diff mbox series

virtio capabilities

Message ID 823b58f1-f17e-6645-11be-406ad1494e06@ozlabs.ru
State New
Headers show
Series virtio capabilities | expand

Commit Message

Alexey Kardashevskiy Dec. 13, 2019, 6:05 a.m. UTC 
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,


[    3.489492] ___K___ (0) virtio_pci_modern_probe 642
[    3.489697] ___K___ (0) virtio_pci_find_capability 492: FIND a cap
[    3.490070] ___K___ (0) virtio_pci_find_capability 494: cap is at 0
[    3.490335] ___K___ (0) virtio_pci_find_capability 492: FIND a cap
10909@1576216763.643271:pci_cfg_read virtio-net-pci 00:0 @0x6 -> 0x10
10909@1576216763.643431:pci_cfg_read virtio-net-pci 00:0 @0x34 -> 0x98
10909@1576216763.643591:pci_cfg_read virtio-net-pci 00:0 @0x98 -> 0x8411
10909@1576216763.643747:pci_cfg_read virtio-net-pci 00:0 @0x84 -> 0x7009
[    3.491264] ___K___ (0) virtio_pci_find_capability 494: cap is at 132
10909@1576216763.644140:pci_cfg_read virtio-net-pci 00:0 @0x87 -> 0x5
10909@1576216763.644287:pci_cfg_read virtio-net-pci 00:0 @0x88 -> 0x0
[    3.491803] ___K___ (0) virtio_pci_find_capability 506: 5 0
10909@1576216763.644632:pci_cfg_read virtio-net-pci 00:0 @0x85 -> 0x70
10909@1576216763.644786:pci_cfg_read virtio-net-pci 00:0 @0x70 -> 0x6009
10909@1576216763.644942:pci_cfg_read virtio-net-pci 00:0 @0x73 -> 0x2
10909@1576216763.645092:pci_cfg_read virtio-net-pci 00:0 @0x74 -> 0x4
[    3.492607] ___K___ (0) virtio_pci_find_capability 506: 2 4





+       }
+       for (;
             pos > 0;
             pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_VNDR)) {
                u8 type, bar;

Comments

Michael S. Tsirkin Dec. 13, 2019, 7:24 a.m. UTC | #1 
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
have a lock around programming the pair of registers,
then one access can conflict with another one.

When using express it's MMIO so shouldn't be a problem.

> 
> [    3.489492] ___K___ (0) virtio_pci_modern_probe 642
> [    3.489697] ___K___ (0) virtio_pci_find_capability 492: FIND a cap
> [    3.490070] ___K___ (0) virtio_pci_find_capability 494: cap is at 0
> [    3.490335] ___K___ (0) virtio_pci_find_capability 492: FIND a cap
> 10909@1576216763.643271:pci_cfg_read virtio-net-pci 00:0 @0x6 -> 0x10
> 10909@1576216763.643431:pci_cfg_read virtio-net-pci 00:0 @0x34 -> 0x98
> 10909@1576216763.643591:pci_cfg_read virtio-net-pci 00:0 @0x98 -> 0x8411
> 10909@1576216763.643747:pci_cfg_read virtio-net-pci 00:0 @0x84 -> 0x7009
> [    3.491264] ___K___ (0) virtio_pci_find_capability 494: cap is at 132
> 10909@1576216763.644140:pci_cfg_read virtio-net-pci 00:0 @0x87 -> 0x5
> 10909@1576216763.644287:pci_cfg_read virtio-net-pci 00:0 @0x88 -> 0x0
> [    3.491803] ___K___ (0) virtio_pci_find_capability 506: 5 0
> 10909@1576216763.644632:pci_cfg_read virtio-net-pci 00:0 @0x85 -> 0x70
> 10909@1576216763.644786:pci_cfg_read virtio-net-pci 00:0 @0x70 -> 0x6009
> 10909@1576216763.644942:pci_cfg_read virtio-net-pci 00:0 @0x73 -> 0x2
> 10909@1576216763.645092:pci_cfg_read virtio-net-pci 00:0 @0x74 -> 0x4
> [    3.492607] ___K___ (0) virtio_pci_find_capability 506: 2 4
> 
> 
> 
> 
> 
> diff --git a/drivers/virtio/virtio_pci_modern.c
> b/drivers/virtio/virtio_pci_modern.c
> index 7abcc50838b8..85b2a7ce96e9 100644
> --- a/drivers/virtio/virtio_pci_modern.c
> +++ b/drivers/virtio/virtio_pci_modern.c
> @@ -486,9 +486,14 @@ static const struct virtio_config_ops
> virtio_pci_config_ops = {
>  static inline int virtio_pci_find_capability(struct pci_dev *dev, u8
> cfg_type,
>                                              u32 ioresource_types, int
> *bars)
>  {
> -       int pos;
> +       int pos = 0;// = pci_find_capability(dev, PCI_CAP_ID_VNDR);
> 
> -       for (pos = pci_find_capability(dev, PCI_CAP_ID_VNDR);
> +       while (!pos) {
> +               pr_err("___K___ (%u) %s %u: FIND a cap\n",
> smp_processor_id(), __func__, __LINE__);
> +               pos = pci_find_capability(dev, PCI_CAP_ID_VNDR);
> +               pr_err("___K___ (%u) %s %u: cap is at %d\n",
> smp_processor_id(), __func__, __LINE__, pos);
> +       }
> +       for (;
>              pos > 0;
>              pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_VNDR)) {
>                 u8 type, bar;
> 
> 
> -- 
> Alexey
Alexey Kardashevskiy Dec. 13, 2019, 8:29 a.m. UTC | #2 
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




