From: Oliver Upton <oliver.upton@linux.dev>
To: kvmarm@lists.linux.dev
Cc: Marc Zyngier <maz@kernel.org>, James Morse <james.morse@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Zenghui Yu <yuzenghui@huawei.com>,
Eric Auger <eric.auger@redhat.com>,
kvm@vger.kernel.org, Oliver Upton <oliver.upton@linux.dev>
Subject: [PATCH v3 05/19] KVM: arm64: vgic-debug: Use an xarray mark for debug iterator
Date: Mon, 22 Apr 2024 20:01:44 +0000 [thread overview]
Message-ID: <20240422200158.2606761-6-oliver.upton@linux.dev> (raw)
In-Reply-To: <20240422200158.2606761-1-oliver.upton@linux.dev>
The vgic debug iterator is the final user of vgic_copy_lpi_list(), but
is a bit more complicated to transition to something else. Use a mark
in the LPI xarray to record the indices 'known' to the debug iterator.
Protect against the LPIs from being freed by associating an additional
reference with the xarray mark.
Rework iter_next() to let the xarray walk 'drive' the iteration after
visiting all of the SGIs, PPIs, and SPIs.
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
---
arch/arm64/kvm/vgic/vgic-debug.c | 82 +++++++++++++++++++++++---------
arch/arm64/kvm/vgic/vgic-its.c | 4 +-
arch/arm64/kvm/vgic/vgic.h | 1 +
include/kvm/arm_vgic.h | 2 +
4 files changed, 64 insertions(+), 25 deletions(-)
diff --git a/arch/arm64/kvm/vgic/vgic-debug.c b/arch/arm64/kvm/vgic/vgic-debug.c
index 389025ce7749..bcbc8c986b1d 100644
--- a/arch/arm64/kvm/vgic/vgic-debug.c
+++ b/arch/arm64/kvm/vgic/vgic-debug.c
@@ -28,27 +28,65 @@ struct vgic_state_iter {
int nr_lpis;
int dist_id;
int vcpu_id;
- int intid;
+ unsigned long intid;
int lpi_idx;
- u32 *lpi_array;
};
-static void iter_next(struct vgic_state_iter *iter)
+static void iter_next(struct kvm *kvm, struct vgic_state_iter *iter)
{
+ struct vgic_dist *dist = &kvm->arch.vgic;
+
if (iter->dist_id == 0) {
iter->dist_id++;
return;
}
+ /*
+ * Let the xarray drive the iterator after the last SPI, as the iterator
+ * has exhausted the sequentially-allocated INTID space.
+ */
+ if (iter->intid >= (iter->nr_spis + VGIC_NR_PRIVATE_IRQS - 1)) {
+ if (iter->lpi_idx < iter->nr_lpis)
+ xa_find_after(&dist->lpi_xa, &iter->intid,
+ VGIC_LPI_MAX_INTID,
+ LPI_XA_MARK_DEBUG_ITER);
+ iter->lpi_idx++;
+ return;
+ }
+
iter->intid++;
if (iter->intid == VGIC_NR_PRIVATE_IRQS &&
++iter->vcpu_id < iter->nr_cpus)
iter->intid = 0;
+}
- if (iter->intid >= (iter->nr_spis + VGIC_NR_PRIVATE_IRQS)) {
- if (iter->lpi_idx < iter->nr_lpis)
- iter->intid = iter->lpi_array[iter->lpi_idx];
- iter->lpi_idx++;
+static int iter_mark_lpis(struct kvm *kvm)
+{
+ struct vgic_dist *dist = &kvm->arch.vgic;
+ struct vgic_irq *irq;
+ unsigned long intid;
+ int nr_lpis = 0;
+
+ xa_for_each(&dist->lpi_xa, intid, irq) {
+ if (!vgic_try_get_irq_kref(irq))
+ continue;
+
+ xa_set_mark(&dist->lpi_xa, intid, LPI_XA_MARK_DEBUG_ITER);
+ nr_lpis++;
+ }
+
+ return nr_lpis;
+}
+
+static void iter_unmark_lpis(struct kvm *kvm)
+{
+ struct vgic_dist *dist = &kvm->arch.vgic;
+ struct vgic_irq *irq;
+ unsigned long intid;
+
+ xa_for_each(&dist->lpi_xa, intid, irq) {
