diff options
| author | Marc Zyngier <maz@kernel.org> | 2025-04-09 11:53:15 +0100 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2025-04-11 13:08:23 +0100 |
| commit | b7628c7973765c856866b3047c9002ae0825add6 (patch) | |
| tree | 8da02e190846d06fd47f90cb1d1d068b8af2c41e /arch/arm64/include/uapi | |
| parent | 022435334393d56f4d6bc398cf16430067807b0a (diff) | |
KVM: arm64: Allow userspace to limit the number of PMU counters for EL2 VMs
As long as we had purely EL1 VMs, we could easily update the number
of guest-visible counters by letting userspace write to PMCR_EL0.N.
With VMs started at EL2, PMCR_EL1.N only reflects MDCR_EL2.HPMN,
and we don't have a good way to limit it.
For this purpose, introduce a new PMUv3 attribute that allows
limiting the maximum number of counters. This requires the explicit
selection of a PMU.
Suggested-by: Oliver Upton <oliver.upton@linux.dev>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Diffstat (limited to 'arch/arm64/include/uapi')
| -rw-r--r-- | arch/arm64/include/uapi/asm/kvm.h | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h index af9d9acaf997..ed5f3892674c 100644 --- a/arch/arm64/include/uapi/asm/kvm.h +++ b/arch/arm64/include/uapi/asm/kvm.h @@ -431,10 +431,11 @@ enum { /* Device Control API on vcpu fd */ #define KVM_ARM_VCPU_PMU_V3_CTRL 0 -#define KVM_ARM_VCPU_PMU_V3_IRQ 0 -#define KVM_ARM_VCPU_PMU_V3_INIT 1 -#define KVM_ARM_VCPU_PMU_V3_FILTER 2 -#define KVM_ARM_VCPU_PMU_V3_SET_PMU 3 +#define KVM_ARM_VCPU_PMU_V3_IRQ 0 +#define KVM_ARM_VCPU_PMU_V3_INIT 1 +#define KVM_ARM_VCPU_PMU_V3_FILTER 2 +#define KVM_ARM_VCPU_PMU_V3_SET_PMU 3 +#define KVM_ARM_VCPU_PMU_V3_SET_NR_COUNTERS 4 #define KVM_ARM_VCPU_TIMER_CTRL 1 #define KVM_ARM_VCPU_TIMER_IRQ_VTIMER 0 #define KVM_ARM_VCPU_TIMER_IRQ_PTIMER 1 |