[PATCH v7 19/19] KVM: ARM64: Add a new kvm ARM PMU device

Shannon Zhao
2015-12-15T08:49:39Z

From: Shannon Zhao <shannon.zhao@linaro.org>

Add a new kvm device type KVM_DEV_TYPE_ARM_PMU_V3 for ARM PMU. Implement
the kvm_device_ops for it.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
---
Documentation/virtual/kvm/devices/arm-pmu.txt | 16 ++++
arch/arm64/include/uapi/asm/kvm.h | 3 +
include/linux/kvm_host.h | 1 +
include/uapi/linux/kvm.h | 2 +
virt/kvm/arm/pmu.c | 115 ++++++++++++++++++++++++++
virt/kvm/kvm_main.c | 4 +
6 files changed, 141 insertions(+)
create mode 100644 Documentation/virtual/kvm/devices/arm-pmu.txt

diff --git a/Documentation/virtual/kvm/devices/arm-pmu.txt b/Documentation/virtual/kvm/devices/arm-pmu.txt
new file mode 100644
index 0000000..5121f1f
--- /dev/null
+++ b/Documentation/virtual/kvm/devices/arm-pmu.txt
@@ -0,0 +1,16 @@
+ARM Virtual Performance Monitor Unit (vPMU)
+===========================================
+
+Device types supported:
+ KVM_DEV_TYPE_ARM_PMU_V3 ARM Performance Monitor Unit v3
+
+Instantiate one PMU instance for per VCPU through this API.
+
+Groups:
+ KVM_DEV_ARM_PMU_GRP_IRQ
+ Attributes:
+ A value describing the interrupt number of PMU overflow interrupt. This
+ interrupt should be a PPI.
+
+ Errors:
+ -EINVAL: Value set is out of the expected range (from 16 to 31)
diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index 2d4ca4b..568afa2 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -204,6 +204,9 @@ struct kvm_arch_memory_slot {
#define KVM_DEV_ARM_VGIC_GRP_CTRL 4
#define KVM_DEV_ARM_VGIC_CTRL_INIT 0

+/* Device Control API: ARM PMU */
+#define KVM_DEV_ARM_PMU_GRP_IRQ 0
+
/* KVM_IRQ_LINE irq field index values */
#define KVM_ARM_IRQ_TYPE_SHIFT 24
#define KVM_ARM_IRQ_TYPE_MASK 0xff
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index c923350..608dea6 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1161,6 +1161,7 @@ extern struct kvm_device_ops kvm_mpic_ops;
extern struct kvm_device_ops kvm_xics_ops;
extern struct kvm_device_ops kvm_arm_vgic_v2_ops;
extern struct kvm_device_ops kvm_arm_vgic_v3_ops;
+extern struct kvm_device_ops kvm_arm_pmu_ops;

#ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT

diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 03f3618..4ba6fdd 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1032,6 +1032,8 @@ enum kvm_device_type {
#define KVM_DEV_TYPE_FLIC KVM_DEV_TYPE_FLIC
KVM_DEV_TYPE_ARM_VGIC_V3,
#define KVM_DEV_TYPE_ARM_VGIC_V3 KVM_DEV_TYPE_ARM_VGIC_V3
+ KVM_DEV_TYPE_ARM_PMU_V3,
+#define KVM_DEV_TYPE_ARM_PMU_V3 KVM_DEV_TYPE_ARM_PMU_V3
KVM_DEV_TYPE_MAX,
};

diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c
index d113ee4..1965d0d 100644
--- a/virt/kvm/arm/pmu.c
+++ b/virt/kvm/arm/pmu.c
@@ -19,6 +19,7 @@
#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <linux/perf_event.h>
+#include <linux/uaccess.h>
#include <asm/kvm_emulate.h>
#include <kvm/arm_pmu.h>
#include <kvm/arm_vgic.h>
@@ -357,3 +358,117 @@ void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data,