+ xa_clear_mark(&dist->lpi_xa, intid, LPI_XA_MARK_DEBUG_ITER);
+ vgic_put_irq(kvm, irq);
}
}
@@ -61,15 +99,12 @@ static void iter_init(struct kvm *kvm, struct vgic_state_iter *iter,
iter->nr_cpus = nr_cpus;
iter->nr_spis = kvm->arch.vgic.nr_spis;
- if (kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3) {
- iter->nr_lpis = vgic_copy_lpi_list(kvm, NULL, &iter->lpi_array);
- if (iter->nr_lpis < 0)
- iter->nr_lpis = 0;
- }
+ if (kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3)
+ iter->nr_lpis = iter_mark_lpis(kvm);
/* Fast forward to the right position if needed */
while (pos--)
- iter_next(iter);
+ iter_next(kvm, iter);
}
static bool end_of_vgic(struct vgic_state_iter *iter)
@@ -114,7 +149,7 @@ static void *vgic_debug_next(struct seq_file *s, void *v, loff_t *pos)
struct vgic_state_iter *iter = kvm->arch.vgic.iter;
++*pos;
- iter_next(iter);
+ iter_next(kvm, iter);
if (end_of_vgic(iter))
iter = NULL;
return iter;
@@ -134,13 +169,14 @@ static void vgic_debug_stop(struct seq_file *s, void *v)
mutex_lock(&kvm->arch.config_lock);
iter = kvm->arch.vgic.iter;
- kfree(iter->lpi_array);
+ iter_unmark_lpis(kvm);
kfree(iter);
kvm->arch.vgic.iter = NULL;
mutex_unlock(&kvm->arch.config_lock);
}
-static void print_dist_state(struct seq_file *s, struct vgic_dist *dist)
+static void print_dist_state(struct seq_file *s, struct vgic_dist *dist,
+ struct vgic_state_iter *iter)
{
bool v3 = dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3;
@@ -149,7 +185,7 @@ static void print_dist_state(struct seq_file *s, struct vgic_dist *dist)
seq_printf(s, "vgic_model:\t%s\n", v3 ? "GICv3" : "GICv2");
seq_printf(s, "nr_spis:\t%d\n", dist->nr_spis);
if (v3)
- seq_printf(s, "nr_lpis:\t%d\n", atomic_read(&dist->lpi_count));
+ seq_printf(s, "nr_lpis:\t%d\n", iter->nr_lpis);
seq_printf(s, "enabled:\t%d\n", dist->enabled);
seq_printf(s, "\n");
@@ -236,7 +272,7 @@ static int vgic_debug_show(struct seq_file *s, void *v)
unsigned long flags;
if (iter->dist_id == 0) {
- print_dist_state(s, &kvm->arch.vgic);
+ print_dist_state(s, &kvm->arch.vgic, iter);
return 0;
}
@@ -246,11 +282,13 @@ static int vgic_debug_show(struct seq_file *s, void *v)
if (iter->vcpu_id < iter->nr_cpus)
vcpu = kvm_get_vcpu(kvm, iter->vcpu_id);
+ /*
+ * Expect this to succeed, as iter_mark_lpis() takes a reference on
+ * every LPI to be visited.
+ */
irq = vgic_get_irq(kvm, vcpu, iter->intid);
- if (!irq) {
- seq_printf(s, " LPI %4d freed\n", iter->intid);
- return 0;
- }
+ if (WARN_ON_ONCE(!irq))
+ return -EINVAL;
raw_spin_lock_irqsave(&irq->irq_lock, flags);
print_irq_state(s, irq, vcpu);
diff --git a/arch/arm64/kvm/vgic/vgic-its.c b/arch/arm64/kvm/vgic/vgic-its.c
index 420a71597b78..5025ac968d27 100644
--- a/arch/arm64/kvm/vgic/vgic-its.c
+++ b/arch/arm64/kvm/vgic/vgic-its.c
@@ -316,8 +316,6 @@ static int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq,
return 0;
}
-#define GIC_LPI_MAX_INTID ((1 << INTERRUPT_ID_BITS_ITS) - 1)
-
/*
* Create a snapshot of the current LPIs targeting @vcpu, so that we can
* enumerate those LPIs without holding any lock.
