FAILED: patch "[PATCH] KVM: arm64: Ignore PMCNTENSET_EL0 while checking for overflow" failed to apply to 4.19-stable tree

PATCH In review [email protected] 3 participants 9 messages Dec 2, 2024 – Dec 13, 2024

Subsystems (3)

Stable branch arm64 KVM arm64

lore

Share & tools

lore

[email protected]

author maintainer

2024-12-02 15:05 UTC #0 lore raw

The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.19.y
git checkout FETCH_HEAD
git cherry-pick -x 54bbee190d42166209185d89070c58a343bf514b
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2024120223-stunner-letter-9d09@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 54bbee190d42166209185d89070c58a343bf514b Mon Sep 17 00:00:00 2001
From: Raghavendra Rao Ananta <[email protected]>
Date: Tue, 19 Nov 2024 16:52:29 -0800
Subject: [PATCH] KVM: arm64: Ignore PMCNTENSET_EL0 while checking for overflow
status

DDI0487K.a D13.3.1 describes the PMU overflow condition, which evaluates to true if any counter's global enable (PMCR_EL0.E), overflow flag (PMOVSSET_EL0[n]), and interrupt enable (PMINTENSET_EL1[n]) are all 1. Of note, this does not require a counter to be enabled
(i.e. PMCNTENSET_EL0[n] = 1) to generate an overflow.

Align kvm_pmu_overflow_status() with the reality of the architecture and stop using PMCNTENSET_EL0 as part of the overflow condition. The bug was discovered while running an SBSA PMU test [*], which only sets PMCR.E, PMOVSSET<0>, PMINTENSET<0>, and expects an overflow interrupt.

Cc [email protected]

Fixes 76d883c4e640 ("arm64: KVM: Add access handler for PMOVSSET and PMOVSCLR register")

Link https://github.com/ARM-software/sbsa-acs/blob/master/test_pool/pmu/operating_system/test_pmu001.c

Signed-off-by Raghavendra Rao Ananta <[email protected]>

[ oliver: massaged changelog ]

Reviewed-by Marc Zyngier <[email protected]>

Link https://lore.kernel.org/r/[email protected] open here

Signed-off-by Oliver Upton <[email protected]>

arch/arm64/kvm/pmu-emul.c +0 -1

index 8ad62284fa23..3855cc9d0ca5 100644
@@ -381,7 +381,6 @@ static u64 kvm_pmu_overflow_status(struct kvm_vcpu *vcpu)
 
 	if ((kvm_vcpu_read_pmcr(vcpu) & ARMV8_PMU_PMCR_E)) {
 		reg = __vcpu_sys_reg(vcpu, PMOVSSET_EL0);
-		reg &= __vcpu_sys_reg(vcpu, PMCNTENSET_EL0);
 		reg &= __vcpu_sys_reg(vcpu, PMINTENSET_EL1);
 	}

Raghavendra Rao Ananta

2024-12-03 19:02 UTC #1 lore raw

PATCH 1/1 KVM: arm64: Ignore PMCNTENSET_EL0 while checking for overflow status

commit 54bbee190d42166209185d89070c58a343bf514b upstream.

Cc [email protected]

Fixes 76d883c4e640 ("arm64: KVM: Add access handler for PMOVSSET and PMOVSCLR register")

Link https://github.com/ARM-software/sbsa-acs/blob/master/test_pool/pmu/operating_system/test_pmu001.c

Signed-off-by Raghavendra Rao Ananta <[email protected]>

[ oliver: massaged changelog ]

Reviewed-by Marc Zyngier <[email protected]>

Link https://lore.kernel.org/r/[email protected] open here

Signed-off-by Oliver Upton <[email protected]>

---
 virt/kvm/arm/pmu.c | 1 -
 1 file changed, 1 deletion(-)

virt/kvm/arm/pmu.c +0 -1

index 6d52fd50c1ff..b92b1d406374 100644
@@ -195,7 +195,6 @@ static u64 kvm_pmu_overflow_status(struct kvm_vcpu *vcpu)
 
 	if ((__vcpu_sys_reg(vcpu, PMCR_EL0) & ARMV8_PMU_PMCR_E)) {
 		reg = __vcpu_sys_reg(vcpu, PMOVSSET_EL0);
-		reg &= __vcpu_sys_reg(vcpu, PMCNTENSET_EL0);
 		reg &= __vcpu_sys_reg(vcpu, PMINTENSET_EL1);
 		reg &= kvm_pmu_valid_counter_mask(vcpu);
 	}

