From: "Lorenzo Stoakes (ARM)" <ljs@kernel.org>
To: Mark Brown <broonie@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>,
Joey Gouly <joey.gouly@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Shuah Khan <shuah@kernel.org>, Oliver Upton <oupton@kernel.org>,
Fuad Tabba <fuad.tabba@linux.dev>,
Peter Maydell <peter.maydell@linaro.org>,
Leonardo Bras <leo.bras@arm.com>,
Wei-Lin Chang <weilin.chang@arm.com>,
Yao Yuan <yaoyuan@linux.alibaba.com>,
linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org,
kvmarm@lists.linux.dev, linux-kselftest@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v20 02/14] KVM: arm64: Fix FGT mapping for HFGITR_EL2.nGCSEPP
Date: Thu, 3 Sep 2026 17:23:38 +0100 [thread overview]
Message-ID: <apmcDT8YTjS6eXE0@gremlin> (raw)
In-Reply-To: <20260901-arm64-gcs-v20-2-f31750bdfadb@kernel.org>
On Tue, Sep 01, 2026 at 10:47:00PM +0100, Mark Brown wrote:
> The encoding to trap mapping currently maps a FGT on OP_GCSPOPX to
> HFGITR_EL2.nGCSEPP but as per DDI0601 2026-06 this FGT controls trapping
> of GCSPUSHX and GCSPOPCX, and not the separate GCSPOPX instruction.
> Update the mapping to reflect the architecture.
>
> Fixes: 863ac38984a82 ("KVM: arm64: Add missing HFGITR_EL2 FGT entries to nested virt")
> Reviewed-by: Leonardo Bras <leo.bras@arm.com>
> Signed-off-by: Mark Brown <broonie@kernel.org>
LGTM so:
Reviewed-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
> ---
> arch/arm64/kvm/emulate-nested.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm64/kvm/emulate-nested.c b/arch/arm64/kvm/emulate-nested.c
> index 625604019fb3..3806ff0920fe 100644
> --- a/arch/arm64/kvm/emulate-nested.c
> +++ b/arch/arm64/kvm/emulate-nested.c
> @@ -1445,7 +1445,7 @@ static const struct encoding_to_trap_config encoding_to_fgt[] __initconst = {
> SR_FGT(OP_AT_S1E1A, HFGITR, ATS1E1A, 1),
> SR_FGT(OP_COSP_RCTX, HFGITR, COSPRCTX, 1),
> SR_FGT(OP_GCSPUSHX, HFGITR, nGCSEPP, 0),
> - SR_FGT(OP_GCSPOPX, HFGITR, nGCSEPP, 0),
> + SR_FGT(OP_GCSPOPCX, HFGITR, nGCSEPP, 0),
Yikes, yeah I see from the doc I referenced in 1/14 that that's the wrong
instruction ([0]).
I guess this wasn't visible before in any case because 9/14 is required to
actually enable this in practice?
> SR_FGT(OP_GCSPUSHM, HFGITR, nGCSPUSHM_EL1, 0),
> SR_FGT(OP_BRB_IALL, HFGITR, nBRBIALL, 0),
> SR_FGT(OP_BRB_INJ, HFGITR, nBRBINJ, 0),
>
> --
> 2.47.3
>
>
[0]: https://support.arm.com/documentation/111107/2026-06/AArch64-Registers/HFGITR-EL2--Hypervisor-Fine-Grained-Instruction-Trap-Register
--
Cheers, Lorenzo
next prev parent reply other threads:[~2026-09-03 16:23 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-01 21:46 [PATCH v20 00/14] KVM: arm64: Provide guest support for GCS Mark Brown
2026-09-01 21:46 ` [PATCH v20 01/14] arm64/gcs: Ensure FGTs for EL1 GCS instructions are disabled Mark Brown
2026-09-03 16:10 ` Lorenzo Stoakes (ARM)
2026-09-01 21:47 ` [PATCH v20 02/14] KVM: arm64: Fix FGT mapping for HFGITR_EL2.nGCSEPP Mark Brown
2026-09-03 16:23 ` Lorenzo Stoakes (ARM) [this message]
2026-09-03 19:29 ` Mark Brown
2026-09-01 21:47 ` [PATCH v20 03/14] KVM: arm64: Manage GCS access and registers for guests Mark Brown
2026-09-02 16:44 ` Leonardo Bras
2026-09-03 20:52 ` Mark Brown
2026-09-03 18:13 ` Lorenzo Stoakes (ARM)
2026-09-03 20:41 ` Mark Brown
2026-09-01 21:47 ` [PATCH v20 04/14] KVM: arm64: Ensure GCS memory effects are visible Mark Brown
2026-09-02 16:30 ` Leonardo Bras
2026-09-01 21:47 ` [PATCH v20 05/14] KVM: arm64: Set PSTATE.EXLOCK when entering an exception Mark Brown
2026-09-03 14:25 ` Leonardo Bras
2026-09-03 16:20 ` Mark Brown
2026-09-03 16:40 ` Leonardo Bras
2026-09-01 21:47 ` [PATCH v20 06/14] KVM: arm64: Validate GCS exception lock when emulating ERET Mark Brown
2026-09-03 15:37 ` Leonardo Bras
2026-09-03 19:22 ` Mark Brown
2026-09-01 21:47 ` [PATCH v20 07/14] KVM: arm64: Forward GCS exceptions to nested guests Mark Brown
2026-09-01 21:47 ` [PATCH v20 08/14] KVM: arm64: Enforce EXLOCK for SPSR and ELR Mark Brown
2026-09-01 21:47 ` [PATCH v20 09/14] KVM: arm64: Allow GCS to be enabled for guests Mark Brown
2026-09-01 21:47 ` [PATCH v20 10/14] KVM: selftests: arm64: Add GCS registers to get-reg-list Mark Brown
2026-09-01 21:47 ` [PATCH v20 11/14] KVM: selftests: arm64: Add GCS to set_id_regs Mark Brown
2026-09-01 21:47 ` [PATCH v20 12/14] KVM: selftests: arm64: Only restore SPSR_EL1 and ELR_EL1 if they change Mark Brown
2026-09-01 21:47 ` [PATCH v20 13/14] tools: Synchronise the kernel esr.h Mark Brown
2026-09-01 21:47 ` [PATCH v20 14/14] KVM: selftests: arm64: Add GCS EXLOCK exception emulation test Mark Brown
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