Qxl problem with xen domU, is xen spice and/or qemu bugs?

Hi,

Post by Fabio Fantoni
Someone can help me to find the problem that makes qxl unusable please?

#1 git cherry-pick c58c7b959b93b864a27fd6b3646ee1465ab8832b

#2 When using f19 try without X11 first. You should have a working
framebuffer console on qxldrmfb before trying to get X11 going.

#3 qxl has a bunch of tracepoints. Enable them, then compare xen
results with kvm/tcg results to see where things start going wrong.

#4 qxl needs a permanent mapping of the two pci memory bars as the
(host virtual) memory location of these bars is passed to the
spice-server library. That might need some special care on xen
due to the mapcache. Disclamer: It's been a few years I looked
closer at this, so things in the xen world might have changed
meanwhile ...

HTH,
Gerd

Fabio Fantoni

2013-09-26 13:04:30 UTC

Post by Fabio Fantoni
Someone can help me to find the problem that makes qxl unusable please?

#1 git cherry-pick c58c7b959b93b864a27fd6b3646ee1465ab8832b

Thanks for reply, did this on my new test build.

Post by Gerd Hoffmann
#2 When using f19 try without X11 first. You should have a working
framebuffer console on qxldrmfb before trying to get X11 going.

I tried on Fedora19 minimal installation and with qxl the text console
is working and lsmod show also qxl.
Is this your intended or is there something else I must test before X11?

Post by Gerd Hoffmann
#3 qxl has a bunch of tracepoints. Enable them, then compare xen
results with kvm/tcg results to see where things start going wrong.

-global qxl-vga.debug=1 -global qxl-vga.guestdebug=20
With Fedora19 I have some difficult to found exact problem and compare
with kvm.
I tried to test Fedora19 on debian sid kvm host same qemu version
(1.6) on both sides but with qxl fails to start the DE, also in
fallback mode. Probably there are also regression on qemu and/or spice
about qxl.
The qemu log returns nothing relevant with only few lines on xen test
with also qxl debug enabled.
domU starts, loads correctly the DE, vdagent and mouse are both
working, but screen refreshing is very lagging (also only open of
start menu).
The qemu log become of 22 mb in only few minutes, mainly qxl debug.
Can you check the W7 qemu log on attachment to see if there are
strange things to solve also on spice and/or qemu?

Previous mail was reject by mailing lists because attachment was too
big, I upload it here:
http://www.filedropper.com/qemu-dm-w7

Thanks for any reply.

Post by Gerd Hoffmann
#4 qxl needs a permanent mapping of the two pci memory bars as the
(host virtual) memory location of these bars is passed to the
spice-server library. That might need some special care on xen
due to the mapcache. Disclamer: It's been a few years I looked
closer at this, so things in the xen world might have changed
meanwhile ...
HTH,
Gerd

Gerd Hoffmann

2013-09-27 08:51:20 UTC

Hi,

Post by Gerd Hoffmann
#2 When using f19 try without X11 first. You should have a working
framebuffer console on qxldrmfb before trying to get X11 going.

I tried on Fedora19 minimal installation and with qxl the text console
is working and lsmod show also qxl.

Good, so the kernel driver is running fine.

Is this your intended?

Yes.

Post by Gerd Hoffmann
#3 qxl has a bunch of tracepoints. Enable them, then compare xen
results with kvm/tcg results to see where things start going wrong.

-global qxl-vga.debug=1 -global qxl-vga.guestdebug=20

debug=1 doesn't do much, most is in tracepoints these days. I'm using
the stderr tracer most of the time (enable it using configure). Then
you can turn on qxl_* either in monitor (trace-events command) or via
-trace events=<file-with-event-names>.

I tried to test Fedora19 on debian sid kvm host same qemu version
(1.6) on both sides but with qxl fails to start the DE, also in
fallback mode. Probably there are also regression on qemu and/or spice
about qxl.

I'm not aware of any regressions.
I'd suggest to try latest spice-server release.

HTH,
Gerd

Fabio Fantoni

2013-09-27 13:53:33 UTC

Post by Gerd Hoffmann
#2 When using f19 try without X11 first. You should have a working
framebuffer console on qxldrmfb before trying to get X11 going.

I tried on Fedora19 minimal installation and with qxl the text console
is working and lsmod show also qxl.

Good, so the kernel driver is running fine.

Is this your intended?

Yes.

Post by Gerd Hoffmann
#3 qxl has a bunch of tracepoints. Enable them, then compare xen
results with kvm/tcg results to see where things start going wrong.

-global qxl-vga.debug=1 -global qxl-vga.guestdebug=20

Thanks for reply, I used trace of qxl_* instead of -global debug options
(is it right or must I maintain also global qxl debug option?).
On attachment the new qemu log of windows 7 test with qxl vga.