> have a lock around programming the pair of registers,
> then one access can conflict with another one.
> 
> When using express it's MMIO so shouldn't be a problem.
> 
>>
>> [    3.489492] ___K___ (0) virtio_pci_modern_probe 642
>> [    3.489697] ___K___ (0) virtio_pci_find_capability 492: FIND a cap
>> [    3.490070] ___K___ (0) virtio_pci_find_capability 494: cap is at 0
>> [    3.490335] ___K___ (0) virtio_pci_find_capability 492: FIND a cap
>> 10909@1576216763.643271:pci_cfg_read virtio-net-pci 00:0 @0x6 -> 0x10
>> 10909@1576216763.643431:pci_cfg_read virtio-net-pci 00:0 @0x34 -> 0x98
>> 10909@1576216763.643591:pci_cfg_read virtio-net-pci 00:0 @0x98 -> 0x8411
>> 10909@1576216763.643747:pci_cfg_read virtio-net-pci 00:0 @0x84 -> 0x7009
>> [    3.491264] ___K___ (0) virtio_pci_find_capability 494: cap is at 132
>> 10909@1576216763.644140:pci_cfg_read virtio-net-pci 00:0 @0x87 -> 0x5
>> 10909@1576216763.644287:pci_cfg_read virtio-net-pci 00:0 @0x88 -> 0x0
>> [    3.491803] ___K___ (0) virtio_pci_find_capability 506: 5 0
>> 10909@1576216763.644632:pci_cfg_read virtio-net-pci 00:0 @0x85 -> 0x70
>> 10909@1576216763.644786:pci_cfg_read virtio-net-pci 00:0 @0x70 -> 0x6009
>> 10909@1576216763.644942:pci_cfg_read virtio-net-pci 00:0 @0x73 -> 0x2
>> 10909@1576216763.645092:pci_cfg_read virtio-net-pci 00:0 @0x74 -> 0x4
>> [    3.492607] ___K___ (0) virtio_pci_find_capability 506: 2 4
>>
>>
>>
>>
>>
>> diff --git a/drivers/virtio/virtio_pci_modern.c
>> b/drivers/virtio/virtio_pci_modern.c
>> index 7abcc50838b8..85b2a7ce96e9 100644
>> --- a/drivers/virtio/virtio_pci_modern.c
>> +++ b/drivers/virtio/virtio_pci_modern.c
>> @@ -486,9 +486,14 @@ static const struct virtio_config_ops
>> virtio_pci_config_ops = {
>>  static inline int virtio_pci_find_capability(struct pci_dev *dev, u8
>> cfg_type,
>>                                              u32 ioresource_types, int
>> *bars)
>>  {
>> -       int pos;
>> +       int pos = 0;// = pci_find_capability(dev, PCI_CAP_ID_VNDR);
>>
>> -       for (pos = pci_find_capability(dev, PCI_CAP_ID_VNDR);
>> +       while (!pos) {
>> +               pr_err("___K___ (%u) %s %u: FIND a cap\n",
>> smp_processor_id(), __func__, __LINE__);
>> +               pos = pci_find_capability(dev, PCI_CAP_ID_VNDR);
>> +               pr_err("___K___ (%u) %s %u: cap is at %d\n",
>> smp_processor_id(), __func__, __LINE__, pos);
>> +       }
>> +       for (;
>>              pos > 0;
>>              pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_VNDR)) {
>>                 u8 type, bar;
>>
>>
>> -- 
>> Alexey
>
Michael S. Tsirkin Dec. 13, 2019, 8:36 a.m. UTC | #3 
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

