diff mbox series

[v6,2/4] hw/cxl: QMP based poison injection support

Message ID 20230519141803.29713-3-Jonathan.Cameron@huawei.com (mailing list archive)
State New, archived
Headers show
Series hw/cxl: Poison get, inject, clear | expand

Commit Message

Jonathan Cameron May 19, 2023, 2:18 p.m. UTC
Inject poison using qmp command cxl-inject-poison to add an entry to the
poison list.

For now, the poison is not returned CXL.mem reads, but only via the
mailbox command Get Poison List. So a normal memory read to an address
that is on the poison list will not yet result in a synchronous exception
(and similar for partial cacheline writes).
That is left for a future patch.

See CXL rev 3.0, sec 8.2.9.8.4.1 Get Poison list (Opcode 4300h)

Kernel patches to use this interface here:
https://lore.kernel.org/linux-cxl/cover.1665606782.git.alison.schofield@intel.com/

To inject poison using qmp (telnet to the qmp port)
{ "execute": "qmp_capabilities" }

{ "execute": "cxl-inject-poison",
    "arguments": {
         "path": "/machine/peripheral/cxl-pmem0",
         "start": 2048,
         "length": 256
    }
}

Adjusted to select a device on your machine.

Note that the poison list supported is kept short enough to avoid the
complexity of state machine that is needed to handle the MORE flag.

Reviewed-by: Fan Ni <fan.ni@samsung.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
 hw/cxl/cxl-mailbox-utils.c  | 90 +++++++++++++++++++++++++++++++++++++
 hw/mem/cxl_type3.c          | 56 +++++++++++++++++++++++
 hw/mem/cxl_type3_stubs.c    |  6 +++
 include/hw/cxl/cxl.h        |  1 +
 include/hw/cxl/cxl_device.h | 20 +++++++++
 qapi/cxl.json               | 18 ++++++++
 6 files changed, 191 insertions(+)

Comments

Jonathan Cameron May 22, 2023, 11:20 a.m. UTC | #1
On Fri, 19 May 2023 15:18:01 +0100
Jonathan Cameron <Jonathan.Cameron@huawei.com> wrote:

> Inject poison using qmp command cxl-inject-poison to add an entry to the
> poison list.
> 
> For now, the poison is not returned CXL.mem reads, but only via the
> mailbox command Get Poison List. So a normal memory read to an address
> that is on the poison list will not yet result in a synchronous exception
> (and similar for partial cacheline writes).
> That is left for a future patch.
> 
> See CXL rev 3.0, sec 8.2.9.8.4.1 Get Poison list (Opcode 4300h)
> 
> Kernel patches to use this interface here:
> https://lore.kernel.org/linux-cxl/cover.1665606782.git.alison.schofield@intel.com/
> 
> To inject poison using qmp (telnet to the qmp port)
> { "execute": "qmp_capabilities" }
> 
> { "execute": "cxl-inject-poison",
>     "arguments": {
>          "path": "/machine/peripheral/cxl-pmem0",
>          "start": 2048,
>          "length": 256
>     }
> }
> 
> Adjusted to select a device on your machine.
> 
> Note that the poison list supported is kept short enough to avoid the
> complexity of state machine that is needed to handle the MORE flag.
> 
> Reviewed-by: Fan Ni <fan.ni@samsung.com>
> Reviewed-by: Ira Weiny <ira.weiny@intel.com>
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
For reference.  Markus Armbruster gave some feedback on v5 that crossed this this.
I'll incorporate into v7.

