path: root/virt
diff options
authorPeter Xu <peterx@redhat.com>2019-05-05 16:56:42 +0800
committerPaolo Bonzini <pbonzini@redhat.com>2019-05-24 21:27:12 +0200
commit654f1f13ea56b92bacade8ce2725aea0457f91c0 (patch)
treec15b056aac1508450ab54caef254c419f9963ce2 /virt
parentc9bcd3e3335d0a29d89fabd2c385e1b989e6f1b0 (diff)
kvm: Check irqchip mode before assign irqfd
When assigning kvm irqfd we didn't check the irqchip mode but we allow KVM_IRQFD to succeed with all the irqchip modes. However it does not make much sense to create irqfd even without the kernel chips. Let's provide a arch-dependent helper to check whether a specific irqfd is allowed by the arch. At least for x86, it should make sense to check: - when irqchip mode is NONE, all irqfds should be disallowed, and, - when irqchip mode is SPLIT, irqfds that are with resamplefd should be disallowed. For either of the case, previously we'll silently ignore the irq or the irq ack event if the irqchip mode is incorrect. However that can cause misterious guest behaviors and it can be hard to triage. Let's fail KVM_IRQFD even earlier to detect these incorrect configurations. CC: Paolo Bonzini <pbonzini@redhat.com> CC: Radim Krčmář <rkrcmar@redhat.com> CC: Alex Williamson <alex.williamson@redhat.com> CC: Eduardo Habkost <ehabkost@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'virt')
1 files changed, 9 insertions, 0 deletions
diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
index 001aeda4c154..3972a9564c76 100644
--- a/virt/kvm/eventfd.c
+++ b/virt/kvm/eventfd.c
@@ -44,6 +44,12 @@
static struct workqueue_struct *irqfd_cleanup_wq;
+bool __attribute__((weak))
+kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args)
+ return true;
static void
irqfd_inject(struct work_struct *work)
@@ -297,6 +303,9 @@ kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd *args)
if (!kvm_arch_intc_initialized(kvm))
return -EAGAIN;
+ if (!kvm_arch_irqfd_allowed(kvm, args))
+ return -EINVAL;
irqfd = kzalloc(sizeof(*irqfd), GFP_KERNEL_ACCOUNT);
if (!irqfd)
return -ENOMEM;