From: Marc Zyngier <maz@kernel•org>
To: kvmarm@lists•linux.dev, linux-arm-kernel@lists•infradead.org,
kvm@vger•kernel.org
Cc: Steffen Eiden <seiden@linux•ibm.com>,
Joey Gouly <joey.gouly@arm•com>,
Suzuki K Poulose <suzuki.poulose@arm•com>,
Oliver Upton <oupton@kernel•org>,
Zenghui Yu <yuzenghui@huawei•com>
Subject: [PATCH 3/3] arm64: cpufeature: Expose ID_AA64ISAR2_EL1.ATS1A to KVM
Date: Tue, 2 Jun 2026 16:54:29 +0100 [thread overview]
Message-ID: <20260602155430.2088142-4-maz@kernel.org> (raw)
In-Reply-To: <20260602155430.2088142-1-maz@kernel.org>
KVM needs to know if the HW implements FEAT_ATS1A in order to correctly
sanitise HFGITR_EL2.ATS1E1A, which otherwise defaults to RES0 and
AT S1E1A traps are handled as UNDEF.
Solves this by exposing ID_AA64ISAR2_EL1.ATS1A to the rest of the kernel.
Fixes: ff987ffc0c18c ("KVM: arm64: nv: Add support for FEAT_ATS1A")
Signed-off-by: Marc Zyngier <maz@kernel•org>
---
arch/arm64/kernel/cpufeature.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 6d53bb15cf7bb..62b0d77217eeb 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -266,6 +266,7 @@ static const struct arm64_ftr_bits ftr_id_aa64isar1[] = {
};
static const struct arm64_ftr_bits ftr_id_aa64isar2[] = {
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR2_EL1_ATS1A_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64ISAR2_EL1_LUT_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64ISAR2_EL1_CSSC_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64ISAR2_EL1_RPRFM_SHIFT, 4, 0),
--
2.47.3
next prev parent reply other threads:[~2026-06-02 15:54 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-02 15:54 [PATCH 0/3] KVM: arm64: FEAT_{S1POE,ATS1A} support fixes Marc Zyngier
2026-06-02 15:54 ` [PATCH 1/3] KVM: arm64: Key CPTR_EL2.E0POE propagation on FEAT_S1POE Marc Zyngier
2026-06-02 15:54 ` [PATCH 2/3] KVM: arm64: Wire AT S1E1A in the system instruction handling table Marc Zyngier
2026-06-02 15:54 ` Marc Zyngier [this message]
2026-06-02 17:49 ` [PATCH 0/3] KVM: arm64: FEAT_{S1POE,ATS1A} support fixes Oliver Upton
2026-06-03 10:41 ` Joey Gouly
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