Re: [PATCH 02/16] hw/block/nvme: add mapping helpers

[Minwoo Im <minwoo.im.dev@gmail.com>]

Hi Klaus,

On 20-07-20 13:37:34, Klaus Jensen wrote:
> From: Klaus Jensen <k.jensen@samsung.com>
> 
> Add nvme_map_addr, nvme_map_addr_cmb and nvme_addr_to_cmb helpers and
> use them in nvme_map_prp.
> 
> This fixes a bug where in the case of a CMB transfer, the device would
> map to the buffer with a wrong length.
> 
> Fixes: b2b2b67a00574 ("nvme: Add support for Read Data and Write Data in CMBs.")
> Signed-off-by: Klaus Jensen <k.jensen@samsung.com>

>  static uint16_t nvme_map_prp(QEMUSGList *qsg, QEMUIOVector *iov, uint64_t prp1,
>                               uint64_t prp2, uint32_t len, NvmeCtrl *n)
>  {
>      hwaddr trans_len = n->page_size - (prp1 % n->page_size);
>      trans_len = MIN(len, trans_len);
>      int num_prps = (len >> n->page_bits) + 1;
> +    uint16_t status;
>  
>      if (unlikely(!prp1)) {
>          trace_pci_nvme_err_invalid_prp();
>          return NVME_INVALID_FIELD | NVME_DNR;
> -    } else if (n->bar.cmbsz && prp1 >= n->ctrl_mem.addr &&
> -               prp1 < n->ctrl_mem.addr + int128_get64(n->ctrl_mem.size)) {
> -        qsg->nsg = 0;
> +    }
> +
> +    if (nvme_addr_is_cmb(n, prp1)) {
>          qemu_iovec_init(iov, num_prps);
> -        qemu_iovec_add(iov, (void *)&n->cmbuf[prp1 - n->ctrl_mem.addr], trans_len);
>      } else {
>          pci_dma_sglist_init(qsg, &n->parent_obj, num_prps);
> -        qemu_sglist_add(qsg, prp1, trans_len);
>      }
> +
> +    status = nvme_map_addr(n, qsg, iov, prp1, trans_len);
> +    if (status) {
> +        goto unmap;
> +    }
> +
>      len -= trans_len;
>      if (len) {
>          if (unlikely(!prp2)) {
>              trace_pci_nvme_err_invalid_prp2_missing();
> +            status = NVME_INVALID_FIELD | NVME_DNR;
>              goto unmap;
>          }
>          if (len > n->page_size) {
> @@ -242,6 +309,7 @@ static uint16_t nvme_map_prp(QEMUSGList *qsg, QEMUIOVector *iov, uint64_t prp1,
>                  if (i == n->max_prp_ents - 1 && len > n->page_size) {
>                      if (unlikely(!prp_ent || prp_ent & (n->page_size - 1))) {
>                          trace_pci_nvme_err_invalid_prplist_ent(prp_ent);
> +                        status = NVME_INVALID_FIELD | NVME_DNR;
>                          goto unmap;
>                      }
>  
> @@ -255,14 +323,14 @@ static uint16_t nvme_map_prp(QEMUSGList *qsg, QEMUIOVector *iov, uint64_t prp1,
>  
>                  if (unlikely(!prp_ent || prp_ent & (n->page_size - 1))) {
>                      trace_pci_nvme_err_invalid_prplist_ent(prp_ent);
> +                    status = NVME_INVALID_FIELD | NVME_DNR;
>                      goto unmap;
>                  }
>  
>                  trans_len = MIN(len, n->page_size);
> -                if (qsg->nsg){
> -                    qemu_sglist_add(qsg, prp_ent, trans_len);
> -                } else {
> -                    qemu_iovec_add(iov, (void *)&n->cmbuf[prp_ent - n->ctrl_mem.addr], trans_len);
> +                status = nvme_map_addr(n, qsg, iov, prp_ent, trans_len);
> +                if (status) {
> +                    goto unmap;
>                  }
>                  len -= trans_len;
>                  i++;
> @@ -270,20 +338,27 @@ static uint16_t nvme_map_prp(QEMUSGList *qsg, QEMUIOVector *iov, uint64_t prp1,
>          } else {
>              if (unlikely(prp2 & (n->page_size - 1))) {
>                  trace_pci_nvme_err_invalid_prp2_align(prp2);
> +                status = NVME_INVALID_FIELD | NVME_DNR;
>                  goto unmap;
>              }
> -            if (qsg->nsg) {
> -                qemu_sglist_add(qsg, prp2, len);
> -            } else {
> -                qemu_iovec_add(iov, (void *)&n->cmbuf[prp2 - n->ctrl_mem.addr], trans_len);
> +            status = nvme_map_addr(n, qsg, iov, prp2, len);
> +            if (status) {
> +                goto unmap;

I like these parts which is much better to read the codes.

Reviewed-by: Minwoo Im <minwoo.im.dev@gmail.com>

Thanks,