[PATCH 09/60] kvm: Introduce struct kvm_plane
From: Jörg Rödel <joro@8bytes.org>
Date: 2026-06-08 14:43:15
Also in:
kvm, kvm-riscv, kvmarm, linux-mips, lkml, loongarch
Subsystem:
kernel virtual machine (kvm), the rest · Maintainers:
Paolo Bonzini, Linus Torvalds
From: Paolo Bonzini <pbonzini@redhat.com> Introduce a data structure to keep VM-wide per-plane state. Initialize the structure with a back-pointer to struct kvm and the plane level the structure represents. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Co-developed-by: Joerg Roedel <redacted> Signed-off-by: Joerg Roedel <redacted> --- include/linux/kvm_host.h | 7 +++++++ include/uapi/linux/kvm.h | 6 ++++++ virt/kvm/kvm_main.c | 41 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 54 insertions(+)
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 4c14aee1fb06..5be4c9f118b4 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h@@ -767,6 +767,11 @@ struct kvm_memslots { int node_idx; }; +struct kvm_plane { + struct kvm *kvm; + unsigned level; +}; + struct kvm { #ifdef KVM_HAVE_MMU_RWLOCK rwlock_t mmu_lock;
@@ -806,6 +811,8 @@ struct kvm { spinlock_t gpc_lock; struct list_head gpc_list; + struct kvm_plane *planes[KVM_MAX_PLANES]; + /* * created_vcpus is protected by kvm->lock, and is incremented * at the beginning of KVM_CREATE_VCPU. online_vcpus is only
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 6c8afa2047bf..813f964a6dc1 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h@@ -730,6 +730,11 @@ struct kvm_enable_cap { #define KVM_GET_EMULATED_CPUID _IOWR(KVMIO, 0x09, struct kvm_cpuid2) #define KVM_GET_MSR_FEATURE_INDEX_LIST _IOWR(KVMIO, 0x0a, struct kvm_msr_list) +/* + * Maximum number of supported planes + */ +#define KVM_MAX_PLANES 16 + /* * Extension capability list. */
@@ -996,6 +1001,7 @@ struct kvm_enable_cap { #define KVM_CAP_S390_USER_OPEREXEC 246 #define KVM_CAP_S390_KEYOP 247 #define KVM_CAP_S390_VSIE_ESAMODE 248 +#define KVM_CAP_PLANES 249 struct kvm_irq_routing_irqchip { __u32 irqchip;
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 881f92d7a469..a68469c6d12e 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c@@ -1095,6 +1095,38 @@ static inline struct kvm_io_bus *kvm_get_bus_for_destruction(struct kvm *kvm, static int kvm_enable_virtualization(void); static void kvm_disable_virtualization(void); +static struct kvm_plane *kvm_create_plane(struct kvm *kvm, unsigned plane_level) +{ + struct kvm_plane *plane = kzalloc(sizeof(*plane), GFP_KERNEL_ACCOUNT); + + if (!plane) + return NULL; + + plane->kvm = kvm; + plane->level = plane_level; + + kvm->planes[plane_level] = plane; + + return plane; +} + +static void kvm_destroy_one_plane(struct kvm_plane *plane) +{ + kfree(plane); +} + +static void kvm_destroy_planes(struct kvm *kvm) +{ + int i; + + for (i = 0; i < KVM_MAX_PLANES; ++i) { + if (kvm->planes[i] == NULL) + continue; + kvm_destroy_one_plane(kvm->planes[i]); + kvm->planes[i] = NULL; + } +} + static struct kvm *kvm_create_vm(unsigned long type, const char *fdname) { struct kvm *kvm = kvm_arch_alloc_vm();
@@ -1127,6 +1159,12 @@ static struct kvm *kvm_create_vm(unsigned long type, const char *fdname) BUILD_BUG_ON(KVM_MEM_SLOTS_NUM > SHRT_MAX); + /* Initialize planes array and allocate plane 0 */ + if (kvm_create_plane(kvm, 0) == NULL) { + r = -ENOMEM; + goto out_no_planes; + } + /* * Force subsequent debugfs file creations to fail if the VM directory * is not created (by kvm_create_vm_debugfs()).
@@ -1225,6 +1263,8 @@ static struct kvm *kvm_create_vm(unsigned long type, const char *fdname) out_err_no_irq_srcu: cleanup_srcu_struct(&kvm->srcu); out_err_no_srcu: + kvm_destroy_planes(kvm); +out_no_planes: kvm_arch_free_vm(kvm); mmdrop(current->mm); return ERR_PTR(r);
@@ -1304,6 +1344,7 @@ static void kvm_destroy_vm(struct kvm *kvm) xa_destroy(&kvm->mem_attr_array); #endif kvm_arch_free_vm(kvm); + kvm_destroy_planes(kvm); preempt_notifier_dec(); kvm_disable_virtualization(); mmdrop(mm);
--
2.53.0