Merge branch 'kvm-arm64/pmu-5.9' into kvmarm-master/next

Signed-off-by: Marc Zyngier <maz@kernel.org>

Documentation/virt/kvm/devices/vcpu.rst

@@ -25,8 +25,10 @@ Returns:
 
 	 =======  ========================================================
 	 -EBUSY   The PMU overflow interrupt is already set
-	 -ENXIO   The overflow interrupt not set when attempting to get it
-	 -ENODEV  PMUv3 not supported
+	 -EFAULT  Error reading interrupt number
+	 -ENXIO   PMUv3 not supported or the overflow interrupt not set
+		  when attempting to get it
+	 -ENODEV  KVM_ARM_VCPU_PMU_V3 feature missing from VCPU
 	 -EINVAL  Invalid PMU overflow interrupt number supplied or
 		  trying to set the IRQ number without using an in-kernel
 		  irqchip.
@@ -45,9 +47,10 @@ all vcpus, while as an SPI it must be a separate number per vcpu.
 Returns:
 
 	 =======  ======================================================
+	 -EEXIST  Interrupt number already used
 	 -ENODEV  PMUv3 not supported or GIC not initialized
-	 -ENXIO   PMUv3 not properly configured or in-kernel irqchip not
-		  configured as required prior to calling this attribute
+	 -ENXIO   PMUv3 not supported, missing VCPU feature or interrupt
+		  number not set
 	 -EBUSY   PMUv3 already initialized
 	 =======  ======================================================
 
@@ -55,6 +58,52 @@ Request the initialization of the PMUv3.  If using the PMUv3 with an in-kernel
 virtual GIC implementation, this must be done after initializing the in-kernel
 irqchip.
 
+1.3 ATTRIBUTE: KVM_ARM_VCPU_PMU_V3_FILTER
+-----------------------------------------
+
+:Parameters: in kvm_device_attr.addr the address for a PMU event filter is a
+             pointer to a struct kvm_pmu_event_filter
+
+:Returns:
+
+	 =======  ======================================================
+	 -ENODEV: PMUv3 not supported or GIC not initialized
+	 -ENXIO:  PMUv3 not properly configured or in-kernel irqchip not
+	 	  configured as required prior to calling this attribute
+	 -EBUSY:  PMUv3 already initialized
+	 -EINVAL: Invalid filter range
+	 =======  ======================================================
+
+Request the installation of a PMU event filter described as follows:
+
+struct kvm_pmu_event_filter {
+	__u16	base_event;
+	__u16	nevents;
+
+#define KVM_PMU_EVENT_ALLOW	0
+#define KVM_PMU_EVENT_DENY	1
+
+	__u8	action;
+	__u8	pad[3];
+};
+
+A filter range is defined as the range [@base_event, @base_event + @nevents),
+together with an @action (KVM_PMU_EVENT_ALLOW or KVM_PMU_EVENT_DENY). The
+first registered range defines the global policy (global ALLOW if the first
+@action is DENY, global DENY if the first @action is ALLOW). Multiple ranges
+can be programmed, and must fit within the event space defined by the PMU
+architecture (10 bits on ARMv8.0, 16 bits from ARMv8.1 onwards).
+
+Note: "Cancelling" a filter by registering the opposite action for the same
+range doesn't change the default action. For example, installing an ALLOW
+filter for event range [0:10) as the first filter and then applying a DENY
+action for the same range will leave the whole range as disabled.
+
+Restrictions: Event 0 (SW_INCR) is never filtered, as it doesn't count a
+hardware event. Filtering event 0x1E (CHAIN) has no effect either, as it
+isn't strictly speaking an event. Filtering the cycle counter is possible
+using event 0x11 (CPU_CYCLES).
+
 
