Re: [PATCH v6 14/42] nvme: add missing mandatory features

[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 support for returning a resonable response to Get/Set Features of
> mandatory features.
> 
> Signed-off-by: Klaus Jensen <klaus.jensen@cnexlabs.com>
> Acked-by: Keith Busch <kbusch@kernel.org>
> ---
>  hw/block/nvme.c       | 60 ++++++++++++++++++++++++++++++++++++++++++-
>  hw/block/trace-events |  2 ++
>  include/block/nvme.h  |  6 ++++-
>  3 files changed, 66 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/block/nvme.c b/hw/block/nvme.c
> index ff8975cd6667..eb9c722df968 100644
> --- a/hw/block/nvme.c
> +++ b/hw/block/nvme.c
> @@ -1025,7 +1025,15 @@ static uint16_t nvme_get_feature(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
>      uint32_t dw11 = le32_to_cpu(cmd->cdw11);
>      uint32_t result;
>  
> +    trace_nvme_dev_getfeat(nvme_cid(req), dw10);
> +
>      switch (dw10) {
> +    case NVME_ARBITRATION:
> +        result = cpu_to_le32(n->features.arbitration);
> +        break;
> +    case NVME_POWER_MANAGEMENT:
> +        result = cpu_to_le32(n->features.power_mgmt);
> +        break;
>      case NVME_TEMPERATURE_THRESHOLD:
>          result = 0;
>  
> @@ -1046,9 +1054,12 @@ static uint16_t nvme_get_feature(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
>              break;
>          }
>  
> +        break;
> +    case NVME_ERROR_RECOVERY:
> +        result = cpu_to_le32(n->features.err_rec);
>          break;
>      case NVME_VOLATILE_WRITE_CACHE:
> -        result = blk_enable_write_cache(n->conf.blk);
> +        result = cpu_to_le32(blk_enable_write_cache(n->conf.blk));
>          trace_nvme_dev_getfeat_vwcache(result ? "enabled" : "disabled");
>          break;
>      case NVME_NUMBER_OF_QUEUES:
> @@ -1058,6 +1069,19 @@ static uint16_t nvme_get_feature(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
>          break;
>      case NVME_TIMESTAMP:
>          return nvme_get_feature_timestamp(n, cmd);
> +    case NVME_INTERRUPT_COALESCING:
> +        result = cpu_to_le32(n->features.int_coalescing);
> +        break;
> +    case NVME_INTERRUPT_VECTOR_CONF:
> +        if ((dw11 & 0xffff) > n->params.max_ioqpairs + 1) {
> +            return NVME_INVALID_FIELD | NVME_DNR;
> +        }
I still think that this should be >= since the interrupt vector is not zero based.
So if we have for example 3 IO queues, then we have 4 queues in total
which translates to irq numbers 0..3.

BTW the user of the device doesn't have to have 1:1 mapping between qid and msi interrupt index,
in fact when MSI is not used, all the queues will map to the same vector, which will be interrupt 0
from point of view of the device IMHO.
So it kind of makes sense IMHO to have num_irqs or something, even if it technically equals to number of queues.


> +
> +        result = cpu_to_le32(n->features.int_vector_config[dw11 & 0xffff]);
> +        break;
> +    case NVME_WRITE_ATOMICITY:
> +        result = cpu_to_le32(n->features.write_atomicity);
> +        break;
>      case NVME_ASYNCHRONOUS_EVENT_CONF:
>          result = cpu_to_le32(n->features.async_config);
>          break;
> @@ -1093,6 +1117,8 @@ static uint16_t nvme_set_feature(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
>      uint32_t dw10 = le32_to_cpu(cmd->cdw10);
>      uint32_t dw11 = le32_to_cpu(cmd->cdw11);
>  
> +    trace_nvme_dev_setfeat(nvme_cid(req), dw10, dw11);
> +
>      switch (dw10) {
>      case NVME_TEMPERATURE_THRESHOLD:
>          if (NVME_TEMP_TMPSEL(dw11)) {
> @@ -1120,6 +1146,10 @@ static uint16_t nvme_set_feature(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
>  
>          break;
>      case NVME_VOLATILE_WRITE_CACHE:
> +        if (blk_enable_write_cache(n->conf.blk)) {
> +            blk_flush(n->conf.blk);
> +        }

(not your fault) but the blk_enable_write_cache function name is highly misleading,
since it doesn't enable anything but just gets the flag if the write cache is enabled.
It really should be called blk_get_enable_write_cache.

