[PATCH 10/60] kvm: Move vcpu_array to struct kvm_plane
Jörg Rödel
joro at 8bytes.org
Mon Jun 8 07:42:02 PDT 2026
From: Paolo Bonzini <pbonzini at redhat.com>
Each plane will have its own set of VCPUs, so move the vcpu_array to
the plane structure.
Signed-off-by: Paolo Bonzini <pbonzini at redhat.com>
Co-developed-by: Joerg Roedel <joerg.roedel at amd.com>
Signed-off-by: Joerg Roedel <joerg.roedel at amd.com>
---
include/linux/kvm_host.h | 30 +++++++++++++++++++++---------
virt/kvm/kvm_main.c | 33 +++++++++++++++++++++++++--------
2 files changed, 46 insertions(+), 17 deletions(-)
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 5be4c9f118b4..5a72f73a2f31 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -324,12 +324,14 @@ struct kvm_mmio_fragment {
struct kvm_vcpu {
struct kvm *kvm;
+ struct kvm_plane *plane;
+
#ifdef CONFIG_PREEMPT_NOTIFIERS
struct preempt_notifier preempt_notifier;
#endif
int cpu;
int vcpu_id; /* id given by userspace at creation */
- int vcpu_idx; /* index into kvm->vcpu_array */
+ int vcpu_idx; /* index into kvm->planes[]->vcpu_array */
int ____srcu_idx; /* Don't use this directly. You've been warned. */
#ifdef CONFIG_PROVE_RCU
int srcu_depth;
@@ -770,6 +772,9 @@ struct kvm_memslots {
struct kvm_plane {
struct kvm *kvm;
unsigned level;
+
+ /* Per-Plane VCPU array */
+ struct xarray vcpu_array;
};
struct kvm {
@@ -795,7 +800,6 @@ struct kvm {
struct kvm_memslots __memslots[KVM_MAX_NR_ADDRESS_SPACES][2];
/* The current active memslot set for each address space */
struct kvm_memslots __rcu *memslots[KVM_MAX_NR_ADDRESS_SPACES];
- struct xarray vcpu_array;
/*
* Protected by slots_lock, but can be read outside if an
* incorrect answer is acceptable.
@@ -996,9 +1000,9 @@ static inline struct kvm_io_bus *kvm_get_bus(struct kvm *kvm, enum kvm_bus idx)
lockdep_is_held(&kvm->slots_lock));
}
-static inline struct kvm_vcpu *kvm_get_vcpu(struct kvm *kvm, int i)
+static inline struct kvm_vcpu *plane_get_vcpu(struct kvm_plane *plane, int i)
{
- int num_vcpus = atomic_read(&kvm->online_vcpus);
+ int num_vcpus = atomic_read(&plane->kvm->online_vcpus);
/*
* Explicitly verify the target vCPU is online, as the anti-speculation
@@ -1012,13 +1016,21 @@ static inline struct kvm_vcpu *kvm_get_vcpu(struct kvm *kvm, int i)
/* Pairs with smp_wmb() in kvm_vm_ioctl_create_vcpu. */
smp_rmb();
- return xa_load(&kvm->vcpu_array, i);
+ return xa_load(&plane->vcpu_array, i);
}
-#define kvm_for_each_vcpu(idx, vcpup, kvm) \
- if (atomic_read(&kvm->online_vcpus)) \
- xa_for_each_range(&kvm->vcpu_array, idx, vcpup, 0, \
- (atomic_read(&kvm->online_vcpus) - 1))
+static inline struct kvm_vcpu *kvm_get_vcpu(struct kvm *kvm, int i)
+{
+ return plane_get_vcpu(kvm->planes[0], i);
+}
+
+#define plane_for_each_vcpu(idx, vcpup, plane) \
+ if (atomic_read(&plane->kvm->online_vcpus)) \
+ xa_for_each_range(&plane->vcpu_array, idx, vcpup, 0, \
+ (atomic_read(&plane->kvm->online_vcpus) - 1))
+
+#define kvm_for_each_vcpu(idx, vcpup, kvm) \
+ plane_for_each_vcpu(idx, vcpup, kvm->planes[0])
static inline struct kvm_vcpu *kvm_get_vcpu_by_id(struct kvm *kvm, int id)
{
