RE: [PATCH 8/9] hw/block/nvme: add trace event for requests with non-zero status code

[Dmitry Fomichev]

> -----Original Message-----
> From: Keith Busch <kbusch@kernel.org>
> Sent: Wednesday, September 30, 2020 6:04 PM
> To: qemu-block@nongnu.org; qemu-devel@nongnu.org; Klaus Jensen
> <k.jensen@samsung.com>
> Cc: Niklas Cassel <Niklas.Cassel@wdc.com>; Dmitry Fomichev
> <Dmitry.Fomichev@wdc.com>; Kevin Wolf <kwolf@redhat.com>; Philippe
> Mathieu-Daudé <philmd@redhat.com>; Keith Busch <kbusch@kernel.org>
> Subject: [PATCH 8/9] hw/block/nvme: add trace event for requests with
> non-zero status code
> 
> From: Klaus Jensen <k.jensen@samsung.com>
> 
> If a command results in a non-zero status code, trace it.
> 
> Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
> Signed-off-by: Keith Busch <kbusch@kernel.org>
> ---
>  hw/block/nvme.c       | 6 ++++++
>  hw/block/trace-events | 1 +
>  2 files changed, 7 insertions(+)
> 
> diff --git a/hw/block/nvme.c b/hw/block/nvme.c
> index dc971c9653..16804d0278 100644
> --- a/hw/block/nvme.c
> +++ b/hw/block/nvme.c
> @@ -777,6 +777,12 @@ static void
> nvme_enqueue_req_completion(NvmeCQueue *cq, NvmeRequest *req)
>      assert(cq->cqid == req->sq->cqid);
>      trace_pci_nvme_enqueue_req_completion(nvme_cid(req), cq->cqid,
>                                            req->status);
> +
> +    if (req->status) {
> +        trace_pci_nvme_err_req_status(nvme_cid(req), nvme_nsid(req->ns),
> +                                      req->status, req->cmd.opcode);
> +    }
> +

Very useful.
Reviewed-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>

>      QTAILQ_REMOVE(&req->sq->out_req_list, req, entry);
>      QTAILQ_INSERT_TAIL(&cq->req_list, req, entry);
>      timer_mod(cq->timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) +
> 500);
> diff --git a/hw/block/trace-events b/hw/block/trace-events
> index 180c43d258..ff3ca4bbf6 100644
> --- a/hw/block/trace-events
> +++ b/hw/block/trace-events
> @@ -89,6 +89,7 @@ pci_nvme_mmio_shutdown_cleared(void) "shutdown
> bit cleared"
> 
>  # nvme traces for error conditions
>  pci_nvme_err_mdts(uint16_t cid, size_t len) "cid %"PRIu16" len %zu"
> +pci_nvme_err_req_status(uint16_t cid, uint32_t nsid, uint16_t status,
> uint8_t opc) "cid %"PRIu16" nsid %"PRIu32" status 0x%"PRIx16" opc
> 0x%"PRIx8""
>  pci_nvme_err_addr_read(uint64_t addr) "addr 0x%"PRIx64""
>  pci_nvme_err_addr_write(uint64_t addr) "addr 0x%"PRIx64""
>  pci_nvme_err_cfs(void) "controller fatal status"
> --
> 2.24.1