KVM: Break dependency between vcpu index in vcpus array and vcpu_id.

Archs are free to use vcpu_id as they see fit. For x86 it is used as
vcpu's apic id. New ioctl is added to configure boot vcpu id that was
assumed to be 0 till now.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Gleb Natapov 2009-06-09 15:56:28 +03:00 committed by Avi Kivity
parent 1ed0ce000a
commit 73880c80aa
9 changed files with 55 additions and 33 deletions

View file

@ -465,7 +465,6 @@ struct kvm_arch {
unsigned long metaphysical_rr4;
unsigned long vmm_init_rr;
int online_vcpus;
int is_sn2;
struct kvm_ioapic *vioapic;

View file

@ -25,6 +25,7 @@ config KVM
select PREEMPT_NOTIFIERS
select ANON_INODES
select HAVE_KVM_IRQCHIP
select KVM_APIC_ARCHITECTURE
---help---
Support hosting fully virtualized guest machines using hardware
virtualization extensions. You will need a fairly recent

View file

@ -338,7 +338,7 @@ static struct kvm_vcpu *lid_to_vcpu(struct kvm *kvm, unsigned long id,
union ia64_lid lid;
int i;
for (i = 0; i < kvm->arch.online_vcpus; i++) {
for (i = 0; i < atomic_read(&kvm->online_vcpus); i++) {
if (kvm->vcpus[i]) {
lid.val = VCPU_LID(kvm->vcpus[i]);
if (lid.id == id && lid.eid == eid)
@ -412,7 +412,7 @@ static int handle_global_purge(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
call_data.ptc_g_data = p->u.ptc_g_data;
for (i = 0; i < kvm->arch.online_vcpus; i++) {
for (i = 0; i < atomic_read(&kvm->online_vcpus); i++) {
if (!kvm->vcpus[i] || kvm->vcpus[i]->arch.mp_state ==
KVM_MP_STATE_UNINITIALIZED ||
vcpu == kvm->vcpus[i])
@ -852,8 +852,6 @@ struct kvm *kvm_arch_create_vm(void)
kvm_init_vm(kvm);
kvm->arch.online_vcpus = 0;
return kvm;
}
@ -1356,8 +1354,6 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm,
goto fail;
}
kvm->arch.online_vcpus++;
return vcpu;
fail:
return ERR_PTR(r);

View file

@ -831,7 +831,7 @@ static void vcpu_set_itc(struct kvm_vcpu *vcpu, u64 val)
kvm = (struct kvm *)KVM_VM_BASE;
if (kvm_vcpu_is_bsp(vcpu)) {
for (i = 0; i < kvm->arch.online_vcpus; i++) {
for (i = 0; i < atomic_read(&kvm->online_vcpus); i++) {
v = (struct kvm_vcpu *)((char *)vcpu +
sizeof(struct kvm_vcpu_data) * i);
VMX(v, itc_offset) = itc_offset;

View file

@ -27,6 +27,7 @@ config KVM
select ANON_INODES
select HAVE_KVM_IRQCHIP
select HAVE_KVM_EVENTFD
select KVM_APIC_ARCHITECTURE
---help---
Support hosting fully virtualized guest machines using hardware
virtualization extensions. You will need a fairly recent

View file

@ -430,6 +430,7 @@ struct kvm_trace_rec {
#ifdef __KVM_HAVE_PIT
#define KVM_CAP_PIT2 33
#endif
#define KVM_CAP_SET_BOOT_CPU_ID 34
#ifdef KVM_CAP_IRQ_ROUTING
@ -537,6 +538,7 @@ struct kvm_irqfd {
#define KVM_DEASSIGN_DEV_IRQ _IOW(KVMIO, 0x75, struct kvm_assigned_irq)
#define KVM_IRQFD _IOW(KVMIO, 0x76, struct kvm_irqfd)
#define KVM_CREATE_PIT2 _IOW(KVMIO, 0x77, struct kvm_pit_config)
#define KVM_SET_BOOT_CPU_ID _IO(KVMIO, 0x78)
/*
* ioctls for vcpu fds

View file

@ -131,8 +131,12 @@ struct kvm {
int nmemslots;
struct kvm_memory_slot memslots[KVM_MEMORY_SLOTS +
KVM_PRIVATE_MEM_SLOTS];
#ifdef CONFIG_KVM_APIC_ARCHITECTURE
u32 bsp_vcpu_id;
struct kvm_vcpu *bsp_vcpu;
#endif
struct kvm_vcpu *vcpus[KVM_MAX_VCPUS];
atomic_t online_vcpus;
struct list_head vm_list;
struct mutex lock;
struct kvm_io_bus mmio_bus;
@ -550,8 +554,10 @@ static inline void kvm_irqfd_release(struct kvm *kvm) {}
#endif /* CONFIG_HAVE_KVM_EVENTFD */
#ifdef CONFIG_KVM_APIC_ARCHITECTURE
static inline bool kvm_vcpu_is_bsp(struct kvm_vcpu *vcpu)
{
return vcpu->kvm->bsp_vcpu == vcpu;
}
#endif
#endif

