Bug 462380

Summary: qemu-kvm -no-kvm segfaults with >4GB of RAM
Product: [Fedora] Fedora Reporter: Eduardo Habkost <ehabkost>
Component: kvmAssignee: Glauber Costa <gcosta>
Status: CLOSED WONTFIX QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: low Docs Contact:
Priority: medium    
Version: 10CC: berrange, clalance, virt-maint
Target Milestone: ---Keywords: Triaged
Target Release: ---   
Hardware: All   
OS: Linux   
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2009-12-18 01:23:46 EST Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

Description Eduardo Habkost 2008-09-15 15:09:10 EDT
Version-Release number of selected component (if applicable):

Steps to Reproduce:

[root@Rawhide-64 ~]# gdb --args qemu-kvm -no-kvm -m 5000 -hda /mnt/common/images/f9-64f.img
GNU gdb Fedora (6.8-19.fc10)
Copyright (C) 2008 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-redhat-linux-gnu"...
(gdb) r
Starting program: /usr/bin/qemu-kvm -no-kvm -m 5000 -hda /mnt/common/images/f9-64f.img

Program received signal SIGSEGV, Segmentation fault.
tb_alloc_page () at /usr/src/debug/kvm-74/qemu/exec.c:1081

This happens because the translation block code doesn't support addresses larger than 32-bits on the l1_map array.

(gdb) bt full
#0  tb_alloc_page () at /usr/src/debug/kvm-74/qemu/exec.c:1081
        p = (PageDesc *) 0x5a1
        last_first_tb = <value optimized out>
#1  tb_link_phys (tb=0x7f4782017f10, phys_pc=5201186336, phys_page2=18446744073709551615) at /usr/src/debug/kvm-74/qemu/exec.c:1171
No locals.
#2  0x00000000004a35ef in tb_gen_code (env=0x299c0d0, pc=139904157867552, cs_base=<value optimized out>, flags=<value optimized out>, cflags=<value optimized out>)
    at /usr/src/debug/kvm-74/qemu/exec.c:855
        tb = (TranslationBlock *) 0x7f4782017f10
        phys_page2 = 1
        virt_page2 = 139904157863936
        code_gen_size = <value optimized out>
#3  0x00000000004a5ce9 in tb_find_slow () at /usr/src/debug/kvm-74/qemu/cpu-exec.c:157
No locals.
#4  tb_find_fast () at /usr/src/debug/kvm-74/qemu/cpu-exec.c:238
        cs_base = 6
        pc = 139904157867552
        flags = 115383
#5  cpu_x86_exec (env1=<value optimized out>) at /usr/src/debug/kvm-74/qemu/cpu-exec.c:597
        reg_AREG0 = <value optimized out>
        saved_AREG0 = (volatile host_reg_t) 0x0
        reg_AREG1 = <value optimized out>
        saved_AREG1 = (volatile host_reg_t) 0x7ffff57c8a00
        reg_AREG2 = <value optimized out>
        saved_AREG2 = (volatile host_reg_t) 0x1
        reg_AREG3 = <value optimized out>
        saved_AREG3 = (volatile host_reg_t) 0xffff
        ret = <value optimized out>
        interrupt_request  <value optimized out>
        tb = (TranslationBlock *) 0x0
        next_tb = 0
#6  0x0000000000412372 in main_loop () at /usr/src/debug/kvm-74/qemu/vl.c:8213
No locals.
#7  main (argc=6, argv=0x7ffff57c94a8) at /usr/src/debug/kvm-74/qemu/vl.c:10130
Comment 1 Glauber Costa 2008-09-15 17:33:38 EDT
http://koji.fedoraproject.org/koji/taskinfo?taskID=826758 should fix it.
Comment 2 Eduardo Habkost 2008-09-16 11:07:27 EDT
The page_find() fix you included needs the fix from qemu svn revision 5104, also (http://svn.savannah.gnu.org/viewvc/trunk/exec.c?root=qemu&r1=5104&r2=5103&pathrev=5104).

However, neither of them fix the segfault for the -no-kvm case, but only avoid some uncommon segfaults when running KVM, such as on the backtrace shown here: http://marc.info/?l=kvm&m=122124602701405&w=2
Comment 3 Bug Zapper 2008-11-25 22:05:42 EST
This bug appears to have been reported against 'rawhide' during the Fedora 10 development cycle.
Changing version to '10'.

More information and reason for this action is here:
Comment 4 Bug Zapper 2009-11-18 04:16:53 EST
This message is a reminder that Fedora 10 is nearing its end of life.
Approximately 30 (thirty) days from now Fedora will stop maintaining
and issuing updates for Fedora 10.  It is Fedora's policy to close all
bug reports from releases that are no longer maintained.  At that time
this bug will be closed as WONTFIX if it remains open with a Fedora 
'version' of '10'.

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Comment 5 Bug Zapper 2009-12-18 01:23:46 EST
Fedora 10 changed to end-of-life (EOL) status on 2009-12-17. Fedora 10 is 
no longer maintained, which means that it will not receive any further 
security or bug fix updates. As a result we are closing this bug.

If you can reproduce this bug against a currently maintained version of 
Fedora please feel free to reopen this bug against that version.

Thank you for reporting this bug and we are sorry it could not be fixed.