Re: [Xen-devel] Upstream qemu-xen, log verbosity and compile errors when enabling debug, filenaming

[Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>]

On Fri, 7 Dec 2012, Sander Eikelenboom wrote:
> Friday, December 7, 2012, 6:01:43 PM, you wrote:
> 
> > On Thu, 6 Dec 2012, Sander Eikelenboom wrote:
> >> Hi All,
> >> 
> >> Yesterday I have tried building and using upstream qemu and seabios.
> >> Config.mk:
> >> QEMU_UPSTREAM_URL ?= git://git.qemu.org/qemu.git
> >> QEMU_UPSTREAM_REVISION ?= master
> >> 
> >> SEABIOS_UPSTREAM_URL ?= git://git.qemu.org/seabios.git
> >> SEABIOS_UPSTREAM_TAG ?= master
> >> 
> >> And i'm happy to say that it works quite ok, even with (secondary pci) 
> >> pci-passthrough ( using an ATI gfx adapter and windows7 as guest os) :-).
> >> 
> >> But it seems to have an issue with a USB controller which is trying to use 
> >> msi-X interrupts, which makes xl dmesg report:
> >> (XEN) [2012-12-06 16:07:24] vmsi.c:108:d32767 Unsupported delivery mode 3
> >> and when "pci_msitranslate=0" is set the error still occurs, only this 
> >> time the correct domain number is reported, instead of the 32767.
> >> 
> >> 
> >> However, when trying to debug, i noticed although making a debug build 
> >> (make debug=y && make debug=y install), qemu-dm-<guestname>.log stays 
> >> almost empty.
> >> It seems all the defines related to debugging are not set.
> >> 
> >> - Would it be appropriated to enable them all when making a debug build ?
> >> - Would it be wise to also have some more verbose logging when not running 
> >> a debug build ?
> 
> > Yes and yes
> 
> >> - And if yes, what would be the nicest way to set the defines ?
> 
> > My guess is that it would be enough to turn on XEN_PT_LOGGING_ENABLED by
> > default
> 
> >> - Should the naming of the debug defines be made more consistent ?
> 
> > Yes
> 
> 
> 
> >> 
> >> When enabling these debug defines by hand:
> >> 
> >> xen-all.c
> >> #define DEBUG_XEN
> >> 
> >> xen-mapcache.c
> >> #define MAPCACHE_DEBUG
> >> 
> >> hw/xen-host-pci-device.c
> >> #define XEN_HOST_PCI_DEVICE_DEBUG
> >> 
> >> hw/xen_platform.c
> >> #define DEBUG_PLATFORM
> >> 
> >> hw/xen_pt.h
> >> #define XEN_PT_LOGGING_ENABLED
> >> #define XEN_PT_DEBUG_PCI_CONFIG_ACCESS
> >> 
> >> I get a lot of compile errors related to wrong types in the debug printf's.
> 
> > That's really bad. I would like upstream QEMU to have the same level of
> > logging as qemu-xen-traditional by default. And they should compile.
> 
> 
> >> Another thing that occurred to me was that the file naming doesn't seem to 
> >> be overly consistent:
> >> 
> >> xen-all.c
> >> xen-mapcache.c
> >> xen-mapcache.h
> >> xen-stub.c
> >> xen_apic.c
> >> hw/xen_backend.c
> >> hw/xen_backend.h
> >> hw/xen_blkif.h
> >> hw/xen_common.h
> >> hw/xen_console.c
> >> hw/xen_devconfig.c
> >> hw/xen_disk.c
> >> hw/xen_domainbuild.c
> >> hw/xen_domainbuild.h
> >> hw/xenfb.c
> >> hw/xen.h
> >> hw/xen-host-pci-device.c
> >> hw/xen-host-pci-device.h
> >> hw/xen_machine_pv.c
> >> hw/xen_nic.c
> >> hw/xen_platform.c
> >> hw/xen_pt.c
> >> hw/xen_pt_config_init.c
> >> hw/xen_pt.h
> >> hw/xen_pt_msi.c
> >> 
> >> Would it be worthwhile to make it:
> >> - consistent all underscore or all minus ?
> >> - allways xen_ (or xen- depending on the above) ?
> 
> > Yes, definitely.
> > Given that the development window for QEMU 1.4 has just opened might
> > even be the right time to make these changes.
> 
> > Are you volunteering? :)
> 
> Erhmm yes i think i should be able to accomplish this :-)
> And yes i did notice the 1.3 release :-)
> 
> Patches would be directly against the qemu-upstream git-tree, first round to 
> xen-devel and when acked send to qemu-list ?

It is best to CC qemu-devel from the start, they are used to high levels
of traffic anyway ;)

> For the filerenaming, the rest of the qemu sources seems to be mixed, but i 
> think it would be more neat for the xen part to stick to one of the two .. 
> but which one would be prefered ?
> 1. all underscores
> 2. all minus

I would go for 1.
However I would keep the renaming patch separate from the others,
because it could start a flame war between underscores supporters
and minuses supporters :)

The other changes (better default debug levels, working debugs, debug
functions naming) should all be non-controversial.

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel