Re: [Qemu-devel] [PATCH] pci: fix bridge IO/BASE

[Michael S. Tsirkin]

On Sun, Mar 04, 2012 at 10:27:24AM +0000, Blue Swirl wrote:
> On Sun, Mar 4, 2012 at 09:46, Michael S. Tsirkin <address@hidden> wrote:
> > commit 5caef97a16010f818ea8b950e2ee24ba876643ad introduced
> > a regression: we do not make IO base/limit upper 16
> > bit registers writeable, so we should report a 16 bit
> > IO range type, not a 32 bit one.
> > Note that PCI_PREF_RANGE_TYPE_32 is 0x0, but PCI_IO_RANGE_TYPE_32 is 0x1.
> >
> > In particular, this broke sparc64.
> >
> > Note: this just reverts to behaviour prior to the patch.
> > Making PCI_IO_BASE_UPPER16 and PCI_IO_LIMIT_UPPER16
> > registers writeable should, and seems to, work just as well, but
> > as no system seems to actually be interested in 32 bit IO,
> > let's not make unnecessary changes.
> >
> > Reported-by: Mark Cave-Ayland <address@hidden>
> > Signed-off-by: Michael S. Tsirkin <address@hidden>
> >
> > Mark, can you confirm that this fixes the bug for you?
> 
> No, running
> qemu-system-sparc64 -serial stdio
> still shows black screen and the following on console:
> OpenBIOS for Sparc64
> Unhandled Exception 0x0000000000000032
> PC = 0x00000000ffd19e18 NPC = 0x00000000ffd19e1c
> Stopping execution

The weird thing is the range type does not seem to be accessed
at all. So I guessed there's some memory corruption here.
Running valgrind shows this:

--11114-- WARNING: unhandled syscall: 340
--11114-- You may be able to write your own handler.
--11114-- Read the file README_MISSING_SYSCALL_OR_IOCTL.
--11114-- Nevertheless we consider this a bug.  Please report
--11114-- it at http://valgrind.org/support/bug_reports.html.
==11114== Invalid read of size 4
==11114==    at 0x2A68C0: pci_apb_init (apb_pci.c:350)
==11114==    by 0x2F7A84: sun4uv_init (sun4u.c:779)
==11114==    by 0x13D716: main (vl.c:3397)
==11114==  Address 0x156c7d30 is 0 bytes after a block of size 64
alloc'd
==11114==    at 0x557DD69: malloc (vg_replace_malloc.c:236)
==11114==    by 0x225F56: malloc_and_trace (vl.c:2156)
==11114==    by 0x584AFEC: ??? (in /lib/libglib-2.0.so.0.2800.8)
==11114==    by 0x584B528: g_malloc0 (in /lib/libglib-2.0.so.0.2800.8)
==11114==    by 0x19C50C: qemu_allocate_irqs (irq.c:47)
==11114==    by 0x2F7A4C: sun4uv_init (sun4u.c:778)
==11114==    by 0x13D716: main (vl.c:3397)
==11114== 
apb: here
==11114== Warning: client switching stacks?  SP change: 0xfec42cbc -->
0x16894008
==11114==          to suppress, use: --max-stackframe=398791500 or
greater
==11114== Warning: client switching stacks?  SP change: 0x16893fa0 -->
0xfec42cc0
==11114==          to suppress, use: --max-stackframe=398791392 or
greater
==11114== Warning: client switching stacks?  SP change: 0xfec42fe0 -->
0x16893fd0
==11114==          to suppress, use: --max-stackframe=398790640 or
greater
==11114==          further instances of this message will not be shown.
QEMU 1.0.50 monitor - type 'help' for more information
(qemu) ==11114== Thread 2:
==11114== Conditional jump or move depends on uninitialised value(s)
==11114==    at 0x2A8351: compute_all_sub (cc_helper.c:37)
==11114==    by 0x2A8782: helper_compute_psr (cc_helper.c:470)
==11114==    by 0x9AD9A19: ???
==11114== 
==11114== Conditional jump or move depends on uninitialised value(s)
==11114==    at 0x2A827C: compute_all_sub_xcc (cc_helper.c:60)
==11114==    by 0x2A8795: helper_compute_psr (cc_helper.c:473)
==11114==    by 0x9AD9A19: ???
==11114== 
==11114== Conditional jump or move depends on uninitialised value(s)
==11114==    at 0x2A8296: compute_all_sub_xcc (cc_helper.c:295)
==11114==    by 0x2A8795: helper_compute_psr (cc_helper.c:473)
==11114==    by 0x9AD9A19: ???
==11114== 

Is the above a problem?

