Re: [PATCH] hw/block/nvme: improve invalid zasl value reporting

[Dmitry Fomichev]

On Mon, 2021-02-08 at 09:25 +0100, Klaus Jensen wrote:
> From: Klaus Jensen <k.jensen@samsung.com>
> 
> The Zone Append Size Limit (ZASL) must be at least 4096 bytes, so
> improve the user experience by adding an early parameter check in
> nvme_check_constraints.
> 
> When ZASL is still too small due to the host configuring the device for
> an even larger page size, convert the trace point in nvme_start_ctrl to
> an NVME_GUEST_ERR such that this is logged by QEMU instead of only
> traced.
> 
> Reported-by: "info@dantalion.nl" <info@dantalion.nl>
> Cc: Dmitry Fomichev <Dmitry.Fomichev@wdc.com>
> Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
> ---
>  hw/block/nvme.c | 12 ++++++++++--
>  1 file changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/block/nvme.c b/hw/block/nvme.c
> index c2f0c88fbf39..d96888cd2333 100644
> --- a/hw/block/nvme.c
> +++ b/hw/block/nvme.c
> @@ -3983,8 +3983,10 @@ static int nvme_start_ctrl(NvmeCtrl *n)
>          n->zasl = n->params.mdts;
>      } else {
>          if (n->params.zasl_bs < n->page_size) {
> -            trace_pci_nvme_err_startfail_zasl_too_small(n->params.zasl_bs,
> -                                                        n->page_size);
> +            NVME_GUEST_ERR(pci_nvme_err_startfail_zasl_too_small,
> +                           "Zone Append Size Limit (ZASL) of %d bytes is too 
> "
> +                           "small; must be at least %d bytes",
> +                           n->params.zasl_bs, n->page_size);
>              return -1;
>          }
>          n->zasl = 31 - clz32(n->params.zasl_bs / n->page_size);
> @@ -4503,6 +4505,12 @@ static void nvme_check_constraints(NvmeCtrl *n, Error 
> **errp)
>              error_setg(errp, "zone append size limit has to be a power of 
> 2");
>              return;
>          }
> +
> +        if (n->params.zasl_bs < 4096) {
> +            error_setg(errp, "zone append size limit must be at least "
> +                       "4096 bytes");
> +            return;
> +        }
>      }
>  }

The guest error is less confusing than simply a trace. LGTM.
Reviewed-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>

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