From: Oliver Upton <oliver.upton@linux.dev>
To: Fuad Tabba <tabba@google.com>
Cc: kvmarm@lists.linux.dev, maz@kernel.org, catalin.marinas@arm.com,
james.morse@arm.com, suzuki.poulose@arm.com,
yuzenghui@huawei.com, will@kernel.org
Subject: Re: [PATCH v1 2/5] KVM: arm64: Disable SME Traps for (h)VHE at setup
Date: Wed, 19 Jul 2023 17:34:12 +0000 [thread overview]
Message-ID: <ZLgelCk3+W3YOpVx@linux.dev> (raw)
In-Reply-To: <20230719150639.1968034-3-tabba@google.com>
On Wed, Jul 19, 2023 at 04:06:36PM +0100, Fuad Tabba wrote:
> Ensure that SME traps are disabled for (h)VHE when setting up
> EL2, as they are for nVHE.
>
> Signed-off-by: Fuad Tabba <tabba@google.com>
> ---
> arch/arm64/include/asm/el2_setup.h | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/arch/arm64/include/asm/el2_setup.h b/arch/arm64/include/asm/el2_setup.h
> index c106b31d776c..7001b6db3ccc 100644
> --- a/arch/arm64/include/asm/el2_setup.h
> +++ b/arch/arm64/include/asm/el2_setup.h
> @@ -292,9 +292,21 @@
> check_override id_aa64pfr1, ID_AA64PFR1_EL1_SME_SHIFT, .Linit_sme_\@, .Lskip_sme_\@, x1, x2
>
> .Linit_sme_\@: /* SME register access and priority mapping */
> + mrs x1, hcr_el2
> + and x1, x1, #HCR_E2H
> + cbz x1, .Lcptr_nvhe_sme_\@
Hmm.. Our test for hVHE is repeated enough times, it might make sense
for readability to wrap it up in a macro:
.macro check_hvhe pass, fail, tmp
mrs \tmp, hcr_el2
and \tmp, \tmp, #HCR_E2H
cbnz \tmp, \pass
b \fail
.endm
So long as we tolerate the additional word of bloat for the extra branch
:)
> + // (h)VHE case
> + mrs x0, cpacr_el1 // Disable SME traps
> + orr x0, x0, #(CPACR_EL1_SMEN_EL0EN | CPACR_EL1_SMEN_EL1EN)
> + msr cpacr_el1, x0
> + b .Lskip_set_cptr_sme_\@
> +
> +.Lcptr_nvhe_sme_\@: // nVHE case
> mrs x0, cptr_el2 // Disable SME traps
> bic x0, x0, #CPTR_EL2_TSM
> msr cptr_el2, x0
> +.Lskip_set_cptr_sme_\@:
> isb
>
> mrs x1, sctlr_el2
> --
> 2.41.0.255.g8b1d071c50-goog
>
--
Thanks,
Oliver
next prev parent reply other threads:[~2023-07-19 17:34 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 [this message]
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 ` [PATCH v1 0/5] Fix setting SVE and SME traps in (h)VHE Marc Zyngier
2023-07-20 8:42 ` Fuad Tabba
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