[PATCH v6 36/43] arm64: RME: Initialize PMCR.N with number counter supported by RMM

[Steven Price]

From: Jean-Philippe Brucker <jean-philippe at linaro.org>

Provide an accurate number of available PMU counters to userspace when
setting up a Realm.

Signed-off-by: Jean-Philippe Brucker <jean-philippe at linaro.org>
Signed-off-by: Steven Price <steven.price at arm.com>
---
 arch/arm64/include/asm/kvm_rme.h | 1 +
 arch/arm64/kvm/pmu-emul.c        | 3 +++
 arch/arm64/kvm/rme.c             | 5 +++++
 3 files changed, 9 insertions(+)

diff --git a/arch/arm64/include/asm/kvm_rme.h b/arch/arm64/include/asm/kvm_rme.h
index f8e37907e2d5..7839ef81c20e 100644
--- a/arch/arm64/include/asm/kvm_rme.h
+++ b/arch/arm64/include/asm/kvm_rme.h
@@ -84,6 +84,7 @@ struct realm_rec {
 void kvm_init_rme(void);
 u32 kvm_realm_ipa_limit(void);
 u32 kvm_realm_vgic_nr_lr(void);
+u8 kvm_realm_max_pmu_counters(void);
 
 u64 kvm_realm_reset_id_aa64dfr0_el1(const struct kvm_vcpu *vcpu, u64 val);
 
diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c
index 5628b573ca41..f201f86ed7c8 100644
--- a/arch/arm64/kvm/pmu-emul.c
+++ b/arch/arm64/kvm/pmu-emul.c
@@ -1016,6 +1016,9 @@ u8 kvm_arm_pmu_get_max_counters(struct kvm *kvm)
 {
 	struct arm_pmu *arm_pmu = kvm->arch.arm_pmu;
 
+	if (kvm_is_realm(kvm))
+		return kvm_realm_max_pmu_counters();
+
 	/*
 	 * The arm_pmu->cntr_mask considers the fixed counter(s) as well.
 	 * Ignore those and return only the general-purpose counters.
diff --git a/arch/arm64/kvm/rme.c b/arch/arm64/kvm/rme.c
index d77754ce8d14..1230550e2a71 100644
--- a/arch/arm64/kvm/rme.c
+++ b/arch/arm64/kvm/rme.c
@@ -63,6 +63,11 @@ u32 kvm_realm_vgic_nr_lr(void)
 	return u64_get_bits(rmm_feat_reg0, RMI_FEATURE_REGISTER_0_GICV3_NUM_LRS);
 }
 
+u8 kvm_realm_max_pmu_counters(void)
+{
+	return u64_get_bits(rmm_feat_reg0, RMI_FEATURE_REGISTER_0_PMU_NUM_CTRS);
+}
+
 u64 kvm_realm_reset_id_aa64dfr0_el1(const struct kvm_vcpu *vcpu, u64 val)
 {
 	u32 bps = u64_get_bits(rmm_feat_reg0, RMI_FEATURE_REGISTER_0_NUM_BPS);
-- 
2.43.0