Re: [Qemu-devel] [FYI] Soft feature freeze for 1.0 is 10/15 (three weeks away)

[Alexander Graf]

Am 29.09.2011 um 21:28 schrieb Blue Swirl <address@hidden>:

> On Wed, Sep 28, 2011 at 9:21 PM, Alexander Graf <address@hidden> wrote:
>> 
>> On 27.09.2011, at 21:19, Blue Swirl wrote:
>> 
>> On Tue, Sep 27, 2011 at 4:44 PM, Avi Kivity <address@hidden> wrote:
>> 
>> On 09/27/2011 07:39 PM, Blue Swirl wrote:
>> 
>> 
>>  Well, it's not that easy.  As the other mapping is part of an ordinary
>> 
>> BAR,
>> 
>>  you need to setup the device (at least PCI_COMMAND and
>> 
>> PCI_BASE_ADDRESS_0)
>> 
>>  so it responds to memory requests, and also enable the bridge.
>> 
>>  We could hack it by having a low-priority mapping at 0x80013000, but it
>> 
>>  seems wrong.  Maybe the firmware should configure that BAR first?  What
>> 
>>  happens on real hardware?
>> 
>> In this message I seem to confess that the address is arbitrary and in
>> 
>> the subsequent messages the overlap with PCI region is also discussed.
>> 
>> http://lists.nongnu.org/archive/html/qemu-devel/2009-01/msg00542.html
>> 
>> Maybe the address of macio should be fixed as Laurent suggested.
>> 
>> I'll leave it up to you - I'm out of my depth here.
>> 
>> Meanwhile I suggest applying the pci alias patch - the bug is independent of
>> 
>> the vga issue.
>> 
>> OK, pushed.
>> 
>> 
>> Ah, after digging into the issue for a while myself I stumbled over this
>> thread, explaining what I figured would be the culprit. Please CC qemu-ppc
>> for these discussions :).
>> Either way, I'm seeing 2 issues here. I enhanced the "info mtree" command to
>> also display the region we're currently looking at, so the first tuple shows
>> the region we're in, the second tuple the region we're trying to map into
>> the first region (addresses aligned on each other). I also print out alias
>> information directly:
> 
> That way you miss for example vga.chain4.
> 
>> [ 00000000-7ffffffffffffffe ] 00000000-7ffffffffffffffe : system
>>   [ 80013000-8001303f ] 80013000-8001303f : escc
>>   [ fee00000-fee00fff ] fee00000-fee00fff : pci-data-idx
>>   [ fec00000-fec00fff ] fec00000-fec00fff : pci-conf-idx
>>   [ 80000000-fdffffff ] 80000000-fdffffff : pci-hole
>>    -> alias (0000000080000000, 0000000000000000)
>>     [ 80000000-fdffffff ] 00000000-ffffffff : pci-mmio
>>       [ 80880000-808fffff ] 80880000-808fffff : macio
>>         [ 808e0000-808fffff ] 808e0000-808fffff : macio-nvram
>>         [ 808a0000-808a0fff ] 808a0000-808a0fff : pmac-ide
>>         [ 80896000-80897fff ] 80896000-80897fff : cuda
>>         [ 80893000-8089303f ] 80893000-8089303f : escc-bar
>>          -> alias (0000000000000000, 0000000080013000)
>>           [ 80893000-8089303f ] 80893000-8089303f : escc
>>         [ 80888000-80888fff ] 80888000-80888fff : dbdma
>>         [ 80880000-80880fff ] 80880000-80880fff : heathrow-pic
>>       [ 80800000-8080ffff ] 80800000-8080ffff : vga.rom
>>       [ 80000000-807fffff ] 80000000-807fffff : vga.vram
>>   [ fe000000-fe1fffff ] fe000000-fe1fffff : isa-mmio
>> I/O
>> [ 00000000-0000ffff ] 00000000-0000ffff : io
>>   [ 00000700-0000070f ] 00000700-0000070f : cmd646-bmdma
>>     [ 0000070c-0000070f ] 0000070c-0000070f : cmd646-bmdma-ioport
>>     [ 00000708-0000070b ] 00000708-0000070b : cmd646-bmdma-bus
>>     [ 00000704-00000707 ] 00000704-00000707 : cmd646-bmdma-ioport
>>     [ 00000700-00000703 ] 00000700-00000703 : cmd646-bmdma-bus
>>   [ 00000680-00000683 ] 00000680-00000683 : cmd646-cmd
>>   [ 00000600-00000607 ] 00000600-00000607 : cmd646-data
>>   [ 00000580-00000583 ] 00000580-00000583 : cmd646-cmd
>>   [ 00000500-00000507 ] 00000500-00000507 : cmd646-data
>>   [ 00000400-000004ff ] 00000400-000004ff : ne2000
>> I did another small hack to display the flat memory view:
>>   ranges[0] = { 80000000, 13000 } vga.vram
>>   ranges[1] = { 80013000, 40 } escc
>>   ranges[2] = { 80013040, 7ecfc0 } vga.vram
>>   ranges[3] = { 80800000, 10000 } vga.rom
>>   ranges[4] = { 80880000, 1000 } heathrow-pic
>>   ranges[5] = { 80888000, 1000 } dbdma
>>   ranges[6] = { 80893000, 40 } escc
>>   ranges[7] = { 80896000, 2000 } cuda
>>   ranges[8] = { 808a0000, 1000 } pmac-ide
>>   ranges[9] = { 808e0000, 20000 } macio-nvram
>>   ranges[10] = { fe000000, 200000 } isa-mmio
>>   ranges[11] = { fec00000, 1000 } pci-conf-idx
>>   ranges[12] = { fee00000, 1000 } pci-data-idx
>> Now to the issues:
>> 1)
>> ESCC is mapped inside the VGA region. That's what you discussed in this
>> thread. It's wrong. Please check this bug for a dump of a real G3 Beige's
>> memory layout:
>>   http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=555651
>> I don't think we really need to have serial available before PCI enum, so
>> let's just ditch the first map.
> 
> OK, though it would be useful for -nographic mode. OpenBIOS can queue
> the output until a serial device has been probed and then print the
> buffer, but if it crashes before that, we're out of luck.

Then we need to gdb into openBIOS and read out the buffer. I do that with 
Linux's log_buf all the time :)

> 
> BTW, -nographic does not work anymore for PPC, there is no output.

Hrm. That's new. Last time I checked there was output. I'll look at what's 
going on...

Alex

>