arm64: KVM: Define PMU data structure for each vcpu

Here we plan to support virtual PMU for guest by full software
emulation, so define some basic structs and functions preparing for
futher steps. Define struct kvm_pmc for performance monitor counter and
struct kvm_pmu for performance monitor unit for each vcpu. According to
ARMv8 spec, the PMU contains at most 32(ARMV8_PMU_MAX_COUNTERS)
counters.

Since this only supports ARM64 (or PMUv3), add a separate config symbol
for it.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index a5272c07d1cb..de7450df7629 100644
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -36,6 +36,7 @@ config KVM
         select HAVE_KVM_EVENTFD
         select HAVE_KVM_IRQFD
         select KVM_ARM_VGIC_V3
+        select KVM_ARM_PMU if HW_PERF_EVENTS
         ---help---
           Support hosting virtualized guest machines.
           We don't support KVM with 16K page tables yet, due to the multiple
@@ -48,6 +49,12 @@ config KVM_ARM_HOST
         ---help---
           Provides host support for ARM processors.
 
+config KVM_ARM_PMU
+        bool
+        ---help---
+          Adds support for a virtual Performance Monitoring Unit (PMU) in
+          virtual machines.
+
 source drivers/vhost/Kconfig
 
 endif # VIRTUALIZATION