Re: [PATCH v10 32/43] arm64: RME: Enable PMU support with a realm guest

[Gavin Shan <gshan@redhat.com>]

On 8/21/25 12:55 AM, Steven Price wrote:
> Use the PMU registers from the RmiRecExit structure to identify when an
> overflow interrupt is due and inject it into the guest. Also hook up the
> configuration option for enabling the PMU within the guest.
> 
> When entering a realm guest with a PMU interrupt pending, it is
> necessary to disable the physical interrupt. Otherwise when the RMM
> restores the PMU state the physical interrupt will trigger causing an
> immediate exit back to the host. The guest is expected to acknowledge
> the interrupt causing a host exit (to update the GIC state) which gives
> the opportunity to re-enable the physical interrupt before the next PMU
> event.
> 
> Number of PMU counters is configured by the VMM by writing to PMCR.N.
> 
> Signed-off-by: Steven Price <steven.price@arm.com>
> ---
> Changes since v2:
>   * Add a macro kvm_pmu_get_irq_level() to avoid compile issues when PMU
>     support is disabled.
> ---
>   arch/arm64/kvm/arm.c      | 11 +++++++++++
>   arch/arm64/kvm/guest.c    |  7 +++++++
>   arch/arm64/kvm/pmu-emul.c |  3 +++
>   arch/arm64/kvm/rme.c      |  8 ++++++++
>   arch/arm64/kvm/sys_regs.c |  5 +++--
>   include/kvm/arm_pmu.h     |  4 ++++
>   6 files changed, 36 insertions(+), 2 deletions(-)
> 

Reviewed-by: Gavin Shan <gshan@redhat.com>