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-rw-r--r--virt/kvm/arm/pmu.c48
-rw-r--r--virt/kvm/coalesced_mmio.c8
-rw-r--r--virt/kvm/kvm_main.c50
3 files changed, 70 insertions, 36 deletions
diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c
index 362a01886bab..8731dfeced8b 100644
--- a/virt/kvm/arm/pmu.c
+++ b/virt/kvm/arm/pmu.c
@@ -8,6 +8,7 @@
#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <linux/perf_event.h>
+#include <linux/perf/arm_pmu.h>
#include <linux/uaccess.h>
#include <asm/kvm_emulate.h>
#include <kvm/arm_pmu.h>
@@ -146,8 +147,7 @@ u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, u64 select_idx)
if (kvm_pmu_pmc_is_chained(pmc) &&
kvm_pmu_idx_is_high_counter(select_idx))
counter = upper_32_bits(counter);
-
- else if (!kvm_pmu_idx_is_64bit(vcpu, select_idx))
+ else if (select_idx != ARMV8_PMU_CYCLE_IDX)
counter = lower_32_bits(counter);
return counter;
@@ -193,7 +193,7 @@ static void kvm_pmu_release_perf_event(struct kvm_pmc *pmc)
*/
static void kvm_pmu_stop_counter(struct kvm_vcpu *vcpu, struct kvm_pmc *pmc)
{
- u64 counter, reg;
+ u64 counter, reg, val;
pmc = kvm_pmu_get_canonical_pmc(pmc);
if (!pmc->perf_event)
@@ -201,16 +201,19 @@ static void kvm_pmu_stop_counter(struct kvm_vcpu *vcpu, struct kvm_pmc *pmc)
counter = kvm_pmu_get_pair_counter_value(vcpu, pmc);
- if (kvm_pmu_pmc_is_chained(pmc)) {
- reg = PMEVCNTR0_EL0 + pmc->idx;
- __vcpu_sys_reg(vcpu, reg) = lower_32_bits(counter);
- __vcpu_sys_reg(vcpu, reg + 1) = upper_32_bits(counter);
+ if (pmc->idx == ARMV8_PMU_CYCLE_IDX) {
+ reg = PMCCNTR_EL0;
+ val = counter;
} else {
- reg = (pmc->idx == ARMV8_PMU_CYCLE_IDX)
- ? PMCCNTR_EL0 : PMEVCNTR0_EL0 + pmc->idx;
- __vcpu_sys_reg(vcpu, reg) = lower_32_bits(counter);
+ reg = PMEVCNTR0_EL0 + pmc->idx;
+ val = lower_32_bits(counter);
}
+ __vcpu_sys_reg(vcpu, reg) = val;
+
+ if (kvm_pmu_pmc_is_chained(pmc))
+ __vcpu_sys_reg(vcpu, reg + 1) = upper_32_bits(counter);
+
kvm_pmu_release_perf_event(pmc);
}
@@ -440,8 +443,25 @@ static void kvm_pmu_perf_overflow(struct perf_event *perf_event,
struct pt_regs *regs)
{
struct kvm_pmc *pmc = perf_event->overflow_handler_context;
+ struct arm_pmu *cpu_pmu = to_arm_pmu(perf_event->pmu);
struct kvm_vcpu *vcpu = kvm_pmc_to_vcpu(pmc);
int idx = pmc->idx;
+ u64 period;
+
+ cpu_pmu->pmu.stop(perf_event, PERF_EF_UPDATE);
+
+ /*
+ * Reset the sample period to the architectural limit,
+ * i.e. the point where the counter overflows.
+ */
+ period = -(local64_read(&perf_event->count));
+
+ if (!kvm_pmu_idx_is_64bit(vcpu, pmc->idx))
+ period &= GENMASK(31, 0);
+
+ local64_set(&perf_event->hw.period_left, 0);
+ perf_event->attr.sample_period = period;
+ perf_event->hw.sample_period = period;
__vcpu_sys_reg(vcpu, PMOVSSET_EL0) |= BIT(idx);
@@ -449,6 +469,8 @@ static void kvm_pmu_perf_overflow(struct perf_event *perf_event,
kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
kvm_vcpu_kick(vcpu);
}
+
+ cpu_pmu->pmu.start(perf_event, PERF_EF_RELOAD);
}
/**
@@ -567,12 +589,12 @@ static void kvm_pmu_create_perf_event(struct kvm_vcpu *vcpu, u64 select_idx)
* high counter.
