From: Sasha Levin <sashal@kernel.org>
To: stable@vger.kernel.org
Cc: Mark Brown <broonie@kernel.org>, Sasha Levin <sashal@kernel.org>
Subject: Re: [PATCH 6.12 v2 4/8] KVM: arm64: Remove VHE host restore of CPACR_EL1.ZEN
Date: Fri, 21 Mar 2025 13:26:02 -0400 [thread overview]
Message-ID: <20250321111017-2c5cd1053133bcc8@stable.kernel.org> (raw)
In-Reply-To: <20250321-stable-sve-6-12-v2-4-417ca2278d18@kernel.org>
[ Sasha's backport helper bot ]
Hi,
✅ All tests passed successfully. No issues detected.
No action required from the submitter.
The upstream commit SHA1 provided is correct: 459f059be702056d91537b99a129994aa6ccdd35
WARNING: Author mismatch between patch and upstream commit:
Backport author: Mark Brown<broonie@kernel.org>
Commit author: Mark Rutland<mark.rutland@arm.com>
Status in newer kernel trees:
6.13.y | Present (different SHA1: 73882a98030a)
Note: The patch differs from the upstream commit:
---
1: 459f059be7020 ! 1: 416ce5863c885 KVM: arm64: Remove VHE host restore of CPACR_EL1.ZEN
@@ Metadata
## Commit message ##
KVM: arm64: Remove VHE host restore of CPACR_EL1.ZEN
+ [ Upstream commit 459f059be702056d91537b99a129994aa6ccdd35 ]
+
When KVM is in VHE mode, the host kernel tries to save and restore the
configuration of CPACR_EL1.ZEN (i.e. CPTR_EL2.ZEN when HCR_EL2.E2H=1)
across kvm_arch_vcpu_load_fp() and kvm_arch_vcpu_put_fp(), since the
@@ Commit message
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20250210195226.1215254-4-mark.rutland@arm.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
+ [Rework for refactoring of where the flags are stored -- broonie]
+ Signed-off-by: Mark Brown <broonie@kernel.org>
## arch/arm64/include/asm/kvm_host.h ##
-@@ arch/arm64/include/asm/kvm_host.h: struct cpu_sve_state {
- struct kvm_host_data {
- #define KVM_HOST_DATA_FLAG_HAS_SPE 0
- #define KVM_HOST_DATA_FLAG_HAS_TRBE 1
--#define KVM_HOST_DATA_FLAG_HOST_SVE_ENABLED 2
- #define KVM_HOST_DATA_FLAG_HOST_SME_ENABLED 3
- #define KVM_HOST_DATA_FLAG_TRBE_ENABLED 4
- #define KVM_HOST_DATA_FLAG_EL1_TRACING_CONFIGURED 5
+@@ arch/arm64/include/asm/kvm_host.h: struct kvm_vcpu_arch {
+ /* Save TRBE context if active */
+ #define DEBUG_STATE_SAVE_TRBE __vcpu_single_flag(iflags, BIT(6))
+
+-/* SVE enabled for host EL0 */
+-#define HOST_SVE_ENABLED __vcpu_single_flag(sflags, BIT(0))
+ /* SME enabled for EL0 */
+ #define HOST_SME_ENABLED __vcpu_single_flag(sflags, BIT(1))
+ /* Physical CPU not in supported_cpus */
## arch/arm64/kvm/fpsimd.c ##
@@ arch/arm64/kvm/fpsimd.c: void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu)
fpsimd_save_and_flush_cpu_state();
*host_data_ptr(fp_owner) = FP_STATE_FREE;
-- host_data_clear_flag(HOST_SVE_ENABLED);
+- vcpu_clear_flag(vcpu, HOST_SVE_ENABLED);
- if (read_sysreg(cpacr_el1) & CPACR_EL1_ZEN_EL0EN)
-- host_data_set_flag(HOST_SVE_ENABLED);
+- vcpu_set_flag(vcpu, HOST_SVE_ENABLED);
-
if (system_supports_sme()) {
- host_data_clear_flag(HOST_SME_ENABLED);
+ vcpu_clear_flag(vcpu, HOST_SME_ENABLED);
if (read_sysreg(cpacr_el1) & CPACR_EL1_SMEN_EL0EN)
@@ arch/arm64/kvm/fpsimd.c: void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu)
* when needed.
@@ arch/arm64/kvm/fpsimd.c: void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu)
- * for EL0. To avoid spurious traps, restore the trap state
- * seen by kvm_arch_vcpu_load_fp():
- */
-- if (host_data_test_flag(HOST_SVE_ENABLED))
+- if (vcpu_get_flag(vcpu, HOST_SVE_ENABLED))
- sysreg_clear_set(CPACR_EL1, 0, CPACR_EL1_ZEN_EL0EN);
- else
- sysreg_clear_set(CPACR_EL1, CPACR_EL1_ZEN_EL0EN, 0);
---
Results of testing on various branches:
| Branch | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.13.y | Success | Success |
next prev parent reply other threads:[~2025-03-21 17:26 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-03-21 0:12 [PATCH 6.12 v2 0/8] KVM: arm64: Backport of SVE fixes to v6.12 Mark Brown
2025-03-21 0:12 ` [PATCH 6.12 v2 1/8] KVM: arm64: Calculate cptr_el2 traps on activating traps Mark Brown
2025-03-21 17:28 ` Sasha Levin
2025-03-21 0:12 ` [PATCH 6.12 v2 2/8] KVM: arm64: Unconditionally save+flush host FPSIMD/SVE/SME state Mark Brown
2025-03-21 17:27 ` Sasha Levin
2025-03-21 0:12 ` [PATCH 6.12 v2 3/8] KVM: arm64: Remove host FPSIMD saving for non-protected KVM Mark Brown
2025-03-21 0:15 ` kernel test robot
2025-03-21 0:21 ` Mark Brown
2025-03-21 17:26 ` Sasha Levin
2025-03-21 0:13 ` [PATCH 6.12 v2 4/8] KVM: arm64: Remove VHE host restore of CPACR_EL1.ZEN Mark Brown
2025-03-21 17:26 ` Sasha Levin [this message]
2025-03-21 0:13 ` [PATCH 6.12 v2 5/8] KVM: arm64: Remove VHE host restore of CPACR_EL1.SMEN Mark Brown
2025-03-21 17:29 ` Sasha Levin
2025-03-21 0:13 ` [PATCH 6.12 v2 6/8] KVM: arm64: Refactor exit handlers Mark Brown
2025-03-21 17:25 ` Sasha Levin
2025-03-21 0:13 ` [PATCH 6.12 v2 7/8] KVM: arm64: Mark some header functions as inline Mark Brown
2025-03-21 17:27 ` Sasha Levin
2025-03-21 0:13 ` [PATCH 6.12 v2 8/8] KVM: arm64: Eagerly switch ZCR_EL{1,2} Mark Brown
2025-03-21 17:29 ` Sasha Levin
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