Re: [PATCH v5 04/15] block/nvme: Define INDEX macros to ease code review

[Stefano Garzarella]

On Thu, Aug 20, 2020 at 06:58:50PM +0200, Philippe Mathieu-Daudé wrote:
> Use definitions instead of '0' or '1' indexes. Also this will
> be useful when using multi-queues later.
> 
> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
>  block/nvme.c | 33 +++++++++++++++++++--------------
>  1 file changed, 19 insertions(+), 14 deletions(-)

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>

> 
> diff --git a/block/nvme.c b/block/nvme.c
> index e1893b4e792..003809fbd83 100644
> --- a/block/nvme.c
> +++ b/block/nvme.c
> @@ -103,6 +103,9 @@ typedef volatile struct {
>  
>  QEMU_BUILD_BUG_ON(offsetof(NVMeRegs, doorbells) != 0x1000);
>  
> +#define INDEX_ADMIN     0
> +#define INDEX_IO(n)     (1 + n)
> +
>  struct BDRVNVMeState {
>      AioContext *aio_context;
>      QEMUVFIOState *vfio;
> @@ -531,7 +534,7 @@ static void nvme_identify(BlockDriverState *bs, int 
> namespace, Error **errp)
>      }
>      cmd.prp1 = cpu_to_le64(iova);
>  
> -    if (nvme_cmd_sync(bs, s->queues[0], &cmd)) {
> +    if (nvme_cmd_sync(bs, s->queues[INDEX_ADMIN], &cmd)) {
>          error_setg(errp, "Failed to identify controller");
>          goto out;
>      }
> @@ -555,7 +558,7 @@ static void nvme_identify(BlockDriverState *bs, int 
> namespace, Error **errp)
>  
>      cmd.cdw10 = 0;
>      cmd.nsid = cpu_to_le32(namespace);
> -    if (nvme_cmd_sync(bs, s->queues[0], &cmd)) {
> +    if (nvme_cmd_sync(bs, s->queues[INDEX_ADMIN], &cmd)) {
>          error_setg(errp, "Failed to identify namespace");
>          goto out;
>      }
> @@ -644,7 +647,7 @@ static bool nvme_add_io_queue(BlockDriverState *bs, Error 
> **errp)
>          .cdw10 = cpu_to_le32(((queue_size - 1) << 16) | (n & 0xFFFF)),
>          .cdw11 = cpu_to_le32(0x3),
>      };
> -    if (nvme_cmd_sync(bs, s->queues[0], &cmd)) {
> +    if (nvme_cmd_sync(bs, s->queues[INDEX_ADMIN], &cmd)) {
>          error_setg(errp, "Failed to create io queue [%d]", n);
>          nvme_free_queue_pair(q);
>          return false;
> @@ -655,7 +658,7 @@ static bool nvme_add_io_queue(BlockDriverState *bs, Error 
> **errp)
>          .cdw10 = cpu_to_le32(((queue_size - 1) << 16) | (n & 0xFFFF)),
>          .cdw11 = cpu_to_le32(0x1 | (n << 16)),
>      };
> -    if (nvme_cmd_sync(bs, s->queues[0], &cmd)) {
> +    if (nvme_cmd_sync(bs, s->queues[INDEX_ADMIN], &cmd)) {
>          error_setg(errp, "Failed to create io queue [%d]", n);
>          nvme_free_queue_pair(q);
>          return false;
> @@ -739,16 +742,18 @@ static int nvme_init(BlockDriverState *bs, const char 
> *device, int namespace,
>  
>      /* Set up admin queue. */
>      s->queues = g_new(NVMeQueuePair *, 1);
> -    s->queues[0] = nvme_create_queue_pair(bs, 0, NVME_QUEUE_SIZE, errp);
> -    if (!s->queues[0]) {
> +    s->queues[INDEX_ADMIN] = nvme_create_queue_pair(bs, 0,
> +                                                          NVME_QUEUE_SIZE,
