Re: [PATCH 8/9] cxl-mailbox-utils: 0x5604 - FMAPI Initiate DC Add

[Jonathan Cameron <Jonathan.Cameron@huawei.com>]

On Mon, 5 May 2025 16:40:18 +0000
Anisa Su <anisa.su887@gmail.com> wrote:

> On Thu, Apr 24, 2025 at 12:19:59PM +0100, Jonathan Cameron wrote:
> > On Mon, 17 Mar 2025 16:31:35 +0000
> > anisa.su887@gmail.com wrote:
> >   
> > > From: Anisa Su <anisa.su@samsung.com>
> > > 
> > > FM DCD Management command 0x5604 implemented per CXL r3.2 Spec Section 7.6.7.6.5
> > > 
> > > Signed-off-by: Anisa Su <anisa.su@samsung.com>
> > > ---  
> ...
> > > +        /* Create event record and insert to event log */
> > > +        cxl_mbox_dc_event_create_record_hdr(ct3d, &event_rec.hdr);
> > > +        event_rec.type = DC_EVENT_ADD_CAPACITY;
> > > +        /* FIXME: for now, validity flag is cleared */  
> > 
> > This stuff is probably all valid.  If we can return remaining extents though we might
> > as well.
> >   
> > > +        event_rec.validity_flags = 0;
> > > +        /* FIXME: Currently only support 1 host */
> > > +        event_rec.host_id = 0;
> > > +        /* updated_region_id only valid for DC_EVENT_REGION_CONFIG_UPDATED */
> > > +        event_rec.updated_region_id = 0;  
> > 
> > The event_rec is zeroed anyway so probably just don't set this at all
> > and no need for the comment.
> >   
> > > +        for (i = 0; i < in->ext_count; i++) {  
> > 
> > Why can't we combine this with the earlier loop and avoid the
> > need for separate storage of extents in event_rec_exts?
> >   
> I discussed with Fan and for add specifically, we will need 2 loops
> because the pending list is of type CXLDCExtentGroupList. We must use the
> first loop to create a CXLDCExtentGroup from all of the extents and
> append the entire thing to the pending list before triggering any interrupts for
> event records.
> This is necessary to preserve the ordering/grouping in order for the
> memdev_add_rsp command to know what to remove from the pending list if
> no extents were accepted.

Ah. That makes sense. Thanks!

> But the storage of extents in event_rec_exts is unnecessary and for
> release, we only need 1 loop.
> 
> Thanks,
> Anisa
> > > +            memcpy(&event_rec.dynamic_capacity_extent,
> > > +                   &event_rec_exts[i],
> > > +                   sizeof(CXLDCExtentRaw));
> > > +
> > > +            event_rec.flags = 0;
> > > +            if (i < in->ext_count - 1) {
> > > +                /* Set "More" flag */
> > > +                event_rec.flags |= BIT(0);
> > > +            }
> > > +
> > > +            if (cxl_event_insert(&ct3d->cxl_dstate,
> > > +                                 CXL_EVENT_TYPE_DYNAMIC_CAP,
> > > +                                 (CXLEventRecordRaw *)&event_rec)) {
> > > +                cxl_event_irq_assert(ct3d);
> > > +            }
> > > +        }
> > > +
> > > +        return CXL_MBOX_SUCCESS;
> > > +    default:
> > > +        qemu_log_mask(LOG_UNIMP,
> > > +                      "CXL extent selection policy not supported.\n");
> > > +        return CXL_MBOX_INVALID_INPUT;
> > > +    }
> > > +
> > > +    return CXL_MBOX_SUCCESS;
> > > +}
> > > +
> > >  static const struct cxl_cmd cxl_cmd_set[256][256] = {
> > >      [INFOSTAT][BACKGROUND_OPERATION_ABORT] = { "BACKGROUND_OPERATION_ABORT",
> > >          cmd_infostat_bg_op_abort, 0, 0 },
> > > @@ -3804,6 +3970,13 @@ static const struct cxl_cmd cxl_cmd_set_fm_dcd[256][256] = {
> > >           CXL_MBOX_IMMEDIATE_DATA_CHANGE)},
> > >      [FMAPI_DCD_MGMT][GET_DC_REGION_EXTENT_LIST] = { "GET_DC_REGION_EXTENT_LIST",
> > >          cmd_fm_get_dc_region_extent_list, 12, 0},
> > > +    [FMAPI_DCD_MGMT][INITIATE_DC_ADD] = { "INIT_DC_ADD",
> > > +        cmd_fm_initiate_dc_add, ~0,
> > > +        (CXL_MBOX_CONFIG_CHANGE_COLD_RESET |
> > > +        CXL_MBOX_CONFIG_CHANGE_CONV_RESET |
> > > +        CXL_MBOX_CONFIG_CHANGE_CXL_RESET |
> > > +        CXL_MBOX_IMMEDIATE_CONFIG_CHANGE |
> > > +        CXL_MBOX_IMMEDIATE_DATA_CHANGE)},
> > >  };
> > >  
> > >  /*
> > > diff --git a/hw/mem/cxl_type3.c b/hw/mem/cxl_type3.c
> > > index b742b2bb8d..ccc619fe10 100644
> > > --- a/hw/mem/cxl_type3.c
> > > +++ b/hw/mem/cxl_type3.c
> > > @@ -1982,8 +1982,8 @@ void qmp_cxl_inject_memory_module_event(const char *path, CxlEventLog log,
> > >   * the list.
> > >   * Return value: return true if has overlaps; otherwise, return false
> > >   */
> > > -static bool cxl_extents_overlaps_dpa_range(CXLDCExtentList *list,
> > > -                                           uint64_t dpa, uint64_t len)
> > > +bool cxl_extents_overlaps_dpa_range(CXLDCExtentList *list,
> > > +                                    uint64_t dpa, uint64_t len)
> > >  {
> > >      CXLDCExtent *ent;
> > >      Range range1, range2;
> > > @@ -2028,8 +2028,8 @@ bool cxl_extents_contains_dpa_range(CXLDCExtentList *list,
> > >      return false;
> > >  }
> > >  
> > > -static bool cxl_extent_groups_overlaps_dpa_range(CXLDCExtentGroupList *list,
> > > -                                                 uint64_t dpa, uint64_t len)
> > > +bool cxl_extent_groups_overlaps_dpa_range(CXLDCExtentGroupList *list,
> > > +                                          uint64_t dpa, uint64_t len)
> > >  {
> > >      CXLDCExtentGroup *group;
> > >  
> > > diff --git a/include/hw/cxl/cxl_device.h b/include/hw/cxl/cxl_device.h
> > > index 217003a29d..1d5831a0b6 100644
> > > --- a/include/hw/cxl/cxl_device.h
> > > +++ b/include/hw/cxl/cxl_device.h
> > > @@ -809,4 +809,8 @@ bool ct3_test_region_block_backed(CXLType3Dev *ct3d, uint64_t dpa,
> > >  void cxl_assign_event_header(CXLEventRecordHdr *hdr,
> > >                               const QemuUUID *uuid, uint32_t flags,
> > >                               uint8_t length, uint64_t timestamp);
> > > +bool cxl_extents_overlaps_dpa_range(CXLDCExtentList *list,
> > > +                                    uint64_t dpa, uint64_t len);
> > > +bool cxl_extent_groups_overlaps_dpa_range(CXLDCExtentGroupList *list,
> > > +                                          uint64_t dpa, uint64_t len);
> > >  #endif  
> >   
>