> This unassigned memory exception is triggered because CMD646 IDE I/O
> registers are not accessible:
> 
> (qemu) info pci
>   Bus  0, device   0, function 0:
>     Host bridge: PCI device 108e:a000
>       id ""
>   Bus  0, device   1, function 0:
>     PCI bridge: PCI device 108e:5000
>       BUS 0.
>       secondary bus 1.
>       subordinate bus 1.
>       IO range [0x0000, 0x0fff]
>       memory range [0x00000000, 0x000fffff]
>       prefetchable memory range [0x00000000, 0x000fffff]
>       id ""
>   Bus  0, device   1, function 1:
>     PCI bridge: PCI device 108e:5000
>       BUS 0.
>       secondary bus 2.
>       subordinate bus 2.
>       IO range [0x0000, 0x0fff]
>       memory range [0x00000000, 0x000fffff]
>       prefetchable memory range [0x00000000, 0x000fffff]
>       id ""
>   Bus  0, device   2, function 0:
>     VGA controller: PCI device 1234:1111
>       BAR0: 32 bit prefetchable memory at 0x00800000 [0x00ffffff].
>       BAR6: 32 bit memory at 0x01000000 [0x0100ffff].
>       id ""
>   Bus  0, device   3, function 0:
>     Bridge: PCI device 108e:1000
>       BAR0: 32 bit memory at 0x02000000 [0x02ffffff].
>       BAR1: 32 bit memory at 0x03000000 [0x037fffff].
>       id ""
>   Bus  0, device   4, function 0:
>     Ethernet controller: PCI device 10ec:8029
>       IRQ 0.
>       BAR0: I/O at 0xffffffffffffffff [0x00fe].
>       BAR6: 32 bit memory at 0x03800000 [0x0380ffff].
>       id ""
>   Bus  0, device   5, function 0:
>     IDE controller: PCI device 1095:0646
>       IRQ 1.
>       BAR0: I/O at 0xffffffffffffffff [0x0006].
>       BAR1: I/O at 0xffffffffffffffff [0x0002].
>       BAR2: I/O at 0xffffffffffffffff [0x0006].
>       BAR3: I/O at 0xffffffffffffffff [0x0002].
>       BAR4: I/O at 0xffffffffffffffff [0x000e].
>       id ""
> (qemu) info mtree
> memory
> 0000000000000000-7ffffffffffffffe (prio 0, RW): system
>   0000000000000000-0000000007ffffff (prio 0, RW): sun4u.ram
>   000001fe00000000-000001fe0000ffff (prio 0, RW): apb-config
>   000001fe01000000-000001fe01ffffff (prio 0, RW): apb-pci-config
>   000001fe02000000-000001fe0200ffff (prio 0, RW): apb-pci-ioport
>   000001ff00000000-000001ffffffffff (prio 0, RW): pci-mmio
>     000001ff00000000-000001ff000fffff (prio 1, RW): alias
> pci_bridge_mem @pci_bridge_pci 0000000000000000-00000000000fffff
>     000001ff00000000-000001ff000fffff (prio 1, RW): alias
> pci_bridge_pref_mem @pci_bridge_pci 0000000000000000-00000000000fffff
>     000001ff00000000-000001ff000fffff (prio 1, RW): alias
> pci_bridge_mem @pci_bridge_pci 0000000000000000-00000000000fffff
