* Ryan Harper <ry...@us.ibm.com> [2011-01-04 09:49]:
> * Aurelien Jarno <aurel...@aurel32.net> [2010-12-25 16:37]:
> > On Wed, Dec 08, 2010 at 04:27:45PM -0200, Luiz Capitulino wrote:
> > > On Wed, 08 Dec 2010 12:23:12 -0600
> > > Anthony Liguori <aligu...@linux.vnet.ibm.com> wrote:
> > >
> > > > On 12/08/2010 12:01 PM, Luiz Capitulino wrote:
> > > > > Currently, x86_64-softmmu qemu segfaults when trying to use> 4095M
> > > > > memsize.
> > > > > This patch adds a simple check and error message (much like the 2047
> > > > > limit on
> > > > > 32-bit hosts) on ram_size in the control path after we determine we're
> > > > > not using kvm
> > > > >
> > > > > Upstream qemu-kvm is affected if using the -no-kvm option; this patch
> > > > > address
> > > > > the segfault there as well.
> > > > >
> > > > > Signed-off-by: Ryan Harper<ry...@us.ibm.com>
> > > > > Signed-off-by: Aurelien Jarno<aurel...@aurel32.net>
> > > > > ---
> > > > > NOTE: this patch was applied in the v0.12.x branch, but it seems it
> > > > > got
> > > > > lost for master
> > > > >
> > > >
> > > > No, it was intentional. We should fix the segv, this is not a known
> > > > limitation but rather a bug.
> > >
> > > A TCG bug, I presume?
> > >
> >
> > Do you have more details about this issue and how to reproduce it?
>
> At the time of the bug, it was something simple like:
>
> qemu-system-x86_64 -m 4097 -hda /dev/null
>
> we'd get an imediate segfault. As you say, I'm not seeing it now on
> current git; I'll see about bisecting to see if we did get a fix for the
> issue.
I attempted to bisect, but there a couple commits around where the issue
was fixed that broke git bisect =( That narrowed it down to about 5
commits to check.
This the last git commit where I can reproduce the segfault with the
above test case (qemu invocation).
commit 0aef4261ac0ec9089ade0e3a92f986cb4ba7317e
Author: Aurelien Jarno <aurel...@aurel32.net>
Date: Thu Mar 11 21:29:42 2010 +0100
target-ppc: fix evsrwu and evsrws (second try)
Signed-off-by: Aurelien Jarno <aurel...@aurel32.net>
The next 4 commits don't compile so they are untest-able:
commit 14f24e1465edc44b9b4d89fbbea66e06088154e1
- fails to build with:
- ./configure --target-list=x86_64-softmmu && make clean && make
/home/rharper/work/git/qemu/exec.c: In function 'phys_page_find_alloc':
/home/rharper/work/git/qemu/exec.c:341: error: #error unsupported
TARGET_PHYS_ADDR_SPACE_BITS
/home/rharper/work/git/qemu/exec.c: In function 'phys_page_for_each':
/home/rharper/work/git/qemu/exec.c:1670: error: #error unsupported
TARGET_PHYS_ADDR_SPACE_BITS
make[1]: *** [exec.o] Error 1
make: *** [subdir-x86_64-softmmu] Error 2
commit 7bc7b099dfa38a856b1bc892c0f9f3d6fe28e170
- fails to build with:
- ./configure --target-list=x86_64-softmmu && make clean && make
/home/rharper/work/git/qemu/exec.c: In function 'phys_page_find_alloc':
/home/rharper/work/git/qemu/exec.c:341: error: #error unsupported
TARGET_PHYS_ADDR_SPACE_BITS
/home/rharper/work/git/qemu/exec.c: In function 'phys_page_for_each':
/home/rharper/work/git/qemu/exec.c:1670: error: #error unsupported
TARGET_PHYS_ADDR_SPACE_BITS
make[1]: *** [exec.o] Error 1
make: *** [subdir-x86_64-softmmu] Error 2
commit b9f83121a13153536d886305414b540460c34508
- fails to build with:
- ./configure --target-list=x86_64-softmmu && make clean && make
/home/rharper/work/git/qemu/exec.c: In function 'phys_page_find_alloc':
/home/rharper/work/git/qemu/exec.c:341: error: #error unsupported
TARGET_PHYS_ADDR_SPACE_BITS
/home/rharper/work/git/qemu/exec.c: In function 'phys_page_for_each':
/home/rharper/work/git/qemu/exec.c:1670: error: #error unsupported
TARGET_PHYS_ADDR_SPACE_BITS
make[1]: *** [exec.o] Error 1
make: *** [subdir-x86_64-softmmu] Error 2
commit 5270589032f450ae7c3448730855aa18ff68ccff
- fails to build with:
- ./configure --target-list=x86_64-softmmu && make clean && make
/home/rharper/work/git/qemu/exec.c: In function 'phys_page_find_alloc':
/home/rharper/work/git/qemu/exec.c:341: error: #error unsupported
TARGET_PHYS_ADDR_SPACE_BITS
/home/rharper/work/git/qemu/exec.c: In function 'phys_page_for_each':
/home/rharper/work/git/qemu/exec.c:1670: error: #error unsupported
TARGET_PHYS_ADDR_SPACE_BITS
make[1]: *** [exec.o] Error 1
make: *** [subdir-x86_64-softmmu] Error 2
And this commit compiles and the test case no longer segfaults. So I'd
say things are fixed at this point.
commit 5cd2c5b6ad75c46d40118ac67c0c09d4e7930a65
- compiles and issue is no longer present.
- ./configure --target-list=x86_64-softmmu && make clean && make &&
sudo x86_64-softmmu/qemu-syem-x86_64 -L pc-bios -hda /dev/null -m 4097
--
Ryan Harper
Software Engineer; Linux Technology Center
IBM Corp., Austin, Tx
ry...@us.ibm.com