Thanks,

Jonathan
 
> ---
>  hw/cxl/cxl-mailbox-utils.c  | 90 +++++++++++++++++++++++++++++++++++++
>  hw/mem/cxl_type3.c          | 56 +++++++++++++++++++++++
>  hw/mem/cxl_type3_stubs.c    |  6 +++
>  include/hw/cxl/cxl.h        |  1 +
>  include/hw/cxl/cxl_device.h | 20 +++++++++
>  qapi/cxl.json               | 18 ++++++++
>  6 files changed, 191 insertions(+)
> 
> diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
> index 702e16ca20..1f74b26ea2 100644
> --- a/hw/cxl/cxl-mailbox-utils.c
> +++ b/hw/cxl/cxl-mailbox-utils.c
> @@ -62,6 +62,8 @@ enum {
>          #define GET_PARTITION_INFO     0x0
>          #define GET_LSA       0x2
>          #define SET_LSA       0x3
> +    MEDIA_AND_POISON = 0x43,
> +        #define GET_POISON_LIST        0x0
>  };
>  
>  /* 8.2.8.4.5.1 Command Return Codes */
> @@ -295,6 +297,10 @@ static CXLRetCode cmd_identify_memory_device(struct cxl_cmd *cmd,
>      stq_le_p(&id->persistent_capacity, cxl_dstate->pmem_size / CXL_CAPACITY_MULTIPLIER);
>      stq_le_p(&id->volatile_capacity, cxl_dstate->vmem_size / CXL_CAPACITY_MULTIPLIER);
>      stl_le_p(&id->lsa_size, cvc->get_lsa_size(ct3d));
> +    /* 256 poison records */
> +    st24_le_p(id->poison_list_max_mer, 256);
> +    /* No limit - so limited by main poison record limit */
> +    stw_le_p(&id->inject_poison_limit, 0);
>  
>      *len = sizeof(*id);
>      return CXL_MBOX_SUCCESS;
> @@ -384,6 +390,88 @@ static CXLRetCode cmd_ccls_set_lsa(struct cxl_cmd *cmd,
>      return CXL_MBOX_SUCCESS;
>  }
>  
> +/*
> + * This is very inefficient, but good enough for now!
> + * Also the payload will always fit, so no need to handle the MORE flag and
> + * make this stateful. We may want to allow longer poison lists to aid
> + * testing that kernel functionality.
> + */
> +static CXLRetCode 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);
> +    uint16_t record_count = 0, i = 0;
> +    uint64_t query_start, query_length;
> +    CXLPoisonList *poison_list = &ct3d->poison_list;
> +    CXLPoison *ent;
> +    uint16_t out_pl_len;
> +
> +    query_start = ldq_le_p(&in->pa);
> +    /* 64 byte alignemnt required */
> +    if (query_start & 0x3f) {
> +        return CXL_MBOX_INVALID_INPUT;
> +    }
> +    query_length = ldq_le_p(&in->length) * CXL_CACHE_LINE_SIZE;
> +
> +    QLIST_FOREACH(ent, poison_list, node) {
> +        /* Check for no overlap */
> +        if (ent->start >= query_start + query_length ||
> +            ent->start + ent->length <= query_start) {
> +            continue;
> +        }
> +        record_count++;
> +    }
> +    out_pl_len = sizeof(*out) + record_count * sizeof(out->records[0]);
> +    assert(out_pl_len <= CXL_MAILBOX_MAX_PAYLOAD_SIZE);
> +
> +    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;
> +        }
> +
> +        /* Deal with overlap */
> +        start = MAX(ROUND_DOWN(ent->start, 64ull), query_start);
> +        stop = MIN(ROUND_DOWN(ent->start, 64ull) + ent->length,
> +                   query_start + query_length);
> +        stq_le_p(&out->records[i].addr, start | (ent->type & 0x7));
> +        stl_le_p(&out->records[i].length, (stop - start) / CXL_CACHE_LINE_SIZE);
> +        i++;
> +    }
> +    if (ct3d->poison_list_overflowed) {
