[SeaBIOS] Re: [PATCH 1/3] nvme: Record maximum allowed request size

[Alexander Graf]

On 30.09.20 12:22, Sironi, Filippo wrote:
> From: Alexander Graf 
> Sent: Tuesday, September 29, 2020 20:36
> To: [e-mail]
> Subject: [UNVERIFIED SENDER] [SeaBIOS] [PATCH 1/3] nvme: Record maximum allowed request size
>
> NVMe has a limit on how many sectors it can handle at most within a single
> request. Remember that number, so that in a follow-up patch, we can verify
> that we don't exceed it.
> Signed-off-by: Alexander Graf
>
> src/hw/nvme-int.h |  8 +++++++-
>   src/hw/nvme.c     | 13 +++++++++++--
>   2 files changed, 18 insertions(+), 3 deletions(-)
>
> diff --git a/src/hw/nvme-int.h b/src/hw/nvme-int.h
> index 9f95dd8..674008a 100644
> --- a/src/hw/nvme-int.h
> +++ b/src/hw/nvme-int.h
> @@ -117,6 +117,7 @@ struct nvme_namespace {
>   u32 block_size;
>   u32 metadata_size;
>
> u32 max_req_size;
>
> /* Page aligned buffer of size NVME_PAGE_SIZE. */
>  char *dma_buffer;
>
> @@ -131,7 +132,12 @@ struct nvme_identify_ctrl {
>       char mn[40];
>       char fr[8];
> char _boring[516 - 72];
>
> u8 rab;
>
> u8 ieee[3];
>
> u8 cmic;
>
> u8 mdts;
>
> char _boring[516 - 78];
>
> u32 nn;                     /* number of namespaces */
> };
>
> diff --git a/src/hw/nvme.c b/src/hw/nvme.c
> index 6a01204..2cde6a7 100644
> --- a/src/hw/nvme.c
> +++ b/src/hw/nvme.c
> @@ -238,7 +238,8 @@ nvme_admin_identify_ns(struct nvme_ctrl *ctrl, u32 ns_id)
>   }
>
> static void
> -nvme_probe_ns(struct nvme_ctrl *ctrl, struct nvme_namespace *ns, u32 ns_id)
> +nvme_probe_ns(struct nvme_ctrl *ctrl, struct nvme_namespace *ns, u32 ns_id,
>          u8 mdts)
> {
>     ns->ctrl  = ctrl;
>     ns->ns_id = ns_id;
>
> @@ -281,6 +282,14 @@ nvme_probe_ns(struct nvme_ctrl *ctrl, struct nvme_namespace *ns, u32 ns_id)
>       ns->drive.blksize   = ns->block_size;
>       ns->drive.sectors   = ns->lba_count;
> if (mdts) {
>    ns->max_req_size = 1U << mdts;
>    dprintf(3, "NVME NS %u max request size: %d sectors\n",
>            ns->max_req_size);
>
> The use of dprintf is incorrect, you're only providing one variable to print instead of two. You're missing the number of sectors.

Yikes, I fixed that one locally before I hit git format-patch. I 
promise! My machine probably just went back in time and pulled this 
broken state out of the abyss :).

Kidding aside, I'll submit the right one for v2. Thanks for noticing!

Alex

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