RE: [PATCH v3 4/4] vdpa/octeon_ep: read vendor-specific PCI capability
From: Shijith Thotton
Date: Fri Dec 13 2024 - 09:21:04 EST
>>>
>>> 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.
>
Small correction, I meant __attribute__((packed, aligned(4))).
Thanks,
Shijith