pmc->perf_event = event;
}
+
+static inline bool kvm_arm_pmu_initialized(struct kvm_vcpu *vcpu)
+{
+ return vcpu->arch.pmu.irq_num != -1;
+}
+
+static int kvm_arm_pmu_irq_access(struct kvm *kvm, int *irq, bool is_set)
+{
+ int j;
+ struct kvm_vcpu *vcpu;
+
+ kvm_for_each_vcpu(j, vcpu, kvm) {
+ struct kvm_pmu *pmu = &vcpu->arch.pmu;
+
+ if (!is_set) {
+ if (!kvm_arm_pmu_initialized(vcpu))
+ return -EBUSY;
+
+ *irq = pmu->irq_num;
+ break;
+ }
+
+ if (kvm_arm_pmu_initialized(vcpu))
+ return -EBUSY;
+
+ kvm_debug("Set kvm ARM PMU irq: %d\n", *irq);
+ pmu->irq_num = *irq;
+ }
+
+ return 0;
+}
+
+static int kvm_arm_pmu_create(struct kvm_device *dev, u32 type)
+{
+ int i;
+ struct kvm_vcpu *vcpu;
+ struct kvm *kvm = dev->kvm;
+
+ kvm_for_each_vcpu(i, vcpu, kvm) {
+ struct kvm_pmu *pmu = &vcpu->arch.pmu;
+
+ memset(pmu, 0, sizeof(*pmu));
+ kvm_pmu_vcpu_reset(vcpu);
+ pmu->irq_num = -1;
+ }
+
+ return 0;
+}
+
+static void kvm_arm_pmu_destroy(struct kvm_device *dev)
+{
+ kfree(dev);
+}
+
+static int kvm_arm_pmu_set_attr(struct kvm_device *dev,
+ struct kvm_device_attr *attr)
+{
+ switch (attr->group) {
+ case KVM_DEV_ARM_PMU_GRP_IRQ: {
+ int __user *uaddr = (int __user *)(long)attr->addr;
+ int reg;
+
+ if (get_user(reg, uaddr))
+ return -EFAULT;
+
+ if (reg < VGIC_NR_SGIS || reg >= VGIC_NR_PRIVATE_IRQS)
+ return -EINVAL;
+
+ return kvm_arm_pmu_irq_access(dev->kvm, &reg, true);
+ }
+ }
+
+ return -ENXIO;
+}
+
+static int kvm_arm_pmu_get_attr(struct kvm_device *dev,
+ struct kvm_device_attr *attr)
+{
+ int ret;
+
+ switch (attr->group) {
+ case KVM_DEV_ARM_PMU_GRP_IRQ: {
+ int __user *uaddr = (int __user *)(long)attr->addr;
+ int reg = -1;
+
+ ret = kvm_arm_pmu_irq_access(dev->kvm, &reg, false);
+ if (ret)
+ return ret;
+ return put_user(reg, uaddr);
+ }
+ }
+
+ return -ENXIO;
+}
+
+static int kvm_arm_pmu_has_attr(struct kvm_device *dev,
+ struct kvm_device_attr *attr)
+{
+ switch (attr->group) {
+ case KVM_DEV_ARM_PMU_GRP_IRQ:
+ return 0;
+ }
+
+ return -ENXIO;
+}
+
+struct kvm_device_ops kvm_arm_pmu_ops = {
+ .name = "kvm-arm-pmu",
+ .create = kvm_arm_pmu_create,
+ .destroy = kvm_arm_pmu_destroy,
+ .set_attr = kvm_arm_pmu_set_attr,
+ .get_attr = kvm_arm_pmu_get_attr,
+ .has_attr = kvm_arm_pmu_has_attr,
+};
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 484079e..81a42cc 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2647,6 +2647,10 @@ static struct kvm_device_ops *kvm_device_ops_table[KVM_DEV_TYPE_MAX] = {
#ifdef CONFIG_KVM_XICS
[KVM_DEV_TYPE_XICS] = &kvm_xics_ops,
#endif
+
+#ifdef CONFIG_KVM_ARM_PMU
+ [KVM_DEV_TYPE_ARM_PMU_V3] = &kvm_arm_pmu_ops,
+#endif
};

int kvm_register_device_ops(struct kvm_device_ops *ops, u32 type)
--
2.0.4