> +                                                          errp);
> +    if (!s->queues[INDEX_ADMIN]) {
>          ret = -EINVAL;
>          goto out;
>      }
>      s->nr_queues = 1;
>      QEMU_BUILD_BUG_ON(NVME_QUEUE_SIZE & 0xF000);
>      s->regs->aqa = cpu_to_le32((NVME_QUEUE_SIZE << 16) | NVME_QUEUE_SIZE);
> -    s->regs->asq = cpu_to_le64(s->queues[0]->sq.iova);
> -    s->regs->acq = cpu_to_le64(s->queues[0]->cq.iova);
> +    s->regs->asq = cpu_to_le64(s->queues[INDEX_ADMIN]->sq.iova);
> +    s->regs->acq = cpu_to_le64(s->queues[INDEX_ADMIN]->cq.iova);
>  
>      /* After setting up all control registers we can enable device now. */
>      s->regs->cc = cpu_to_le32((ctz32(NVME_CQ_ENTRY_BYTES) << 20) |
> @@ -839,7 +844,7 @@ static int 
> nvme_enable_disable_write_cache(BlockDriverState *bs, bool enable,
>          .cdw11 = cpu_to_le32(enable ? 0x01 : 0x00),
>      };
>  
> -    ret = nvme_cmd_sync(bs, s->queues[0], &cmd);
> +    ret = nvme_cmd_sync(bs, s->queues[INDEX_ADMIN], &cmd);
>      if (ret) {
>          error_setg(errp, "Failed to configure NVMe write cache");
>      }
> @@ -1056,7 +1061,7 @@ static coroutine_fn int 
> nvme_co_prw_aligned(BlockDriverState *bs,
>  {
>      int r;
>      BDRVNVMeState *s = bs->opaque;
> -    NVMeQueuePair *ioq = s->queues[1];
> +    NVMeQueuePair *ioq = s->queues[INDEX_IO(0)];
>      NVMeRequest *req;
>  
>      uint32_t cdw12 = (((bytes >> s->blkshift) - 1) & 0xFFFF) |
> @@ -1171,7 +1176,7 @@ static coroutine_fn int 
> nvme_co_pwritev(BlockDriverState *bs,
>  static coroutine_fn int nvme_co_flush(BlockDriverState *bs)
>  {
>      BDRVNVMeState *s = bs->opaque;
> -    NVMeQueuePair *ioq = s->queues[1];
> +    NVMeQueuePair *ioq = s->queues[INDEX_IO(0)];
>      NVMeRequest *req;
>      NvmeCmd cmd = {
>          .opcode = NVME_CMD_FLUSH,
> @@ -1202,7 +1207,7 @@ static coroutine_fn int 
> nvme_co_pwrite_zeroes(BlockDriverState *bs,
>                                                BdrvRequestFlags flags)
>  {
>      BDRVNVMeState *s = bs->opaque;
> -    NVMeQueuePair *ioq = s->queues[1];
> +    NVMeQueuePair *ioq = s->queues[INDEX_IO(0)];
>      NVMeRequest *req;
>  
>      uint32_t cdw12 = ((bytes >> s->blkshift) - 1) & 0xFFFF;
> @@ -1255,7 +1260,7 @@ static int coroutine_fn 
> nvme_co_pdiscard(BlockDriverState *bs,
>                                           int bytes)
>  {
>      BDRVNVMeState *s = bs->opaque;
> -    NVMeQueuePair *ioq = s->queues[1];
> +    NVMeQueuePair *ioq = s->queues[INDEX_IO(0)];
>      NVMeRequest *req;
>      NvmeDsmRange *buf;
>      QEMUIOVector local_qiov;
> @@ -1398,7 +1403,7 @@ static void nvme_aio_unplug(BlockDriverState *bs)
>      BDRVNVMeState *s = bs->opaque;
>      assert(s->plugged);
>      s->plugged = false;
> -    for (i = 1; i < s->nr_queues; i++) {
> +    for (i = INDEX_IO(0); i < s->nr_queues; i++) {
>          NVMeQueuePair *q = s->queues[i];
>          qemu_mutex_lock(&q->lock);
>          nvme_kick(q);
> -- 
> 2.26.2
> 
>