Re: [QEMU PATCH 1/1] hw/cxl/cxl-mailbox-utils: Enable FMAPI Initiate Add for MHSLD

[Jonathan Cameron via <qemu-devel@nongnu.org>]

On Sat, 27 Sep 2025 00:18:07 +0000
anisa.su887@gmail.com wrote:

> From: Anisa Su <anisa.su@samsung.com>
> 
> Call mhd_reserve_extents in FMAPI Init Add (5604h)to enable sending
> FMAPI Add command to MHSLD.
> 
> Signed-off-by: Anisa Su <anisa.su@samsung.com>
Hi Anisa,

I've not been quick on this one partly because it sits on top of the MHSLD
work that I think needs a proper revisit to establish what is an up streamable
path, but I haven't had time to do that :(

Anyhow in meantime I'll take a look.  I suppose nothing stops me carrying
this on top.

Just one minor comment inline.
> ---
>  hw/cxl/cxl-mailbox-utils.c | 25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
> 
> diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
> index c5177dfd92..9ac60db4e1 100644
> --- a/hw/cxl/cxl-mailbox-utils.c
> +++ b/hw/cxl/cxl-mailbox-utils.c
> @@ -24,6 +24,7 @@
>  #include "system/hostmem.h"
>  #include "qemu/range.h"
>  #include "qapi/qapi-types-cxl.h"
> +#include "hw/cxl/mhsld/mhsld.h"
>  
>  #define CXL_CAPACITY_MULTIPLIER   (256 * MiB)
>  #define CXL_DC_EVENT_LOG_SIZE 8
> @@ -4163,6 +4164,8 @@ static CXLRetCode cmd_fm_initiate_dc_add(const struct cxl_cmd *cmd,
>          CXLDCExtentRaw extents[];
>      } QEMU_PACKED *in = (void *)payload_in;
>      CXLType3Dev *ct3d = CXL_TYPE3(cci->d);
> +    CXLType3Class *cvc = CXL_TYPE3_GET_CLASS(ct3d);
> +    CXLDCRegion *region = &ct3d->dc.regions[in->reg_num];
>      int i, rc;
>  
>      switch (in->selection_policy) {
> @@ -4201,6 +4204,28 @@ static CXLRetCode cmd_fm_initiate_dc_add(const struct cxl_cmd *cmd,
>                  return rc;
>              }
>  
> +            /* If this is an MHD, attempt to reserve the extents */
> +            if (cvc->mhd_reserve_extents) {
> +                g_autofree CxlDynamicCapacityExtentList *records =
> +                    g_malloc0(in->ext_count * sizeof(*records));

I think it makes sense to use g_malloc0_n for these

I changed this whilst applying it locally so it'll be there next time
I push out a tree.

Thanks,

Jonathan


> +                g_autofree CxlDynamicCapacityExtent *dc_exts =
> +                    g_malloc0(in->ext_count * sizeof(*dc_exts));
> +
> +                for (i = 0; i < in->ext_count; i++) {
> +                    CxlDynamicCapacityExtent *value = &dc_exts[i];
> +                    value->offset =
> +                        in->extents[i].start_dpa - region->base;
> +                    value->len = in->extents[i].len;
> +
> +                    records[i].value = value;
> +                    records[i].next = &records[i + 1];
> +                }
> +                records[in->ext_count - 1].next = NULL;
> +                if (!cvc->mhd_reserve_extents(&ct3d->parent_obj, records, in->reg_num)) {
> +                    return CXL_MBOX_INVALID_INPUT;
> +                }
> +            }
> +
>              CXLDCExtentGroup *group = NULL;
>              for (i = 0; i < in->ext_count; i++) {
>                  CXLDCExtentRaw *ext = &in->extents[i];