[PATCH kvmtool v2 7/7] arm64: Improve KVM_ARM_VCPU_PMU_V3_CTRL diagnostics

[Alexandru Elisei]

kvmtool issues several ioctls when configuring the PMU, and each of them
can fail for different reasons. Be more specific about the ioctl that
failed when that happens.

Signed-off-by: Alexandru Elisei <alexandru.elisei at arm.com>
---
 arm64/pmu.c | 31 ++++++++++++++++++++++++-------
 1 file changed, 24 insertions(+), 7 deletions(-)

diff --git a/arm64/pmu.c b/arm64/pmu.c
index 92cacd62479e..78c15f153fad 100644
--- a/arm64/pmu.c
+++ b/arm64/pmu.c
@@ -12,6 +12,24 @@
 
 #include "asm/pmu.h"
 
+static const char *pmu_attr_names[] = {
+	[KVM_ARM_VCPU_PMU_V3_IRQ]	= "KVM_ARM_VCPU_PMU_V3_IRQ",
+	[KVM_ARM_VCPU_PMU_V3_INIT]	= "KVM_ARM_VCPU_PMU_V3_INIT",
+	[KVM_ARM_VCPU_PMU_V3_FILTER]	= "KVM_ARM_VCPU_PMU_V3_FILTER",
+	[KVM_ARM_VCPU_PMU_V3_SET_PMU]	= "KVM_ARM_VCPU_PMU_V3_SET_PMU",
+	[KVM_ARM_VCPU_PMU_V3_SET_NR_COUNTERS] = "KVM_ARM_VCPU_PMU_V3_SET_NR_COUNTER",
+};
+
+static const char *pmu_get_attr_name(u64 attr)
+{
+	switch (attr) {
+	case KVM_ARM_VCPU_PMU_V3_IRQ ... KVM_ARM_VCPU_PMU_V3_SET_NR_COUNTERS:
+		return pmu_attr_names[attr];
+	default:
+		return "UNKNOWN";
+	}
+}
+
 static bool pmu_has_attr(struct kvm_cpu *vcpu, u64 attr)
 {
 	struct kvm_device_attr pmu_attr = {
@@ -32,13 +50,12 @@ static void set_pmu_attr(struct kvm_cpu *vcpu, void *addr, u64 attr)
 	};
 	int ret;
 
-	if (pmu_has_attr(vcpu, attr)) {
-		ret = ioctl(vcpu->vcpu_fd, KVM_SET_DEVICE_ATTR, &pmu_attr);
-		if (ret)
-			die_perror("PMU KVM_SET_DEVICE_ATTR");
-	} else {
-		die_perror("PMU KVM_HAS_DEVICE_ATTR");
-	}
+	if (!pmu_has_attr(vcpu, attr))
+		die_perror("KVM_HAS_DEVICE_ATTR(%s)", pmu_get_attr_name(attr));
+
+	ret = ioctl(vcpu->vcpu_fd, KVM_SET_DEVICE_ATTR, &pmu_attr);
+	if (ret)
+		die_perror("KVM_SET_DEVICE_ATTR(%s)", pmu_get_attr_name(attr));
 }
 
 #define SYS_EVENT_SOURCE	"/sys/bus/event_source/devices/"
-- 
2.54.0