[PATCH v8 0/4] hw/cxl: Poison get, inject, clear

[PATCH v8 0/4] hw/cxl: Poison get, inject, clear

[Jonathan Cameron via]

v8: Formatting fixes for QMP docs from Markus Armbruster (thanks!)

The bswap naming discussions seems to have died down, so I'll stick
with this version (24)

Precursors now all upstream which make this email easier to write :)

The kernel support for Poison handling is now upstream.

This code has been very useful for testing and helped identify various
corner cases.

Updated cover letter.

The series supports:
1) Injection of variable length poison regions via QMP (to fake real
   memory corruption and ensure we deal with odd overflow corner cases
   such as clearing the middle of a large region making the list overflow
   as we go from one long entry to two smaller entries.
2) Read of poison list via the CXL mailbox.
3) Injection via the poison injection mailbox command (limited to 64 byte
   entries - spec constraint)
4) Clearing of poison injected via either method.

The implementation is meant to be a valid combination of impdef choices
based on what the spec allowed. There are a number of places where it could
be made more sophisticated that we might consider in future:
* Fusing adjacent poison entries if the types match.
* Separate injection list and main poison list, to test out limits on
  injected poison list being smaller than the main list.
* Poison list overflow event (needs event log support in general)
* Connecting up to the poison list error record generation (rather complex
  and not needed for currently kernel handling testing).
* Triggering the synchronous and asynchronous errors that occur on reads
  and writes of the memory when the host receives poison.

As the kernel code is currently fairly simple, it is likely that the above
does not yet matter but who knows what will turn up in future!

Ira Weiny (1):
  bswap: Add the ability to store to an unaligned 24 bit field

Jonathan Cameron (3):
  hw/cxl: QMP based poison injection support
  hw/cxl: Add poison injection via the mailbox.
  hw/cxl: Add clear poison mailbox command support.

 docs/devel/loads-stores.rst |   2 +
 qapi/cxl.json               |  21 ++++
 include/hw/cxl/cxl.h        |   1 +
 include/hw/cxl/cxl_device.h |  21 ++++
 include/qemu/bswap.h        |  25 +++++
 hw/cxl/cxl-mailbox-utils.c  | 214 ++++++++++++++++++++++++++++++++++++
 hw/mem/cxl_type3.c          |  93 ++++++++++++++++
 hw/mem/cxl_type3_stubs.c    |   6 +
 8 files changed, 383 insertions(+)

-- 
2.39.2

[PATCH v8 1/4] bswap: Add the ability to store to an unaligned 24 bit field

[Jonathan Cameron via]

From: Ira Weiny <ira.weiny@intel.com>

CXL has 24 bit unaligned fields which need to be stored to.  CXL is
specified as little endian.

Define st24_le_p() and the supporting functions to store such a field
from a 32 bit host native value.

The use of b, w, l, q as the size specifier is limiting.  So "24" was
used for the size part of the function name.

Reviewed-by: Fan Ni <fan.ni@samsung.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
 docs/devel/loads-stores.rst |  2 ++
 include/qemu/bswap.h        | 25 +++++++++++++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/docs/devel/loads-stores.rst b/docs/devel/loads-stores.rst
index d2cefc77a2..dab6dfa0ac 100644
--- a/docs/devel/loads-stores.rst
+++ b/docs/devel/loads-stores.rst
@@ -36,6 +36,7 @@ store: ``st{size}_{endian}_p(ptr, val)``
 ``size``
  - ``b`` : 8 bits
  - ``w`` : 16 bits
+ - ``24`` : 24 bits
  - ``l`` : 32 bits
  - ``q`` : 64 bits
 
@@ -65,6 +66,7 @@ of size ``sz`` bytes.
 Regexes for git grep
  - ``\<ld[us]\?[bwlq]\(_[hbl]e\)\?_p\>``
  - ``\<st[bwlq]\(_[hbl]e\)\?_p\>``
+ - ``\<st24\(_[hbl]e\)\?_p\>``
  - ``\<ldn_\([hbl]e\)?_p\>``
  - ``\<stn_\([hbl]e\)?_p\>``
 
diff --git a/include/qemu/bswap.h b/include/qemu/bswap.h
index 15a78c0db5..933a66ee87 100644
--- a/include/qemu/bswap.h
+++ b/include/qemu/bswap.h
@@ -8,11 +8,23 @@
 #undef  bswap64
 #define bswap64(_x) __builtin_bswap64(_x)
 
