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| author | Paolo Bonzini <pbonzini@redhat.com> | 2022-12-28 11:33:41 +0100 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-12-28 11:53:57 +0100 |
| commit | a79b53aaaab53de017517bf9579b6106397a523c (patch) | |
| tree | 9dd186153aa405173b6b792843191932244df4c9 /tools | |
| parent | KVM: x86/xen: Documentation updates and clarifications (diff) | |
| download | linux-a79b53aaaab53de017517bf9579b6106397a523c.tar.xz linux-a79b53aaaab53de017517bf9579b6106397a523c.zip | |
KVM: x86: fix deadlock for KVM_XEN_EVTCHN_RESET
While KVM_XEN_EVTCHN_RESET is usually called with no vCPUs running,
if that happened it could cause a deadlock. This is due to
kvm_xen_eventfd_reset() doing a synchronize_srcu() inside
a kvm->lock critical section.
To avoid this, first collect all the evtchnfd objects in an
array and free all of them once the kvm->lock critical section
is over and th SRCU grace period has expired.
Reported-by: Michal Luczaj <mhal@rbox.co>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c b/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c index 721f6a693799..dae510c263b4 100644 --- a/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c +++ b/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c @@ -962,6 +962,12 @@ int main(int argc, char *argv[]) } done: + struct kvm_xen_hvm_attr evt_reset = { + .type = KVM_XEN_ATTR_TYPE_EVTCHN, + .u.evtchn.flags = KVM_XEN_EVTCHN_RESET, + }; + vm_ioctl(vm, KVM_XEN_HVM_SET_ATTR, &evt_reset); + alarm(0); clock_gettime(CLOCK_REALTIME, &max_ts); |