Re: [PATCH v2 05/17] xen/arm: Add PHYSDEVOP_pci_device_* support for ARM

[Rahul Singh <Rahul.Singh@arm.com>]

Hi Stefano,

> On 22 Sep 2021, at 11:37 pm, Stefano Stabellini <sstabellini@kernel.org> wrote:
> 
> On Wed, 22 Sep 2021, 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.
>> 
>> Also implement PHYSDEVOP_pci_device_remove(..) to remove the PCI device.
>> 
>> As most of the code for PHYSDEVOP_pci_device_* is the same between x86
>> and ARM, move the code to a common file to avoid duplication.
>> 
>> Signed-off-by: Rahul Singh <rahul.singh@arm.com>
>> ---
>> Change in v2:
>> - Add support for PHYSDEVOP_pci_device_remove()
>> - Move code to common code
>> ---
>> xen/arch/arm/physdev.c          |  5 +-
>> xen/arch/x86/physdev.c          | 50 +-------------------
>> xen/arch/x86/x86_64/physdev.c   |  4 +-
>> xen/common/Makefile             |  1 +
>> xen/common/physdev.c            | 81 +++++++++++++++++++++++++++++++++
>> xen/include/asm-arm/hypercall.h |  2 -
>> xen/include/asm-arm/numa.h      |  5 ++
>> xen/include/asm-x86/hypercall.h |  9 ++--
>> xen/include/xen/hypercall.h     |  8 ++++
>> 9 files changed, 106 insertions(+), 59 deletions(-)
>> create mode 100644 xen/common/physdev.c
>> 
>> diff --git a/xen/arch/arm/physdev.c b/xen/arch/arm/physdev.c
>> index e91355fe22..4e00b03aab 100644
>> --- a/xen/arch/arm/physdev.c
>> +++ b/xen/arch/arm/physdev.c
>> @@ -8,10 +8,9 @@
>> #include <xen/lib.h>
>> #include <xen/errno.h>
>> #include <xen/sched.h>
>> -#include <asm/hypercall.h>
>> +#include <xen/hypercall.h>
>> 
>> -
>> -int do_physdev_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
>> +long arch_physdev_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
>> {
>>     gdprintk(XENLOG_DEBUG, "PHYSDEVOP cmd=%d: not implemented\n", cmd);
>>     return -ENOSYS;
>> diff --git a/xen/arch/x86/physdev.c b/xen/arch/x86/physdev.c
>> index 23465bcd00..c00cc99404 100644
>> --- a/xen/arch/x86/physdev.c
>> +++ b/xen/arch/x86/physdev.c
>> @@ -174,7 +174,7 @@ int physdev_unmap_pirq(domid_t domid, int pirq)
>> }
>> #endif /* COMPAT */
>> 
>> -ret_t do_physdev_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
>> +ret_t arch_physdev_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
>> {
>>     int irq;
>>     ret_t ret;
>> @@ -480,54 +480,6 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
>>         break;
>>     }
>> 
>> -    case PHYSDEVOP_pci_device_add: {
>> -        struct physdev_pci_device_add add;
>> -        struct pci_dev_info pdev_info;
>> -        nodeid_t 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;
>> -
>> -        if ( add.flags & XEN_PCI_DEV_PXM )
>> -        {
>> -            uint32_t pxm;
>> -            size_t optarr_off = offsetof(struct physdev_pci_device_add, optarr) /
>> -                                sizeof(add.optarr[0]);
>> -
>> -            if ( copy_from_guest_offset(&pxm, arg, optarr_off, 1) )
>> -                break;
>> -
>> -            node = pxm_to_node(pxm);
>> -        }
>> -        else
>> -            node = NUMA_NO_NODE;
>> -
>> -        ret = pci_add_device(add.seg, add.bus, add.devfn, &pdev_info, node);
>> -        break;
>> -    }
>> -
>> -    case PHYSDEVOP_pci_device_remove: {
>> -        struct physdev_pci_device dev;
>> -
>> -        ret = -EFAULT;
>> -        if ( copy_from_guest(&dev, arg, 1) != 0 )
>> -            break;