+static inline uint32_t bswap24(uint32_t x)
+{
+    return (((x & 0x000000ffU) << 16) |
+            ((x & 0x0000ff00U) <<  0) |
+            ((x & 0x00ff0000U) >> 16));
+}
+
 static inline void bswap16s(uint16_t *s)
 {
     *s = __builtin_bswap16(*s);
 }
 
+static inline void bswap24s(uint32_t *s)
+{
+    *s = bswap24(*s & 0x00ffffffU);
+}
+
 static inline void bswap32s(uint32_t *s)
 {
     *s = __builtin_bswap32(*s);
@@ -26,11 +38,13 @@ static inline void bswap64s(uint64_t *s)
 #if HOST_BIG_ENDIAN
 #define be_bswap(v, size) (v)
 #define le_bswap(v, size) glue(__builtin_bswap, size)(v)
+#define le_bswap24(v) bswap24(v)
 #define be_bswaps(v, size)
 #define le_bswaps(p, size) \
             do { *p = glue(__builtin_bswap, size)(*p); } while (0)
 #else
 #define le_bswap(v, size) (v)
+#define le_bswap24(v) (v)
 #define be_bswap(v, size) glue(__builtin_bswap, size)(v)
 #define le_bswaps(v, size)
 #define be_bswaps(p, size) \
@@ -176,6 +190,7 @@ CPU_CONVERT(le, 64, uint64_t)
  * size is:
  *   b: 8 bits
  *   w: 16 bits
+ *   24: 24 bits
  *   l: 32 bits
  *   q: 64 bits
  *
@@ -248,6 +263,11 @@ static inline void stw_he_p(void *ptr, uint16_t v)
     __builtin_memcpy(ptr, &v, sizeof(v));
 }
 
+static inline void st24_he_p(void *ptr, uint32_t v)
+{
+    __builtin_memcpy(ptr, &v, 3);
+}
+
 static inline int ldl_he_p(const void *ptr)
 {
     int32_t r;
@@ -297,6 +317,11 @@ static inline void stw_le_p(void *ptr, uint16_t v)
     stw_he_p(ptr, le_bswap(v, 16));
 }
 
+static inline void st24_le_p(void *ptr, uint32_t v)
+{
+    st24_he_p(ptr, le_bswap24(v));
+}
+
 static inline void stl_le_p(void *ptr, uint32_t v)
 {
     stl_he_p(ptr, le_bswap(v, 32));
-- 
2.39.2

Re: [PATCH v8 1/4] bswap: Add the ability to store to an unaligned 24 bit field

[Philippe Mathieu-Daudé]

Hi Ira & Jonathan,

On 26/5/23 19:00, Jonathan Cameron wrote:
> From: Ira Weiny <ira.weiny@intel.com>
> 
> CXL has 24 bit unaligned fields which need to be stored to.  CXL is
> specified as little endian.
> 
> Define st24_le_p() and the supporting functions to store such a field
> from a 32 bit host native value.
> 
> The use of b, w, l, q as the size specifier is limiting.  So "24" was
> used for the size part of the function name.
> 
> Reviewed-by: Fan Ni <fan.ni@samsung.com>
> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> Signed-off-by: Ira Weiny <ira.weiny@intel.com>
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> ---
>   docs/devel/loads-stores.rst |  2 ++
>   include/qemu/bswap.h        | 25 +++++++++++++++++++++++++
>   2 files changed, 27 insertions(+)
> 
> diff --git a/docs/devel/loads-stores.rst b/docs/devel/loads-stores.rst
> index d2cefc77a2..dab6dfa0ac 100644
> --- a/docs/devel/loads-stores.rst
> +++ b/docs/devel/loads-stores.rst
> @@ -36,6 +36,7 @@ store: ``st{size}_{endian}_p(ptr, val)``
>   ``size``
>    - ``b`` : 8 bits
>    - ``w`` : 16 bits
> + - ``24`` : 24 bits
>    - ``l`` : 32 bits
>    - ``q`` : 64 bits
>   
> @@ -65,6 +66,7 @@ of size ``sz`` bytes.
>   Regexes for git grep
>    - ``\<ld[us]\?[bwlq]\(_[hbl]e\)\?_p\>``
>    - ``\<st[bwlq]\(_[hbl]e\)\?_p\>``
> + - ``\<st24\(_[hbl]e\)\?_p\>``

