[SeaBIOS] WfW setup and DOS display.sys hanging
kraxel at redhat.com
Wed Feb 5 14:19:58 CET 2014
[ adding seabios list ]
On Di, 2014-02-04 at 20:47 +0100, Kevin Wolf wrote:
> Hi Gerd,
> Am 09.01.2014 um 00:20 hat Sebastian geschrieben:
> > Hi,
> > I noticed in newer versions of Qemu (Debian Jessie) a regression
> > causing DISPLAY.SYS from MS-DOS 6.22 to hang the system as soon as
> > loaded.
> now that you sent a pull request for a SeaBIOS update, I tried what
> would happen with this one. Sadly, while it does fix my hanging Win 7
> boot, DOS still hangs while loading display.sys.
[ This is http://www.kraxel.org/cgit/qemu/tag/?id=pull-roms-1
with the 1.7.4 update ]
Digged out my prehistoric msdos floppy images. Can confirm the hang.
Using default vga (i.e. cirrus).
Switching back to lgplvgabios ("make -C roms lgplvgabios" in qemu src
tree) makes the hang go away.
> Any ideas where to look, or are you going to have a look yourself? When
> I tried to debug it a while ago, I didn't see anything obvious, but then
> I didn't invest that much time for it either.
"perf kvm stat live" shows tons of NMIs:
VM-EXIT Samples Samples% Time% Min Time Max Time Avg time
EXCEPTION_NMI 660538 99.82% 99.40% 0us 183us 0.67us ( +- 0.14% )
EXTERNAL_INTERRUPT 1133 0.17% 0.58% 0us 43us 2.25us ( +- 4.86% )
IO_INSTRUCTION 18 0.00% 0.01% 1us 5us 3.39us ( +- 6.50% )
PENDING_INTERRUPT 17 0.00% 0.01% 1us 11us 2.15us ( +- 26.24% )
How can one get a trace log of all the kvm tracepoints these days?
'perf list' shows a bunch of kvm trace events,
but "perf trace -e '*kvm*' doesn't show me anything ...
> I haven't tried out any of the other cases described below.
[ keeping full quote for seabios list ]
> > The Windows for Workgroups 3.11 SETUP.EXE file hangs with a cleared
> > screen and the cursor blinking in the top left of the screen. The
> > DOSIDLE.EXE file hangs after printing out some system
> > information.
> > Git-Bisecting returned "roms: update vgabios binaries" (commit
> > 6eefccc0bb9c34051b1e21880fc3a1c1c8686edd) as the bad commit.
> > I tested the i386-softmmu target on Debian 7.3 (wheezy), x86_64 host
> > and gcc 4.7.2 (Debian 4.7.2-5) without KVM support.
> >  Source and binary are available e.g. at
> > http://maribu.home.xs4all.nl/zeurkous/download/mirror/dosidle/
> > Best Regards,
> > Sebastian
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