Re: [PATCH v2 04/10] cxl-mailbox-utils: 0x5601 - FMAPI Get Host Region Config

[Fan Ni <nifan.cxl@gmail.com>]

On Thu, May 08, 2025 at 12:01:00AM +0000, anisa.su887@gmail.com wrote:
> From: Anisa Su <anisa.su@samsung.com>
> 
> FM DCD Management command 0x5601 implemented per CXL r3.2 Spec Section 7.6.7.6.2
> 
> Signed-off-by: Anisa Su <anisa.su@samsung.com>

One minor comment inline. Otherwise,

Reviewed-by: Fan Ni <fan.ni@samsung.com>

> ---
>  hw/cxl/cxl-mailbox-utils.c   | 102 +++++++++++++++++++++++++++++++++++
>  include/hw/cxl/cxl_opcodes.h |   1 +
>  2 files changed, 103 insertions(+)
> 
> diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
> index d3c69233b8..6afc45833d 100644
> --- a/hw/cxl/cxl-mailbox-utils.c
> +++ b/hw/cxl/cxl-mailbox-utils.c
> @@ -3326,6 +3326,106 @@ static CXLRetCode cmd_fm_get_dcd_info(const struct cxl_cmd *cmd,
>      return CXL_MBOX_SUCCESS;
>  }
>  
> +static void build_dsmas_flags(uint8_t *flags, CXLDCRegion *region)
> +{
> +    *flags = 0;
> +
> +    if (region->nonvolatile) {
> +        *flags |= BIT(CXL_DSMAS_FLAGS_NONVOLATILE);
> +    }
> +    if (region->sharable) {
> +        *flags |= BIT(CXL_DSMAS_FLAGS_SHARABLE);
> +    }
> +    if (region->hw_managed_coherency) {
> +        *flags |= BIT(CXL_DSMAS_FLAGS_HW_MANAGED_COHERENCY);
> +    }
> +    if (region->ic_specific_dc_management) {
> +        *flags |= BIT(CXL_DSMAS_FLAGS_IC_SPECIFIC_DC_MANAGEMENT);
> +    }
> +    if (region->rdonly) {
> +        *flags |= BIT(CXL_DSMAS_FLAGS_RDONLY);
> +    }
> +}
> +
> +/* CXL r3.2 section 7.6.7.6.2: Get Host DC Region Configuration (Opcode 5601h) */
> +static CXLRetCode cmd_fm_get_host_dc_region_config(const struct cxl_cmd *cmd,
> +                                                   uint8_t *payload_in,
> +                                                   size_t len_in,
> +                                                   uint8_t *payload_out,
> +                                                   size_t *len_out,
> +                                                   CXLCCI *cci)
> +{
> +    struct {
> +        uint16_t host_id;
> +        uint8_t region_cnt;
> +        uint8_t start_rid;
> +    } QEMU_PACKED *in = (void *)payload_in;
> +    struct {
> +        uint16_t host_id;
> +        uint8_t num_regions;
> +        uint8_t regions_returned;
> +        struct {
> +            uint64_t base;
> +            uint64_t decode_len;
> +            uint64_t region_len;
> +            uint64_t block_size;
> +            uint8_t dsmas_flags;
> +            uint8_t rsvd1[3];
> +            uint8_t sanitize;

We may have other flags in the future, maybe we want to generalize the
name of the field.  Maybe "flags"?

Fan
> +            uint8_t rsvd2[3];
> +        } QEMU_PACKED records[];
> +    } QEMU_PACKED *out = (void *)payload_out;
> +    struct {
> +        uint32_t num_extents_supported;
> +        uint32_t num_extents_available;
> +        uint32_t num_tags_supported;
> +        uint32_t num_tags_available;
> +    } QEMU_PACKED *extra_out;
> +    CXLType3Dev *ct3d = CXL_TYPE3(cci->d);
> +    uint16_t record_count, out_pl_len, i;
> +
> +    if (in->start_rid >= ct3d->dc.num_regions) {
> +        return CXL_MBOX_INVALID_INPUT;
> +    }
> +    record_count = MIN(ct3d->dc.num_regions - in->start_rid, in->region_cnt);
> +
> +    out_pl_len = sizeof(*out) + record_count * sizeof(out->records[0]);
> +    extra_out = (void *)out + out_pl_len;
> +    out_pl_len += sizeof(*extra_out);
> +
> +    assert(out_pl_len <= CXL_MAILBOX_MAX_PAYLOAD_SIZE);
> +
> +    stw_le_p(&out->host_id, 0);
> +    out->num_regions = ct3d->dc.num_regions;
> +    out->regions_returned = record_count;
> +
> +    for (i = 0; i < record_count; i++) {
> +        stq_le_p(&out->records[i].base,
> +                 ct3d->dc.regions[in->start_rid + i].base);
> +        stq_le_p(&out->records[i].decode_len,
> +                 ct3d->dc.regions[in->start_rid + i].decode_len /
> +                 CXL_CAPACITY_MULTIPLIER);
> +        stq_le_p(&out->records[i].region_len,
> +                 ct3d->dc.regions[in->start_rid + i].len);
> +        stq_le_p(&out->records[i].block_size,
> +                 ct3d->dc.regions[in->start_rid + i].block_size);
> +        build_dsmas_flags(&out->records[i].dsmas_flags,
> +                          &ct3d->dc.regions[in->start_rid + i]);
> +        /* Sanitize is bit 0 of flags. */
> +        out->records[i].sanitize =
> +            ct3d->dc.regions[in->start_rid + i].flags & BIT(0);
> +    }
> +
> +    stl_le_p(&extra_out->num_extents_supported, CXL_NUM_EXTENTS_SUPPORTED);
> +    stl_le_p(&extra_out->num_extents_available, CXL_NUM_EXTENTS_SUPPORTED -
> +             ct3d->dc.total_extent_count);
> +    stl_le_p(&extra_out->num_tags_supported, CXL_NUM_TAGS_SUPPORTED);
> +    stl_le_p(&extra_out->num_tags_available, CXL_NUM_TAGS_SUPPORTED);
> +
> +    *len_out = out_pl_len;
> +    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 },
> @@ -3450,6 +3550,8 @@ static const struct cxl_cmd cxl_cmd_set_sw[256][256] = {
>  static const struct cxl_cmd cxl_cmd_set_fm_dcd[256][256] = {
>      [FMAPI_DCD_MGMT][GET_DCD_INFO] = { "GET_DCD_INFO",
>          cmd_fm_get_dcd_info, 0, 0 },
> +    [FMAPI_DCD_MGMT][GET_HOST_DC_REGION_CONFIG] = { "GET_HOST_DC_REGION_CONFIG",
> +        cmd_fm_get_host_dc_region_config, 4, 0 },
>  };
>  
>  /*
> diff --git a/include/hw/cxl/cxl_opcodes.h b/include/hw/cxl/cxl_opcodes.h
> index c4c233665e..68ad68291c 100644
> --- a/include/hw/cxl/cxl_opcodes.h
> +++ b/include/hw/cxl/cxl_opcodes.h
> @@ -63,5 +63,6 @@ enum {
>          #define GET_MHD_INFO 0x0
>      FMAPI_DCD_MGMT = 0x56,
>          #define GET_DCD_INFO 0x0
> +        #define GET_HOST_DC_REGION_CONFIG 0x1
>      GLOBAL_MEMORY_ACCESS_EP_MGMT = 0X59
>  };
> -- 
> 2.47.2
> 

-- 
Fan Ni