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
next prev 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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20250929160458.3351788-14-maz@kernel.org \
--to=maz@kernel.org \
--cc=joey.gouly@arm.com \
--cc=kvm@vger.kernel.org \
--cc=kvmarm@lists.linux.dev \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=oliver.upton@linux.dev \
--cc=suzuki.poulose@arm.com \
--cc=yuzenghui@huawei.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).