Interestingly this regexp mentions st24_be_p() but this patch
only adds st24_le_p() and st24_he_p().

No need to update the regexp, I'll post a patch with st24_be_p()
since I have use for it.

>    - ``\<ldn_\([hbl]e\)?_p\>``
>    - ``\<stn_\([hbl]e\)?_p\>``
>   
> diff --git a/include/qemu/bswap.h b/include/qemu/bswap.h
> index 15a78c0db5..933a66ee87 100644
> --- a/include/qemu/bswap.h
> +++ b/include/qemu/bswap.h
> @@ -8,11 +8,23 @@
>   #undef  bswap64
>   #define bswap64(_x) __builtin_bswap64(_x)
>   
> +static inline uint32_t bswap24(uint32_t x)
> +{
> +    return (((x & 0x000000ffU) << 16) |
> +            ((x & 0x0000ff00U) <<  0) |
> +            ((x & 0x00ff0000U) >> 16));
> +}
> +
>   static inline void bswap16s(uint16_t *s)
>   {
>       *s = __builtin_bswap16(*s);
>   }
>   
> +static inline void bswap24s(uint32_t *s)
> +{
> +    *s = bswap24(*s & 0x00ffffffU);
> +}
> +
>   static inline void bswap32s(uint32_t *s)
>   {
>       *s = __builtin_bswap32(*s);
> @@ -26,11 +38,13 @@ static inline void bswap64s(uint64_t *s)
>   #if HOST_BIG_ENDIAN
>   #define be_bswap(v, size) (v)
>   #define le_bswap(v, size) glue(__builtin_bswap, size)(v)
> +#define le_bswap24(v) bswap24(v)
>   #define be_bswaps(v, size)
>   #define le_bswaps(p, size) \
>               do { *p = glue(__builtin_bswap, size)(*p); } while (0)
>   #else
>   #define le_bswap(v, size) (v)
> +#define le_bswap24(v) (v)
>   #define be_bswap(v, size) glue(__builtin_bswap, size)(v)
>   #define le_bswaps(v, size)
>   #define be_bswaps(p, size) \
> @@ -176,6 +190,7 @@ CPU_CONVERT(le, 64, uint64_t)
>    * size is:
>    *   b: 8 bits
>    *   w: 16 bits
> + *   24: 24 bits
>    *   l: 32 bits
>    *   q: 64 bits
>    *
> @@ -248,6 +263,11 @@ static inline void stw_he_p(void *ptr, uint16_t v)
>       __builtin_memcpy(ptr, &v, sizeof(v));
>   }
>   
> +static inline void st24_he_p(void *ptr, uint32_t v)
> +{
> +    __builtin_memcpy(ptr, &v, 3);
> +}
> +
>   static inline int ldl_he_p(const void *ptr)
>   {
>       int32_t r;
> @@ -297,6 +317,11 @@ static inline void stw_le_p(void *ptr, uint16_t v)
>       stw_he_p(ptr, le_bswap(v, 16));
>   }
>   
> +static inline void st24_le_p(void *ptr, uint32_t v)
> +{
> +    st24_he_p(ptr, le_bswap24(v));
> +}
> +
>   static inline void stl_le_p(void *ptr, uint32_t v)
>   {
>       stl_he_p(ptr, le_bswap(v, 32));

[PATCH v8 2/4] hw/cxl: QMP based poison injection support

[Jonathan Cameron via]