*/
attr.sample_period = (-counter) & GENMASK(63, 0);
+ if (kvm_pmu_counter_is_enabled(vcpu, pmc->idx + 1))
+ attr.config1 |= PERF_ATTR_CFG1_KVM_PMU_CHAINED;
+
event = perf_event_create_kernel_counter(&attr, -1, current,
kvm_pmu_perf_overflow,
pmc + 1);
-
- if (kvm_pmu_counter_is_enabled(vcpu, pmc->idx + 1))
- attr.config1 |= PERF_ATTR_CFG1_KVM_PMU_CHAINED;
} else {
/* The initial sample period (overflow count) of an event. */
if (kvm_pmu_idx_is_64bit(vcpu, pmc->idx))
diff --git a/virt/kvm/coalesced_mmio.c b/virt/kvm/coalesced_mmio.c
index 8ffd07e2a160..00c747dbc82e 100644
--- a/virt/kvm/coalesced_mmio.c
+++ b/virt/kvm/coalesced_mmio.c
@@ -110,14 +110,11 @@ static const struct kvm_io_device_ops coalesced_mmio_ops = {
int kvm_coalesced_mmio_init(struct kvm *kvm)
{
struct page *page;
- int ret;
- ret = -ENOMEM;
page = alloc_page(GFP_KERNEL | __GFP_ZERO);
if (!page)
- goto out_err;
+ return -ENOMEM;
- ret = 0;
kvm->coalesced_mmio_ring = page_address(page);
/*
@@ -128,8 +125,7 @@ int kvm_coalesced_mmio_init(struct kvm *kvm)
spin_lock_init(&kvm->ring_lock);
INIT_LIST_HEAD(&kvm->coalesced_zones);
-out_err:
- return ret;
+ return 0;
}
void kvm_coalesced_mmio_free(struct kvm *kvm)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 66a977472a1c..5f8b89f8d915 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -772,6 +772,18 @@ void kvm_put_kvm(struct kvm *kvm)
}
EXPORT_SYMBOL_GPL(kvm_put_kvm);
+/*
+ * Used to put a reference that was taken on behalf of an object associated
+ * with a user-visible file descriptor, e.g. a vcpu or device, if installation
+ * of the new file descriptor fails and the reference cannot be transferred to
+ * its final owner. In such cases, the caller is still actively using @kvm and
+ * will fail miserably if the refcount unexpectedly hits zero.
+ */
+void kvm_put_kvm_no_destroy(struct kvm *kvm)
+{
+ WARN_ON(refcount_dec_and_test(&kvm->users_count));
+}
+EXPORT_SYMBOL_GPL(kvm_put_kvm_no_destroy);
static int kvm_vm_release(struct inode *inode, struct file *filp)
{
@@ -2360,20 +2372,23 @@ out:
kvm_arch_vcpu_unblocking(vcpu);
block_ns = ktime_to_ns(cur) - ktime_to_ns(start);
- if (!vcpu_valid_wakeup(vcpu))
- shrink_halt_poll_ns(vcpu);
- else if (halt_poll_ns) {
- if (block_ns <= vcpu->halt_poll_ns)
- ;
- /* we had a long block, shrink polling */
- else if (vcpu->halt_poll_ns && block_ns > halt_poll_ns)
+ if (!kvm_arch_no_poll(vcpu)) {
+ if (!vcpu_valid_wakeup(vcpu)) {
shrink_halt_poll_ns(vcpu);
- /* we had a short halt and our poll time is too small */
- else if (vcpu->halt_poll_ns < halt_poll_ns &&
- block_ns < halt_poll_ns)
- grow_halt_poll_ns(vcpu);
- } else
- vcpu->halt_poll_ns = 0;
+ } else if (halt_poll_ns) {
+ if (block_ns <= vcpu->halt_poll_ns)
+ ;
+ /* we had a long block, shrink polling */
+ else if (vcpu->halt_poll_ns && block_ns > halt_poll_ns)
+ shrink_halt_poll_ns(vcpu);
+ /* we had a short halt and our poll time is too small */
+ else if (vcpu->halt_poll_ns < halt_poll_ns &&
+ block_ns < halt_poll_ns)
+ grow_halt_poll_ns(vcpu);
+ } else {
+ vcpu->halt_poll_ns = 0;
+ }
+ }
trace_kvm_vcpu_wakeup(block_ns, waited, vcpu_valid_wakeup(vcpu));
kvm_arch_vcpu_block_finish(vcpu);
@@ -2670,17 +2685,18 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
goto unlock_vcpu_destroy;
}
- BUG_ON(kvm->vcpus[atomic_read(&kvm->online_vcpus)]);
+ vcpu->vcpu_idx = atomic_read(&kvm->online_vcpus);
+ BUG_ON(kvm->vcpus[vcpu->vcpu_idx]);
/* Now it's all set up, let userspace reach it */
kvm_get_kvm(kvm);
r = create_vcpu_fd(vcpu);
if (r < 0) {
- kvm_put_kvm(kvm);
+ kvm_put_kvm_no_destroy(kvm);
goto unlock_vcpu_destroy;
}
- kvm->vcpus[atomic_read(&kvm->online_vcpus)] = vcpu;
+ kvm->vcpus[vcpu->vcpu_idx] = vcpu;
/*
* Pairs with smp_rmb() in kvm_get_vcpu. Write kvm->vcpus
@@ -3114,7 +3130,7 @@ static int kvm_ioctl_create_device(struct kvm *kvm,
kvm_get_kvm(kvm);
ret = anon_inode_getfd(ops->name, &kvm_device_fops, dev, O_RDWR | O_CLOEXEC);
if (ret < 0) {
- kvm_put_kvm(kvm);
+ kvm_put_kvm_no_destroy(kvm);
mutex_lock(&kvm->lock);
list_del(&dev->vm_node);
mutex_unlock(&kvm->lock);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.