zenghui Yu
2020-03-04 20:33 ` [PATCH v5 04/23] irqchip/gic-v4.1: Wait for completion of redistributor's INVALL operation Marc Zyngier
2020-03-20 14:23   ` Auger Eric
2020-03-04 20:33 ` [PATCH v5 05/23] irqchip/gic-v4.1: Ensure mutual exclusion betwen invalidations on the same RD Marc Zyngier
2020-03-12  7:11   ` Zenghui Yu
2020-03-20 14:23   ` Auger Eric
2020-03-04 20:33 ` [PATCH v5 06/23] irqchip/gic-v4.1: Advertise support v4.1 to KVM Marc Zyngier
2020-03-16 17:10   ` Auger Eric
2020-03-04 20:33 ` [PATCH v5 07/23] irqchip/gic-v4.1: Map the ITS SGIR register page Marc Zyngier
2020-03-16 17:10   ` Auger Eric
2020-03-04 20:33 ` [PATCH v5 08/23] irqchip/gic-v4.1: Plumb skeletal VSGI irqchip Marc Zyngier
2020-03-16 17:10   ` Auger Eric
2020-03-19 10:03     ` Marc Zyngier
2020-03-04 20:33 ` [PATCH v5 09/23] irqchip/gic-v4.1: Add initial SGI configuration Marc Zyngier
2020-03-16 17:53   ` Auger Eric
2020-03-17  2:02     ` Zenghui Yu
2020-03-17  8:36       ` Auger Eric
2020-03-19 10:20     ` Marc Zyngier
2020-03-04 20:33 ` [PATCH v5 10/23] irqchip/gic-v4.1: Plumb mask/unmask SGI callbacks Marc Zyngier
2020-03-16 18:15   ` Auger Eric
2020-03-04 20:33 ` [PATCH v5 11/23] irqchip/gic-v4.1: Plumb get/set_irqchip_state " Marc Zyngier
2020-03-12  7:41   ` Zenghui Yu
2020-03-16 21:43   ` Auger Eric
2020-03-19 10:27     ` Marc Zyngier
2020-03-04 20:33 ` [PATCH v5 12/23] irqchip/gic-v4.1: Plumb set_vcpu_affinity " Marc Zyngier
2020-03-17 10:35   ` Auger Eric
2020-03-04 20:33 ` [PATCH v5 13/23] irqchip/gic-v4.1: Move doorbell management to the GICv4 abstraction layer Marc Zyngier
2020-03-12  8:20   ` Zenghui Yu
2020-03-04 20:33 ` [PATCH v5 14/23] irqchip/gic-v4.1: Add VSGI allocation/teardown Marc Zyngier
2020-03-12  8:06   ` Zenghui Yu
2020-03-04 20:33 ` [PATCH v5 15/23] irqchip/gic-v4.1: Add VSGI property setup Marc Zyngier
2020-03-12  8:09   ` Zenghui Yu
2020-03-17 10:30   ` Auger Eric
2020-03-19 10:57     ` Marc Zyngier
2020-03-04 20:33 ` [PATCH v5 16/23] irqchip/gic-v4.1: Eagerly vmap vPEs Marc Zyngier
2020-03-12  8:12   ` Zenghui Yu
2020-03-17  2:49   ` Zenghui Yu
2020-03-19 10:55     ` Marc Zyngier
2020-03-20  2:31       ` Zenghui Yu
2020-03-04 20:33 ` [PATCH v5 17/23] KVM: arm64: GICv4.1: Let doorbells be auto-enabled Marc Zyngier
2020-03-12  8:15   ` Zenghui Yu
2020-03-17 11:04   ` Auger Eric
2020-03-04 20:33 ` [PATCH v5 18/23] KVM: arm64: GICv4.1: Add direct injection capability to SGI registers Marc Zyngier
2020-03-18  3:28   ` Zenghui Yu
2020-03-20  8:11   ` Auger Eric
2020-03-20 10:05     ` Marc Zyngier
2020-03-20 10:56       ` Auger Eric
2020-03-04 20:33 ` [PATCH v5 19/23] KVM: arm64: GICv4.1: Allow SGIs to switch between HW and SW interrupts Marc Zyngier
2020-03-19 16:16   ` Auger Eric
2020-03-19 19:52     ` Marc Zyngier
2020-03-19 20:13       ` Auger Eric
2020-03-20  9:17         ` Marc Zyngier
2020-03-20  4:22   ` Zenghui Yu
2020-03-04 20:33 ` [PATCH v5 20/23] KVM: arm64: GICv4.1: Plumb SGI implementation selection in the distributor Marc Zyngier
2020-03-18  6:34   ` Zenghui Yu
2020-03-19 12:10     ` Marc Zyngier
2020-03-19 20:38       ` Auger Eric
2020-03-20  3:08         ` Zenghui Yu
2020-03-20  7:59           ` Auger Eric
2020-03-20  9:46             ` Marc Zyngier
2020-03-20 11:09               ` Auger Eric
2020-03-20 11:20                 ` Marc Zyngier
2020-03-20  3:53       ` Zenghui Yu
2020-03-20  9:01         ` Marc Zyngier
2020-03-23  8:11           ` Zenghui Yu
2020-03-23  8:25             ` Marc Zyngier
2020-03-23 12:40               ` Zenghui Yu
2020-03-04 20:33 ` [PATCH v5 21/23] KVM: arm64: GICv4.1: Reload VLPI configuration on distributor enable/disable Marc Zyngier
2020-03-18  3:17   ` Zenghui Yu
2020-03-19 12:18     ` Marc Zyngier
2020-03-04 20:33 ` [PATCH v5 22/23] KVM: arm64: GICv4.1: Allow non-trapping WFI when using HW SGIs Marc Zyngier
2020-03-20  4:23   ` Zenghui Yu
2020-03-20  8:12   ` Auger Eric
2020-03-04 20:33 ` [PATCH v5 23/23] KVM: arm64: GICv4.1: Expose HW-based SGIs in debugfs Marc Zyngier
2020-03-18  3:19   ` Zenghui Yu
2020-03-19 15:05   ` Auger Eric
2020-03-19 15:21     ` Marc Zyngier
2020-03-19 15:43       ` Auger Eric
2020-03-19 16:16         ` Marc Zyngier
2020-03-19 16:17           ` Auger Eric
2020-03-20  4:38       ` Zenghui Yu
2020-03-20  9:09         ` Marc Zyngier
2020-03-20 11:35           ` Zenghui Yu [this message]
2020-03-20 11:46             ` Marc Zyngier
2020-03-20 12:09               ` Zenghui Yu
2020-03-05  3:39 ` [PATCH v5 00/23] irqchip/gic-v4: GICv4.1 architecture support Zenghui Yu
2020-03-09  8:17 ` Zenghui Yu
2020-03-09  8:46   ` Marc Zyngier

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