[ 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 ...
cheers, Gerd
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[1] 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.
[1] Source and binary are available e.g. at http://maribu.home.xs4all.nl/zeurkous/download/mirror/dosidle/
Best Regards, Sebastian