> +        out->flags = (1 << 1);
> +        stq_le_p(&out->overflow_timestamp, ct3d->poison_list_overflow_ts);
> +    }
> +    stw_le_p(&out->count, record_count);
> +    *len = out_pl_len;
> +    return CXL_MBOX_SUCCESS;
> +}
> +
>  #define IMMEDIATE_CONFIG_CHANGE (1 << 1)
>  #define IMMEDIATE_DATA_CHANGE (1 << 2)
>  #define IMMEDIATE_POLICY_CHANGE (1 << 3)
> @@ -411,6 +499,8 @@ static struct cxl_cmd cxl_cmd_set[256][256] = {
>      [CCLS][GET_LSA] = { "CCLS_GET_LSA", cmd_ccls_get_lsa, 8, 0 },
>      [CCLS][SET_LSA] = { "CCLS_SET_LSA", cmd_ccls_set_lsa,
>          ~0, IMMEDIATE_CONFIG_CHANGE | IMMEDIATE_DATA_CHANGE },
> +    [MEDIA_AND_POISON][GET_POISON_LIST] = { "MEDIA_AND_POISON_GET_POISON_LIST",
> +        cmd_media_get_poison_list, 16, 0 },
>  };
>  
>  void cxl_process_mailbox(CXLDeviceState *cxl_dstate)
> diff --git a/hw/mem/cxl_type3.c b/hw/mem/cxl_type3.c
> index 2adacbd01b..ab600735eb 100644
> --- a/hw/mem/cxl_type3.c
> +++ b/hw/mem/cxl_type3.c
> @@ -947,6 +947,62 @@ static void set_lsa(CXLType3Dev *ct3d, const void *buf, uint64_t size,
>       */
>  }
>  
> +void cxl_set_poison_list_overflowed(CXLType3Dev *ct3d)
> +{
> +        ct3d->poison_list_overflowed = true;
> +        ct3d->poison_list_overflow_ts =
> +            cxl_device_get_timestamp(&ct3d->cxl_dstate);
> +}
> +
> +void qmp_cxl_inject_poison(const char *path, uint64_t start, uint64_t length,
> +                           Error **errp)
> +{
> +    Object *obj = object_resolve_path(path, NULL);
> +    CXLType3Dev *ct3d;
> +    CXLPoison *p;
> +
> +    if (length % 64) {
> +        error_setg(errp, "Poison injection must be in multiples of 64 bytes");
> +        return;
> +    }
> +    if (start % 64) {
> +        error_setg(errp, "Poison start address must be 64 byte aligned");
> +        return;
> +    }
> +    if (!obj) {
> +        error_setg(errp, "Unable to resolve path");
> +        return;
> +    }
> +    if (!object_dynamic_cast(obj, TYPE_CXL_TYPE3)) {
> +        error_setg(errp, "Path does not point to a CXL type 3 device");
> +        return;
> +    }
> +
> +    ct3d = CXL_TYPE3(obj);
> +
> +    QLIST_FOREACH(p, &ct3d->poison_list, node) {
> +        if (((start >= p->start) && (start < p->start + p->length)) ||
> +            ((start + length > p->start) &&
> +             (start + length <= p->start + p->length))) {
> +            error_setg(errp, "Overlap with existing poisoned region not supported");
> +            return;
> +        }
> +    }
> +
> +    if (ct3d->poison_list_cnt == CXL_POISON_LIST_LIMIT) {
> +        cxl_set_poison_list_overflowed(ct3d);
> +        return;
> +    }
> +
> +    p = g_new0(CXLPoison, 1);
> +    p->length = length;
> +    p->start = start;
> +    p->type = CXL_POISON_TYPE_INTERNAL; /* Different from injected via the mbox */
> +
> +    QLIST_INSERT_HEAD(&ct3d->poison_list, p, node);
> +    ct3d->poison_list_cnt++;
> +}
> +
>  /* For uncorrectable errors include support for multiple header recording */
>  void qmp_cxl_inject_uncorrectable_errors(const char *path,
>                                           CXLUncorErrorRecordList *errors,
> diff --git a/hw/mem/cxl_type3_stubs.c b/hw/mem/cxl_type3_stubs.c