> 
> 
> > have a lock around programming the pair of registers,
> > then one access can conflict with another one.
> > 
> > When using express it's MMIO so shouldn't be a problem.
> > 
> >>
> >> [    3.489492] ___K___ (0) virtio_pci_modern_probe 642
> >> [    3.489697] ___K___ (0) virtio_pci_find_capability 492: FIND a cap
> >> [    3.490070] ___K___ (0) virtio_pci_find_capability 494: cap is at 0
> >> [    3.490335] ___K___ (0) virtio_pci_find_capability 492: FIND a cap
> >> 10909@1576216763.643271:pci_cfg_read virtio-net-pci 00:0 @0x6 -> 0x10
> >> 10909@1576216763.643431:pci_cfg_read virtio-net-pci 00:0 @0x34 -> 0x98
> >> 10909@1576216763.643591:pci_cfg_read virtio-net-pci 00:0 @0x98 -> 0x8411
> >> 10909@1576216763.643747:pci_cfg_read virtio-net-pci 00:0 @0x84 -> 0x7009
> >> [    3.491264] ___K___ (0) virtio_pci_find_capability 494: cap is at 132
> >> 10909@1576216763.644140:pci_cfg_read virtio-net-pci 00:0 @0x87 -> 0x5
> >> 10909@1576216763.644287:pci_cfg_read virtio-net-pci 00:0 @0x88 -> 0x0
> >> [    3.491803] ___K___ (0) virtio_pci_find_capability 506: 5 0
> >> 10909@1576216763.644632:pci_cfg_read virtio-net-pci 00:0 @0x85 -> 0x70
> >> 10909@1576216763.644786:pci_cfg_read virtio-net-pci 00:0 @0x70 -> 0x6009
> >> 10909@1576216763.644942:pci_cfg_read virtio-net-pci 00:0 @0x73 -> 0x2
> >> 10909@1576216763.645092:pci_cfg_read virtio-net-pci 00:0 @0x74 -> 0x4
> >> [    3.492607] ___K___ (0) virtio_pci_find_capability 506: 2 4
> >>
> >>
> >>
> >>
> >>
> >> diff --git a/drivers/virtio/virtio_pci_modern.c
> >> b/drivers/virtio/virtio_pci_modern.c
> >> index 7abcc50838b8..85b2a7ce96e9 100644
> >> --- a/drivers/virtio/virtio_pci_modern.c
> >> +++ b/drivers/virtio/virtio_pci_modern.c
> >> @@ -486,9 +486,14 @@ static const struct virtio_config_ops
> >> virtio_pci_config_ops = {
> >>  static inline int virtio_pci_find_capability(struct pci_dev *dev, u8
> >> cfg_type,
> >>                                              u32 ioresource_types, int
> >> *bars)
> >>  {
> >> -       int pos;
> >> +       int pos = 0;// = pci_find_capability(dev, PCI_CAP_ID_VNDR);
> >>
> >> -       for (pos = pci_find_capability(dev, PCI_CAP_ID_VNDR);
> >> +       while (!pos) {
> >> +               pr_err("___K___ (%u) %s %u: FIND a cap\n",
> >> smp_processor_id(), __func__, __LINE__);
> >> +               pos = pci_find_capability(dev, PCI_CAP_ID_VNDR);
> >> +               pr_err("___K___ (%u) %s %u: cap is at %d\n",
> >> smp_processor_id(), __func__, __LINE__, pos);
> >> +       }
> >> +       for (;
> >>              pos > 0;
> >>              pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_VNDR)) {
> >>                 u8 type, bar;
> >>
> >>
> >> -- 
> >> Alexey
> > 
> 
> -- 
> Alexey
Alexey Kardashevskiy Dec. 18, 2019, 5:19 a.m. UTC | #4 
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
Michael S. Tsirkin Dec. 18, 2019, 5:27 a.m. UTC | #5 
On Wed, Dec 18, 2019 at 04:19:57PM +1100, Alexey Kardashevskiy wrote:
> 
> 
> 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?

E.g. i440fx:

static void i440fx_pcihost_realize(DeviceState *dev, Error **errp)
{
    PCIHostState *s = PCI_HOST_BRIDGE(dev);
    SysBusDevice *sbd = SYS_BUS_DEVICE(dev);

    sysbus_add_io(sbd, 0xcf8, &s->conf_mem);
    sysbus_init_ioports(sbd, 0xcf8, 4);

    sysbus_add_io(sbd, 0xcfc, &s->data_mem);
    sysbus_init_ioports(sbd, 0xcfc, 4);

    /* register i440fx 0xcf8 port as coalesced pio */
    memory_region_set_flush_coalesced(&s->data_mem);
    memory_region_add_coalescing(&s->conf_mem, 0, 4);
}



> 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
diff mbox series

Patch

diff --git a/drivers/virtio/virtio_pci_modern.c
b/drivers/virtio/virtio_pci_modern.c
index 7abcc50838b8..85b2a7ce96e9 100644
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -486,9 +486,14 @@  static const struct virtio_config_ops
virtio_pci_config_ops = {
 static inline int virtio_pci_find_capability(struct pci_dev *dev, u8
cfg_type,
                                             u32 ioresource_types, int
*bars)
 {
-       int pos;
+       int pos = 0;// = pci_find_capability(dev, PCI_CAP_ID_VNDR);

-       for (pos = pci_find_capability(dev, PCI_CAP_ID_VNDR);
+       while (!pos) {
+               pr_err("___K___ (%u) %s %u: FIND a cap\n",
smp_processor_id(), __func__, __LINE__);
+               pos = pci_find_capability(dev, PCI_CAP_ID_VNDR);
+               pr_err("___K___ (%u) %s %u: cap is at %d\n",
smp_processor_id(), __func__, __LINE__, pos);