>> -
>> -        ret = pci_remove_device(dev.seg, dev.bus, dev.devfn);
>> -        break;
>> -    }
>> -
>>     case PHYSDEVOP_prepare_msix:
>>     case PHYSDEVOP_release_msix: {
>>         struct physdev_pci_device dev;
>> diff --git a/xen/arch/x86/x86_64/physdev.c b/xen/arch/x86/x86_64/physdev.c
>> index 0a50cbd4d8..5f72652ff7 100644
>> --- a/xen/arch/x86/x86_64/physdev.c
>> +++ b/xen/arch/x86/x86_64/physdev.c
>> @@ -9,9 +9,10 @@ EMIT_FILE;
>> #include <compat/xen.h>
>> #include <compat/event_channel.h>
>> #include <compat/physdev.h>
>> -#include <asm/hypercall.h>
>> +#include <xen/hypercall.h>
>> 
>> #define do_physdev_op compat_physdev_op
>> +#define arch_physdev_op arch_compat_physdev_op
>> 
>> #define physdev_apic               compat_physdev_apic
>> #define physdev_apic_t             physdev_apic_compat_t
>> @@ -82,6 +83,7 @@ CHECK_physdev_pci_device
>> typedef int ret_t;
>> 
>> #include "../physdev.c"
>> +#include "../../../common/physdev.c"
>> 
>> /*
>>  * Local variables:
>> diff --git a/xen/common/Makefile b/xen/common/Makefile
>> index 54de70d422..bcb1c8fb03 100644
>> --- a/xen/common/Makefile
>> +++ b/xen/common/Makefile
>> @@ -29,6 +29,7 @@ obj-y += notifier.o
>> obj-y += page_alloc.o
>> obj-$(CONFIG_HAS_PDX) += pdx.o
>> obj-$(CONFIG_PERF_COUNTERS) += perfc.o
>> +obj-y += physdev.o
>> obj-y += preempt.o
>> obj-y += random.o
>> obj-y += rangeset.o
>> diff --git a/xen/common/physdev.c b/xen/common/physdev.c
>> new file mode 100644
>> index 0000000000..8d44b20db8
>> --- /dev/null
>> +++ b/xen/common/physdev.c
>> @@ -0,0 +1,81 @@
>> +
>> +#include <xen/guest_access.h>
>> +#include <xen/hypercall.h>
>> +#include <xen/init.h>
>> +
>> +#ifndef COMPAT
>> +typedef long ret_t;
>> +#endif
>> +
>> +ret_t do_physdev_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
>> +{
>> +    ret_t ret;
>> +
>> +    switch ( cmd )
>> +    {
>> +#ifdef CONFIG_HAS_PCI
>> +    case PHYSDEVOP_pci_device_add: {
>> +        struct physdev_pci_device_add add;
>> +        struct pci_dev_info pdev_info;
>> +        nodeid_t 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;
>> +
>> +        if ( add.flags & XEN_PCI_DEV_PXM )
>> +        {
>> +            uint32_t pxm;
>> +            size_t optarr_off = offsetof(struct physdev_pci_device_add, optarr) /
>> +                                sizeof(add.optarr[0]);
>> +
>> +            if ( copy_from_guest_offset(&pxm, arg, optarr_off, 1) )
>> +                break;
>> +
>> +            node = pxm_to_node(pxm);
>> +        }
>> +        else
>> +            node = NUMA_NO_NODE;
>> +
>> +        ret = pci_add_device(add.seg, add.bus, add.devfn, &pdev_info, node);
>> +        break;
>> +    }
>> +
>> +    case PHYSDEVOP_pci_device_remove: {
>> +        struct physdev_pci_device dev;
>> +
>> +        ret = -EFAULT;
>> +        if ( copy_from_guest(&dev, arg, 1) != 0 )
>> +            break;
>> +
>> +        ret = pci_remove_device(dev.seg, dev.bus, dev.devfn);
>> +        break;
>> +    }
>> +#endif
>> +    default:
>> +        ret = arch_physdev_op(cmd, arg);;
>                                           ^ a typo?
Ack.
> 
> The ARM and common parts are fine. I am not well-versed in the x86
> compat stuff; we need one of the x86 maintainers to review the x86
> changes.

Yes. I need one of the x86 maintainers to review the code.
Regards,
Rahul