On 2014-07-02 09:20, Hu, Robert wrote: >> -----Original Message----- >> From: Wanpeng Li [mailto:wanpeng.li@xxxxxxxxxxxxxxx] >> Sent: Wednesday, July 2, 2014 2:54 PM >> To: Paolo Bonzini; Jan Kiszka; Gleb Natapov >> Cc: Hu, Robert; kvm@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Wanpeng Li >> Subject: [PATCH] KVM: nVMX: Fix IRQs inject to L2 which belong to L1 since race >> >> This patch fix bug https://bugzilla.kernel.org/show_bug.cgi?id=72381 >> >> If we didn't inject a still-pending event to L1 since nested_run_pending, >> KVM_REQ_EVENT should be requested after the vmexit in order to inject the >> event to L1. However, current log blindly request a KVM_REQ_EVENT even if >> there is no still-pending event to L1 which blocked by nested_run_pending. >> There is a race which lead to an interrupt will be injected to L2 which >> belong to L1 if L0 send an interrupt to L1 during this window. >> >> VCPU0 another thread >> >> L1 intr not blocked on L2 first entry >> vmx_vcpu_run req event >> kvm check request req event >> check_nested_events don't have any intr >> not nested exit >> intr occur (8254, lapic timer >> etc) >> inject_pending_event now have intr >> inject interrupt >> >> This patch fix this race by introduced a l1_events_blocked field in nested_vmx >> which indicates there is still-pending event which blocked by >> nested_run_pending, >> and smart request a KVM_REQ_EVENT if there is a still-pending event which >> blocked >> by nested_run_pending. >> >> Signed-off-by: Wanpeng Li <wanpeng.li@xxxxxxxxxxxxxxx> > Tested-by: Robert Hu<robert.hu@xxxxxxxxx> Do you happen to have a kvm-unit-test for this race? Or how did you test? Just curious, and if there is a test, it would be good to integrate it. Jan -- Siemens AG, Corporate Technology, CT RTC ITP SES-DE Corporate Competence Center Embedded Linux -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