> index d574c58f9a..fd1166a610 100644
> --- a/hw/mem/cxl_type3_stubs.c
> +++ b/hw/mem/cxl_type3_stubs.c
> @@ -3,6 +3,12 @@
>  #include "qapi/error.h"
>  #include "qapi/qapi-commands-cxl.h"
>  
> +void qmp_cxl_inject_poison(const char *path, uint64_t start, uint64_t length,
> +                           Error **errp)
> +{
> +    error_setg(errp, "CXL Type 3 support is not compiled in");
> +}
> +
>  void qmp_cxl_inject_uncorrectable_errors(const char *path,
>                                           CXLUncorErrorRecordList *errors,
>                                           Error **errp)
> diff --git a/include/hw/cxl/cxl.h b/include/hw/cxl/cxl.h
> index c453983e83..56c9e7676e 100644
> --- a/include/hw/cxl/cxl.h
> +++ b/include/hw/cxl/cxl.h
> @@ -18,6 +18,7 @@
>  #include "cxl_component.h"
>  #include "cxl_device.h"
>  
> +#define CXL_CACHE_LINE_SIZE 64
>  #define CXL_COMPONENT_REG_BAR_IDX 0
>  #define CXL_DEVICE_REG_BAR_IDX 2
>  
> diff --git a/include/hw/cxl/cxl_device.h b/include/hw/cxl/cxl_device.h
> index 02befda0f6..32c234ea91 100644
> --- a/include/hw/cxl/cxl_device.h
> +++ b/include/hw/cxl/cxl_device.h
> @@ -242,6 +242,18 @@ typedef struct CXLError {
>  
>  typedef QTAILQ_HEAD(, CXLError) CXLErrorList;
>  
> +typedef struct CXLPoison {
> +    uint64_t start, length;
> +    uint8_t type;
> +#define CXL_POISON_TYPE_EXTERNAL 0x1
> +#define CXL_POISON_TYPE_INTERNAL 0x2
> +#define CXL_POISON_TYPE_INJECTED 0x3
> +    QLIST_ENTRY(CXLPoison) node;
> +} CXLPoison;
> +
> +typedef QLIST_HEAD(, CXLPoison) CXLPoisonList;
> +#define CXL_POISON_LIST_LIMIT 256
> +
>  struct CXLType3Dev {
>      /* Private */
>      PCIDevice parent_obj;
> @@ -264,6 +276,12 @@ struct CXLType3Dev {
>  
>      /* Error injection */
>      CXLErrorList error_list;
> +
> +    /* Poison Injection - cache */
> +    CXLPoisonList poison_list;
> +    unsigned int poison_list_cnt;
> +    bool poison_list_overflowed;
> +    uint64_t poison_list_overflow_ts;
>  };
>  
>  #define TYPE_CXL_TYPE3 "cxl-type3"
> @@ -289,4 +307,6 @@ MemTxResult cxl_type3_write(PCIDevice *d, hwaddr host_addr, uint64_t data,
>  
>  uint64_t cxl_device_get_timestamp(CXLDeviceState *cxlds);
>  
> +void cxl_set_poison_list_overflowed(CXLType3Dev *ct3d);
> +
>  #endif
> diff --git a/qapi/cxl.json b/qapi/cxl.json
> index b21c9b4c1c..dcf9e7b715 100644
> --- a/qapi/cxl.json
> +++ b/qapi/cxl.json
> @@ -5,6 +5,24 @@
>  # = CXL devices
>  ##
>  
> +##
> +# @cxl-inject-poison:
> +#
> +# Poison records indicate that a CXL memory device knows that a particular
> +# memory region may be corrupted. This may be because of locally detected
> +# errors (e.g. ECC failure) or poisoned writes received from other components
> +# in the system. This injection mechanism enables testing of the OS handling
> +# of poison records which may be queried via the CXL mailbox.
> +#
> +# @path: CXL type 3 device canonical QOM path
> +# @start: Start address - must be 64 byte aligned.
> +# @length: Length of poison to inject - must be a multiple of 64 bytes.
> +#
> +# Since: 8.1
> +##
> +{ 'command': 'cxl-inject-poison',
> +  'data': { 'path': 'str', 'start': 'uint64', 'length': 'uint64' }}
> +
>  ##
>  # @CxlUncorErrorType:
>  #
diff mbox series

