| Message ID | 1243504487-25796-4-git-send-email-gleb@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, May 28, 2009 at 12:54:46PM +0300, Gleb Natapov wrote: > 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> > --- > include/linux/kvm.h | 2 + > include/linux/kvm_host.h | 2 + > virt/kvm/kvm_main.c | 50 ++++++++++++++++++++++++++------------------- > 3 files changed, 33 insertions(+), 21 deletions(-) > > diff --git a/include/linux/kvm.h b/include/linux/kvm.h > index 632a856..d10ab5d 100644 > --- a/include/linux/kvm.h > +++ b/include/linux/kvm.h > @@ -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 > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h > index e9e0cd8..e368a14 100644 > --- a/include/linux/kvm_host.h > +++ b/include/linux/kvm_host.h > @@ -130,8 +130,10 @@ struct kvm { > int nmemslots; > struct kvm_memory_slot memslots[KVM_MEMORY_SLOTS + > KVM_PRIVATE_MEM_SLOTS]; > + u32 bsp_vcpu_id; > struct kvm_vcpu *bsp_vcpu; > struct kvm_vcpu *vcpus[KVM_MAX_VCPUS]; > + atomic_t online_vcpus; > struct list_head vm_list; > struct kvm_io_bus mmio_bus; > struct kvm_io_bus pio_bus; > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index 5a55fe0..d65c637 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -693,11 +693,6 @@ 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)) { > @@ -1713,15 +1708,12 @@ static int create_vcpu_fd(struct kvm_vcpu *vcpu) > /* > * 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); > > @@ -1732,25 +1724,36 @@ 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); > + > + if (kvm->bsp_vcpu_id == id) > + kvm->bsp_vcpu = vcpu; > + 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); > @@ -2223,6 +2226,10 @@ static long kvm_vm_ioctl(struct file *filp, > r = kvm_irqfd(kvm, data.fd, data.gsi, data.flags); > break; > } > + case KVM_SET_BOOT_CPU_ID: > + kvm->bsp_vcpu_id = arg; > + r = 0; > + break; Don't you also need to update the bsp_vcpu pointer? And aren't these two (bsp_vcpu pointer and bsp_vcpu_id) somewhat redundant? Other than looks fine. > default: > r = kvm_arch_vm_ioctl(filp, ioctl, arg); > } > @@ -2289,6 +2296,7 @@ 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: > + case KVM_CAP_SET_BOOT_CPU_ID: > return 1; > #ifdef CONFIG_HAVE_KVM_IRQCHIP > case KVM_CAP_IRQ_ROUTING: > -- > 1.6.2.1 > > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Jun 02, 2009 at 09:38:08AM -0300, Marcelo Tosatti wrote: > > @@ -2223,6 +2226,10 @@ static long kvm_vm_ioctl(struct file *filp, > > r = kvm_irqfd(kvm, data.fd, data.gsi, data.flags); > > break; > > } > > + case KVM_SET_BOOT_CPU_ID: > > + kvm->bsp_vcpu_id = arg; > > + r = 0; > > + break; > > Don't you also need to update the bsp_vcpu pointer? And aren't these two Actually I think I need to return an error if userspace tries to change BSP after BSP cpu is already created. > (bsp_vcpu pointer and bsp_vcpu_id) somewhat redundant? > Sometimes pointer to bsp vcpu is needed. It can be found looping over all vcpus, but I prefer to have the pointer handy. -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/linux/kvm.h b/include/linux/kvm.h index 632a856..d10ab5d 100644 --- a/include/linux/kvm.h +++ b/include/linux/kvm.h @@ -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 diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index e9e0cd8..e368a14 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -130,8 +130,10 @@ struct kvm { int nmemslots; struct kvm_memory_slot memslots[KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS]; + u32 bsp_vcpu_id; struct kvm_vcpu *bsp_vcpu; struct kvm_vcpu *vcpus[KVM_MAX_VCPUS]; + atomic_t online_vcpus; struct list_head vm_list; struct kvm_io_bus mmio_bus; struct kvm_io_bus pio_bus; diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 5a55fe0..d65c637 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -693,11 +693,6 @@ 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)) { @@ -1713,15 +1708,12 @@ static int create_vcpu_fd(struct kvm_vcpu *vcpu) /* * 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); @@ -1732,25 +1724,36 @@ 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); + + if (kvm->bsp_vcpu_id == id) + kvm->bsp_vcpu = vcpu; + 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); @@ -2223,6 +2226,10 @@ static long kvm_vm_ioctl(struct file *filp, r = kvm_irqfd(kvm, data.fd, data.gsi, data.flags); break; } + case KVM_SET_BOOT_CPU_ID: + kvm->bsp_vcpu_id = arg; + r = 0; + break; default: r = kvm_arch_vm_ioctl(filp, ioctl, arg); } @@ -2289,6 +2296,7 @@ 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: + case KVM_CAP_SET_BOOT_CPU_ID: return 1; #ifdef CONFIG_HAVE_KVM_IRQCHIP case KVM_CAP_IRQ_ROUTING:
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> --- include/linux/kvm.h | 2 + include/linux/kvm_host.h | 2 + virt/kvm/kvm_main.c | 50 ++++++++++++++++++++++++++------------------- 3 files changed, 33 insertions(+), 21 deletions(-)