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>
Acked-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
 qapi/cxl.json               | 21 +++++++++
 include/hw/cxl/cxl.h        |  1 +
 include/hw/cxl/cxl_device.h | 20 +++++++++
 hw/cxl/cxl-mailbox-utils.c  | 90 +++++++++++++++++++++++++++++++++++++
 hw/mem/cxl_type3.c          | 56 +++++++++++++++++++++++
 hw/mem/cxl_type3_stubs.c    |  6 +++
 6 files changed, 194 insertions(+)

diff --git a/qapi/cxl.json b/qapi/cxl.json
index b21c9b4c1c..ed1c7eea3a 100644
--- a/qapi/cxl.json
+++ b/qapi/cxl.json
@@ -5,6 +5,27 @@
 # = 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': 'size' }}
+
 ##
 # @CxlUncorErrorType:
 #
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/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)
-- 
2.39.2

[PATCH v8 3/4] hw/cxl: Add poison injection via the mailbox.

[Jonathan Cameron via]

Very simple implementation to allow testing of corresponding
kernel code. Note that for now we track each 64 byte section
independently.  Whilst a valid implementation choice, it may
make sense to fuse entries so as to prove out more complex
corners of the kernel code.

Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Fan Ni <fan.ni@samsung.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
 hw/cxl/cxl-mailbox-utils.c | 42 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
index 1f74b26ea2..6c476ad7f4 100644
--- a/hw/cxl/cxl-mailbox-utils.c
+++ b/hw/cxl/cxl-mailbox-utils.c
@@ -64,6 +64,7 @@ enum {
         #define SET_LSA       0x3
     MEDIA_AND_POISON = 0x43,
         #define GET_POISON_LIST        0x0
+        #define INJECT_POISON          0x1
 };
 
 /* 8.2.8.4.5.1 Command Return Codes */
@@ -472,6 +473,45 @@ static CXLRetCode cmd_media_get_poison_list(struct cxl_cmd *cmd,
     return CXL_MBOX_SUCCESS;
 }
 
+static CXLRetCode cmd_media_inject_poison(struct cxl_cmd *cmd,
+                                          CXLDeviceState *cxl_dstate,
+                                          uint16_t *len_unused)
+{
+    CXLType3Dev *ct3d = container_of(cxl_dstate, CXLType3Dev, cxl_dstate);
+    CXLPoisonList *poison_list = &ct3d->poison_list;
+    CXLPoison *ent;
+    struct inject_poison_pl {
+        uint64_t dpa;
+    };
+    struct inject_poison_pl *in = (void *)cmd->payload;
+    uint64_t dpa = ldq_le_p(&in->dpa);
+    CXLPoison *p;
+
+    QLIST_FOREACH(ent, poison_list, node) {
+        if (dpa >= ent->start &&
+            dpa + CXL_CACHE_LINE_SIZE <= ent->start + ent->length) {
+            return CXL_MBOX_SUCCESS;
+        }
+    }
+
+    if (ct3d->poison_list_cnt == CXL_POISON_LIST_LIMIT) {
+        return CXL_MBOX_INJECT_POISON_LIMIT;
+    }
+    p = g_new0(CXLPoison, 1);
+
+    p->length = CXL_CACHE_LINE_SIZE;
+    p->start = dpa;
+    p->type = CXL_POISON_TYPE_INJECTED;
+
+    /*
+     * Possible todo: Merge with existing entry if next to it and if same type
+     */
+    QLIST_INSERT_HEAD(poison_list, p, node);
+    ct3d->poison_list_cnt++;
+
+    return CXL_MBOX_SUCCESS;
+}
+
 #define IMMEDIATE_CONFIG_CHANGE (1 << 1)
 #define IMMEDIATE_DATA_CHANGE (1 << 2)
 #define IMMEDIATE_POLICY_CHANGE (1 << 3)
@@ -501,6 +541,8 @@ static struct cxl_cmd cxl_cmd_set[256][256] = {
         ~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 },
+    [MEDIA_AND_POISON][INJECT_POISON] = { "MEDIA_AND_POISON_INJECT_POISON",
+        cmd_media_inject_poison, 8, 0 },
 };
 
 void cxl_process_mailbox(CXLDeviceState *cxl_dstate)
-- 
2.39.2

[PATCH v8 4/4] hw/cxl: Add clear poison mailbox command support.

