Re: [Qemu-devel] Re: ACPI error when mapping a 2GB BAR w/ 4GB of RAM

[Cam Macdonell]

On Fri, Sep 17, 2010 at 2:52 PM, Cam Macdonell <cam@xxxxxxxxxxxxxx> wrote:
> On Fri, Sep 17, 2010 at 2:04 PM, Chris Wright <chrisw@xxxxxxxxxx> wrote:
>> * Cam Macdonell (cam@xxxxxxxxxxxxxx) wrote:
>>> After fixing the resource_size_t return value with
>>> pci_resource_alignment, I see one other strange behaviour only when
>>> using 4GB of RAM and a 2GB BAR.  I haven't found any other combination
>>> of RAM/BAR size that triggers this bug.  I am using 2.6.36-rc3.
>>>
>>> ACPI Error: The DSDT has been corrupted or replaced - old, new headers
>>> below (20100702/tbutils-372)
>>> ACPI: DSDT (null) 01F15 (v01   BXPC   BXDSDT 00000001 INTL 20090123)
>>> ACPI:      (null) 00000 (v00                 00000000      00000000)
>>> ACPI Error: Please send DMI info to linux-acpi@xxxxxxxxxxxxxxx
>>> If system does not work as expected, please boot with acpi=copy_dsdt
>>> (20100702/tbutils-378)
>>> ACPI: PCI Interrupt Link [LNKC] disabled and referenced, BIOS bug
>>> ACPI Exception: AE_AML_INVALID_RESOURCE_TYPE, Evaluating _CRS
>>> (20100702/pci_link-283)
>>> ACPI: Unable to set IRQ for PCI Interrupt Link [LNKC]. Try pci=noacpi
>>> or acpi=off
>>> virtio-pci 0000:00:03.0: PCI INT A: no GSI - using ISA IRQ 11
>>> Non-volatile memory driver v1.3
>>> Linux agpgart interface v0.103
>>> Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
>>
>> IIRC,  the pci hole is only 1.5G in the BIOS, can you verify that
>> seabios is doing the right thing?
>
> I'm not sure what the right thing for seabios to do is.  Here is the
> seabios output related to the device.
>
> PCI: bus=0 devfn=0x20: vendor_id=0x1af4 device_id=0x1110
> region 0: 0xf2040000
> init smm
> init boot device ordering
>
> <snip>
>
> Attempting to init PCI bdf 00:04.0 (vd 1af4:1110)
> Attempting to map option rom on dev 00:04.0
> Option rom sizing returned 0 0
> Checking rom 0x000c9800 (sig aa55 size 17)
> Checking rom 0x000cc000 (sig aa55 size 2)
> Checking rom 0x000c9000 (sig aa55 size 4)
> Checking rom 0x000c9800 (sig aa55 size 17)
> Checking rom 0x000cc000 (sig aa55 size 2)
> Mapping hd drive 0x000fdb50 to 0
> Running option rom at c980:0003
> Running option rom at cc00:0003
> pmm_malloc zone=0x000f515c handle=ffffffff size=36 align=10
> ret=0x000fdaf0 (detail=0x7ffefca0)
> ebda moved from 9fc00 to 9f400
> pmm_malloc zone=0x000f5154 handle=ffffffff size=2048 align=10
> ret=0x0009f800 (detail=0x7ffefb40)
> finalize PMM
> malloc finalize
>
> when using a BAR of 2GB or less, there is an additional write to the
> PCI space of the device, which may be from the bios
>
> pci_write_config: (val) 0xffffffff -> 0x18 (addr)
> pci_read_config: (val) 0x80000004 <- 0x18 (addr)
> pci_write_config: (val) 0x4 -> 0x18 (addr)
> pci_write_config: (val) 0x3 -> 0x4 (addr)
> pci_read_config: (val) 0x0 <- 0x1c (addr)
> pci_write_config: (val) 0xffffffff -> 0x1c (addr)
> IVSHMEM: guest pci addr = ffffffff00000000, guest h/w addr =
> 4312137728, size = 80000000
>
> so is it succeeding with smaller sizes (> 2GB) because it fits in the
> bios' pci hole?

sorry that should be "< 2GB".

>
> Cam
>
>>
>> thanks,
>> -chris
>>
>>
>
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