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index a68469c6d12e..668645dd3945 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -443,6 +443,7 @@ static void kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
mutex_init(&vcpu->mutex);
vcpu->cpu = -1;
vcpu->kvm = kvm;
+ vcpu->plane = kvm->planes[0];
vcpu->vcpu_id = id;
vcpu->pid = NULL;
rwlock_init(&vcpu->pid_lock);
@@ -479,14 +480,14 @@ static void kvm_vcpu_destroy(struct kvm_vcpu *vcpu)
kmem_cache_free(kvm_vcpu_cache, vcpu);
}
-void kvm_destroy_vcpus(struct kvm *kvm)
+static void plane_destroy_vcpus(struct kvm_plane *plane)
{
unsigned long i;
struct kvm_vcpu *vcpu;
- kvm_for_each_vcpu(i, vcpu, kvm) {
+ plane_for_each_vcpu(i, vcpu, plane) {
kvm_vcpu_destroy(vcpu);
- xa_erase(&kvm->vcpu_array, i);
+ xa_erase(&plane->vcpu_array, i);
/*
* Assert that the vCPU isn't visible in any way, to ensure KVM
@@ -494,7 +495,22 @@ void kvm_destroy_vcpus(struct kvm *kvm)
* in VM-wide request, e.g. to flush remote TLBs when tearing
* down MMUs, or to mark the VM dead if a KVM_BUG_ON() fires.
*/
- WARN_ON_ONCE(xa_load(&kvm->vcpu_array, i) || kvm_get_vcpu(kvm, i));
+ WARN_ON_ONCE(xa_load(&plane->vcpu_array, i) || plane_get_vcpu(plane, i));
+ }
+
+}
+
+void kvm_destroy_vcpus(struct kvm *kvm)
+{
+ unsigned lvl;
+
+ for (lvl = KVM_MAX_PLANES; lvl > 0; lvl--) {
+ struct kvm_plane *plane = kvm->planes[lvl - 1];
+
+ if (plane == NULL)
+ continue;
+
+ plane_destroy_vcpus(plane);
}
atomic_set(&kvm->online_vcpus, 0);
@@ -1105,6 +1121,8 @@ static struct kvm_plane *kvm_create_plane(struct kvm *kvm, unsigned plane_level)
plane->kvm = kvm;
plane->level = plane_level;
+ xa_init(&plane->vcpu_array);
+
kvm->planes[plane_level] = plane;
return plane;
@@ -1146,7 +1164,6 @@ static struct kvm *kvm_create_vm(unsigned long type, const char *fdname)
mutex_init(&kvm->slots_arch_lock);
spin_lock_init(&kvm->mn_invalidate_lock);
rcuwait_init(&kvm->mn_memslots_update_rcuwait);
- xa_init(&kvm->vcpu_array);
#ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES
xa_init(&kvm->mem_attr_array);
#endif
@@ -4039,7 +4056,7 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool yield_to_kernel_mode)
if (idx == me->vcpu_idx)
continue;
- vcpu = xa_load(&kvm->vcpu_array, idx);
+ vcpu = xa_load(&kvm->planes[0]->vcpu_array, idx);
if (!READ_ONCE(vcpu->ready))
continue;
if (kvm_vcpu_is_blocking(vcpu) && !vcpu_dy_runnable(vcpu))
@@ -4258,7 +4275,7 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, unsigned long id)
}
vcpu->vcpu_idx = atomic_read(&kvm->online_vcpus);
- r = xa_insert(&kvm->vcpu_array, vcpu->vcpu_idx, vcpu, GFP_KERNEL_ACCOUNT);
+ r = xa_insert(&kvm->planes[0]->vcpu_array, vcpu->vcpu_idx, vcpu, GFP_KERNEL_ACCOUNT);
WARN_ON_ONCE(r == -EBUSY);
if (r)
goto unlock_vcpu_destroy;
@@ -4293,7 +4310,7 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, unsigned long id)
kvm_put_xa_erase:
mutex_unlock(&vcpu->mutex);
kvm_put_kvm_no_destroy(kvm);
- xa_erase(&kvm->vcpu_array, vcpu->vcpu_idx);
+ xa_erase(&kvm->planes[0]->vcpu_array, vcpu->vcpu_idx);
unlock_vcpu_destroy:
mutex_unlock(&kvm->lock);
kvm_dirty_ring_free(&vcpu->dirty_ring);
--
2.53.0
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