[PATCH 08/29] KVM: move vcpu_array to struct kvm_plane

[Paolo Bonzini <pbonzini@redhat.com>]

Different planes may have only a subset of the vCPUs available in
the initial plane, therefore vcpu_array must also be moved to
struct kvm_plane.  New functions allow accessing the vCPUs of
a struct kvm_plane and, as usual, the older names automatically
go through kvm->planes[0].

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 include/linux/kvm_host.h | 29 +++++++++++++++++++++--------
 virt/kvm/kvm_main.c      | 22 +++++++++++++++-------
 2 files changed, 36 insertions(+), 15 deletions(-)

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 0db27814294f..0a91b556767e 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -763,6 +763,7 @@ struct kvm_memslots {
 
 struct kvm_plane {
 	struct kvm *kvm;
+	struct xarray vcpu_array;
 #ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES
 	/* Protected by slots_locks (for writes) and RCU (for reads) */
 	struct xarray mem_attr_array;
@@ -795,7 +796,6 @@ 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;
 
 	struct kvm_plane *planes[KVM_MAX_VCPU_PLANES];
 
@@ -990,20 +990,20 @@ static inline struct kvm_io_bus *kvm_get_bus(struct kvm *kvm, enum kvm_bus idx)
 				      !refcount_read(&kvm->users_count));
 }
 
-static inline struct kvm_vcpu *kvm_get_vcpu(struct kvm *kvm, int i)
+static inline struct kvm_vcpu *kvm_get_plane_vcpu(struct kvm_plane *plane, int i)
 {
-	struct kvm_vcpu *vcpu = xa_load(&kvm->vcpu_array, i);
+	struct kvm_vcpu *vcpu = xa_load(&plane->vcpu_array, i);
 	if (vcpu && unlikely(vcpu->plane == -1))
 		return NULL;
 
 	return vcpu;
 }
 
-#define kvm_for_each_vcpu(idx, vcpup, kvm)			\
-	xa_for_each(&kvm->vcpu_array, idx, vcpup)		\
+#define kvm_for_each_plane_vcpu(idx, vcpup, plane_)				\
+	xa_for_each(&(plane_)->vcpu_array, idx, vcpup)		\
 		if ((vcpup)->plane == -1) ; else		\
 
-static inline struct kvm_vcpu *kvm_get_vcpu_by_id(struct kvm *kvm, int id)
+static inline struct kvm_vcpu *kvm_get_plane_vcpu_by_id(struct kvm_plane *plane, int id)
 {
 	struct kvm_vcpu *vcpu = NULL;
 	unsigned long i;
@@ -1011,15 +1011,28 @@ static inline struct kvm_vcpu *kvm_get_vcpu_by_id(struct kvm *kvm, int id)
 	if (id < 0)
 		return NULL;
 	if (id < KVM_MAX_VCPUS)
-		vcpu = kvm_get_vcpu(kvm, id);
+		vcpu = kvm_get_plane_vcpu(plane, id);
 	if (vcpu && vcpu->vcpu_id == id)
 		return vcpu;
-	kvm_for_each_vcpu(i, vcpu, kvm)
+	kvm_for_each_plane_vcpu(i, vcpu, plane)
 		if (vcpu->vcpu_id == id)
 			return vcpu;
 	return NULL;
 }
 
+static inline struct kvm_vcpu *kvm_get_vcpu(struct kvm *kvm, int i)
+{
+	return kvm_get_plane_vcpu(kvm->planes[0], i);
+}
+
+#define kvm_for_each_vcpu(idx, vcpup, kvm)				\
+	kvm_for_each_plane_vcpu(idx, vcpup, kvm->planes[0])
+
+static inline struct kvm_vcpu *kvm_get_vcpu_by_id(struct kvm *kvm, int id)
+{
+	return kvm_get_plane_vcpu_by_id(kvm->planes[0], id);
+}
+
 void kvm_destroy_vcpus(struct kvm *kvm);
 
 void vcpu_load(struct kvm_vcpu *vcpu);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index eba02cb7cc57..cd4dfc399cad 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -481,12 +481,19 @@ static void kvm_vcpu_destroy(struct kvm_vcpu *vcpu)
 
 void kvm_destroy_vcpus(struct kvm *kvm)
 {
+	int j;
 	unsigned long i;
 	struct kvm_vcpu *vcpu;
 
-	kvm_for_each_vcpu(i, vcpu, kvm) {
-		kvm_vcpu_destroy(vcpu);
-		xa_erase(&kvm->vcpu_array, i);
+	for (j = ARRAY_SIZE(kvm->planes) - 1; j >= 0; j--) {
+		struct kvm_plane *plane = kvm->planes[j];
+		if (!plane)
+			continue;
+
+		kvm_for_each_plane_vcpu(i, vcpu, plane) {
+			kvm_vcpu_destroy(vcpu);
+			xa_erase(&plane->vcpu_array, i);
+		}
 	}
 
 	atomic_set(&kvm->online_vcpus, 0);
@@ -1110,6 +1117,7 @@ static struct kvm_plane *kvm_create_vm_plane(struct kvm *kvm, unsigned plane_id)
 	plane->kvm = kvm;
 	plane->plane = plane_id;
 
+	xa_init(&plane->vcpu_array);
 #ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES
 	xa_init(&plane->mem_attr_array);
 #endif
@@ -1137,7 +1145,6 @@ 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);
 
 	INIT_LIST_HEAD(&kvm->gpc_list);
 	spin_lock_init(&kvm->gpc_lock);
@@ -3930,6 +3937,7 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool yield_to_kernel_mode)
 {
 	int nr_vcpus, start, i, idx, yielded;
 	struct kvm *kvm = me->kvm;
+	struct kvm_plane *plane = kvm->planes[me->plane];
 	struct kvm_vcpu *vcpu;
 	int try = 3;
 
@@ -3967,7 +3975,7 @@ 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(&plane->vcpu_array, idx);
 		if (!READ_ONCE(vcpu->ready))
 			continue;
 		if (kvm_vcpu_is_blocking(vcpu) && !vcpu_dy_runnable(vcpu))
@@ -4192,7 +4200,7 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, unsigned long id)
 	 */
 	vcpu->plane = -1;
 	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;
@@ -4228,7 +4236,7 @@ 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);
-- 
2.49.0