KVM: Disable interrupts around get_kernel_ns()

get_kernel_ns() wants preemption disabled.  It doesn't make a lot of sense
during the get/set ioctls (no way to make them non-racy) but the callee wants
it.

Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ffcb90669ec5..e96038e1bc3a 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3469,8 +3469,10 @@ long kvm_arch_vm_ioctl(struct file *filp,
                         goto out;
 
                 r = 0;
+                local_irq_disable();
                 now_ns = get_kernel_ns();
                 delta = user_ns.clock - now_ns;
+                local_irq_enable();
                 kvm->arch.kvmclock_offset = delta;
                 break;
         }
@@ -3478,8 +3480,10 @@ long kvm_arch_vm_ioctl(struct file *filp,
                 struct kvm_clock_data user_ns;
                 u64 now_ns;
 
+                local_irq_disable();
                 now_ns = get_kernel_ns();
                 user_ns.clock = kvm->arch.kvmclock_offset + now_ns;
+                local_irq_enable();
                 user_ns.flags = 0;
 
                 r = -EFAULT;