[Jonathan Cameron via]

Current implementation is very simple so many of the corner
cases do not exist (e.g. fragmenting larger poison list entries)

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>
---
 include/hw/cxl/cxl_device.h |  1 +
 hw/cxl/cxl-mailbox-utils.c  | 82 +++++++++++++++++++++++++++++++++++++
 hw/mem/cxl_type3.c          | 37 +++++++++++++++++
 3 files changed, 120 insertions(+)

diff --git a/include/hw/cxl/cxl_device.h b/include/hw/cxl/cxl_device.h
index 32c234ea91..73328a52cf 100644
--- a/include/hw/cxl/cxl_device.h
+++ b/include/hw/cxl/cxl_device.h
@@ -298,6 +298,7 @@ struct CXLType3Class {
                         uint64_t offset);
     void (*set_lsa)(CXLType3Dev *ct3d, const void *buf, uint64_t size,
                     uint64_t offset);
+    bool (*set_cacheline)(CXLType3Dev *ct3d, uint64_t dpa_offset, uint8_t *data);
 };
 
 MemTxResult cxl_type3_read(PCIDevice *d, hwaddr host_addr, uint64_t *data,
diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
index 6c476ad7f4..e3401b6be8 100644
--- a/hw/cxl/cxl-mailbox-utils.c
+++ b/hw/cxl/cxl-mailbox-utils.c
@@ -65,6 +65,7 @@ enum {
     MEDIA_AND_POISON = 0x43,
         #define GET_POISON_LIST        0x0
         #define INJECT_POISON          0x1
+        #define CLEAR_POISON           0x2
 };
 
 /* 8.2.8.4.5.1 Command Return Codes */
@@ -512,6 +513,85 @@ static CXLRetCode cmd_media_inject_poison(struct cxl_cmd *cmd,
     return CXL_MBOX_SUCCESS;
 }
 
+static CXLRetCode cmd_media_clear_poison(struct cxl_cmd *cmd,
+                                         CXLDeviceState *cxl_dstate,
+                                         uint16_t *len_unused)
+{
+    CXLType3Dev *ct3d = container_of(cxl_dstate, CXLType3Dev, cxl_dstate);
+    CXLPoisonList *poison_list = &ct3d->poison_list;
+    CXLType3Class *cvc = CXL_TYPE3_GET_CLASS(ct3d);
+    struct clear_poison_pl {
+        uint64_t dpa;
+        uint8_t data[64];
+    };
+    CXLPoison *ent;
+    uint64_t dpa;
+
+    struct clear_poison_pl *in = (void *)cmd->payload;
+
+    dpa = ldq_le_p(&in->dpa);
+    if (dpa + CXL_CACHE_LINE_SIZE > cxl_dstate->mem_size) {
+        return CXL_MBOX_INVALID_PA;
+    }
+
+    /* Clearing a region with no poison is not an error so always do so */
+    if (cvc->set_cacheline) {
+        if (!cvc->set_cacheline(ct3d, dpa, in->data)) {
+            return CXL_MBOX_INTERNAL_ERROR;
+        }
+    }
+
+    QLIST_FOREACH(ent, poison_list, node) {
+        /*
+         * Test for contained in entry. Simpler than general case
+         * as clearing 64 bytes and entries 64 byte aligned
+         */
+        if ((dpa >= ent->start) && (dpa < ent->start + ent->length)) {
+            break;
+        }
+    }
+    if (!ent) {
+        return CXL_MBOX_SUCCESS;
+    }
+
+    QLIST_REMOVE(ent, node);
+    ct3d->poison_list_cnt--;
+
+    if (dpa > ent->start) {
+        CXLPoison *frag;
+        /* Cannot overflow as replacing existing entry */
+
+        frag = g_new0(CXLPoison, 1);
+
+        frag->start = ent->start;
+        frag->length = dpa - ent->start;
+        frag->type = ent->type;
+
+        QLIST_INSERT_HEAD(poison_list, frag, node);
+        ct3d->poison_list_cnt++;
+    }
+
+    if (dpa + CXL_CACHE_LINE_SIZE < ent->start + ent->length) {
+        CXLPoison *frag;
+
+        if (ct3d->poison_list_cnt == CXL_POISON_LIST_LIMIT) {
+            cxl_set_poison_list_overflowed(ct3d);
+        } else {
+            frag = g_new0(CXLPoison, 1);
+
+            frag->start = dpa + CXL_CACHE_LINE_SIZE;
+            frag->length = ent->start + ent->length - frag->start;
+            frag->type = ent->type;
+            QLIST_INSERT_HEAD(poison_list, frag, node);
+            ct3d->poison_list_cnt++;
+        }
+    }
+    /* Any fragments have been added, free original entry */
+    g_free(ent);
+
+    return CXL_MBOX_SUCCESS;
+}
+
 #define IMMEDIATE_CONFIG_CHANGE (1 << 1)
 #define IMMEDIATE_DATA_CHANGE (1 << 2)
 #define IMMEDIATE_POLICY_CHANGE (1 << 3)
@@ -543,6 +623,8 @@ static struct cxl_cmd cxl_cmd_set[256][256] = {
         cmd_media_get_poison_list, 16, 0 },
     [MEDIA_AND_POISON][INJECT_POISON] = { "MEDIA_AND_POISON_INJECT_POISON",
         cmd_media_inject_poison, 8, 0 },
+    [MEDIA_AND_POISON][CLEAR_POISON] = { "MEDIA_AND_POISON_CLEAR_POISON",
+        cmd_media_clear_poison, 72, 0 },
 };
 
