Re: [PATCH qemu 07/11] hw/cxl: mailbox-utils: 0x5602 - FMAPI Set DC Region Config

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, Jul 02, 2025 at 05:02:13PM +0100, Jonathan Cameron wrote:
> From: Anisa Su <anisa.su@samsung.com>
> 
> FM DCD Management command 0x5602 implemented per CXL r3.2 Spec Section 7.6.7.6.3
> 
> Reviewed-by: Fan Ni <fan.ni@samsung.com>
> Signed-off-by: Anisa Su <anisa.su@samsung.com>
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> ---
>  include/hw/cxl/cxl_device.h  |  3 ++
>  include/hw/cxl/cxl_mailbox.h |  6 +++
>  hw/cxl/cxl-mailbox-utils.c   | 86 ++++++++++++++++++++++++++++++++++++
>  hw/mem/cxl_type3.c           |  6 +--
>  4 files changed, 98 insertions(+), 3 deletions(-)
> 
> diff --git a/include/hw/cxl/cxl_device.h b/include/hw/cxl/cxl_device.h
> index 96ef9be444..76af75d2d0 100644
> --- a/include/hw/cxl/cxl_device.h
> +++ b/include/hw/cxl/cxl_device.h
> @@ -721,4 +721,7 @@ void ct3_clear_region_block_backed(CXLType3Dev *ct3d, uint64_t dpa,
>                                     uint64_t len);
>  bool ct3_test_region_block_backed(CXLType3Dev *ct3d, uint64_t dpa,
>                                    uint64_t len);
> +void cxl_assign_event_header(CXLEventRecordHdr *hdr,
> +                             const QemuUUID *uuid, uint32_t flags,
> +                             uint8_t length, uint64_t timestamp);
>  #endif
> diff --git a/include/hw/cxl/cxl_mailbox.h b/include/hw/cxl/cxl_mailbox.h
> index 9008402d1c..a05d7cb5b7 100644
> --- a/include/hw/cxl/cxl_mailbox.h
> +++ b/include/hw/cxl/cxl_mailbox.h
> @@ -8,6 +8,7 @@
>  #ifndef CXL_MAILBOX_H
>  #define CXL_MAILBOX_H
>  
> +#define CXL_MBOX_CONFIG_CHANGE_COLD_RESET (1)
>  #define CXL_MBOX_IMMEDIATE_CONFIG_CHANGE (1 << 1)
>  #define CXL_MBOX_IMMEDIATE_DATA_CHANGE (1 << 2)
>  #define CXL_MBOX_IMMEDIATE_POLICY_CHANGE (1 << 3)
> @@ -15,5 +16,10 @@
>  #define CXL_MBOX_SECURITY_STATE_CHANGE (1 << 5)
>  #define CXL_MBOX_BACKGROUND_OPERATION (1 << 6)
>  #define CXL_MBOX_BACKGROUND_OPERATION_ABORT (1 << 7)
> +#define CXL_MBOX_SECONDARY_MBOX_SUPPORTED (1 << 8)
> +#define CXL_MBOX_REQUEST_ABORT_BACKGROUND_OP_SUPPORTED (1 << 9)
> +#define CXL_MBOX_CEL_10_TO_11_VALID (1 << 10)
> +#define CXL_MBOX_CONFIG_CHANGE_CONV_RESET (1 << 11)
> +#define CXL_MBOX_CONFIG_CHANGE_CXL_RESET (1 << 12)
>  
>  #endif
> diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
> index bf1710b251..1fc453f70d 100644
> --- a/hw/cxl/cxl-mailbox-utils.c
> +++ b/hw/cxl/cxl-mailbox-utils.c
> @@ -121,6 +121,7 @@ enum {
>      FMAPI_DCD_MGMT = 0x56,
>          #define GET_DCD_INFO    0x0
>          #define GET_HOST_DC_REGION_CONFIG   0x1
> +        #define SET_DC_REGION_CONFIG        0x2
>  };
>  
>  /* CCI Message Format CXL r3.1 Figure 7-19 */
> @@ -3390,6 +3391,84 @@ static CXLRetCode cmd_fm_get_host_dc_region_config(const struct cxl_cmd *cmd,
>      return CXL_MBOX_SUCCESS;
>  }
>  
> +/* CXL r3.2 section 7.6.7.6.3: Set Host DC Region Configuration (Opcode 5602) */
> +static CXLRetCode cmd_fm_set_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 {
> +        uint8_t reg_id;
> +        uint8_t rsvd[3];
> +        uint64_t block_sz;
> +        uint8_t flags;
> +        uint8_t rsvd2[3];
> +    } QEMU_PACKED *in = (void *)payload_in;
> +    CXLType3Dev *ct3d = CXL_TYPE3(cci->d);
> +    CXLEventDynamicCapacity dcEvent = {};
> +    CXLDCRegion *region = &ct3d->dc.regions[in->reg_id];
> +
> +    /*
> +     * CXL r3.2 7.6.7.6.3: Set DC Region Configuration
> +     * This command shall fail with Unsupported when the Sanitize on Release
> +     * field does not match the region’s configuration... and the device
> +     * does not support reconfiguration of the Sanitize on Release setting.
> +     *
> +     * Currently not reconfigurable, so always fail if sanitize bit (bit 0)
> +     * doesn't match.
> +     */
> +    if ((in->flags & 0x1) != (region->flags & 0x1)) {
> +        return CXL_MBOX_UNSUPPORTED;
> +    }
> +
> +    if (in->reg_id >= DCD_MAX_NUM_REGION) {
> +        return CXL_MBOX_UNSUPPORTED;
> +    }
> +
> +    /* Check that no extents are in the region being reconfigured */
> +    if (!bitmap_empty(region->blk_bitmap, region->len / region->block_size)) {
> +        return CXL_MBOX_UNSUPPORTED;
> +    }
> +
> +    /* Check that new block size is supported */
> +    if (!test_bit(BIT((int) log2(in->block_sz)),
> +                  &region->supported_blk_size_bitmask)) {
> +        return CXL_MBOX_INVALID_INPUT;
> +    }