Patch

diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
index 702e16ca20..1f74b26ea2 100644
--- a/hw/cxl/cxl-mailbox-utils.c
+++ b/hw/cxl/cxl-mailbox-utils.c
@@ -62,6 +62,8 @@  enum {
         #define GET_PARTITION_INFO     0x0
         #define GET_LSA       0x2
         #define SET_LSA       0x3
+    MEDIA_AND_POISON = 0x43,
+        #define GET_POISON_LIST        0x0
 };
 
 /* 8.2.8.4.5.1 Command Return Codes */
@@ -295,6 +297,10 @@  static CXLRetCode cmd_identify_memory_device(struct cxl_cmd *cmd,
     stq_le_p(&id->persistent_capacity, cxl_dstate->pmem_size / CXL_CAPACITY_MULTIPLIER);
     stq_le_p(&id->volatile_capacity, cxl_dstate->vmem_size / CXL_CAPACITY_MULTIPLIER);
     stl_le_p(&id->lsa_size, cvc->get_lsa_size(ct3d));
+    /* 256 poison records */
+    st24_le_p(id->poison_list_max_mer, 256);
+    /* No limit - so limited by main poison record limit */
+    stw_le_p(&id->inject_poison_limit, 0);
 
     *len = sizeof(*id);
     return CXL_MBOX_SUCCESS;
@@ -384,6 +390,88 @@  static CXLRetCode cmd_ccls_set_lsa(struct cxl_cmd *cmd,
     return CXL_MBOX_SUCCESS;
 }
 
+/*
+ * This is very inefficient, but good enough for now!
+ * Also the payload will always fit, so no need to handle the MORE flag and
+ * make this stateful. We may want to allow longer poison lists to aid
+ * testing that kernel functionality.
+ */
+static CXLRetCode 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);
+    uint16_t record_count = 0, i = 0;
+    uint64_t query_start, query_length;
+    CXLPoisonList *poison_list = &ct3d->poison_list;
+    CXLPoison *ent;
+    uint16_t out_pl_len;
+
+    query_start = ldq_le_p(&in->pa);
+    /* 64 byte alignemnt required */
+    if (query_start & 0x3f) {
+        return CXL_MBOX_INVALID_INPUT;
+    }
+    query_length = ldq_le_p(&in->length) * CXL_CACHE_LINE_SIZE;
+
+    QLIST_FOREACH(ent, poison_list, node) {
+        /* Check for no overlap */
+        if (ent->start >= query_start + query_length ||
+            ent->start + ent->length <= query_start) {
+            continue;
+        }
+        record_count++;
+    }
+    out_pl_len = sizeof(*out) + record_count * sizeof(out->records[0]);
+    assert(out_pl_len <= CXL_MAILBOX_MAX_PAYLOAD_SIZE);
+
+    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;
+        }
+
+        /* Deal with overlap */
+        start = MAX(ROUND_DOWN(ent->start, 64ull), query_start);
+        stop = MIN(ROUND_DOWN(ent->start, 64ull) + ent->length,
+                   query_start + query_length);
+        stq_le_p(&out->records[i].addr, start | (ent->type & 0x7));
+        stl_le_p(&out->records[i].length, (stop - start) / CXL_CACHE_LINE_SIZE);
+        i++;
+    }
+    if (ct3d->poison_list_overflowed) {
+        out->flags = (1 << 1);
+        stq_le_p(&out->overflow_timestamp, ct3d->poison_list_overflow_ts);
+    }
+    stw_le_p(&out->count, record_count);
+    *len = out_pl_len;
+    return CXL_MBOX_SUCCESS;
+}
+
 #define IMMEDIATE_CONFIG_CHANGE (1 << 1)
 #define IMMEDIATE_DATA_CHANGE (1 << 2)
 #define IMMEDIATE_POLICY_CHANGE (1 << 3)
@@ -411,6 +499,8 @@  static struct cxl_cmd cxl_cmd_set[256][256] = {
     [CCLS][GET_LSA] = { "CCLS_GET_LSA", cmd_ccls_get_lsa, 8, 0 },
     [CCLS][SET_LSA] = { "CCLS_SET_LSA", cmd_ccls_set_lsa,
         ~0, IMMEDIATE_CONFIG_CHANGE | IMMEDIATE_DATA_CHANGE },
+    [MEDIA_AND_POISON][GET_POISON_LIST] = { "MEDIA_AND_POISON_GET_POISON_LIST",
+        cmd_media_get_poison_list, 16, 0 },
 };
 
