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From: Marc Zyngier <maz@kernel.org>
To: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org,
	kvm@vger.kernel.org
Cc: Joey Gouly <joey.gouly@arm.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Oliver Upton <oliver.upton@linux.dev>,
	Zenghui Yu <yuzenghui@huawei.com>
Subject: [PATCH 13/13] KVM: arm64: selftest: Fix misleading comment about virtual timer encoding
Date: Mon, 29 Sep 2025 17:04:57 +0100	[thread overview]
Message-ID: <20250929160458.3351788-14-maz@kernel.org> (raw)
In-Reply-To: <20250929160458.3351788-1-maz@kernel.org>

The userspace-visible encoding for CNTV_CVAL_EL0 and CNTVCNT_EL0
have been swapped for as long as usersapce has had access to the
registers. This is documented in arch/arm64/include/uapi/asm/kvm.h.

Despite that, the get_reg_list test has unhelpful comments indicating
the wrong register for the encoding.

Replace this with definitions exposed in the include file, and
a comment explaining again the brokenness.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 .../testing/selftests/kvm/arm64/get-reg-list.c  | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/kvm/arm64/get-reg-list.c b/tools/testing/selftests/kvm/arm64/get-reg-list.c
index 7a238755f0728..c9b84eeaab6b2 100644
--- a/tools/testing/selftests/kvm/arm64/get-reg-list.c
+++ b/tools/testing/selftests/kvm/arm64/get-reg-list.c
@@ -348,9 +348,20 @@ static __u64 base_regs[] = {
 	KVM_REG_ARM_FW_FEAT_BMAP_REG(1),	/* KVM_REG_ARM_STD_HYP_BMAP */
 	KVM_REG_ARM_FW_FEAT_BMAP_REG(2),	/* KVM_REG_ARM_VENDOR_HYP_BMAP */
 	KVM_REG_ARM_FW_FEAT_BMAP_REG(3),	/* KVM_REG_ARM_VENDOR_HYP_BMAP_2 */
-	ARM64_SYS_REG(3, 3, 14, 3, 1),	/* CNTV_CTL_EL0 */
-	ARM64_SYS_REG(3, 3, 14, 3, 2),	/* CNTV_CVAL_EL0 */
-	ARM64_SYS_REG(3, 3, 14, 0, 2),
+
+	/*
+	 * EL0 Virtual Timer Registers
+	 *
+	 * WARNING:
+	 * KVM_REG_ARM_TIMER_CVAL and KVM_REG_ARM_TIMER_CNT are not defined
+	 * with the appropriate register encodings.  Their values have been
+	 * accidentally swapped.  As this is set API, the definitions here
+	 * must be used, rather than ones derived from the encodings.
+	 */
+	KVM_ARM64_SYS_REG(SYS_CNTV_CTL_EL0),
+	KVM_REG_ARM_TIMER_CVAL,
+	KVM_REG_ARM_TIMER_CNT,
+
 	ARM64_SYS_REG(3, 0, 0, 0, 0),	/* MIDR_EL1 */
 	ARM64_SYS_REG(3, 0, 0, 0, 6),	/* REVIDR_EL1 */
 	ARM64_SYS_REG(3, 1, 0, 0, 1),	/* CLIDR_EL1 */
-- 
2.47.3



  parent reply	other threads:[~2025-09-29 16:05 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-09-29 16:04 [PATCH 00/13] KVM: arm64: De-specialise the timer UAPI Marc Zyngier
2025-09-29 16:04 ` [PATCH 01/13] KVM: arm64: Hide CNTHV_*_EL2 from userspace for nVHE guests Marc Zyngier
2025-09-30  0:35   ` Oliver Upton
2025-09-30  7:44     ` Marc Zyngier
2025-09-29 16:04 ` [PATCH 02/13] KVM: arm64: Introduce timer_context_to_vcpu() helper Marc Zyngier
2025-09-29 16:04 ` [PATCH 03/13] KVM: arm64: Replace timer context vcpu pointer with timer_id Marc Zyngier
2025-09-30 10:13   ` Joey Gouly
2025-09-29 16:04 ` [PATCH 04/13] KVM: arm64: Make timer_set_offset() generally accessible Marc Zyngier
2025-09-29 16:04 ` [PATCH 05/13] KVM: arm64: Add timer UAPI workaround to sysreg infrastructure Marc Zyngier
2025-09-30  0:41   ` Oliver Upton
2025-09-30  7:48     ` Marc Zyngier
2025-09-29 16:04 ` [PATCH 06/13] KVM: arm64: Move CNT*_CTL_EL0 userspace accessors to generic infrastructure Marc Zyngier
2025-09-29 16:04 ` [PATCH 07/13] KVM: arm64: Move CNT*_CVAL_EL0 " Marc Zyngier
2025-09-29 16:04 ` [PATCH 08/13] KVM: arm64: Move CNT*CT_EL0 " Marc Zyngier
2025-09-30 10:45   ` Joey Gouly
2025-09-30 12:05     ` Marc Zyngier
2025-09-30 12:41       ` Joey Gouly
2025-09-29 16:04 ` [PATCH 09/13] KVM: arm64: Fix WFxT handling of nested virt Marc Zyngier
2025-09-29 16:04 ` [PATCH 10/13] KVM: arm64: Kill leftovers of ad-hoc timer userspace access Marc Zyngier
2025-09-29 16:04 ` [PATCH 11/13] KVM: arm64: selftests: Make dependencies on VHE-specific registers explicit Marc Zyngier
2025-09-29 16:04 ` [PATCH 12/13] KVM: arm64: selftests: Add an E2H=0-specific configuration to get_reg_list Marc Zyngier
2025-09-29 16:04 ` Marc Zyngier [this message]
2025-10-13 16:55 ` [PATCH 00/13] KVM: arm64: De-specialise the timer UAPI Marc Zyngier

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