>     000001ff00000000-000001ff000fffff (prio 1, RW): alias
> pci_bridge_pref_mem @pci_bridge_pci 0000000000000000-00000000000fffff
>     000001ff000a0000-000001ff000affff (prio 2, RW): alias vga.chain4
> @vga.vram 0000000000000000-000000000000ffff
>     000001ff000a0000-000001ff000bffff (prio 1, RW): vga-lowmem
>     000001ff00800000-000001ff00ffffff (prio 1, RW): vga.vram
>     000001ff01000000-000001ff0100ffff (prio 1, RW): vga.rom
>     000001ff02000000-000001ff02ffffff (prio 1, RW): isa-mmio
>     000001ff03000000-000001ff037fffff (prio 1, RW): isa-mmio
>     000001ff03800000-000001ff0380ffff (prio 1, RW): ne2000.rom
>   000001fff0000000-000001fff03fffff (prio 0, R-): sun4u.prom
> pci_bridge_pci
> 0000000000000000-7ffffffffffffffe (prio 0, RW): pci_bridge_pci
> pci_bridge_pci
> 0000000000000000-7ffffffffffffffe (prio 0, RW): pci_bridge_pci
> vga.vram
> 0000000000800000-0000000000ffffff (prio 1, RW): vga.vram
> I/O
> 0000000000000000-000000000000ffff (prio 0, RW): io
>   0000000000000000-0000000000000fff (prio 1, RW): alias pci_bridge_io
> @pci_bridge_io 0000000000000000-0000000000000fff
>   0000000000000000-0000000000000fff (prio 1, RW): alias pci_bridge_io
> @pci_bridge_io 0000000000000000-0000000000000fff
>   0000000000000060-0000000000000060 (prio 0, RW): i8042-data
>   0000000000000064-0000000000000064 (prio 0, RW): i8042-cmd
>   0000000000000074-0000000000000077 (prio 0, RW): m48t59
>   00000000000001ce-00000000000001ce (prio 0, RW): alias vbe @vbe
> 00000000000001ce-00000000000001ce
>   00000000000001d0-00000000000001d0 (prio 0, RW): alias vbe @vbe
> 00000000000001d0-00000000000001d0
>   0000000000000378-000000000000037f (prio 0, RW): alias parallel
> @parallel 0000000000000378-000000000000037f
>   00000000000003b4-00000000000003b5 (prio 0, RW): alias vga @vga
> 00000000000003b4-00000000000003b5
>   00000000000003ba-00000000000003ba (prio 0, RW): alias vga @vga
> 00000000000003ba-00000000000003ba
>   00000000000003c0-00000000000003cf (prio 0, RW): alias vga @vga
> 00000000000003c0-00000000000003cf
>   00000000000003d4-00000000000003d5 (prio 0, RW): alias vga @vga
> 00000000000003d4-00000000000003d5
>   00000000000003da-00000000000003da (prio 0, RW): alias vga @vga
> 00000000000003da-00000000000003da
>   00000000000003f1-00000000000003f5 (prio 0, RW): alias fdc @fdc
> 00000000000003f1-00000000000003f5
>   00000000000003f7-00000000000003f7 (prio 0, RW): alias fdc @fdc
> 00000000000003f7-00000000000003f7
>   00000000000003f8-00000000000003ff (prio 0, RW): serial
>   0000000000000510-0000000000000511 (prio 0, RW): fwcfg

