diff options
| author | Avi Kivity <avi@redhat.com> | 2012-03-05 14:23:29 +0200 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2012-05-31 00:43:10 +0100 |
| commit | 645b177cbfce6b695bdbe0b4c131de584821840d (patch) | |
| tree | 7320d673f3a10cf732fd19bce58c5727060ad5a4 | |
| parent | 51155201f92e585d40d8921893a508e8b99b2d0e (diff) | |
KVM: Ensure all vcpus are consistent with in-kernel irqchip settings
(cherry picked from commit 3e515705a1f46beb1c942bb8043c16f8ac7b1e9e)
If some vcpus are created before KVM_CREATE_IRQCHIP, then
irqchip_in_kernel() and vcpu->arch.apic will be inconsistent, leading
to potential NULL pointer dereferences.
Fix by:
- ensuring that no vcpus are installed when KVM_CREATE_IRQCHIP is called
- ensuring that a vcpu has an apic if it is installed after KVM_CREATE_IRQCHIP
This is somewhat long winded because vcpu->arch.apic is created without
kvm->lock held.
Based on earlier patch by Michael Ellerman.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | arch/ia64/kvm/kvm-ia64.c | 5 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 8 | ||||
| -rw-r--r-- | include/linux/kvm_host.h | 7 | ||||
| -rw-r--r-- | virt/kvm/kvm_main.c | 4 |
4 files changed, 24 insertions, 0 deletions
diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c index 43f4c92816e..7073185bbb7 100644 --- a/arch/ia64/kvm/kvm-ia64.c +++ b/arch/ia64/kvm/kvm-ia64.c @@ -1169,6 +1169,11 @@ out: #define PALE_RESET_ENTRY 0x80000000ffffffb0UL +bool kvm_vcpu_compatible(struct kvm_vcpu *vcpu) +{ + return irqchip_in_kernel(vcpu->kcm) == (vcpu->arch.apic != NULL); +} + int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu) { struct kvm_vcpu *v; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index e04cae195e1..4fc53233ae7 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3579,6 +3579,9 @@ long kvm_arch_vm_ioctl(struct file *filp, r = -EEXIST; if (kvm->arch.vpic) goto create_irqchip_unlock; + r = -EINVAL; + if (atomic_read(&kvm->online_vcpus)) + goto create_irqchip_unlock; r = -ENOMEM; vpic = kvm_create_pic(kvm); if (vpic) { @@ -6486,6 +6489,11 @@ void kvm_arch_check_processor_compat(void *rtn) kvm_x86_ops->check_processor_compatibility(rtn); } +bool kvm_vcpu_compatible(struct kvm_vcpu *vcpu) +{ + return irqchip_in_kernel(vcpu->kvm) == (vcpu->arch.apic != NULL); +} + int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu) { struct page *page; diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 35410ef9cf6..61368211a7c 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -744,6 +744,13 @@ static inline bool kvm_vcpu_is_bsp(struct kvm_vcpu *vcpu) { return vcpu->kvm->bsp_vcpu_id == vcpu->vcpu_id; } + +bool kvm_vcpu_compatible(struct kvm_vcpu *vcpu); + +#else + +static inline bool kvm_vcpu_compatible(struct kvm_vcpu *vcpu) { return true; } + #endif #ifdef __KVM_HAVE_DEVICE_ASSIGNMENT diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 9ffac2e0d16..ec747dc48e5 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1667,6 +1667,10 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id) goto vcpu_destroy; mutex_lock(&kvm->lock); + if (!kvm_vcpu_compatible(vcpu)) { + r = -EINVAL; + goto unlock_vcpu_destroy; + } if (atomic_read(&kvm->online_vcpus) == KVM_MAX_VCPUS) { r = -EINVAL; goto unlock_vcpu_destroy; |