Re: [RFC PATCH] hw/cxl: Initial poison injection support.

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

> > +/*
> > + * This is very inefficient, but good enough for now!
> > + * Also thed payload will always fit, so no need to handle the MORE flag and
> > + * make this stateful.
> > + */
> > +static ret_code cmd_media_get_poison_list(struct cxl_cmd *cmd,
> > +                                          CXLDeviceState *cxl_dstate,
> > +                                          uint16_t *len)
> > +{
> > +    struct get_poison_list_pl {
> > +        uint64_t pa;
> > +        uint64_t length;
> > +    } QEMU_PACKED;
> > +
> > +    struct get_poison_list_out_pl {
> > +        uint8_t flags;
> > +        uint8_t rsvd1;
> > +        uint64_t overflow_timestamp;
> > +        uint16_t count;
> > +        uint8_t rsvd2[0x14];
> > +        struct {
> > +            uint64_t addr;
> > +            uint32_t length;
> > +            uint32_t resv;
> > +        } QEMU_PACKED records[];
> > +    } QEMU_PACKED;
> > +
> > +    struct get_poison_list_pl *in = (void *)cmd->payload;
> > +    struct get_poison_list_out_pl *out = (void *)cmd->payload;
> > +    CXLType3Dev *ct3d = container_of(cxl_dstate, CXLType3Dev, cxl_dstate);
> > +    CXLType3Class *cvc = CXL_TYPE3_GET_CLASS(ct3d);
> > +    uint16_t record_count = 0, i = 0;
> > +    uint64_t query_start = in->pa;
> > +    uint64_t query_length = in->length;
> > +    CXLPoisonList *poison_list;
> > +    CXLPoison *ent;
> > +    uint16_t out_pl_len;
> > +
> > +    poison_list = cvc->get_poison_list(ct3d);
> > +
> > +    QLIST_FOREACH(ent, poison_list, node) {
> > +        /* Check for no overlap */
> > +        if (ent->start >= query_start + query_length ||
> > +            ent->start + ent->length <= query_start) {
> > +            continue;
> > +        }
> > +        if (record_count == 256) {
> > +            /* For now just return 256 max */
> > +            break;
> > +        }
> > +        record_count++;
> > +    }
> > +    out_pl_len = sizeof(*out) + record_count * sizeof(out->records[0]);
> > +    assert(out_pl_len > CXL_MAILBOX_MAX_PAYLOAD_SIZE);
* embarrassed cough*.  Check is inverted.  Naught me tidied up a runtime
check into this but forgot to invert the sense + clearly didn't build
the right tree for final testing.

> > +
> > +    memset(out, 0, out_pl_len);
> > +    QLIST_FOREACH(ent, poison_list, node) {
> > +        uint64_t start, stop;
> > +
> > +        /* Check for no overlap */
> > +        if (ent->start >= query_start + query_length ||
> > +            ent->start + ent->length <= query_start) {
> > +            continue;
> > +        }
> > +        if (i == 256) {
> > +            break;
> > +        }
> > +        /* Deal with overlap */
> > +        start = MAX(ent->start & 0xffffffffffffffc0, query_start);
> > +        stop = MIN((ent->start & 0xffffffffffffffc0) + ent->length,
> > +                   query_start + query_length);
> > +        out->records[i].addr = start | 0x2; /* internal error */
> > +        out->records[i].length = (stop - start) / 64;
> > +        i++;
> > +    }
> > +    out->count = record_count;
> > +    *len = out_pl_len;
> > +    return CXL_MBOX_SUCCESS;
> > +}
> > +