 2. GROUP: KVM_ARM_VCPU_TIMER_CTRL
 =================================

arch/arm64/include/asm/kvm_host.h

@@ -111,6 +111,13 @@ struct kvm_arch {
 	 * supported.
 	 */
 	bool return_nisv_io_abort_to_user;
+
+	/*
+	 * VM-wide PMU filter, implemented as a bitmap and big enough for
+	 * up to 2^10 events (ARMv8.0) or 2^16 events (ARMv8.1+).
+	 */
+	unsigned long *pmu_filter;
+	unsigned int pmuver;
 };
 
 struct kvm_vcpu_fault_info {

arch/arm64/include/uapi/asm/kvm.h

@@ -159,6 +159,21 @@ struct kvm_sync_regs {
 struct kvm_arch_memory_slot {
 };
 
+/*
+ * PMU filter structure. Describe a range of events with a particular
+ * action. To be used with KVM_ARM_VCPU_PMU_V3_FILTER.
+ */
+struct kvm_pmu_event_filter {
+	__u16	base_event;
+	__u16	nevents;
+
+#define KVM_PMU_EVENT_ALLOW	0
+#define KVM_PMU_EVENT_DENY	1
+
+	__u8	action;
+	__u8	pad[3];
+};
+
 /* for KVM_GET/SET_VCPU_EVENTS */
 struct kvm_vcpu_events {
 	struct {
@@ -329,6 +344,7 @@ struct kvm_vcpu_events {
 #define KVM_ARM_VCPU_PMU_V3_CTRL	0
 #define   KVM_ARM_VCPU_PMU_V3_IRQ	0
 #define   KVM_ARM_VCPU_PMU_V3_INIT	1
+#define   KVM_ARM_VCPU_PMU_V3_FILTER	2
 #define KVM_ARM_VCPU_TIMER_CTRL		1
 #define   KVM_ARM_VCPU_TIMER_IRQ_VTIMER		0
 #define   KVM_ARM_VCPU_TIMER_IRQ_PTIMER		1

arch/arm64/kvm/arm.c

@@ -147,6 +147,8 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
 {
 	int i;
 
+	bitmap_free(kvm->arch.pmu_filter);
+
 	kvm_vgic_destroy(kvm);
 
 	for (i = 0; i < KVM_MAX_VCPUS; ++i) {

arch/arm64/kvm/pmu-emul.c

@@ -20,6 +20,21 @@ static void kvm_pmu_stop_counter(struct kvm_vcpu *vcpu, struct kvm_pmc *pmc);
 
 #define PERF_ATTR_CFG1_KVM_PMU_CHAINED 0x1
 
+static u32 kvm_pmu_event_mask(struct kvm *kvm)
+{
+	switch (kvm->arch.pmuver) {
+	case 1:			/* ARMv8.0 */
+		return GENMASK(9, 0);
+	case 4:			/* ARMv8.1 */
+	case 5:			/* ARMv8.4 */
+	case 6:			/* ARMv8.5 */
+		return GENMASK(15, 0);
+	default:		/* Shouldn't be here, just for sanity */
+		WARN_ONCE(1, "Unknown PMU version %d\n", kvm->arch.pmuver);
+		return 0;
+	}
+}
+
 /**
  * kvm_pmu_idx_is_64bit - determine if select_idx is a 64bit counter
  * @vcpu: The vcpu pointer
@@ -100,7 +115,7 @@ static bool kvm_pmu_idx_has_chain_evtype(struct kvm_vcpu *vcpu, u64 select_idx)
 		return false;
 
 	reg = PMEVTYPER0_EL0 + select_idx;
-	eventsel = __vcpu_sys_reg(vcpu, reg) & ARMV8_PMU_EVTYPE_EVENT;
+	eventsel = __vcpu_sys_reg(vcpu, reg) & kvm_pmu_event_mask(vcpu->kvm);
 
 	return eventsel == ARMV8_PMUV3_PERFCTR_CHAIN;
 }
@@ -495,7 +510,7 @@ void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u64 val)
 
 		/* PMSWINC only applies to ... SW_INC! */
 		type = __vcpu_sys_reg(vcpu, PMEVTYPER0_EL0 + i);
-		type &= ARMV8_PMU_EVTYPE_EVENT;
+		type &= kvm_pmu_event_mask(vcpu->kvm);
 		if (type != ARMV8_PMUV3_PERFCTR_SW_INCR)
 			continue;
 