Post by Gerd Hoffmann
domU starts, loads correctly the DE, vdagent and mouse are both
working, but screen refreshing is very lagging (also only open of
start menu).

Can you check the log to see if there are strange things to fix also on
spice and/or qemu?
Thanks for any reply.

Post by Gerd Hoffmann

I'm not aware of any regressions.
I'd suggest to try latest spice-server release.

I double checked and is already to latest version:
http://packages.debian.org/sid/libspice-server1

Post by Gerd Hoffmann
HTH,
Gerd

Fabio Fantoni

2013-10-01 12:52:55 UTC

Post by Gerd Hoffmann
#2 When using f19 try without X11 first. You should have a working
framebuffer console on qxldrmfb before trying to get X11 going.

I tried on Fedora19 minimal installation and with qxl the text console
is working and lsmod show also qxl.

Good, so the kernel driver is running fine.

Is this your intended?

Yes.

Post by Gerd Hoffmann
#3 qxl has a bunch of tracepoints. Enable them, then compare xen
results with kvm/tcg results to see where things start going wrong.

-global qxl-vga.debug=1 -global qxl-vga.guestdebug=20

Thanks for reply, I used trace of qxl_* instead of -global debug
options (is it right or must I maintain also global qxl debug option?).
On attachment the new qemu log of windows 7 test with qxl vga.

Post by Gerd Hoffmann
domU starts, loads correctly the DE, vdagent and mouse are both
working, but screen refreshing is very lagging (also only open of
start menu).

Can you check the log to see if there are strange things to fix also
on spice and/or qemu?
Thanks for any reply.

Post by Gerd Hoffmann

I'm not aware of any regressions.
I'd suggest to try latest spice-server release.

http://packages.debian.org/sid/libspice-server1

After I updated Fedora19 vm on kvm, it works with qxl.

I compared xen and kvm logs and the only relevant difference that I

Post by Fabio Fantoni
ioremap error for 0xfc001000-0xfc002000, requested 0x10, got 0x0

I attached all messages and Xorg logs for both xen and kvm (Fedora19)
tests with qxl.

And about xen hypervisor logs (with xl dmesg) the only difference
between stdvga and qxl (same domU) is that qxl log has 3 "pci dev bar"
more. Full logs on attachments.

Thanks for any reply.

Post by Gerd Hoffmann
HTH,
Gerd

Fabio Fantoni

2013-12-04 16:10:32 UTC

Post by Gerd Hoffmann
#2 When using f19 try without X11 first. You should have a working
framebuffer console on qxldrmfb before trying to get X11 going.

I tried on Fedora19 minimal installation and with qxl the text console
is working and lsmod show also qxl.

Good, so the kernel driver is running fine.

Is this your intended?

Yes.

Post by Gerd Hoffmann
#3 qxl has a bunch of tracepoints. Enable them, then compare xen
results with kvm/tcg results to see where things start going wrong.

-global qxl-vga.debug=1 -global qxl-vga.guestdebug=20

Thanks for reply, I used trace of qxl_* instead of -global debug
options (is it right or must I maintain also global qxl debug option?).
On attachment the new qemu log of windows 7 test with qxl vga.

Post by Gerd Hoffmann
domU starts, loads correctly the DE, vdagent and mouse are both
working, but screen refreshing is very lagging (also only open of
start menu).

Can you check the log to see if there are strange things to fix also
on spice and/or qemu?
Thanks for any reply.

Post by Gerd Hoffmann

I'm not aware of any regressions.
I'd suggest to try latest spice-server release.

http://packages.debian.org/sid/libspice-server1

After I updated Fedora19 vm on kvm, it works with qxl.
I compared xen and kvm logs and the only relevant difference that I

Post by Fabio Fantoni
ioremap error for 0xfc001000-0xfc002000, requested 0x10, got 0x0

I attached all messages and Xorg logs for both xen and kvm (Fedora19)
tests with qxl.
And about xen hypervisor logs (with xl dmesg) the only difference
between stdvga and qxl (same domU) is that qxl log has 3 "pci dev bar"
more. Full logs on attachments.
Thanks for any reply.

Post by Gerd Hoffmann
HTH,
Gerd

I made other tests with qxl using xen_platform_pci=0 (now that it is
functioning with qemu upstream too).
On a W7 domU the main problem with performances with qxl drivers seems
to be solved but unfortunately I didn't find a way to have both qxl and
xen gplpv working.
On a Saucy domU (ubuntu 13.10) with this kernel patch applied (see below):
http://lists.xen.org/archives/html/xen-devel/2013-12/msg00583.html
the black screen and X process to 100% persists.
Attached the xorg log with a backtrace in it.
Anyone on this please?

Thanks for any reply.

Fabio Fantoni

2013-09-26 10:28:24 UTC