Re: [PATCH v6 30/42] nvme: add check for mdts

[Maxim Levitsky <mlevitsk@redhat.com>]

On Mon, 2020-03-16 at 07:29 -0700, Klaus Jensen wrote:
> From: Klaus Jensen <k.jensen@samsung.com>
> 
> Add 'mdts' device parameter to control the Maximum Data Transfer Size of
> the controller and check that it is respected.
> 
> Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
> ---
>  hw/block/nvme.c       | 29 ++++++++++++++++++++++++++++-
>  hw/block/nvme.h       |  4 +++-
>  hw/block/trace-events |  1 +
>  3 files changed, 32 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/block/nvme.c b/hw/block/nvme.c
> index ba520c76bae5..7d5340c272c6 100644
> --- a/hw/block/nvme.c
> +++ b/hw/block/nvme.c
> @@ -19,7 +19,8 @@
>   *      -drive file=<file>,if=none,id=<drive_id>
>   *      -device nvme,drive=<drive_id>,serial=<serial>,id=<id[optional]>, \
>   *              cmb_size_mb=<cmb_size_mb[optional]>, \
> - *              max_ioqpairs=<N[optional]>
> + *              max_ioqpairs=<N[optional]>, \
> + *              mdts=<mdts[optional]>
>   *
>   * Note cmb_size_mb denotes size of CMB in MB. CMB is assumed to be at
>   * offset 0 in BAR2 and supports only WDS, RDS and SQS for now.
> @@ -491,6 +492,19 @@ static void nvme_clear_events(NvmeCtrl *n, uint8_t event_type)
>      }
>  }
>  
> +static inline uint16_t nvme_check_mdts(NvmeCtrl *n, size_t len,
> +                                       NvmeRequest *req)
> +{
> +    uint8_t mdts = n->params.mdts;
> +
> +    if (mdts && len > n->page_size << mdts) {
> +        trace_nvme_dev_err_mdts(nvme_cid(req), n->page_size << mdts, len);
> +        return NVME_INVALID_FIELD | NVME_DNR;
> +    }
> +
> +    return NVME_SUCCESS;
> +}
> +
>  static inline uint16_t nvme_check_bounds(NvmeCtrl *n, NvmeNamespace *ns,
>                                           uint64_t slba, uint32_t nlb,
>                                           NvmeRequest *req)
> @@ -581,6 +595,12 @@ static uint16_t nvme_rw(NvmeCtrl *n, NvmeNamespace *ns, NvmeCmd *cmd,
>  
>      trace_nvme_dev_rw(is_write ? "write" : "read", nlb, data_size, slba);
>  
> +    status = nvme_check_mdts(n, data_size, req);
> +    if (status) {
> +        block_acct_invalid(blk_get_stats(n->conf.blk), acct);
> +        return status;
> +    }
> +
>      status = nvme_check_bounds(n, ns, slba, nlb, req);
>      if (status) {
>          block_acct_invalid(blk_get_stats(n->conf.blk), acct);
> @@ -871,6 +891,7 @@ static uint16_t nvme_get_log(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
>      uint32_t numdl, numdu;
>      uint64_t off, lpol, lpou;
>      size_t   len;
> +    uint16_t status;
>  
>      numdl = (dw10 >> 16);
>      numdu = (dw11 & 0xffff);
> @@ -886,6 +907,11 @@ static uint16_t nvme_get_log(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
>  
>      trace_nvme_dev_get_log(nvme_cid(req), lid, lsp, rae, len, off);
>  
> +    status = nvme_check_mdts(n, len, req);
> +    if (status) {
> +        return status;
> +    }
> +
>      switch (lid) {
>      case NVME_LOG_ERROR_INFO:
>          return nvme_error_info(n, cmd, rae, len, off, req);
> @@ -2011,6 +2037,7 @@ static void nvme_init_ctrl(NvmeCtrl *n)
>      id->ieee[0] = 0x00;
>      id->ieee[1] = 0x02;
>      id->ieee[2] = 0xb3;
> +    id->mdts = params->mdts;
>      id->ver = cpu_to_le32(NVME_SPEC_VER);
>      id->oacs = cpu_to_le16(0);
>  
> diff --git a/hw/block/nvme.h b/hw/block/nvme.h
> index 442b17bf1701..b05c2153aebf 100644
> --- a/hw/block/nvme.h
> +++ b/hw/block/nvme.h
> @@ -9,7 +9,8 @@
>      DEFINE_PROP_UINT32("num_queues", _state, _props.num_queues, 0), \
>      DEFINE_PROP_UINT32("max_ioqpairs", _state, _props.max_ioqpairs, 64), \
>      DEFINE_PROP_UINT8("aerl", _state, _props.aerl, 3), \
> -    DEFINE_PROP_UINT32("aer_max_queued", _state, _props.aer_max_queued, 64)
> +    DEFINE_PROP_UINT32("aer_max_queued", _state, _props.aer_max_queued, 64), \
> +    DEFINE_PROP_UINT8("mdts", _state, _props.mdts, 7)
>  
>  typedef struct NvmeParams {
>      char     *serial;
> @@ -18,6 +19,7 @@ typedef struct NvmeParams {
>      uint32_t cmb_size_mb;
>      uint8_t  aerl;
>      uint32_t aer_max_queued;
> +    uint8_t  mdts;
>  } NvmeParams;
>  
>  typedef struct NvmeAsyncEvent {
> diff --git a/hw/block/trace-events b/hw/block/trace-events
> index e31e652fa04e..2df6aa38df1b 100644
> --- a/hw/block/trace-events
> +++ b/hw/block/trace-events
> @@ -79,6 +79,7 @@ nvme_dev_mmio_doorbell_cq(uint16_t cqid, uint16_t new_head) "cqid %"PRIu16" new_
>  nvme_dev_mmio_doorbell_sq(uint16_t sqid, uint16_t new_tail) "cqid %"PRIu16" new_tail %"PRIu16""
>  
>  # nvme traces for error conditions
> +nvme_dev_err_mdts(uint16_t cid, size_t mdts, size_t len) "cid %"PRIu16" mdts %"PRIu64" len %"PRIu64""
>  nvme_dev_err_invalid_dma(void) "PRP/SGL is too small for transfer size"
>  nvme_dev_err_invalid_prplist_ent(uint64_t prplist) "PRP list entry is null or not page aligned: 0x%"PRIx64""
>  nvme_dev_err_invalid_prp2_align(uint64_t prp2) "PRP2 is not page aligned: 0x%"PRIx64""


Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>

Best regards,
	Maxim Levitsky