Peter Xu <peterx@xxxxxxxxxx> writes: > On Mon, Aug 26, 2019 at 10:25:55AM +0200, Vitaly Kuznetsov wrote: >> Peter Xu <peterx@xxxxxxxxxx> writes: >> >> > The dirty_log_test is failing on some old machines like Xeon E3-1220 >> > with tripple faults when writting to the tracked memory region: >> >> s,writting,writing, >> >> > >> > Test iterations: 32, interval: 10 (ms) >> > Testing guest mode: PA-bits:52, VA-bits:48, 4K pages >> > guest physical test memory offset: 0x7fbffef000 >> > ==== Test Assertion Failure ==== >> > dirty_log_test.c:138: false >> > pid=6137 tid=6139 - Success >> > 1 0x0000000000401ca1: vcpu_worker at dirty_log_test.c:138 >> > 2 0x00007f3dd9e392dd: ?? ??:0 >> > 3 0x00007f3dd9b6a132: ?? ??:0 >> > Invalid guest sync status: exit_reason=SHUTDOWN >> > >> >> This patch breaks on my AMD machine with >> >> # cpuid -1 -l 0x80000008 >> CPU: >> Physical Address and Linear Address Size (0x80000008/eax): >> maximum physical address bits = 0x30 (48) >> maximum linear (virtual) address bits = 0x30 (48) >> maximum guest physical address bits = 0x0 (0) >> >> >> Pre-patch: >> >> # ./dirty_log_test >> Test iterations: 32, interval: 10 (ms) >> Testing guest mode: PA-bits:52, VA-bits:48, 4K pages >> guest physical test memory offset: 0x7fbffef000 >> Dirtied 139264 pages >> Total bits checked: dirty (135251), clear (7991709), track_next (29789) >> >> Post-patch: >> >> # ./dirty_log_test >> Test iterations: 32, interval: 10 (ms) >> Testing guest mode: PA-bits:52, VA-bits:48, 4K pages >> Supported guest physical address width: 48 >> guest physical test memory offset: 0xffffbffef000 >> ==== Test Assertion Failure ==== >> dirty_log_test.c:141: false >> pid=77983 tid=77985 - Success >> 1 0x0000000000401d12: vcpu_worker at dirty_log_test.c:138 >> 2 0x00007f636374358d: ?? ??:0 >> 3 0x00007f63636726a2: ?? ??:0 >> Invalid guest sync status: exit_reason=SHUTDOWN > > Vitaly, > > Are you using shadow paging? If so, could you try NPT=off? > Yep, test passes with shadow paging, fails when NPT is enabled. > I finally found a AMD host and I also found that it's passing with > shadow MMU mode which is strange. If so I would suspect it's a real > bug in AMD NTP path but I'd like to see whether it's also happening on > your side. Sounds like a bug indeed. -- Vitaly
