Re: [RFC PATCH v1 2/4] xen/arm: Discovering PCI devices and add the PCI devices in XEN.

[Oleksandr Andrushchenko <Oleksandr_Andrushchenko@xxxxxxxx>]

On 7/23/20 11:44 PM, Stefano Stabellini wrote:
> On Thu, 23 Jul 2020, Rahul Singh wrote:
>> Hardware domain is in charge of doing the PCI enumeration and will
>> discover the PCI devices and then will communicate to XEN via hyper
>> call PHYSDEVOP_pci_device_add to add the PCI devices in XEN.
>>
>> Change-Id: Ie87e19741689503b4b62da911c8dc2ee318584ac
> Same question about Change-Id
>
>
>> Signed-off-by: Rahul Singh <rahul.singh@xxxxxxx>
>> ---
>>   xen/arch/arm/physdev.c | 42 +++++++++++++++++++++++++++++++++++++++---
>>   1 file changed, 39 insertions(+), 3 deletions(-)
>>
>> diff --git a/xen/arch/arm/physdev.c b/xen/arch/arm/physdev.c
>> index e91355fe22..274720f98a 100644
>> --- a/xen/arch/arm/physdev.c
>> +++ b/xen/arch/arm/physdev.c
>> @@ -9,12 +9,48 @@
>>   #include <xen/errno.h>
>>   #include <xen/sched.h>
>>   #include <asm/hypercall.h>
>> -
>> +#include <xen/guest_access.h>
>> +#include <xsm/xsm.h>
>>   
>>   int do_physdev_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
>>   {
>> -    gdprintk(XENLOG_DEBUG, "PHYSDEVOP cmd=%d: not implemented\n", cmd);
>> -    return -ENOSYS;
>> +    int ret = 0;
>> +
>> +    switch ( cmd )
>> +    {
>> +#ifdef CONFIG_HAS_PCI

In the cover letter you were saying "we are not enabling the HAS_PCI and 
HAS_VPCI flags for ARM".

Is this still valid?

>> +        case PHYSDEVOP_pci_device_add:
>> +            {
>> +                struct physdev_pci_device_add add;
>> +                struct pci_dev_info pdev_info;
>> +                nodeid_t node = NUMA_NO_NODE;
>> +
>> +                ret = -EFAULT;
>> +                if ( copy_from_guest(&add, arg, 1) != 0 )
>> +                    break;
>> +
>> +                pdev_info.is_extfn = !!(add.flags & XEN_PCI_DEV_EXTFN);
>> +                if ( add.flags & XEN_PCI_DEV_VIRTFN )
>> +                {
>> +                    pdev_info.is_virtfn = 1;
>> +                    pdev_info.physfn.bus = add.physfn.bus;
>> +                    pdev_info.physfn.devfn = add.physfn.devfn;
>> +                }
>> +                else
>> +                    pdev_info.is_virtfn = 0;
>> +
>> +                ret = pci_add_device(add.seg, add.bus, add.devfn,
>> +                                &pdev_info, node);
>> +
>> +                break;
>> +            }
>> +#endif
>> +        default:
>> +            gdprintk(XENLOG_DEBUG, "PHYSDEVOP cmd=%d: not implemented\n", 
>> cmd);
>> +            ret = -ENOSYS;
>> +    }
> I think we should make the implementation common between arm and x86 by
> creating xen/common/physdev.c:do_physdev_op as a shared entry point for
> PHYSDEVOP hypercalls implementations. See for instance:
>
> xen/common/sysctl.c:do_sysctl
>
> and
>
> xen/arch/arm/sysctl.c:arch_do_sysctl
> xen/arch/x86/sysctl.c:arch_do_sysctl
>
>
> Jan, Andrew, Roger, any opinions?
>
>
I think we can also have a look at [1] by Julien. That implementation,

IMO, had some thoughts on making Arm/x86 code common where possible


[1] 
https://xenbits.xen.org/gitweb/?p=people/julieng/xen-unstable.git;a=shortlog;h=refs/heads/dev-pci