Re: [PATCH v3 4/4] vdpa/octeon_ep: read vendor-specific PCI capability

[Shijith Thotton]

>>
>> Added support to read the vendor-specific PCI capability to identify the
>> type of device being emulated.
>>
>> Reviewed-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
>> Signed-off-by: Shijith Thotton <sthotton@xxxxxxxxxxx>
>> ---
>>  drivers/vdpa/octeon_ep/octep_vdpa.h      | 20 ++++++++++++++
>>  drivers/vdpa/octeon_ep/octep_vdpa_hw.c   | 33
>+++++++++++++++++++++++-
>>  drivers/vdpa/octeon_ep/octep_vdpa_main.c |  4 ++-
>>  3 files changed, 55 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/vdpa/octeon_ep/octep_vdpa.h
>b/drivers/vdpa/octeon_ep/octep_vdpa.h
>> index 2cadb878e679..53b020b019f7 100644
>> --- a/drivers/vdpa/octeon_ep/octep_vdpa.h
>> +++ b/drivers/vdpa/octeon_ep/octep_vdpa.h
>> @@ -8,6 +8,7 @@
>>  #include <linux/pci_regs.h>
>>  #include <linux/vdpa.h>
>>  #include <linux/virtio_pci_modern.h>
>> +#include <uapi/linux/virtio_crypto.h>
>>  #include <uapi/linux/virtio_net.h>
>>  #include <uapi/linux/virtio_blk.h>
>>  #include <uapi/linux/virtio_config.h>
>> @@ -52,6 +53,24 @@ struct octep_vring_info {
>>         phys_addr_t notify_pa;
>>  };
>>
>> +enum octep_pci_vndr_cfg_type {
>> +       OCTEP_PCI_VNDR_CFG_TYPE_VIRTIO_ID,
>> +       OCTEP_PCI_VNDR_CFG_TYPE_MAX,
>> +};
>> +
>> +struct octep_pci_vndr_data {
>> +       struct virtio_pci_vndr_data hdr;
>> +       u8 id;
>> +       u8 bar;
>> +       union {
>> +               u64 data;
>> +               struct {
>> +                       u32 offset;
>> +                       u32 length;
>> +               };
>> +       };
>> +};
>
>This seems not to be padded to a multiple of 4 bytes?
>

Looks like, the structure is naturally aligned.

struct virtio_pci_vndr_data {
        uint8_t                    cap_vndr;             /*     0     1 */
        uint8_t                    cap_next;             /*     1     1 */
        uint8_t                    cap_len;              /*     2     1 */
        uint8_t                    cfg_type;             /*     3     1 */
        uint16_t                   vendor_id;            /*     4     2 */
        /* size: 6, cachelines: 1, members: 5 */                                                                                                                                                                                                                      
        /* last cacheline: 6 bytes */
};
struct octep_pci_vndr_data {                                                                                                                                                                                                                                          
        struct virtio_pci_vndr_data hdr;                 /*     0     6 */
        uint8_t                    id;                   /*     6     1 */                                                                                                                                                                                            
        uint8_t                    bar;                  /*     7     1 */                                                                                                                                                                                            
        union {
                uint64_t           data;                 /*     8     8 */
                struct {
                        uint32_t   offset;               /*     8     4 */
                        uint32_t   length;               /*    12     4 */
                };                                       /*     8     8 */
        };                                               /*     8     8 */

        /* size: 16, cachelines: 1, members: 4 */
        /* last cacheline: 16 bytes */
};

I will add __attribute__((aligned(4))) to be safe.

Thanks,
Shijith