> +
>          blk_set_enable_write_cache(n->conf.blk, dw11 & 1);
>          break;
>      case NVME_NUMBER_OF_QUEUES:
> @@ -1135,6 +1165,13 @@ static uint16_t nvme_set_feature(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
>      case NVME_ASYNCHRONOUS_EVENT_CONF:
>          n->features.async_config = dw11;
>          break;
> +    case NVME_ARBITRATION:
> +    case NVME_POWER_MANAGEMENT:
> +    case NVME_ERROR_RECOVERY:
> +    case NVME_INTERRUPT_COALESCING:
> +    case NVME_INTERRUPT_VECTOR_CONF:
> +    case NVME_WRITE_ATOMICITY:
> +        return NVME_FEAT_NOT_CHANGABLE | NVME_DNR;
>      default:
>          trace_nvme_dev_err_invalid_setfeat(dw10);
>          return NVME_INVALID_FIELD | NVME_DNR;
> @@ -1716,6 +1753,25 @@ static void nvme_init_state(NvmeCtrl *n)
>      n->temperature = NVME_TEMPERATURE;
>      n->features.temp_thresh_hi = NVME_TEMPERATURE_WARNING;
>      n->starttime_ms = qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL);
> +
> +    /*
> +     * There is no limit on the number of commands that the controller may
> +     * launch at one time from a particular Submission Queue.
> +     */
> +    n->features.arbitration = NVME_ARB_AB_NOLIMIT;
> +
> +    n->features.int_vector_config = g_malloc0_n(n->params.max_ioqpairs + 1,
> +        sizeof(*n->features.int_vector_config));
> +
> +    for (int i = 0; i < n->params.max_ioqpairs + 1; i++) {
> +        n->features.int_vector_config[i] = i;
> +
> +        /* interrupt coalescing is not supported for the admin queue */
> +        if (i == 0) {
> +            n->features.int_vector_config[i] |= NVME_INTVC_NOCOALESCING;
> +        }
> +    }
> +
>      n->aer_reqs = g_new0(NvmeRequest *, n->params.aerl + 1);
>  }
>  
> @@ -1804,6 +1860,7 @@ static void nvme_init_ctrl(NvmeCtrl *n)
>      id->cqes = (0x4 << 4) | 0x4;
>      id->nn = cpu_to_le32(n->num_namespaces);
>      id->oncs = cpu_to_le16(NVME_ONCS_WRITE_ZEROS | NVME_ONCS_TIMESTAMP);
> +
Unrelated whitespace change
>      id->psd[0].mp = cpu_to_le16(0x9c4);
>      id->psd[0].enlat = cpu_to_le32(0x10);
>      id->psd[0].exlat = cpu_to_le32(0x4);
> @@ -1879,6 +1936,7 @@ static void nvme_exit(PCIDevice *pci_dev)
>      g_free(n->cq);
>      g_free(n->sq);
>      g_free(n->aer_reqs);
> +    g_free(n->features.int_vector_config);
>  
>      if (n->params.cmb_size_mb) {
>          g_free(n->cmbuf);
> diff --git a/hw/block/trace-events b/hw/block/trace-events
> index 3952c36774cf..4cf39961989d 100644
> --- a/hw/block/trace-events
> +++ b/hw/block/trace-events
> @@ -41,6 +41,8 @@ nvme_dev_del_cq(uint16_t cqid) "deleted completion queue, sqid=%"PRIu16""
>  nvme_dev_identify_ctrl(void) "identify controller"
>  nvme_dev_identify_ns(uint16_t ns) "identify namespace, nsid=%"PRIu16""
>  nvme_dev_identify_nslist(uint16_t ns) "identify namespace list, nsid=%"PRIu16""
> +nvme_dev_getfeat(uint16_t cid, uint32_t fid) "cid %"PRIu16" fid 0x%"PRIx32""
> +nvme_dev_setfeat(uint16_t cid, uint32_t fid, uint32_t val) "cid %"PRIu16" fid 0x%"PRIx32" val 0x%"PRIx32""
>  nvme_dev_getfeat_vwcache(const char* result) "get feature volatile write cache, result=%s"
>  nvme_dev_getfeat_numq(int result) "get feature number of queues, result=%d"
>  nvme_dev_setfeat_numq(int reqcq, int reqsq, int gotcq, int gotsq) "requested cq_count=%d sq_count=%d, responding with cq_count=%d sq_count=%d"
> diff --git a/include/block/nvme.h b/include/block/nvme.h
> index f2a8b07c0f2f..ecc02fbe8bb8 100644
> --- a/include/block/nvme.h
> +++ b/include/block/nvme.h
> @@ -490,7 +490,8 @@ enum NvmeStatusCodes {
>      NVME_FW_REQ_RESET           = 0x010b,
>      NVME_INVALID_QUEUE_DEL      = 0x010c,
>      NVME_FID_NOT_SAVEABLE       = 0x010d,
> -    NVME_FID_NOT_NSID_SPEC      = 0x010f,
> +    NVME_FEAT_NOT_CHANGABLE     = 0x010e,
> +    NVME_FEAT_NOT_NS_SPEC       = 0x010f,
>      NVME_FW_REQ_SUSYSTEM_RESET  = 0x0110,
>      NVME_CONFLICTING_ATTRS      = 0x0180,
>      NVME_INVALID_PROT_INFO      = 0x0181,
> @@ -706,6 +707,7 @@ typedef struct NvmeFeatureVal {
>  } NvmeFeatureVal;
>  
>  #define NVME_ARB_AB(arb)    (arb & 0x7)
> +#define NVME_ARB_AB_NOLIMIT 0x7
>  #define NVME_ARB_LPW(arb)   ((arb >> 8) & 0xff)
>  #define NVME_ARB_MPW(arb)   ((arb >> 16) & 0xff)
>  #define NVME_ARB_HPW(arb)   ((arb >> 24) & 0xff)
> @@ -713,6 +715,8 @@ typedef struct NvmeFeatureVal {
>  #define NVME_INTC_THR(intc)     (intc & 0xff)
>  #define NVME_INTC_TIME(intc)    ((intc >> 8) & 0xff)
>  
> +#define NVME_INTVC_NOCOALESCING (0x1 << 16)
> +
>  #define NVME_TEMP_THSEL(temp)  ((temp >> 20) & 0x3)
>  #define NVME_TEMP_TMPSEL(temp) ((temp >> 16) & 0xf)
>  #define NVME_TEMP_TMPTH(temp)  ((temp >>  0) & 0xffff)


Best regards,
	Maxim Levitsky