And with type 32 range it looks like this:

0000000000000000-7ffffffffffffffe (prio 0, RW): system
  0000000000000000-0000000007ffffff (prio 0, RW): sun4u.ram
  000001fe00000000-000001fe0000ffff (prio 0, RW): apb-config
  000001fe01000000-000001fe01ffffff (prio 0, RW): apb-pci-config
  000001fe02000000-000001fe0200ffff (prio 0, RW): apb-pci-ioport
  000001ff00000000-000001ffffffffff (prio 0, RW): pci-mmio
    000001ff00000000-000001ff000fffff (prio 1, RW): alias pci_bridge_mem
@pci_bridge_pci 0000000000000000-00000000000fffff
    000001ff00000000-000001ff000fffff (prio 1, RW): alias
pci_bridge_pref_mem @pci_bridge_pci 0000000000000000-00000000000fffff
    000001ff00000000-000001ff000fffff (prio 1, RW): alias pci_bridge_mem
@pci_bridge_pci 0000000000000000-00000000000fffff
    000001ff00000000-000001ff000fffff (prio 1, RW): alias
pci_bridge_pref_mem @pci_bridge_pci 0000000000000000-00000000000fffff
    000001ff000a0000-000001ff000affff (prio 2, RW): alias vga.chain4
@vga.vram 0000000000000000-000000000000ffff
    000001ff000a0000-000001ff000bffff (prio 1, RW): vga-lowmem
    000001ff00800000-000001ff00ffffff (prio 1, RW): vga.vram
    000001ff01000000-000001ff0100ffff (prio 1, RW): vga.rom
    000001ff02000000-000001ff02ffffff (prio 1, RW): isa-mmio
    000001ff03000000-000001ff037fffff (prio 1, RW): isa-mmio
  000001fff0000000-000001fff03fffff (prio 0, R-): sun4u.prom
pci_bridge_pci
0000000000000000-7ffffffffffffffe (prio 0, RW): pci_bridge_pci
pci_bridge_pci
0000000000000000-7ffffffffffffffe (prio 0, RW): pci_bridge_pci
vga.vram
0000000000800000-0000000000ffffff (prio 1, RW): vga.vram
I/O
0000000000000000-000000000000ffff (prio 0, RW): io
  0000000000000000-0000000000000fff (prio 1, RW): alias pci_bridge_io
@pci_bridge_io 0000000000000000-0000000000000fff
  0000000000000000-0000000000000fff (prio 1, RW): alias pci_bridge_io
@pci_bridge_io 0000000000000000-0000000000000fff
  0000000000000060-0000000000000060 (prio 0, RW): i8042-data
  0000000000000064-0000000000000064 (prio 0, RW): i8042-cmd
  0000000000000074-0000000000000077 (prio 0, RW): m48t59
  00000000000001ce-00000000000001ce (prio 0, RW): vbe
  00000000000001d0-00000000000001d0 (prio 0, RW): vbe
  0000000000000378-000000000000037f (prio 0, RW): parallel
  00000000000003b4-00000000000003b5 (prio 0, RW): vga
  00000000000003ba-00000000000003ba (prio 0, RW): vga
  00000000000003c0-00000000000003cf (prio 0, RW): vga
  00000000000003d4-00000000000003d5 (prio 0, RW): vga
  00000000000003da-00000000000003da (prio 0, RW): vga
  00000000000003f1-00000000000003f5 (prio 0, RW): fdc
  00000000000003f7-00000000000003f7 (prio 0, RW): fdc
  00000000000003f8-00000000000003ff (prio 0, RW): serial
  0000000000000400-00000000000004ff (prio 1, RW): ne2000
  0000000000000500-0000000000000507 (prio 1, RW): cmd646-data
  0000000000000510-0000000000000511 (prio 0, RW): fwcfg
  0000000000000580-0000000000000583 (prio 1, RW): cmd646-cmd
  0000000000000600-0000000000000607 (prio 1, RW): cmd646-data
  0000000000000680-0000000000000683 (prio 1, RW): cmd646-cmd
  0000000000000700-000000000000070f (prio 1, RW): cmd646-bmdma
    0000000000000700-0000000000000703 (prio 0, RW): cmd646-bmdma-bus
    0000000000000704-0000000000000707 (prio 0, RW): cmd646-bmdma-ioport
    0000000000000708-000000000000070b (prio 0, RW): cmd646-bmdma-bus
    000000000000070c-000000000000070f (prio 0, RW): cmd646-bmdma-ioport


Sill trying to understand what all this means.


> >  hw/pci.c |    4 ++--
> >  1 files changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/hw/pci.c b/hw/pci.c
> > index fee27fc..6d08cef 100644
> > --- a/hw/pci.c
> > +++ b/hw/pci.c
> > @@ -633,8 +633,8 @@ static void pci_init_mask_bridge(PCIDevice *d)
> >     memset(d->wmask + PCI_PREF_BASE_UPPER32, 0xff, 8);
> >
> >     /* Supported memory and i/o types */
> > -    d->config[PCI_IO_BASE] |= PCI_IO_RANGE_TYPE_32;
> > -    d->config[PCI_IO_LIMIT] |= PCI_IO_RANGE_TYPE_32;
> > +    d->config[PCI_IO_BASE] |= PCI_IO_RANGE_TYPE_16;
> > +    d->config[PCI_IO_LIMIT] |= PCI_IO_RANGE_TYPE_16;
> >     pci_word_test_and_set_mask(d->config + PCI_PREF_MEMORY_BASE,
> >                                PCI_PREF_RANGE_TYPE_64);
> >     pci_word_test_and_set_mask(d->config + PCI_PREF_MEMORY_LIMIT,
> > --
> > 1.7.9.111.gf3fb0