@@ -578,11 +593,21 @@ static void kvm_pmu_create_perf_event(struct kvm_vcpu *vcpu, u64 select_idx)
 	data = __vcpu_sys_reg(vcpu, reg);
 
 	kvm_pmu_stop_counter(vcpu, pmc);
-	eventsel = data & ARMV8_PMU_EVTYPE_EVENT;
+	if (pmc->idx == ARMV8_PMU_CYCLE_IDX)
+		eventsel = ARMV8_PMUV3_PERFCTR_CPU_CYCLES;
+	else
+		eventsel = data & kvm_pmu_event_mask(vcpu->kvm);
 
-	/* Software increment event does't need to be backed by a perf event */
-	if (eventsel == ARMV8_PMUV3_PERFCTR_SW_INCR &&
-	    pmc->idx != ARMV8_PMU_CYCLE_IDX)
+	/* Software increment event doesn't need to be backed by a perf event */
+	if (eventsel == ARMV8_PMUV3_PERFCTR_SW_INCR)
+		return;
+
+	/*
+	 * If we have a filter in place and that the event isn't allowed, do
+	 * not install a perf event either.
+	 */
+	if (vcpu->kvm->arch.pmu_filter &&
+	    !test_bit(eventsel, vcpu->kvm->arch.pmu_filter))
 		return;
 
 	memset(&attr, 0, sizeof(struct perf_event_attr));
@@ -594,8 +619,7 @@ static void kvm_pmu_create_perf_event(struct kvm_vcpu *vcpu, u64 select_idx)
 	attr.exclude_kernel = data & ARMV8_PMU_EXCLUDE_EL1 ? 1 : 0;
 	attr.exclude_hv = 1; /* Don't count EL2 events */
 	attr.exclude_host = 1; /* Don't count host events */
-	attr.config = (pmc->idx == ARMV8_PMU_CYCLE_IDX) ?
-		ARMV8_PMUV3_PERFCTR_CPU_CYCLES : eventsel;
+	attr.config = eventsel;
 
 	counter = kvm_pmu_get_pair_counter_value(vcpu, pmc);
 
@@ -679,17 +703,95 @@ static void kvm_pmu_update_pmc_chained(struct kvm_vcpu *vcpu, u64 select_idx)
 void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data,
 				    u64 select_idx)
 {
-	u64 reg, event_type = data & ARMV8_PMU_EVTYPE_MASK;
+	u64 reg, mask;
+
+	mask  =  ARMV8_PMU_EVTYPE_MASK;
+	mask &= ~ARMV8_PMU_EVTYPE_EVENT;
+	mask |= kvm_pmu_event_mask(vcpu->kvm);
 
 	reg = (select_idx == ARMV8_PMU_CYCLE_IDX)
 	      ? PMCCFILTR_EL0 : PMEVTYPER0_EL0 + select_idx;
 
-	__vcpu_sys_reg(vcpu, reg) = event_type;
+	__vcpu_sys_reg(vcpu, reg) = data & mask;
 
 	kvm_pmu_update_pmc_chained(vcpu, select_idx);
 	kvm_pmu_create_perf_event(vcpu, select_idx);
 }
 
