mirror-linux/arch/arm64/include/uapi
Marc Zyngier b7628c7973 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>
2025-04-11 13:08:23 +01:00
..
asm KVM: arm64: Allow userspace to limit the number of PMU counters for EL2 VMs 2025-04-11 13:08:23 +01:00