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-rw-r--r--Documentation/virt/kvm/devices/vcpu.rst57
-rw-r--r--arch/arm64/include/asm/kvm_host.h7
-rw-r--r--arch/arm64/include/uapi/asm/kvm.h16
-rw-r--r--arch/arm64/kvm/arm.c2
-rw-r--r--arch/arm64/kvm/pmu-emul.c195
-rw-r--r--arch/arm64/kvm/sys_regs.c5
-rw-r--r--include/kvm/arm_pmu.h5
7 files changed, 257 insertions, 30 deletions
diff --git a/Documentation/virt/kvm/devices/vcpu.rst b/Documentation/virt/kvm/devices/vcpu.rst
index ca374d3fe085..da7c2ef7dafc 100644
--- a/Documentation/virt/kvm/devices/vcpu.rst
+++ b/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
=================================
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index b537ab05a4d3..d56d67c3787e 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/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 {
diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index ba85bb23f060..7b1511d6ce44 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/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
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 28d1e9858743..e49189012af1 100644
--- a/arch/arm64/kvm/arm.c
+++ b/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) {
diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c
index f0d0312c0a55..ee13c5eecd3d 100644
--- a/arch/arm64/kvm/pmu-emul.c
+++ b/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;
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 077293b5115f..20ab2a7d37ca 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/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;
diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h
index 6db030439e29..98cbfe885a53 100644
--- a/include/kvm/arm_pmu.h
+++ b/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
generated by cgit (git 2.34.1) at 2025-10-31 03:18:37 +0000