+static int kvm_pmu_probe_pmuver(void)
+{
+	struct perf_event_attr attr = { };
+	struct perf_event *event;
+	struct arm_pmu *pmu;
+	int pmuver = 0xf;
+
+	/*
+	 * Create a dummy event that only counts user cycles. As we'll never
+	 * leave this function with the event being live, it will never
+	 * count anything. But it allows us to probe some of the PMU
+	 * details. Yes, this is terrible.
+	 */
+	attr.type = PERF_TYPE_RAW;
+	attr.size = sizeof(attr);
+	attr.pinned = 1;
+	attr.disabled = 0;
+	attr.exclude_user = 0;
+	attr.exclude_kernel = 1;
+	attr.exclude_hv = 1;
+	attr.exclude_host = 1;
+	attr.config = ARMV8_PMUV3_PERFCTR_CPU_CYCLES;
+	attr.sample_period = GENMASK(63, 0);
+
+	event = perf_event_create_kernel_counter(&attr, -1, current,
+						 kvm_pmu_perf_overflow, &attr);
+
+	if (IS_ERR(event)) {
+		pr_err_once("kvm: pmu event creation failed %ld\n",
+			    PTR_ERR(event));
+		return 0xf;
+	}
+
+	if (event->pmu) {
+		pmu = to_arm_pmu(event->pmu);
+		if (pmu->pmuver)
+			pmuver = pmu->pmuver;
+	}
+
+	perf_event_disable(event);
+	perf_event_release_kernel(event);
+
+	return pmuver;
+}
+
+u64 kvm_pmu_get_pmceid(struct kvm_vcpu *vcpu, bool pmceid1)
+{
+	unsigned long *bmap = vcpu->kvm->arch.pmu_filter;
+	u64 val, mask = 0;
+	int base, i;
+
+	if (!pmceid1) {
+		val = read_sysreg(pmceid0_el0);
+		base = 0;
+	} else {
+		val = read_sysreg(pmceid1_el0);
+		base = 32;
+	}
+
+	if (!bmap)
+		return val;
+
+	for (i = 0; i < 32; i += 8) {
+		u64 byte;
+
+		byte = bitmap_get_value8(bmap, base + i);
+		mask |= byte << i;
+		byte = bitmap_get_value8(bmap, 0x4000 + base + i);
+		mask |= byte << (32 + i);
+	}
+
+	return val & mask;
+}
+
 bool kvm_arm_support_pmu_v3(void)
 {
 	/*
@@ -735,15 +837,6 @@ int kvm_arm_pmu_v3_enable(struct kvm_vcpu *vcpu)
 
 static int kvm_arm_pmu_v3_init(struct kvm_vcpu *vcpu)
 {
-	if (!kvm_arm_support_pmu_v3())
-		return -ENODEV;
-
-	if (!test_bit(KVM_ARM_VCPU_PMU_V3, vcpu->arch.features))
-		return -ENXIO;
-
-	if (vcpu->arch.pmu.created)
-		return -EBUSY;
-
 	if (irqchip_in_kernel(vcpu->kvm)) {
 		int ret;
 
@@ -796,6 +889,19 @@ static bool pmu_irq_is_valid(struct kvm *kvm, int irq)
 
 int kvm_arm_pmu_v3_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
 {
+	if (!kvm_arm_support_pmu_v3() ||
+	    !test_bit(KVM_ARM_VCPU_PMU_V3, vcpu->arch.features))
+		return -ENODEV;
+
+	if (vcpu->arch.pmu.created)
+		return -EBUSY;
+
+	if (!vcpu->kvm->arch.pmuver)
+		vcpu->kvm->arch.pmuver = kvm_pmu_probe_pmuver();
+
+	if (vcpu->kvm->arch.pmuver == 0xf)
+		return -ENODEV;
+
 	switch (attr->attr) {
 	case KVM_ARM_VCPU_PMU_V3_IRQ: {
 		int __user *uaddr = (int __user *)(long)attr->addr;
@@ -804,9 +910,6 @@ int kvm_arm_pmu_v3_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
 		if (!irqchip_in_kernel(vcpu->kvm))
 			return -EINVAL;
 
-		if (!test_bit(KVM_ARM_VCPU_PMU_V3, vcpu->arch.features))
-			return -ENODEV;
-
 		if (get_user(irq, uaddr))
 			return -EFAULT;
 
