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[v4,37/43] arm64: RME: Initialize PMCR.N with number counter supported by RMM

Message ID 20240821153844.60084-38-steven.price@arm.com (mailing list archive)
State New, archived
Headers show
Series arm64: Support for Arm CCA in KVM | expand

Commit Message

Steven Price Aug. 21, 2024, 3:38 p.m. UTC 
From: Jean-Philippe Brucker <jean-philippe@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@linaro.org>
Signed-off-by: Steven Price <steven.price@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(+)
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Patch

diff --git a/arch/arm64/include/asm/kvm_rme.h b/arch/arm64/include/asm/kvm_rme.h
index 8aa02134c461..c30d7899f58b 100644
--- a/arch/arm64/include/asm/kvm_rme.h
+++ b/arch/arm64/include/asm/kvm_rme.h
@@ -88,6 +88,7 @@  struct realm_rec {
 
 void kvm_init_rme(void);
 u32 kvm_realm_ipa_limit(void);
+u8 kvm_realm_max_pmu_counters(void);
 u64 kvm_realm_reset_id_aa64dfr0_el1(struct kvm_vcpu *vcpu, u64 val);
 
 bool kvm_rme_supports_sve(void);
diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c
index e3dc2363543b..af4e03251503 100644
--- a/arch/arm64/kvm/pmu-emul.c
+++ b/arch/arm64/kvm/pmu-emul.c
@@ -911,6 +911,9 @@  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->num_events considers the cycle counter as well.
 	 * Ignore that and return only the general-purpose counters.
diff --git a/arch/arm64/kvm/rme.c b/arch/arm64/kvm/rme.c
index 42f52b21bdae..a8cb274c9d03 100644
--- a/arch/arm64/kvm/rme.c
+++ b/arch/arm64/kvm/rme.c
@@ -286,6 +286,11 @@  u32 kvm_realm_ipa_limit(void)
 	return u64_get_bits(rmm_feat_reg0, RMI_FEATURE_REGISTER_0_S2SZ);
 }
 
+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(struct kvm_vcpu *vcpu, u64 val)
 {
 	u32 bps = u64_get_bits(rmm_feat_reg0, RMI_FEATURE_REGISTER_0_NUM_BPS);