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Diffstat (limited to 'arch/x86/kvm/pmu.c')
-rw-r--r--arch/x86/kvm/pmu.c101
1 files changed, 86 insertions, 15 deletions
diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index e39741997893..46875bbd0419 100644
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* Kernel-based Virtual Machine -- Performance Monitoring Unit support
*
@@ -7,10 +8,6 @@
* Avi Kivity <avi@redhat.com>
* Gleb Natapov <gleb@redhat.com>
* Wei Huang <wei@redhat.com>
- *
- * This work is licensed under the terms of the GNU GPL, version 2. See
- * the COPYING file in the top-level directory.
- *
*/
#include <linux/types.h>
@@ -22,6 +19,9 @@
#include "lapic.h"
#include "pmu.h"
+/* This is enough to filter the vast majority of currently defined events. */
+#define KVM_PMU_EVENT_FILTER_MAX_EVENTS 300
+
/* NOTE:
* - Each perf counter is defined as "struct kvm_pmc";
* - There are two types of perf counters: general purpose (gp) and fixed.
@@ -131,8 +131,8 @@ static void pmc_reprogram_counter(struct kvm_pmc *pmc, u32 type,
intr ? kvm_perf_overflow_intr :
kvm_perf_overflow, pmc);
if (IS_ERR(event)) {
- printk_once("kvm_pmu: event creation failed %ld\n",
- PTR_ERR(event));
+ pr_debug_ratelimited("kvm_pmu: event creation failed %ld for pmc->idx = %d\n",
+ PTR_ERR(event), pmc->idx);
return;
}
@@ -144,6 +144,10 @@ void reprogram_gp_counter(struct kvm_pmc *pmc, u64 eventsel)
{
unsigned config, type = PERF_TYPE_RAW;
u8 event_select, unit_mask;
+ struct kvm *kvm = pmc->vcpu->kvm;
+ struct kvm_pmu_event_filter *filter;
+ int i;
+ bool allow_event = true;
if (eventsel & ARCH_PERFMON_EVENTSEL_PIN_CONTROL)
printk_once("kvm pmu: pin control bit is ignored\n");
@@ -155,6 +159,22 @@ void reprogram_gp_counter(struct kvm_pmc *pmc, u64 eventsel)
if (!(eventsel & ARCH_PERFMON_EVENTSEL_ENABLE) || !pmc_is_enabled(pmc))
return;
+ filter = srcu_dereference(kvm->arch.pmu_event_filter, &kvm->srcu);
+ if (filter) {
+ for (i = 0; i < filter->nevents; i++)
+ if (filter->events[i] ==
+ (eventsel & AMD64_RAW_EVENT_MASK_NB))
+ break;
+ if (filter->action == KVM_PMU_EVENT_ALLOW &&
+ i == filter->nevents)
+ allow_event = false;
+ if (filter->action == KVM_PMU_EVENT_DENY &&
+ i < filter->nevents)
+ allow_event = false;
+ }
+ if (!allow_event)
+ return;
+
event_select = eventsel & ARCH_PERFMON_EVENTSEL_EVENT;
unit_mask = (eventsel & ARCH_PERFMON_EVENTSEL_UMASK) >> 8;
@@ -186,12 +206,24 @@ void reprogram_fixed_counter(struct kvm_pmc *pmc, u8 ctrl, int idx)
{
unsigned en_field = ctrl & 0x3;
bool pmi = ctrl & 0x8;
+ struct kvm_pmu_event_filter *filter;
+ struct kvm *kvm = pmc->vcpu->kvm;
pmc_stop_counter(pmc);
if (!en_field || !pmc_is_enabled(pmc))