View file

@ -9,3 +9,6 @@ config HAVE_KVM_IRQCHIP
config HAVE_KVM_EVENTFD
bool
select EVENTFD
config KVM_APIC_ARCHITECTURE
bool

View file

@ -689,11 +689,6 @@ out:
}
#endif
static inline int valid_vcpu(int n)
{
return likely(n >= 0 && n < KVM_MAX_VCPUS);
}
inline int kvm_is_mmio_pfn(pfn_t pfn)
{
if (pfn_valid(pfn)) {
@ -1714,24 +1709,18 @@ static struct file_operations kvm_vcpu_fops = {
*/
static int create_vcpu_fd(struct kvm_vcpu *vcpu)
{
int fd = anon_inode_getfd("kvm-vcpu", &kvm_vcpu_fops, vcpu, 0);
if (fd < 0)
kvm_put_kvm(vcpu->kvm);
return fd;
return anon_inode_getfd("kvm-vcpu", &kvm_vcpu_fops, vcpu, 0);
}
/*
* Creates some virtual cpus. Good luck creating more than one.
*/
static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n)
static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
{
int r;
struct kvm_vcpu *vcpu;
if (!valid_vcpu(n))
return -EINVAL;
vcpu = kvm_arch_vcpu_create(kvm, n);
vcpu = kvm_arch_vcpu_create(kvm, id);
if (IS_ERR(vcpu))
return PTR_ERR(vcpu);
@ -1742,25 +1731,38 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n)
return r;
mutex_lock(&kvm->lock);
if (kvm->vcpus[n]) {
r = -EEXIST;
if (atomic_read(&kvm->online_vcpus) == KVM_MAX_VCPUS) {
r = -EINVAL;
goto vcpu_destroy;
}
kvm->vcpus[n] = vcpu;
if (n == 0)
kvm->bsp_vcpu = vcpu;
mutex_unlock(&kvm->lock);
for (r = 0; r < atomic_read(&kvm->online_vcpus); r++)
if (kvm->vcpus[r]->vcpu_id == id) {
r = -EEXIST;
goto vcpu_destroy;
}
BUG_ON(kvm->vcpus[atomic_read(&kvm->online_vcpus)]);
/* Now it's all set up, let userspace reach it */
kvm_get_kvm(kvm);
r = create_vcpu_fd(vcpu);
if (r < 0)
goto unlink;
if (r < 0) {
kvm_put_kvm(kvm);
goto vcpu_destroy;
}
kvm->vcpus[atomic_read(&kvm->online_vcpus)] = vcpu;
smp_wmb();
atomic_inc(&kvm->online_vcpus);
#ifdef CONFIG_KVM_APIC_ARCHITECTURE
if (kvm->bsp_vcpu_id == id)
kvm->bsp_vcpu = vcpu;
#endif
mutex_unlock(&kvm->lock);
return r;
unlink:
mutex_lock(&kvm->lock);
kvm->vcpus[n] = NULL;
vcpu_destroy:
mutex_unlock(&kvm->lock);
kvm_arch_vcpu_destroy(vcpu);
@ -2233,6 +2235,15 @@ static long kvm_vm_ioctl(struct file *filp,
r = kvm_irqfd(kvm, data.fd, data.gsi, data.flags);
break;
}
#ifdef CONFIG_KVM_APIC_ARCHITECTURE
case KVM_SET_BOOT_CPU_ID:
r = 0;
if (atomic_read(&kvm->online_vcpus) != 0)
r = -EBUSY;
else
kvm->bsp_vcpu_id = arg;
break;
#endif
default:
r = kvm_arch_vm_ioctl(filp, ioctl, arg);
}
@ -2299,6 +2310,9 @@ static long kvm_dev_ioctl_check_extension_generic(long arg)
case KVM_CAP_USER_MEMORY:
case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:
case KVM_CAP_JOIN_MEMORY_REGIONS_WORKS:
#ifdef CONFIG_KVM_APIC_ARCHITECTURE
case KVM_CAP_SET_BOOT_CPU_ID:
#endif
return 1;
#ifdef CONFIG_HAVE_KVM_IRQCHIP
case KVM_CAP_IRQ_ROUTING: