On Fri, May 28, 2010 at 12:42 AM, Blue Swirl <blauwir...@gmail.com> wrote: > On Thu, May 27, 2010 at 4:57 PM, Mark Cave-Ayland > <mark.cave-ayl...@siriusit.co.uk> wrote: >> Blue Swirl wrote: >> >>> On Tue, May 25, 2010 at 12:12 PM, Igor V. Kovalenko >>> <igor.v.kovale...@gmail.com> wrote: >>>> >>>> One code cleanup and another pci host bridge remap change, >>>> the latter requires qemu update with patch already posted to qemu list. >>>> >>>> v0->v1: added missing patch moving asi.h to arch includes >>> >>> Thanks, applied all. >> >> Whilst updating to OpenBIOS SVN and qemu git head to test these patches, >> I've found a regression with qemu-system-sparc64 and >> debian-504-sparc-netinst.iso. Rather than getting to the end of the kernel >> boot and being unable to mount the root filesystem, instead I now get the >> following fatal trap message: >> >> >> [ 42.493402] Console: switching to mono PROM 128x96 >> [ 63.440200] [drm] Initialized drm 1.1.0 20060810 >> [ 63.542123] su: probe of ffe2dea0 failed with error -12 >> [ 63.690331] brd: module loaded >> [ 63.787034] loop: module loaded >> [ 63.863989] Uniform Multi-Platform E-IDE driver >> [ 63.961215] ide: Assuming 33MHz system bus speed for PIO modes; override >> with idebus=xx >> [ 64.115119] mice: PS/2 mouse device common for all mice >> [ 64.234482] usbcore: registered new interface driver usbhid >> [ 64.359397] usbhid: v2.6:USB HID core driver >> [ 64.462167] TCP cubic registered >> [ 64.539714] NET: Registered protocol family 17 >> [ 64.642969] registered taskstats version 1 >> [ 64.737822] drivers/rtc/hctosys.c: unable to open rtc device (rtc0) >> qemu: fatal: Trap 0x0068 while trap level (5) >= MAXTL (5), Error state >> pc: 0000000000424d18 npc: 0000000000424d1c >> General Registers: >> %g0-3: 0000000000000000 0000000008000000 0000000000004000 0000000000000002 >> %g4-7: 00000000000003ff 0000000000000001 0000000000000020 0000000000004000 >> >> Current Register Window: >> %o0-3: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 >> %o4-7: 0000000000000000 0000000000000000 00000000fffd3ef0 0000000000000000 >> %l0-3: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 >> %l4-7: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 >> %i0-3: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 >> %i4-7: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 >> >> Floating Point Registers: >> %f00: 000000000.000000 000000000.000000 000000000.000000 000000000.000000 >> %f04: 000000000.000000 000000000.000000 000000000.000000 000000000.000000 >> %f08: 000000000.000000 000000000.000000 000000000.000000 000000000.000000 >> %f12: 000000000.000000 000000000.000000 000000000.000000 000000000.000000 >> %f16: 000000000.000000 000000000.000000 000000000.000000 000000000.000000 >> %f20: 000000000.000000 000000000.000000 000000000.000000 000000000.000000 >> %f24: 000000000.000000 000000000.000000 000000000.000000 000000000.000000 >> %f28: 000000000.000000 000000000.000000 000000000.000000 000000000.000000 >> %f32: 000000000.000000 000000000.000000 000000000.000000 000000000.000000 >> %f36: 000000000.000000 000000000.000000 000000000.000000 000000000.000000 >> %f40: 000000000.000000 000000000.000000 000000000.000000 000000000.000000 >> %f44: 000000000.000000 000000000.000000 000000000.000000 000000000.000000 >> %f48: 000000000.000000 000000000.000000 000000000.000000 000000000.000000 >> %f52: 000000000.000000 000000000.000000 000000000.000000 000000000.000000 >> %f56: 000000000.000000 000000000.000000 000000000.000000 000000000.000000 >> %f60: 000000000.000000 000000000.000000 000000000.000000 000000000.000000 >> pstate: 00000414 ccr: 00 (icc: ---- xcc: ----) asi: 82 tl: 5 pil: 0 >> cansave: 6 canrestore: 0 otherwin: 0 wstate: 2 cleanwin: 0 cwp: 7 >> fsr: 0000000000000000 y: 0000000000000000 fprs: 0000000000000000 >> Aborted >> >> >> Digging deeper, it seems that this was something that was introduced earlier >> than the last set of patches. Reverting to OpenBIOS SVN r777 and using 'git >> bisect', I can identify the offending commit in qemu git as >> 2aae2b8e0abd58e76d616bcbe93c6966d06d0188 "sparc64: fix pstate privilege >> bits". Does that help at all? > > Yes, bisection results are usually very helpful, thanks. > > I think the problem is that previously psrs was always 1 and PSR_HYPV > always set, so maximally permissive MMU_HYPV_INDEX was always selected > by cpu_mmu_index (bug!). Also because PSR_HYPV is no longer set, some > checks in translate.c indicate privilege violations. > > The logic was previously such that if the CPU does not have a > hypervisor mode, for compatibility, supervisor mode would also select > hypervisor mode (or at least that was my intention and probably Igor > wasn't aware of this, sorry). Now that they are separate, CPUs without > hypervisor mode must be handled differently. Perhaps this commit > should be reverted, the fix won't be so trivial.
I'll take a look at this issue. > > The lesson here is also that subtle assumptions like this should be > documented. > -- Kind regards, Igor V. Kovalenko