Signature · 1 line

2.47.0.338.g60cca15819-goog

Sasha Levin

maintainer

2024-12-04 00:45 UTC #2 lore raw

Re: [PATCH] KVM: arm64: Ignore PMCNTENSET_EL0 while checking for overflow status

[ Sasha's backport helper bot ]

Hi,

The upstream commit SHA1 provided is correct: 54bbee190d42166209185d89070c58a343bf514b

Status in newer kernel trees:
6.12.y | Present (different SHA1: 2a68705a5469)

Note: The patch differs from the upstream commit:
---
Failed to apply patch cleanly, falling back to interdiff...
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.12.y       |  Failed     |  N/A       |
| stable/linux-6.11.y       |  Failed     |  N/A       |
| stable/linux-6.6.y        |  Failed     |  N/A       |
| stable/linux-6.1.y        |  Failed     |  N/A       |
| stable/linux-5.15.y       |  Failed     |  N/A       |
| stable/linux-5.10.y       |  Failed     |  N/A       |
| stable/linux-5.4.y        |  Success    |  Success   |
| stable/linux-4.19.y       |  Success    |  Success   |

Greg KH

author maintainer

2024-12-12 07:58 UTC #3 lore raw

Re: [PATCH] KVM: arm64: Ignore PMCNTENSET_EL0 while checking for overflow status

In reply to Raghavendra Rao Ananta

Quoted 21 lines · Raghavendra Rao Ananta

commit 54bbee190d42166209185d89070c58a343bf514b upstream.
DDI0487K.a D13.3.1 describes the PMU overflow condition, which evaluates to true if any counter's global enable (PMCR_EL0.E), overflow flag (PMOVSSET_EL0[n]), and interrupt enable (PMINTENSET_EL1[n]) are all 1. Of note, this does not require a counter to be enabled
(i.e. PMCNTENSET_EL0[n] = 1) to generate an overflow.
Align kvm_pmu_overflow_status() with the reality of the architecture and stop using PMCNTENSET_EL0 as part of the overflow condition. The bug was discovered while running an SBSA PMU test [*], which only sets PMCR.E, PMOVSSET<0>, PMINTENSET<0>, and expects an overflow interrupt.
Cc [email protected]
Fixes 76d883c4e640 ("arm64: KVM: Add access handler for PMOVSSET and PMOVSCLR register")
Link https://github.com/ARM-software/sbsa-acs/blob/master/test_pool/pmu/operating_system/test_pmu001.c
Signed-off-by Raghavendra Rao Ananta <[email protected]>
[ oliver: massaged changelog ]
Reviewed-by Marc Zyngier <[email protected]>
Link https://lore.kernel.org/r/[email protected] open here
Signed-off-by Oliver Upton <[email protected]>

Quoted 3 lines

---
 virt/kvm/arm/pmu.c | 1 -
 1 file changed, 1 deletion(-)

What branch is this patch for?

thanks,

greg k-h

Greg KH

author maintainer

2024-12-12 08:27 UTC #4 lore raw

Re: [PATCH] KVM: arm64: Ignore PMCNTENSET_EL0 while checking for overflow status

In reply to Raghavendra Rao Ananta

Quoted 21 lines · Raghavendra Rao Ananta

commit 54bbee190d42166209185d89070c58a343bf514b upstream.
DDI0487K.a D13.3.1 describes the PMU overflow condition, which evaluates to true if any counter's global enable (PMCR_EL0.E), overflow flag (PMOVSSET_EL0[n]), and interrupt enable (PMINTENSET_EL1[n]) are all 1. Of note, this does not require a counter to be enabled
(i.e. PMCNTENSET_EL0[n] = 1) to generate an overflow.
Align kvm_pmu_overflow_status() with the reality of the architecture and stop using PMCNTENSET_EL0 as part of the overflow condition. The bug was discovered while running an SBSA PMU test [*], which only sets PMCR.E, PMOVSSET<0>, PMINTENSET<0>, and expects an overflow interrupt.
Cc [email protected]
Fixes 76d883c4e640 ("arm64: KVM: Add access handler for PMOVSSET and PMOVSCLR register")
Link https://github.com/ARM-software/sbsa-acs/blob/master/test_pool/pmu/operating_system/test_pmu001.c
Signed-off-by Raghavendra Rao Ananta <[email protected]>
[ oliver: massaged changelog ]
Reviewed-by Marc Zyngier <[email protected]>
Link https://lore.kernel.org/r/[email protected] open here
Signed-off-by Oliver Upton <[email protected]>

Quoted 3 lines

---
 virt/kvm/arm/pmu.c | 1 -
 1 file changed, 1 deletion(-)

What kernel branch(es) is this backport for?

