On 04/16/2018 08:47 PM, George Dunlap wrote: > On 04/13/2018 03:44 PM, Razvan Cojocaru wrote: >> On 04/11/2018 11:04 AM, Razvan Cojocaru wrote: >>> Debugging continues. >> >> Finally, the attached patch seems to get the display unstuck in my >> scenario, although for one guest I get: >> >> (XEN) d2v0 Unexpected vmexit: reason 49 >> (XEN) domain_crash called from vmx.c:4120 >> (XEN) Domain 2 (vcpu#0) crashed on cpu#1: >> (XEN) ----[ Xen-4.11-unstable x86_64 debug=y Not tainted ]---- >> (XEN) CPU: 1 >> (XEN) RIP: 0010:[<fffff96000842354>] >> (XEN) RFLAGS: 0000000000010246 CONTEXT: hvm guest (d2v0) >> (XEN) rax: fffff88003000000 rbx: fffff900c0083db0 rcx: 00000000aa55aa55 >> (XEN) rdx: fffffa80041bdc41 rsi: fffff900c00c69a0 rdi: 0000000000000001 >> (XEN) rbp: 0000000000000000 rsp: fffff88002ee9ef0 r8: fffffa80041bdc40 >> (XEN) r9: fffff80001810e80 r10: fffffa800342aa70 r11: fffff88002ee9e80 >> (XEN) r12: 0000000000000005 r13: 0000000000000001 r14: fffff900c00c08b0 >> (XEN) r15: 0000000000000001 cr0: 0000000080050031 cr4: 00000000000406f8 >> (XEN) cr3: 00000000ef771000 cr2: fffff900c00c8000 >> (XEN) fsb: 00000000fffde000 gsb: fffff80001810d00 gss: 000007fffffdc000 >> (XEN) ds: 002b es: 002b fs: 0053 gs: 002b ss: 0018 cs: 0010 >> >> i.e. EXIT_REASON_EPT_MISCONFIG - so not of the woods yet. I am hoping >> somebody more familiar with the code can point to a more elegant >> solution if one exists. > > I think I have an idea what's going on, but it's complicated. :-) > > Basically, the logdirty functionality isn't simple, and needs careful > thought on how to integrate it. I'll write some more tomorrow, and see > if I can come up with a solution.
I think I know why this happens for the one guest - the other guests start at a certain resolution display-wise and stay that way until shutdown. This particular guest starts with a larger screen, then goes to roughly 2/3rds of it, then tries to go back to the initial larger one - at which point the above happens. I assume this corresponds to some pages being removed and/or added. I'll test this theory more tomorrow - if it's correct I should be able to reproduce the crash (with the patch) by simply resetting the screen resolution (increasing it). Thanks, Razvan _______________________________________________ Xen-devel mailing list Xenfirstname.lastname@example.org https://lists.xenproject.org/mailman/listinfo/xen-devel