This does not work: test_bit works on unsigned long, while
supported_blk_size_bitmask is uint64_t.

Why so funky? what is wrong with:

if (!(BIT_ULL(log2(in->block_sz)) & region->supported_blk_size_bitmask))

And BTW why cast to int here?


> +
> +    /* Return success if new block size == current block size */
> +    if (in->block_sz == region->block_size) {
> +        return CXL_MBOX_SUCCESS;
> +    }
> +
> +    /* Free bitmap and create new one for new block size. */
> +    qemu_mutex_lock(&region->bitmap_lock);
> +    g_free(region->blk_bitmap);
> +    region->blk_bitmap = bitmap_new(region->len / in->block_sz);
> +    qemu_mutex_unlock(&region->bitmap_lock);
> +    region->block_size = in->block_sz;
> +
> +    /* Create event record and insert into event log */
> +    cxl_assign_event_header(&dcEvent.hdr,
> +                            &dynamic_capacity_uuid,
> +                            (1 << CXL_EVENT_TYPE_INFO),
> +                            sizeof(dcEvent),
> +                            cxl_device_get_timestamp(&ct3d->cxl_dstate));
> +    dcEvent.type = DC_EVENT_REGION_CONFIG_UPDATED;
> +    dcEvent.validity_flags = 1;
> +    dcEvent.host_id = 0;
> +    dcEvent.updated_region_id = in->reg_id;
> +
> +    if (cxl_event_insert(&ct3d->cxl_dstate,
> +                         CXL_EVENT_TYPE_DYNAMIC_CAP,
> +                         (CXLEventRecordRaw *)&dcEvent)) {
> +        cxl_event_irq_assert(ct3d);
> +    }
> +    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 },
> @@ -3508,6 +3587,13 @@ static const struct cxl_cmd cxl_cmd_set_fm_dcd[256][256] = {
>          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 },
> +    [FMAPI_DCD_MGMT][SET_DC_REGION_CONFIG] = { "SET_DC_REGION_CONFIG",
> +        cmd_fm_set_dc_region_config, 16,
> +        (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 b872a26173..ee554a77be 100644
> --- a/hw/mem/cxl_type3.c
> +++ b/hw/mem/cxl_type3.c
> @@ -1590,9 +1590,9 @@ void qmp_cxl_inject_correctable_error(const char *path, CxlCorErrorType type,
>      pcie_aer_inject_error(PCI_DEVICE(obj), &err);
>  }
>  
> -static void cxl_assign_event_header(CXLEventRecordHdr *hdr,
> -                                    const QemuUUID *uuid, uint32_t flags,
> -                                    uint8_t length, uint64_t timestamp)
> +void cxl_assign_event_header(CXLEventRecordHdr *hdr,
> +                             const QemuUUID *uuid, uint32_t flags,
> +                             uint8_t length, uint64_t timestamp)
>  {
>      st24_le_p(&hdr->flags, flags);
>      hdr->length = length;
> -- 
> 2.48.1