Re: virtio capabilities

[Alexey Kardashevskiy]

On 13/12/2019 19:36, Michael S. Tsirkin wrote:
> On Fri, Dec 13, 2019 at 07:29:40PM +1100, Alexey Kardashevskiy wrote:
>>
>>
>> On 13/12/2019 18:24, Michael S. Tsirkin wrote:
>>> On Fri, Dec 13, 2019 at 05:05:05PM +1100, Alexey Kardashevskiy wrote:
>>>> Hi!
>>>>
>>>> I am having an issue with capabilities (hopefully the chunk formatting
>>>> won't break).
>>>>
>>>> The problem is that when virtio_pci_find_capability() reads
>>>> pci_find_capability(dev, PCI_CAP_ID_VNDR), 0 is returned; if repeated,
>>>> it returns a valid number (0x84). Timing seems to matter. pci_cfg_read
>>>> trace shows that that first time read does not reach QEMU but others do
>>>> reach QEMU and return what is expected.
>>>>
>>>> How to debug this, any quick ideas?
>>>> The config space is not a MMIO BAR
>>>> or KVM memory slot or anything like this, right? :) Thanks,
>>>
>>> Depends on the platform.
>>>
>>> E.g. on x86, when using cf8/cfc pair, if guest doesn't
>>
>>
>> Is there an easy way to tell if it is this "cf8/cfc" case?
>>
>> I have these bars, is any of them related to cf8/cfc? Thanks,
>>
>> root@le-dbg:~# (qemu) info mtree -f
>> FlatView #0
>>  AS "memory", root: system
>>  AS "cpu-memory-0", root: system
>>  Root memory region: system
>>   0000000000000000-00000000ffffffff (prio 0, ram): ppc_spapr.ram kvm
>>   0000200080000000-000020008000002f (prio 0, i/o): msix-table
>>   0000200080000800-0000200080000807 (prio 0, i/o): msix-pba
>>   0000210000000000-0000210000000fff (prio 0, i/o): virtio-pci-common
>>   0000210000001000-0000210000001fff (prio 0, i/o): virtio-pci-isr
>>   0000210000002000-0000210000002fff (prio 0, i/o): virtio-pci-device
>>   0000210000003000-0000210000003fff (prio 0, i/o): virtio-pci-notify
>>
> 
> 
> No, you want stuff in hw/ppc/spapr_pci.c


The problem was with our firmware, fixing that now.

Out of curiosity. I do not see cf8/cfc on x86 either, or I just do not
recognize those, what is this cf8/cfc? Thanks,

FlatView #2

 AS "memory", root: system

 AS "cpu-memory-0", root: system

 AS "piix3-ide", root: bus master container

 AS "virtio-net-pci", root: bus master container

 Root memory region: system

  0000000000000000-00000000000bffff (prio 0, ram): pc.ram kvm

  00000000000c0000-00000000000c0fff (prio 0, rom): pc.ram
@00000000000c0000 kvm
  00000000000c1000-00000000000c3fff (prio 0, ram): pc.ram
@00000000000c1000 kvm
  00000000000c4000-00000000000e7fff (prio 0, rom): pc.ram
@00000000000c4000 kvm
  00000000000e8000-00000000000effff (prio 0, ram): pc.ram
@00000000000e8000 kvm
  00000000000f0000-00000000000fffff (prio 0, rom): pc.ram
@00000000000f0000 kvm
  0000000000100000-000000007fffffff (prio 0, ram): pc.ram
@0000000000100000 kvm
  00000000febc0000-00000000febc002f (prio 0, i/o): msix-table

  00000000febc0800-00000000febc0807 (prio 0, i/o): msix-pba

  00000000febfc000-00000000febfcfff (prio 0, i/o): virtio-pci-common

  00000000febfd000-00000000febfdfff (prio 0, i/o): virtio-pci-isr

  00000000febfe000-00000000febfefff (prio 0, i/o): virtio-pci-device

  00000000febff000-00000000febfffff (prio 0, i/o): virtio-pci-notify

  00000000fec00000-00000000fec00fff (prio 0, i/o): kvm-ioapic

  00000000fed00000-00000000fed003ff (prio 0, i/o): hpet

  00000000fee00000-00000000feefffff (prio 4096, i/o): kvm-apic-msi

  00000000fffc0000-00000000ffffffff (prio 0, rom): pc.bios kvm



-- 
Alexey