return;
+ filter = srcu_dereference(kvm->arch.pmu_event_filter, &kvm->srcu);
+ if (filter) {
+ if (filter->action == KVM_PMU_EVENT_DENY &&
+ test_bit(idx, (ulong *)&filter->fixed_counter_bitmap))
+ return;
+ if (filter->action == KVM_PMU_EVENT_ALLOW &&
+ !test_bit(idx, (ulong *)&filter->fixed_counter_bitmap))
+ return;
+ }
+
pmc_reprogram_counter(pmc, PERF_TYPE_HARDWARE,
kvm_x86_ops->pmu_ops->find_fixed_event(idx),
!(en_field & 0x2), /* exclude user */
@@ -264,10 +296,10 @@ static int kvm_pmu_rdpmc_vmware(struct kvm_vcpu *vcpu, unsigned idx, u64 *data)
ctr_val = rdtsc();
break;
case VMWARE_BACKDOOR_PMC_REAL_TIME:
- ctr_val = ktime_get_boot_ns();
+ ctr_val = ktime_get_boottime_ns();
break;
case VMWARE_BACKDOOR_PMC_APPARENT_TIME:
- ctr_val = ktime_get_boot_ns() +
+ ctr_val = ktime_get_boottime_ns() +
vcpu->kvm->arch.kvmclock_offset;
break;
default:
@@ -283,7 +315,7 @@ int kvm_pmu_rdpmc(struct kvm_vcpu *vcpu, unsigned idx, u64 *data)
bool fast_mode = idx & (1u << 31);
struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
struct kvm_pmc *pmc;
- u64 ctr_val;
+ u64 mask = fast_mode ? ~0u : ~0ull;
if (!pmu->version)
return 1;
@@ -291,15 +323,11 @@ int kvm_pmu_rdpmc(struct kvm_vcpu *vcpu, unsigned idx, u64 *data)
if (is_vmware_backdoor_pmc(idx))
return kvm_pmu_rdpmc_vmware(vcpu, idx, data);
- pmc = kvm_x86_ops->pmu_ops->msr_idx_to_pmc(vcpu, idx);
+ pmc = kvm_x86_ops->pmu_ops->msr_idx_to_pmc(vcpu, idx, &mask);
if (!pmc)
return 1;
- ctr_val = pmc_read_counter(pmc);
- if (fast_mode)
- ctr_val = (u32)ctr_val;
-
- *data = ctr_val;
+ *data = pmc_read_counter(pmc) & mask;
return 0;
}
@@ -355,3 +383,46 @@ void kvm_pmu_destroy(struct kvm_vcpu *vcpu)
{
kvm_pmu_reset(vcpu);
}
+
+int kvm_vm_ioctl_set_pmu_event_filter(struct kvm *kvm, void __user *argp)
+{
+ struct kvm_pmu_event_filter tmp, *filter;
+ size_t size;
+ int r;
+
+ if (copy_from_user(&tmp, argp, sizeof(tmp)))
+ return -EFAULT;
+
+ if (tmp.action != KVM_PMU_EVENT_ALLOW &&
+ tmp.action != KVM_PMU_EVENT_DENY)
+ return -EINVAL;
+
+ if (tmp.flags != 0)
+ return -EINVAL;
+
+ if (tmp.nevents > KVM_PMU_EVENT_FILTER_MAX_EVENTS)
+ return -E2BIG;
+
+ size = struct_size(filter, events, tmp.nevents);
+ filter = kmalloc(size, GFP_KERNEL_ACCOUNT);
+ if (!filter)
+ return -ENOMEM;
+
+ r = -EFAULT;
+ if (copy_from_user(filter, argp, size))
+ goto cleanup;
+
+ /* Ensure nevents can't be changed between the user copies. */
+ *filter = tmp;
+
+ mutex_lock(&kvm->lock);
+ rcu_swap_protected(kvm->arch.pmu_event_filter, filter,
+ mutex_is_locked(&kvm->lock));
+ mutex_unlock(&kvm->lock);
+
+ synchronize_srcu_expedited(&kvm->srcu);
+ r = 0;
+cleanup:
+ kfree(filter);
+ return r;
+}