Bug 1161563
| Summary: | invalid QEMU NOTEs in vmcore that is dumped for multi-VCPU guests | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 7 | Reporter: | Laszlo Ersek <lersek> |
| Component: | qemu-kvm | Assignee: | Laszlo Ersek <lersek> |
| Status: | CLOSED ERRATA | QA Contact: | Virtualization Bugs <virt-bugs> |
| Severity: | unspecified | Docs Contact: | |
| Priority: | unspecified | ||
| Version: | 7.1 | CC: | hhuang, huding, juzhang, lersek, lmiksik, michen, rbalakri, virt-maint, xfu, xwei |
| Target Milestone: | rc | ||
| Target Release: | --- | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | qemu-kvm-1.5.3-80.el7 | Doc Type: | Bug Fix |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2015-03-05 08:13:20 UTC | Type: | Bug |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
| Bug Depends On: | |||
| Bug Blocks: | 1157798 | ||
Fix included in qemu-kvm-1.5.3-80.el7 Hello Laszlo, what kind of guest cfg is sufficient to verify this bz ? does guest cfg and test steps in below fine ? https://bugzilla.redhat.com/show_bug.cgi?id=1157798#c12 it's a RHEL 7.1 VM with 2vcpu 4G RAM both full memory dump(ELF) and partialily compressed dump(snappy, lzo, zlib) tests performed two methods of elf dump covered. virsh dump --memory-only rhel7.1-bios /root/dump virsh qemu-monitor-command rhel7.1-bios --pretty ' { "execute": "dump-guest-memory", "arguments": { "paging": false, "protocol": "file:/tmp/vmcore.elf", "format": "elf" } }' OVMF guest covered too :-) if above test steps or cfg insufficient, pls tell me. Thank you, Xiaoqing Wei. (In reply to Xiaoqing Wei from comment #8) > does guest cfg and test steps in below fine ? > https://bugzilla.redhat.com/show_bug.cgi?id=1157798#c12 Yes, those config & steps are sufficient. Thanks! Thanks(In reply to Laszlo Ersek from comment #9) > (In reply to Xiaoqing Wei from comment #8) > > > does guest cfg and test steps in below fine ? > > https://bugzilla.redhat.com/show_bug.cgi?id=1157798#c12 > > Yes, those config & steps are sufficient. > Thanks ! now moving to VERIFIED. Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://rhn.redhat.com/errata/RHSA-2015-0349.html |
*** Description of problem: In qemu-kvm-1.5.3-77.el7, the write_elf64_notes() and write_elf32_notes() functions are broken due to upstream commit c72bf4682. commit c72bf468259935a80ea185f2cbe807c3da9c1bbd Author: Jens Freimann <jfrei.ibm.com> Date: Fri Apr 19 16:45:06 2013 +0200 cpu: Move cpu_write_elfXX_note() functions to CPUState Convert cpu_write_elfXX_note() functions to CPUClass methods and pass CPUState as argument. Update target-i386 accordingly. Signed-off-by: Jens Freimann <jfrei.ibm.com> [AF: Retain stubs as CPUClass' default method implementation; style changes] Signed-off-by: Andreas Färber <afaerber> This commit changed the signature of the following functions so that they take CPUState rather than CPUArchState: - cpu_write_elf64_note() - cpu_write_elf64_qemunote() - cpu_write_elf32_note() - cpu_write_elf32_qemunote() The callers of these functions, write_elf64_notes() and write_elf32_notes(), each iterate over CPUArchState objects (starting from "first_cpu") *twice*, the first loop calling cpu_write_elfXX_note(), the second loop calling cpu_write_elfXX_qemunote(). The loop variable is called "env". When calling the above functions after c72bf468, "env" (of type CPUArchState) needs to be converted to CPUState, with the ENV_GET_CPU() macro. Now, even before c72bf468, the *first* loop in each of both callers used to do the conversion already, because cpu_write_elfXX_note() needs a CPU index, and that's only reachable via cpu_index(ENV_GET_CPU(env)). Therefore the first loop in each caller already set the "cpu" local variable correctly, for each "env" in question. However, the *second* loop in each caller had never done that, because cpu_write_elfXX_qemunote() had never needed a CPUState for anything. Upstream commit c72bf4682 simply replaced "env" with "cpu" in both loop bodies (in both callers). This was correct for the first loops (because they already had set "cpu" correctly), but the commit missed to add cpu = ENV_GET_CPU(env); to the second loops. Hence cpu_write_elfXX_qemunote() is always called with the last "cpu" value inherited from the first loop! (Which is why the bug is invisible for single-VCPU guests.) Add the missing assignments. For upstream, this was silently fixed in commit 182735efaf956ccab50b6d74a4fed163e0f35660 Author: Andreas Färber <afaerber> Date: Wed May 29 22:29:20 2013 +0200 cpu: Make first_cpu and next_cpu CPUState Move next_cpu from CPU_COMMON to CPUState. Move first_cpu variable to qom/cpu.h. gdbstub needs to use CPUState::env_ptr for now. cpu_copy() no longer needs to save and restore cpu_next. Acked-by: Paolo Bonzini <pbonzini> [AF: Rebased, simplified cpu_copy()] Signed-off-by: Andreas Färber <afaerber> because it obviated and eliminated the cpu = ENV_GET_CPU(env); conversions completely. The bug-introducing commit c72bf4682 had been released in v1.5.0 (and it persisted even into 1.5.3, which is why we have it in RHEL). The silent / unintended fix (182735ef) is part of v1.6.0 (and we never backported that commit to RHEL-7.0). *** Version-Release number of selected component (if applicable): qemu-kvm-1.5.3-77.el7 *** How reproducible: Not very easily reproducible externally. Bug found by eyeballing the code. Sanity testing by QE with dump-guest-memory will be enough for verifying the fix.