Re: [PATCH 04/17] hw/block/nvme: add temperature threshold feature

[Klaus Jensen]

On Jul  3 00:44, Dmitry Fomichev wrote:
> On Mon, 2020-06-29 at 20:26 +0200, Klaus Jensen wrote:
> > From: Klaus Jensen <k.jensen@samsung.com>
> > 
> > It might seem weird to implement this feature for an emulated device,
> > but it is mandatory to support and the feature is useful for testing
> > asynchronous event request support, which will be added in a later
> > patch.
> > 
> > Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
> > Acked-by: Keith Busch <kbusch@kernel.org>
> > Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
> > ---
> >  hw/block/nvme.c      | 48 ++++++++++++++++++++++++++++++++++++++++++++
> >  hw/block/nvme.h      |  1 +
> >  include/block/nvme.h |  8 +++++++-
> >  3 files changed, 56 insertions(+), 1 deletion(-)
> > 
> > diff --git a/hw/block/nvme.c b/hw/block/nvme.c
> > index b7037a7d3504..5ca50646369e 100644
> > --- a/hw/block/nvme.c
> > +++ b/hw/block/nvme.c
> > @@ -59,6 +59,9 @@
> >  #define NVME_DB_SIZE  4
> >  #define NVME_CMB_BIR 2
> >  #define NVME_PMR_BIR 2
> > +#define NVME_TEMPERATURE 0x143
> > +#define NVME_TEMPERATURE_WARNING 0x157
> > +#define NVME_TEMPERATURE_CRITICAL 0x175
> >  
> >  #define NVME_GUEST_ERR(trace, fmt, ...) \
> >      do { \
> > @@ -827,9 +830,31 @@ static uint16_t nvme_get_feature_timestamp(NvmeCtrl 
> > *n, NvmeCmd *cmd)
> >  static uint16_t nvme_get_feature(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest 
> > *req)
> >  {
> >      uint32_t dw10 = le32_to_cpu(cmd->cdw10);
> > +    uint32_t dw11 = le32_to_cpu(cmd->cdw11);
> >      uint32_t result;
> >  
> >      switch (dw10) {
> > +    case NVME_TEMPERATURE_THRESHOLD:
> > +        result = 0;
> > +
> > +        /*
> > +         * The controller only implements the Composite Temperature 
> > sensor, so
> > +         * return 0 for all other sensors.
> > +         */
> > +        if (NVME_TEMP_TMPSEL(dw11) != NVME_TEMP_TMPSEL_COMPOSITE) {
> > +            break;
> > +        }
> > +
> > +        switch (NVME_TEMP_THSEL(dw11)) {
> > +        case NVME_TEMP_THSEL_OVER:
> > +            result = cpu_to_le16(n->features.temp_thresh_hi);
> > +            break;
> > +        case NVME_TEMP_THSEL_UNDER:
> > +            result = cpu_to_le16(n->features.temp_thresh_low);
> > +            break;
> > +        }
> > +
> > +        break;
> > 
> > >      case NVME_VOLATILE_WRITE_CACHE:
> >          result = blk_enable_write_cache(n->conf.blk);
> >          trace_pci_nvme_getfeat_vwcache(result ? "enabled" : "disabled");
> > @@ -874,6 +899,23 @@ static uint16_t nvme_set_feature(NvmeCtrl *n, NvmeCmd 
> > *cmd, NvmeRequest *req)
> >      uint32_t dw11 = le32_to_cpu(cmd->cdw11);
> >  
> >      switch (dw10) {
> > +    case NVME_TEMPERATURE_THRESHOLD:
> > +        if (NVME_TEMP_TMPSEL(dw11) != NVME_TEMP_TMPSEL_COMPOSITE) {
> > +            break;
> > +        }
> > +
> > +        switch (NVME_TEMP_THSEL(dw11)) {
> > +        case NVME_TEMP_THSEL_OVER:
> > +            n->features.temp_thresh_hi = NVME_TEMP_TMPTH(dw11);
> > +            break;
> > +        case NVME_TEMP_THSEL_UNDER:
> > +            n->features.temp_thresh_low = NVME_TEMP_TMPTH(dw11);
> > +            break;
> > +        default:
> > +            return NVME_INVALID_FIELD | NVME_DNR;
> > +        }
> > +
> > +        break;
> >      case NVME_VOLATILE_WRITE_CACHE:
> >          blk_set_enable_write_cache(n->conf.blk, dw11 & 1);
> >          break;
> > @@ -1454,6 +1496,7 @@ static void nvme_init_state(NvmeCtrl *n)
> >      n->namespaces = g_new0(NvmeNamespace, n->num_namespaces);
> >      n->sq = g_new0(NvmeSQueue *, n->params.max_ioqpairs + 1);
> >      n->cq = g_new0(NvmeCQueue *, n->params.max_ioqpairs + 1);
> > +    n->features.temp_thresh_hi = NVME_TEMPERATURE_WARNING;
> >  }
> >  
> >  static void nvme_init_blk(NvmeCtrl *n, Error **errp)
> > @@ -1611,6 +1654,11 @@ static void nvme_init_ctrl(NvmeCtrl *n, PCIDevice 
> > *pci_dev)
> >      id->acl = 3;
> >      id->frmw = 7 << 1;
> >      id->lpa = 1 << 0;
> > +
> > +    /* recommended default value (~70 C) */
> > +    id->wctemp = cpu_to_le16(NVME_TEMPERATURE_WARNING);
> > +    id->cctemp = cpu_to_le16(NVME_TEMPERATURE_CRITICAL);
> > +
> >      id->sqes = (0x6 << 4) | 0x6;
> >      id->cqes = (0x4 << 4) | 0x4;
> >      id->nn = cpu_to_le32(n->num_namespaces);
> > diff --git a/hw/block/nvme.h b/hw/block/nvme.h
> > index 1bf5c80ed843..3acde10e1d2a 100644
> > --- a/hw/block/nvme.h
> > +++ b/hw/block/nvme.h
> > @@ -107,6 +107,7 @@ typedef struct NvmeCtrl {
> >      NvmeSQueue      admin_sq;
> >      NvmeCQueue      admin_cq;
> >      NvmeIdCtrl      id_ctrl;
> > +    NvmeFeatureVal  features;
> >  } NvmeCtrl;
> >  
> >  /* calculate the number of LBAs that the namespace can accomodate */
> > diff --git a/include/block/nvme.h b/include/block/nvme.h
> > index 6d1fa6ff2228..bb651d0cbf5a 100644
> > --- a/include/block/nvme.h
> > +++ b/include/block/nvme.h
> > @@ -860,7 +860,13 @@ enum NvmeIdCtrlOncs {
> >  typedef struct NvmeFeatureVal {
> >      uint32_t    arbitration;
> >      uint32_t    power_mgmt;
> > -    uint32_t    temp_thresh;
> > +    union {
> > +        struct {
> > +            uint16_t temp_thresh_hi;
> > +            uint16_t temp_thresh_low;
> > +        };
> > +        uint32_t temp_thresh;
> 
> temp_thresh seems unused, is this union really needed?
> 

True. I kept the 32bit member there because it aligns with all other
features. But I guess it can be re-added if it is needed for some reason
in the future, so I removed it.

> > +    };
> >      uint32_t    err_rec;
> >      uint32_t    volatile_wc;
> >      uint32_t    num_queues;