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From: Mark Brown <broonie@kernel.org>
To: Catalin Marinas <catalin.marinas@arm.com>,
	 Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>,
	 Oliver Upton <oliver.upton@linux.dev>,
	Joey Gouly <joey.gouly@arm.com>,
	 Suzuki K Poulose <suzuki.poulose@arm.com>,
	Shuah Khan <shuah@kernel.org>
Cc: 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, Mark Brown <broonie@kernel.org>
Subject: [PATCH v16 1/6] arm64/gcs: Ensure FGTs for EL1 GCS instructions are disabled
Date: Fri, 12 Sep 2025 10:25:27 +0100	[thread overview]
Message-ID: <20250912-arm64-gcs-v16-1-6435e5ec37db@kernel.org> (raw)
In-Reply-To: <20250912-arm64-gcs-v16-0-6435e5ec37db@kernel.org>

The initial EL2 setup for GCS did not include disabling of EL1 usage of
GCS instructions, also disable these traps.  This is the first disabling
of instruction traps, use x2 to store the value to be written.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 arch/arm64/include/asm/el2_setup.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/arm64/include/asm/el2_setup.h b/arch/arm64/include/asm/el2_setup.h
index 46033027510c..d174f405c44a 100644
--- a/arch/arm64/include/asm/el2_setup.h
+++ b/arch/arm64/include/asm/el2_setup.h
@@ -353,6 +353,11 @@
 	orr	x0, x0, #HFGRTR_EL2_nGCS_EL1_MASK
 	orr	x0, x0, #HFGRTR_EL2_nGCS_EL0_MASK
 
+	/* Disable traps of GCS instructions at EL1 */
+	orr	x2, x2, #HFGITR_EL2_nGCSEPP_MASK
+	orr	x2, x2, #HFGITR_EL2_nGCSSTR_EL1_MASK
+	orr	x2, x2, #HFGITR_EL2_nGCSPUSHM_EL1_MASK
+
 .Lskip_gce_fgt_\@:
 
 .Lset_fgt_\@:

-- 
2.47.2


  reply	other threads:[~2025-09-12 11:22 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-09-12  9:25 [PATCH v16 0/6] KVM: arm64: Provide guest support for GCS Mark Brown
2025-09-12  9:25 ` Mark Brown [this message]
2025-09-12  9:25 ` [PATCH v16 2/6] KVM: arm64: Manage GCS access and registers for guests Mark Brown
2025-09-12 11:59   ` Marc Zyngier
2025-09-12 16:33     ` Mark Brown
2025-09-12 17:14       ` Mark Brown
2025-09-12 21:30       ` Marc Zyngier
2025-09-12  9:25 ` [PATCH v16 3/6] KVM: arm64: Set PSTATE.EXLOCK when entering an exception Mark Brown
2025-09-12  9:25 ` [PATCH v16 4/6] KVM: arm64: Validate GCS exception lock when emulating ERET Mark Brown
2025-09-12 12:06   ` Marc Zyngier
2025-09-12  9:25 ` [PATCH v16 5/6] KVM: arm64: Allow GCS to be enabled for guests Mark Brown
2025-09-12 21:44   ` Marc Zyngier
2025-09-12  9:25 ` [PATCH v16 6/6] KVM: selftests: arm64: Add GCS registers to get-reg-list Mark Brown
2025-09-12 21:46   ` Marc Zyngier

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