On 3 October 2016 at 13:14, Laszlo Ersek <lersek@xxxxxxxxxx> wrote: > On 10/03/16 13:34, Emil Velikov wrote: >> On 30 September 2016 at 18:26, Laszlo Ersek <lersek@xxxxxxxxxx> wrote: > >>> This setup (modulo the kernel of course) was known to work, but now the >>> X server actually segfaults (apparently in the >>> xf86PlatformDeviceCheckBusID() function). Please find the logfile attached. >>> >>> (NB: this is unrelated to upstream commit de9ce6757c2e -- which the >>> pristine FC24 build lacks -- because I don't set AutoAddGPU to "off" -- >>> it is left at its default "on" value.) >>> >> Where is this upstream commit again - it shows as unknown for the >> kernel, xserver and libdrm ? > > Apologies, that commit hash belongs to a cherry-picked patch on one of > my private branches; the original is > > ea91db4b8331 config: fix GPUDevice fail when AutoAddGPU off + BusID > > >> So my theory was a bit off - SetVersion is the one responsible to set >> the "BusID", as retrieved by drmGetBusID, regardless if drmOpen or >> open is used. >> >> Here's a bit of a brain dump from the other day: >> >> - The commit mentioned > > (Here I assume you mean kernel commit > > a325725633c2 drm: Lobotomize set_busid nonsense for !pci drivers > > again.) > Correct. >>'affects' the drmSetBusid/DRM_IOCTL_SET_UNIQUE >> userspace codepaths. >> - The latter itself is dri1/legacy (xserver hw/xfree86/dri/) which is >> not functional for platform devices. >> The latter of which seems to be the case for virt-gpu based on the >> kernel module. >> - The modesetting driver should/cannot reach the above xserver codepath >> >> That said, it seems that (at least some) userspace expects a PCI >> device despite the kernel module 'advertising' itself as platform one >> :-\ >> >> Going through the xserver layers is a bit inspiring I'm wondering if >> we can not get a strace before/after the xserver commit >> ca8d88e50310a0d440a127c22a0a383cc149f408 ? It will help us track >> things a lot quicker/easier. > > This commit: > > ca8d88e50310 xfree86: recognize primary BUS_PCI device in > xf86IsPrimaryPlatform() > > is not relevant when running Xorg on QEMU's "virtio-vga" device, it is > only relevant when the "virtio-gpu-pci" device is used. Aarch64 guests > can't have "virtio-vga", only "virgio-gpu-pci", so that commit was > needed for Aarch64 guests primarily. > > In this case however, kernel commit a325725633c2 breaks "virtio-vga" in > x86_64 guests, both with and without xserver commit ca8d88e50310. > > Anyway I'll look into capturing a strace and/or following Xorg with gdb. > If the overall case/issue is irrelevant of the xserver commit we can ignore if for the time being. In that case can you please get a xserver strace before/after the offending kernel commit. Thank you. Emil _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
