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From: Marc Zyngier <maz@kernel.org>
To: Fuad Tabba <tabba@google.com>
Cc: kvmarm@lists.linux.dev, oliver.upton@linux.dev,
	catalin.marinas@arm.com, james.morse@arm.com,
	suzuki.poulose@arm.com, yuzenghui@huawei.com, will@kernel.org
Subject: Re: [PATCH v1 0/5] Fix setting SVE and SME traps in (h)VHE
Date: Wed, 19 Jul 2023 16:20:33 +0100	[thread overview]
Message-ID: <86v8egszb2.wl-maz@kernel.org> (raw)
In-Reply-To: <20230719150639.1968034-1-tabba@google.com>

Hey Fuad,

Many thanks for looking into this, much appreciated. A passing comment
below.

On Wed, 19 Jul 2023 16:06:34 +0100,
Fuad Tabba <tabba@google.com> wrote:
> 
> The (re)setting and disabling of SVE/SME trap handling (mostly)
> done for the hVHE work [*] misses a couple of cases.
> 
> This patch series ensures that these traps are disabled on setup
> and reset. Moreover, it makes the code consistent in using
> CPACR_EL1 or CPTR_EL2, depending on the mode.

To provide context, this last point isn't really a correctness issue.
It only ensures that:

- we don't need to issue a synchronisation when alternating one or the
  other accessor,

- when running hVHE under NV, we don't trap unnecessarily on accessing
  CPTR_EL2, while CPACR_EL1 can be used directly without any trap.

I'll have a look at the actual patches shortly.

Thanks again,

	M.

-- 
Without deviation from the norm, progress is not possible.

  parent reply	other threads:[~2023-07-19 15:20 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-07-19 15:06 [PATCH v1 0/5] Fix setting SVE and SME traps in (h)VHE Fuad Tabba
2023-07-19 15:06 ` [PATCH v1 1/5] KVM: arm64: Use the appropriate feature trap register for SVE at EL2 setup Fuad Tabba
2023-07-19 15:06 ` [PATCH v1 2/5] KVM: arm64: Disable SME Traps for (h)VHE at setup Fuad Tabba
2023-07-19 17:34   ` Oliver Upton
2023-07-20  8:03     ` Fuad Tabba
2023-07-20  8:36       ` Fuad Tabba
2023-07-19 15:06 ` [PATCH v1 3/5] KVM: arm64: Use the appropriate feature trap register when activating traps Fuad Tabba
2023-07-19 17:48   ` Oliver Upton
2023-07-19 18:40     ` Fuad Tabba
2023-07-19 15:06 ` [PATCH v1 4/5] KVM: arm64: Fix resetting SVE trap values on reset for hVHE Fuad Tabba
2023-07-19 15:06 ` [PATCH v1 5/5] KVM: arm64: Fix resetting SME trap values on reset for (h)VHE Fuad Tabba
2023-07-19 15:20 ` Marc Zyngier [this message]
2023-07-20  8:42   ` [PATCH v1 0/5] Fix setting SVE and SME traps in (h)VHE Fuad Tabba

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