** Changed in: qemu Status: Fix Committed => Fix Released -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1127369
Title: i386 emulation unreliable since commit b76f0d8c2e3eac94bc7fd90a510cb7426b2a2699 Status in QEMU: Fix Released Bug description: I am running daily automated tests of the qemu git mainline that involve building qemu on a Linux host (32-bit), booting a NetBSD guest in qemu-system-i386, and running the NetBSD operating system test suite on the guest. Since commit b76f0d8c2e3eac94bc7fd90a510cb7426b2a2699, there has been a marked increase in the number of failing test cases. Before that commit, the number of failing test cases was typically in the range 3 to 6, but since that commit, test runs often show 10 or more failed tests, or they end prematurely due to a segmentation fault in the test framework itself. To aid in reproducing the problem, I have prepared a disk image containing a NetBSD 6.0.1 system configured to automatically run the test suite on boot. To reproduce the problem, run the following shell commands: wget http://www.gson.org/bugs/qemu/NetBSD-6.0.1-i386-test.img.gz gunzip NetBSD-6.0.1-i386-test.img.gz qemu-system-i386 -m 32 -nographic -snapshot -hda NetBSD-6.0.1-i386-test.img The disk image is about 144 MB in size and uncompresses to 2 GB. The test run typically takes a couple of hours, printing progress messages to the terminal as it goes. When it finishes, the virtual machine will be automatically powered down, causing qemu to exit. Near the end of the output, before the shutdown messages, there should be a summary of the test results. The expected output looks like this: Summary for 500 test programs: 2958 passed test cases. 5 failed test cases. 45 expected failed test cases. 70 skipped test cases. A number of "failed test cases" in the range 3 to 6 should be considered normal. Please ignore the "expected failed test cases". Using a version of qemu affected by the bug, the summary will look more like this: Summary for 500 test programs: 2951 passed test cases. 12 failed test cases. 45 expected failed test cases. 69 skipped test cases. Or it may end with a segmentation fault like this: p2k_ffs_race: atf-report: ERROR: 10912: Unexpected token `<<EOF>>'; expected end of test case or test case's stdout/stderr line [1] Segmentation fault (core dumped) atf-run | Done(1) atf-report The problem goes away if the "-m 32" is omitted from the qemu command line, which leads me to suspect that the problem may be related to paging or swapping activity in the guest. The revision listed in the subject, b76f0d8c2e3eac94bc7fd90a510cb7426b2a2699, is the first one exhibiting the excessive test failures, but the bug may already have been introduced in the previous commit, fdbb84d1332ae0827d60f1a2ca03c7d5678c6edd. If I attempt to run the test on fdbb84d1332ae0827d60f1a2ca03c7d5678c6edd, the guest fails to boot. The revision before that, 32761257c0b9fa7ee04d2871a6e48a41f119c469, works as expected. -- Andreas Gustafsson, g...@gson.org To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1127369/+subscriptions