@@ -824,6 +927,53 @@ int kvm_arm_pmu_v3_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
 		vcpu->arch.pmu.irq_num = irq;
 		return 0;
 	}
+	case KVM_ARM_VCPU_PMU_V3_FILTER: {
+		struct kvm_pmu_event_filter __user *uaddr;
+		struct kvm_pmu_event_filter filter;
+		int nr_events;
+
+		nr_events = kvm_pmu_event_mask(vcpu->kvm) + 1;
+
+		uaddr = (struct kvm_pmu_event_filter __user *)(long)attr->addr;
+
+		if (copy_from_user(&filter, uaddr, sizeof(filter)))
+			return -EFAULT;
+
+		if (((u32)filter.base_event + filter.nevents) > nr_events ||
+		    (filter.action != KVM_PMU_EVENT_ALLOW &&
+		     filter.action != KVM_PMU_EVENT_DENY))
+			return -EINVAL;
+
+		mutex_lock(&vcpu->kvm->lock);
+
+		if (!vcpu->kvm->arch.pmu_filter) {
+			vcpu->kvm->arch.pmu_filter = bitmap_alloc(nr_events, GFP_KERNEL);
+			if (!vcpu->kvm->arch.pmu_filter) {
+				mutex_unlock(&vcpu->kvm->lock);
+				return -ENOMEM;
+			}
+
+			/*
+			 * The default depends on the first applied filter.
+			 * If it allows events, the default is to deny.
+			 * Conversely, if the first filter denies a set of
+			 * events, the default is to allow.
+			 */
+			if (filter.action == KVM_PMU_EVENT_ALLOW)
+				bitmap_zero(vcpu->kvm->arch.pmu_filter, nr_events);
+			else
+				bitmap_fill(vcpu->kvm->arch.pmu_filter, nr_events);
+		}
+
+		if (filter.action == KVM_PMU_EVENT_ALLOW)
+			bitmap_set(vcpu->kvm->arch.pmu_filter, filter.base_event, filter.nevents);
+		else
+			bitmap_clear(vcpu->kvm->arch.pmu_filter, filter.base_event, filter.nevents);
+
+		mutex_unlock(&vcpu->kvm->lock);
+
+		return 0;
+	}
 	case KVM_ARM_VCPU_PMU_V3_INIT:
 		return kvm_arm_pmu_v3_init(vcpu);
 	}
@@ -860,6 +1010,7 @@ int kvm_arm_pmu_v3_has_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
 	switch (attr->attr) {
 	case KVM_ARM_VCPU_PMU_V3_IRQ:
 	case KVM_ARM_VCPU_PMU_V3_INIT:
+	case KVM_ARM_VCPU_PMU_V3_FILTER:
 		if (kvm_arm_support_pmu_v3() &&
 		    test_bit(KVM_ARM_VCPU_PMU_V3, vcpu->arch.features))
 			return 0;

arch/arm64/kvm/sys_regs.c

@@ -769,10 +769,7 @@ static bool access_pmceid(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
 	if (pmu_access_el0_disabled(vcpu))
 		return false;
 
-	if (!(p->Op2 & 1))
-		pmceid = read_sysreg(pmceid0_el0);
-	else
-		pmceid = read_sysreg(pmceid1_el0);
+	pmceid = kvm_pmu_get_pmceid(vcpu, (p->Op2 & 1));
 
 	p->regval = pmceid;
 

include/kvm/arm_pmu.h

@@ -34,6 +34,7 @@ struct kvm_pmu {
 u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, u64 select_idx);
 void kvm_pmu_set_counter_value(struct kvm_vcpu *vcpu, u64 select_idx, u64 val);
 u64 kvm_pmu_valid_counter_mask(struct kvm_vcpu *vcpu);
+u64 kvm_pmu_get_pmceid(struct kvm_vcpu *vcpu, bool pmceid1);
 void kvm_pmu_vcpu_init(struct kvm_vcpu *vcpu);
 void kvm_pmu_vcpu_reset(struct kvm_vcpu *vcpu);
 void kvm_pmu_vcpu_destroy(struct kvm_vcpu *vcpu);
@@ -108,6 +109,10 @@ static inline int kvm_arm_pmu_v3_enable(struct kvm_vcpu *vcpu)
 {
 	return 0;
 }
+static inline u64 kvm_pmu_get_pmceid(struct kvm_vcpu *vcpu, bool pmceid1)
+{
+	return 0;
+}
 #endif
 
 #endif