KVM: Dynamically allocate vcpus
This patch converts the vcpus array in "struct kvm" to a pointer
array, and changes the "vcpu_create" and "vcpu_setup" hooks into one
"vcpu_create" call which does the allocation and initialization of the
vcpu (calling back into the kvm_vcpu_init core helper).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index bf8b8f0..69d9ab4 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -266,8 +266,10 @@
atomic_set(&completed, 0);
cpus_clear(cpus);
needed = 0;
- for (i = 0; i < kvm->nvcpus; ++i) {
- vcpu = &kvm->vcpus[i];
+ for (i = 0; i < KVM_MAX_VCPUS; ++i) {
+ vcpu = kvm->vcpus[i];
+ if (!vcpu)
+ continue;
if (test_and_set_bit(KVM_TLB_FLUSH, &vcpu->requests))
continue;
cpu = vcpu->cpu;
@@ -291,10 +293,61 @@
}
}
+int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
+{
+ struct page *page;
+ int r;
+
+ mutex_init(&vcpu->mutex);
+ vcpu->cpu = -1;
+ vcpu->mmu.root_hpa = INVALID_PAGE;
+ vcpu->kvm = kvm;
+ vcpu->vcpu_id = id;
+
+ page = alloc_page(GFP_KERNEL | __GFP_ZERO);
+ if (!page) {
+ r = -ENOMEM;
+ goto fail;
+ }
+ vcpu->run = page_address(page);
+
+ page = alloc_page(GFP_KERNEL | __GFP_ZERO);
+ if (!page) {
+ r = -ENOMEM;
+ goto fail_free_run;
+ }
+ vcpu->pio_data = page_address(page);
+
+ vcpu->host_fx_image = (char*)ALIGN((hva_t)vcpu->fx_buf,
+ FX_IMAGE_ALIGN);
+ vcpu->guest_fx_image = vcpu->host_fx_image + FX_IMAGE_SIZE;
+
+ r = kvm_mmu_create(vcpu);
+ if (r < 0)
+ goto fail_free_pio_data;
+
+ return 0;
+
+fail_free_pio_data:
+ free_page((unsigned long)vcpu->pio_data);
+fail_free_run:
+ free_page((unsigned long)vcpu->run);
+fail:
+ return -ENOMEM;
+}
+EXPORT_SYMBOL_GPL(kvm_vcpu_init);
+
+void kvm_vcpu_uninit(struct kvm_vcpu *vcpu)
+{
+ kvm_mmu_destroy(vcpu);
+ free_page((unsigned long)vcpu->pio_data);
+ free_page((unsigned long)vcpu->run);
+}
+EXPORT_SYMBOL_GPL(kvm_vcpu_uninit);
+
static struct kvm *kvm_create_vm(void)
{
struct kvm *kvm = kzalloc(sizeof(struct kvm), GFP_KERNEL);
- int i;
if (!kvm)
return ERR_PTR(-ENOMEM);
@@ -303,14 +356,6 @@
spin_lock_init(&kvm->lock);
INIT_LIST_HEAD(&kvm->active_mmu_pages);
kvm_io_bus_init(&kvm->mmio_bus);
- for (i = 0; i < KVM_MAX_VCPUS; ++i) {
- struct kvm_vcpu *vcpu = &kvm->vcpus[i];
-
- mutex_init(&vcpu->mutex);
- vcpu->cpu = -1;
- vcpu->kvm = kvm;
- vcpu->mmu.root_hpa = INVALID_PAGE;
- }
spin_lock(&kvm_lock);
list_add(&kvm->vm_list, &vm_list);
spin_unlock(&kvm_lock);
@@ -367,30 +412,11 @@
static void kvm_unload_vcpu_mmu(struct kvm_vcpu *vcpu)
{
- if (!vcpu->valid)
- return;
-
vcpu_load(vcpu);
kvm_mmu_unload(vcpu);
vcpu_put(vcpu);
}
-static void kvm_free_vcpu(struct kvm_vcpu *vcpu)
-{
- if (!vcpu->valid)
- return;
-
- vcpu_load(vcpu);
- kvm_mmu_destroy(vcpu);
- vcpu_put(vcpu);
- kvm_arch_ops->vcpu_free(vcpu);
- free_page((unsigned long)vcpu->run);
- vcpu->run = NULL;
- free_page((unsigned long)vcpu->pio_data);
- vcpu->pio_data = NULL;
- free_pio_guest_pages(vcpu);
-}
-
static void kvm_free_vcpus(struct kvm *kvm)
{
unsigned int i;
@@ -399,9 +425,15 @@
* Unpin any mmu pages first.
