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authorPaolo Bonzini <pbonzini@redhat.com>2016-03-29 11:23:25 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2016-04-01 12:10:09 +0200
commita2b5c3c0c8eea2d5d0eefcfc0fc0bdf386daa260 (patch)
treebec7cf046706e3d2c8ecfaa6bb232f7ef232861a /arch/x86/kvm/hyperv.c
parent321c5658c5e9192dea0d58ab67cf1791e45b2b26 (diff)
KVM: Hyper-V: do not do hypercall userspace exits if SynIC is disabled
If SynIC is disabled, there is nothing that userspace can do to handle these exits; on the other hand, userspace probably will not know about KVM_EXIT_HYPERV_HCALL and complain about it or even exit. Just prevent anything bad from happening by handling the hypercall in KVM and returning an "invalid hypercall" code. Fixes: 83326e43f27e9a8a501427a0060f8af519a39bb2 Cc: Andrey Smetanin <irqlevel@gmail.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/hyperv.c')
-rw-r--r--arch/x86/kvm/hyperv.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index 5ff3485acb60..01bd7b7a6866 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -1116,6 +1116,11 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
break;
case HVCALL_POST_MESSAGE:
case HVCALL_SIGNAL_EVENT:
+ /* don't bother userspace if it has no way to handle it */
+ if (!vcpu_to_synic(vcpu)->active) {
+ res = HV_STATUS_INVALID_HYPERCALL_CODE;
+ break;
+ }
vcpu->run->exit_reason = KVM_EXIT_HYPERV;
vcpu->run->hyperv.type = KVM_EXIT_HYPERV_HCALL;
vcpu->run->hyperv.u.hcall.input = param;