 void cxl_process_mailbox(CXLDeviceState *cxl_dstate)
diff --git a/hw/mem/cxl_type3.c b/hw/mem/cxl_type3.c
index 2adacbd01b..ab600735eb 100644
--- a/hw/mem/cxl_type3.c
+++ b/hw/mem/cxl_type3.c
@@ -947,6 +947,62 @@  static void set_lsa(CXLType3Dev *ct3d, const void *buf, uint64_t size,
      */
 }
 
+void cxl_set_poison_list_overflowed(CXLType3Dev *ct3d)
+{
+        ct3d->poison_list_overflowed = true;
+        ct3d->poison_list_overflow_ts =
+            cxl_device_get_timestamp(&ct3d->cxl_dstate);
+}
+
+void qmp_cxl_inject_poison(const char *path, uint64_t start, uint64_t length,
+                           Error **errp)
+{
+    Object *obj = object_resolve_path(path, NULL);
+    CXLType3Dev *ct3d;
+    CXLPoison *p;
+
+    if (length % 64) {
+        error_setg(errp, "Poison injection must be in multiples of 64 bytes");
+        return;
+    }
+    if (start % 64) {
+        error_setg(errp, "Poison start address must be 64 byte aligned");
+        return;
+    }
+    if (!obj) {
+        error_setg(errp, "Unable to resolve path");
+        return;
+    }
+    if (!object_dynamic_cast(obj, TYPE_CXL_TYPE3)) {
+        error_setg(errp, "Path does not point to a CXL type 3 device");
+        return;
+    }
+
+    ct3d = CXL_TYPE3(obj);
+
+    QLIST_FOREACH(p, &ct3d->poison_list, node) {
+        if (((start >= p->start) && (start < p->start + p->length)) ||
+            ((start + length > p->start) &&
+             (start + length <= p->start + p->length))) {
+            error_setg(errp, "Overlap with existing poisoned region not supported");
+            return;
+        }
+    }
+
+    if (ct3d->poison_list_cnt == CXL_POISON_LIST_LIMIT) {
+        cxl_set_poison_list_overflowed(ct3d);
+        return;
+    }
+
+    p = g_new0(CXLPoison, 1);
+    p->length = length;
+    p->start = start;
+    p->type = CXL_POISON_TYPE_INTERNAL; /* Different from injected via the mbox */
+
+    QLIST_INSERT_HEAD(&ct3d->poison_list, p, node);
+    ct3d->poison_list_cnt++;
+}
+
 /* For uncorrectable errors include support for multiple header recording */
 void qmp_cxl_inject_uncorrectable_errors(const char *path,
                                          CXLUncorErrorRecordList *errors,
diff --git a/hw/mem/cxl_type3_stubs.c b/hw/mem/cxl_type3_stubs.c
index d574c58f9a..fd1166a610 100644
--- a/hw/mem/cxl_type3_stubs.c
+++ b/hw/mem/cxl_type3_stubs.c
@@ -3,6 +3,12 @@ 
 #include "qapi/error.h"
 #include "qapi/qapi-commands-cxl.h"
 