*/
for (i = 0; i < KVM_MAX_VCPUS; ++i)
- kvm_unload_vcpu_mmu(&kvm->vcpus[i]);
- for (i = 0; i < KVM_MAX_VCPUS; ++i)
- kvm_free_vcpu(&kvm->vcpus[i]);
+ if (kvm->vcpus[i])
+ kvm_unload_vcpu_mmu(kvm->vcpus[i]);
+ for (i = 0; i < KVM_MAX_VCPUS; ++i) {
+ if (kvm->vcpus[i]) {
+ kvm_arch_ops->vcpu_free(kvm->vcpus[i]);
+ kvm->vcpus[i] = NULL;
+ }
+ }
+
}
static int kvm_dev_release(struct inode *inode, struct file *filp)
@@ -2372,77 +2404,47 @@
{
int r;
struct kvm_vcpu *vcpu;
- struct page *page;
- r = -EINVAL;
if (!valid_vcpu(n))
- goto out;
+ return -EINVAL;
- vcpu = &kvm->vcpus[n];
- vcpu->vcpu_id = n;
+ vcpu = kvm_arch_ops->vcpu_create(kvm, n);
+ if (IS_ERR(vcpu))
+ return PTR_ERR(vcpu);
- mutex_lock(&vcpu->mutex);
-
- if (vcpu->valid) {
- mutex_unlock(&vcpu->mutex);
- return -EEXIST;
- }
-
- page = alloc_page(GFP_KERNEL | __GFP_ZERO);
- r = -ENOMEM;
- if (!page)
- goto out_unlock;
- vcpu->run = page_address(page);
-
- page = alloc_page(GFP_KERNEL | __GFP_ZERO);
- r = -ENOMEM;
- if (!page)
- goto out_free_run;
- vcpu->pio_data = page_address(page);
-
- vcpu->host_fx_image = (char*)ALIGN((hva_t)vcpu->fx_buf,
- FX_IMAGE_ALIGN);
- vcpu->guest_fx_image = vcpu->host_fx_image + FX_IMAGE_SIZE;
- vcpu->cr0 = 0x10;
-
- r = kvm_arch_ops->vcpu_create(vcpu);
- if (r < 0)
- goto out_free_vcpus;
-
- r = kvm_mmu_create(vcpu);
- if (r < 0)
- goto out_free_vcpus;
-
- kvm_arch_ops->vcpu_load(vcpu);
+ vcpu_load(vcpu);
r = kvm_mmu_setup(vcpu);
- if (r >= 0)
- r = kvm_arch_ops->vcpu_setup(vcpu);
vcpu_put(vcpu);
-
if (r < 0)
- goto out_free_vcpus;
+ goto free_vcpu;
+ spin_lock(&kvm->lock);
+ if (kvm->vcpus[n]) {
+ r = -EEXIST;
+ spin_unlock(&kvm->lock);
+ goto mmu_unload;
+ }
+ kvm->vcpus[n] = vcpu;
+ spin_unlock(&kvm->lock);
+
+ /* Now it's all set up, let userspace reach it */
r = create_vcpu_fd(vcpu);
if (r < 0)
- goto out_free_vcpus;
-
- spin_lock(&kvm_lock);
- if (n >= kvm->nvcpus)
- kvm->nvcpus = n + 1;
- spin_unlock(&kvm_lock);
-
- vcpu->valid = 1;
-
+ goto unlink;
return r;
-out_free_vcpus:
- kvm_free_vcpu(vcpu);
-out_free_run:
- free_page((unsigned long)vcpu->run);
- vcpu->run = NULL;
-out_unlock:
- mutex_unlock(&vcpu->mutex);
-out:
+unlink:
+ spin_lock(&kvm->lock);
+ kvm->vcpus[n] = NULL;
+ spin_unlock(&kvm->lock);
+
+mmu_unload:
+ vcpu_load(vcpu);
+ kvm_mmu_unload(vcpu);
+ vcpu_put(vcpu);
+
+free_vcpu:
+ kvm_arch_ops->vcpu_free(vcpu);
return r;
}
@@ -2935,9 +2937,12 @@
int i;
spin_lock(&kvm_lock);
- list_for_each_entry(vm, &vm_list, vm_list)
+ list_for_each_entry(vm, &vm_list, vm_list) {
+ spin_lock(&vm->lock);
for (i = 0; i < KVM_MAX_VCPUS; ++i) {
- vcpu = &vm->vcpus[i];
+ vcpu = vm->vcpus[i];
+ if (!vcpu)
+ continue;
/*
* If the vcpu is locked, then it is running on some
* other cpu and therefore it is not cached on the
@@ -2954,6 +2959,8 @@
mutex_unlock(&vcpu->mutex);
}
}
+ spin_unlock(&vm->lock);
+ }
spin_unlock(&kvm_lock);
}
@@ -3078,8 +3085,9 @@
spin_lock(&kvm_lock);
list_for_each_entry(kvm, &vm_list, vm_list)
for (i = 0; i < KVM_MAX_VCPUS; ++i) {
- vcpu = &kvm->vcpus[i];
- total += *(u32 *)((void *)vcpu + offset);
+ vcpu = kvm->vcpus[i];
+ if (vcpu)
+ total += *(u32 *)((void *)vcpu + offset);
}
spin_unlock(&kvm_lock);
return total;