Avi Kivity wrote: > Jan Kiszka wrote: >>> Exiting on a pending interrupt is controlled by the vmcs word >>> PIN_BASED_EXEC_CONTROL, bit PIN_BASED_EXT_INTR_MASK. Can you check (via >>> vmcs_read32()) that the bit is indeed set? >>> >>> [if not, a guest can just enter a busy loop and kill a processor] >>> >>> >> I traced it right before and after the asm block, and in all cases >> (including those with low latency exits) it's just 0x1f, which should be >> fine. >> >> > > Yes. > >> Earlier, I also checked GUEST_INTERRUPTIBILITY_INFO and >> GUEST_ACTIVITY_STATE, but found neither some suspicious state nor a >> difference compared to fast exits. >> > > GUEST_* things are unrelated; these talk about whether the guest is > ready to receive an interrupt, but we don't really care, do we?
Nope, of course (looks like my VMX manual interpreter still needs improvements...). > > I don't have any idea why this is happening. This is completely > unrelated to -rt issues -- this is between kvm and the hardware. > > Is this on a uniprocessor system? If not, can you try nosmp? It's both: -rt tests were performed with nosmp (-rt locks up under SMP here), and the Xenomai tests, including the last instrumentation, ran in SMP mode. So I tend to exclude SMP effects. Do you have some suggestion how to analyse what the guest is executing while those IRQs are delayed? As I said, I suspect some interaction of the Bochs BIOS is triggering the effect, because it only shows up (with a Linux guest) before the BIOS prints the first messages. Jan -- Siemens AG, Corporate Technology, CT SE 2 Corporate Competence Center Embedded Linux ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
