Re: [PATCH 16/25] block/nvme: Simplify ADMIN queue access

[Auger Eric <eric.auger@redhat.com>]

On 10/27/20 2:55 PM, Philippe Mathieu-Daudé wrote:
> We don't need to dereference from BDRVNVMeState each time.
> Use a NVMeQueuePair pointer to the admin queue and use it.
double "use"
> The nvme_init() becomes easier to review, matching the style
> of nvme_add_io_queue().>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>

Eric

> ---
>  block/nvme.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/block/nvme.c b/block/nvme.c
> index d5df30ec074..2d3648694b0 100644
> --- a/block/nvme.c
> +++ b/block/nvme.c
> @@ -699,6 +699,7 @@ static int nvme_init(BlockDriverState *bs, const char *device, int namespace,
>                       Error **errp)
>  {
>      BDRVNVMeState *s = bs->opaque;
> +    NVMeQueuePair *q;
>      AioContext *aio_context = bdrv_get_aio_context(bs);
>      int ret;
>      uint64_t cap;
> @@ -781,19 +782,18 @@ static int nvme_init(BlockDriverState *bs, const char *device, int namespace,
>  
>      /* Set up admin queue. */
>      s->queues = g_new(NVMeQueuePair *, 1);
> -    s->queues[INDEX_ADMIN] = nvme_create_queue_pair(s, aio_context, 0,
> -                                                          NVME_QUEUE_SIZE,
> -                                                          errp);
> -    if (!s->queues[INDEX_ADMIN]) {
> +    q = nvme_create_queue_pair(s, aio_context, 0, NVME_QUEUE_SIZE, errp);
> +    if (!q) {
>          ret = -EINVAL;
>          goto out;
>      }
> +    s->queues[INDEX_ADMIN] = q;
>      s->queue_count = 1;
>      QEMU_BUILD_BUG_ON((NVME_QUEUE_SIZE - 1) & 0xF000);
>      regs->aqa = cpu_to_le32(((NVME_QUEUE_SIZE - 1) << AQA_ACQS_SHIFT) |
>                              ((NVME_QUEUE_SIZE - 1) << AQA_ASQS_SHIFT));
> -    regs->asq = cpu_to_le64(s->queues[INDEX_ADMIN]->sq.iova);
> -    regs->acq = cpu_to_le64(s->queues[INDEX_ADMIN]->cq.iova);
> +    regs->asq = cpu_to_le64(q->sq.iova);
> +    regs->acq = cpu_to_le64(q->cq.iova);
>  
>      /* After setting up all control registers we can enable device now. */
>      regs->cc = cpu_to_le32((ctz32(NVME_CQ_ENTRY_BYTES) << CC_IOCQES_SHIFT) |
>