@@ -347,7 +345,7 @@ int vgic_copy_lpi_list(struct kvm *kvm, struct kvm_vcpu *vcpu, u32 **intid_ptr)
raw_spin_lock_irqsave(&dist->lpi_list_lock, flags);
rcu_read_lock();
- xas_for_each(&xas, irq, GIC_LPI_MAX_INTID) {
+ xas_for_each(&xas, irq, VGIC_LPI_MAX_INTID) {
if (i == irq_count)
break;
/* We don't need to "get" the IRQ, as we hold the list lock. */
diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h
index 0c2b82de8fa3..e0c77e1bd9f6 100644
--- a/arch/arm64/kvm/vgic/vgic.h
+++ b/arch/arm64/kvm/vgic/vgic.h
@@ -16,6 +16,7 @@
#define INTERRUPT_ID_BITS_SPIS 10
#define INTERRUPT_ID_BITS_ITS 16
+#define VGIC_LPI_MAX_INTID ((1 << INTERRUPT_ID_BITS_ITS) - 1)
#define VGIC_PRI_BITS 5
#define vgic_irq_is_sgi(intid) ((intid) < VGIC_NR_SGIS)
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 47035946648e..8eb72721dac1 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -276,6 +276,8 @@ struct vgic_dist {
/* Protects the lpi_list. */
raw_spinlock_t lpi_list_lock;
+
+#define LPI_XA_MARK_DEBUG_ITER XA_MARK_0
struct xarray lpi_xa;
atomic_t lpi_count;
--
2.44.0.769.g3c40516874-goog
next prev parent reply other threads:[~2024-04-22 20:02 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-22 20:01 [PATCH v3 00/19] KVM: arm64: Transition to a per-ITS translation cache Oliver Upton
2024-04-22 20:01 ` [PATCH v3 01/19] KVM: Treat the device list as an rculist Oliver Upton
2024-04-23 0:15 ` Sean Christopherson
2024-04-22 20:01 ` [PATCH v3 02/19] KVM: arm64: vgic-its: Walk LPI xarray in its_sync_lpi_pending_table() Oliver Upton
2024-04-22 20:01 ` [PATCH v3 03/19] KVM: arm64: vgic-its: Walk LPI xarray in vgic_its_invall() Oliver Upton
2024-04-22 20:01 ` [PATCH v3 04/19] KVM: arm64: vgic-its: Walk LPI xarray in vgic_its_cmd_handle_movall() Oliver Upton
2024-04-22 20:01 ` Oliver Upton [this message]
2024-04-22 20:01 ` [PATCH v3 06/19] KVM: arm64: vgic-its: Get rid of vgic_copy_lpi_list() Oliver Upton
2024-04-22 20:01 ` [PATCH v3 07/19] KVM: arm64: vgic-its: Scope translation cache invalidations to an ITS Oliver Upton
2024-04-22 20:01 ` [PATCH v3 08/19] KVM: arm64: vgic-its: Maintain a translation cache per ITS Oliver Upton
2024-04-22 20:01 ` [PATCH v3 09/19] KVM: arm64: vgic-its: Spin off helper for finding ITS by doorbell addr Oliver Upton
2024-04-22 20:01 ` [PATCH v3 10/19] KVM: arm64: vgic-its: Use the per-ITS translation cache for injection Oliver Upton
2024-04-22 20:01 ` [PATCH v3 11/19] KVM: arm64: vgic-its: Rip out the global translation cache Oliver Upton
2024-04-22 20:01 ` [PATCH v3 12/19] KVM: arm64: vgic-its: Get rid of the lpi_list_lock Oliver Upton
2024-04-22 20:01 ` [PATCH v3 13/19] KVM: selftests: Align with kernel's GIC definitions Oliver Upton
2024-04-22 20:01 ` [PATCH v3 14/19] KVM: selftests: Standardise layout of GIC frames Oliver Upton
2024-04-22 20:01 ` [PATCH v3 15/19] KVM: selftests: Add quadword MMIO accessors Oliver Upton
2024-04-22 20:01 ` [PATCH v3 16/19] KVM: selftests: Add a minimal library for interacting with an ITS Oliver Upton
2024-04-22 20:01 ` [PATCH v3 17/19] KVM: selftests: Add helper for enabling LPIs on a redistributor Oliver Upton
2024-04-22 20:01 ` [PATCH v3 18/19] KVM: selftests: Use MPIDR_HWID_BITMASK from cputype.h Oliver Upton
2024-04-22 20:01 ` [PATCH v3 19/19] KVM: selftests: Add stress test for LPI injection Oliver Upton
2024-04-25 12:33 ` [PATCH v3 00/19] KVM: arm64: Transition to a per-ITS translation cache Marc Zyngier
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