+void qmp_cxl_inject_poison(const char *path, uint64_t start, uint64_t length,
+                           Error **errp)
+{
+    error_setg(errp, "CXL Type 3 support is not compiled in");
+}
+
 void qmp_cxl_inject_uncorrectable_errors(const char *path,
                                          CXLUncorErrorRecordList *errors,
                                          Error **errp)
diff --git a/include/hw/cxl/cxl.h b/include/hw/cxl/cxl.h
index c453983e83..56c9e7676e 100644
--- a/include/hw/cxl/cxl.h
+++ b/include/hw/cxl/cxl.h
@@ -18,6 +18,7 @@ 
 #include "cxl_component.h"
 #include "cxl_device.h"
 
+#define CXL_CACHE_LINE_SIZE 64
 #define CXL_COMPONENT_REG_BAR_IDX 0
 #define CXL_DEVICE_REG_BAR_IDX 2
 
diff --git a/include/hw/cxl/cxl_device.h b/include/hw/cxl/cxl_device.h
index 02befda0f6..32c234ea91 100644
--- a/include/hw/cxl/cxl_device.h
+++ b/include/hw/cxl/cxl_device.h
@@ -242,6 +242,18 @@  typedef struct CXLError {
 
 typedef QTAILQ_HEAD(, CXLError) CXLErrorList;
 
+typedef struct CXLPoison {
+    uint64_t start, length;
+    uint8_t type;
+#define CXL_POISON_TYPE_EXTERNAL 0x1
+#define CXL_POISON_TYPE_INTERNAL 0x2
+#define CXL_POISON_TYPE_INJECTED 0x3
+    QLIST_ENTRY(CXLPoison) node;
+} CXLPoison;
+
+typedef QLIST_HEAD(, CXLPoison) CXLPoisonList;
+#define CXL_POISON_LIST_LIMIT 256
+
 struct CXLType3Dev {
     /* Private */
     PCIDevice parent_obj;
@@ -264,6 +276,12 @@  struct CXLType3Dev {
 
     /* Error injection */
     CXLErrorList error_list;
+
+    /* Poison Injection - cache */
+    CXLPoisonList poison_list;
+    unsigned int poison_list_cnt;
+    bool poison_list_overflowed;
+    uint64_t poison_list_overflow_ts;
 };
 
 #define TYPE_CXL_TYPE3 "cxl-type3"
@@ -289,4 +307,6 @@  MemTxResult cxl_type3_write(PCIDevice *d, hwaddr host_addr, uint64_t data,
 
 uint64_t cxl_device_get_timestamp(CXLDeviceState *cxlds);
 
+void cxl_set_poison_list_overflowed(CXLType3Dev *ct3d);
+
 #endif
diff --git a/qapi/cxl.json b/qapi/cxl.json
index b21c9b4c1c..dcf9e7b715 100644
--- a/qapi/cxl.json
+++ b/qapi/cxl.json
@@ -5,6 +5,24 @@ 
 # = CXL devices
 ##
 
+##
+# @cxl-inject-poison:
+#
+# Poison records indicate that a CXL memory device knows that a particular
+# memory region may be corrupted. This may be because of locally detected
+# errors (e.g. ECC failure) or poisoned writes received from other components
+# in the system. This injection mechanism enables testing of the OS handling
+# of poison records which may be queried via the CXL mailbox.
+#
+# @path: CXL type 3 device canonical QOM path
+# @start: Start address - must be 64 byte aligned.
+# @length: Length of poison to inject - must be a multiple of 64 bytes.
+#
+# Since: 8.1
+##
+{ 'command': 'cxl-inject-poison',
+  'data': { 'path': 'str', 'start': 'uint64', 'length': 'uint64' }}
+
 ##
 # @CxlUncorErrorType:
 #