Raghavendra Rao Ananta

2024-12-12 17:41 UTC #5 lore raw

Re: [PATCH] KVM: arm64: Ignore PMCNTENSET_EL0 while checking for overflow status

Hi Greg,

This is an adjustment of the original upstream patch aimed towards the 4.19.y stable branch.

Thank you.
Raghavendra

Quoted 28 lines · Greg KH

Quoted 21 lines · Raghavendra Rao Ananta
commit 54bbee190d42166209185d89070c58a343bf514b upstream.
DDI0487K.a D13.3.1 describes the PMU overflow condition, which evaluates to true if any counter's global enable (PMCR_EL0.E), overflow flag (PMOVSSET_EL0[n]), and interrupt enable (PMINTENSET_EL1[n]) are all 1. Of note, this does not require a counter to be enabled
(i.e. PMCNTENSET_EL0[n] = 1) to generate an overflow.
Align kvm_pmu_overflow_status() with the reality of the architecture and stop using PMCNTENSET_EL0 as part of the overflow condition. The bug was discovered while running an SBSA PMU test [*], which only sets PMCR.E, PMOVSSET<0>, PMINTENSET<0>, and expects an overflow interrupt.
Cc [email protected]
Fixes 76d883c4e640 ("arm64: KVM: Add access handler for PMOVSSET and PMOVSCLR register")
Link https://github.com/ARM-software/sbsa-acs/blob/master/test_pool/pmu/operating_system/test_pmu001.c
Signed-off-by Raghavendra Rao Ananta <[email protected]>
[ oliver: massaged changelog ]
Reviewed-by Marc Zyngier <[email protected]>
Link https://lore.kernel.org/r/[email protected] open here
Signed-off-by Oliver Upton <[email protected]>
Quoted 3 lines
---
 virt/kvm/arm/pmu.c | 1 -
 1 file changed, 1 deletion(-)
What kernel branch(es) is this backport for?

Greg KH

author maintainer

2024-12-12 18:07 UTC #6 lore raw

Re: [PATCH] KVM: arm64: Ignore PMCNTENSET_EL0 while checking for overflow status

Quoted 4 lines · Raghavendra Rao Ananta

Hi Greg,
This is an adjustment of the original upstream patch aimed towards the 4.19.y stable branch.

4.19.y is end-of-life, so there's nothing we can do there. But what about 5.4.y? If it matters there, please resend it in a format we can apply it in for that tree.

thanks,

greg k-h

Raghavendra Rao Ananta

2024-12-12 18:52 UTC #7 lore raw

Re: [PATCH] KVM: arm64: Ignore PMCNTENSET_EL0 while checking for overflow status

Quoted 10 lines · Greg KH

Quoted 4 lines · Raghavendra Rao Ananta
Hi Greg,
This is an adjustment of the original upstream patch aimed towards the 4.19.y stable branch.
4.19.y is end-of-life, so there's nothing we can do there. But what about 5.4.y? If it matters there, please resend it in a format we can apply it in for that tree.

The version of the patch from this thread applies to 5.4.y as well. Do you want me to resend it or will you be able to pick this up?

Thank you.
Raghavendra

Raghavendra

Greg KH

author maintainer

2024-12-13 07:23 UTC #8 lore raw

Re: [PATCH] KVM: arm64: Ignore PMCNTENSET_EL0 while checking for overflow status

Quoted 8 lines · Raghavendra Rao Ananta

Quoted 7 lines · Greg KH
Quoted 4 lines · Raghavendra Rao Ananta
Hi Greg,
This is an adjustment of the original upstream patch aimed towards the 4.19.y stable branch.

Quoted 6 lines

Quoted 3 lines
4.19.y is end-of-life, so there's nothing we can do there. But what about 5.4.y? If it matters there, please resend it in a format we can apply it in for that tree.
The version of the patch from this thread applies to 5.4.y as well. Do you want me to resend it or will you be able to pick this up?

Please resend it.

thanks,

greg k-h