 void cxl_process_mailbox(CXLDeviceState *cxl_dstate)
diff --git a/hw/mem/cxl_type3.c b/hw/mem/cxl_type3.c
index ab600735eb..d751803188 100644
--- a/hw/mem/cxl_type3.c
+++ b/hw/mem/cxl_type3.c
@@ -947,6 +947,42 @@ static void set_lsa(CXLType3Dev *ct3d, const void *buf, uint64_t size,
      */
 }
 
+static bool set_cacheline(CXLType3Dev *ct3d, uint64_t dpa_offset, uint8_t *data)
+{
+    MemoryRegion *vmr = NULL, *pmr = NULL;
+    AddressSpace *as;
+
+    if (ct3d->hostvmem) {
+        vmr = host_memory_backend_get_memory(ct3d->hostvmem);
+    }
+    if (ct3d->hostpmem) {
+        pmr = host_memory_backend_get_memory(ct3d->hostpmem);
+    }
+
+    if (!vmr && !pmr) {
+        return false;
+    }
+
+    if (dpa_offset + CXL_CACHE_LINE_SIZE > ct3d->cxl_dstate.mem_size) {
+        return false;
+    }
+
+    if (vmr) {
+        if (dpa_offset < memory_region_size(vmr)) {
+            as = &ct3d->hostvmem_as;
+        } else {
+            as = &ct3d->hostpmem_as;
+            dpa_offset -= memory_region_size(vmr);
+        }
+    } else {
+        as = &ct3d->hostpmem_as;
+    }
+
+    address_space_write(as, dpa_offset, MEMTXATTRS_UNSPECIFIED, &data,
+                        CXL_CACHE_LINE_SIZE);
+    return true;
+}
+
 void cxl_set_poison_list_overflowed(CXLType3Dev *ct3d)
 {
         ct3d->poison_list_overflowed = true;
@@ -1168,6 +1204,7 @@ static void ct3_class_init(ObjectClass *oc, void *data)
     cvc->get_lsa_size = get_lsa_size;
     cvc->get_lsa = get_lsa;
     cvc->set_lsa = set_lsa;
+    cvc->set_cacheline = set_cacheline;
 }
 
 static const TypeInfo ct3d_info = {
-- 
2.39.2

Re: [PATCH v8 0/4] hw/cxl: Poison get, inject, clear

[Michael S. Tsirkin]

On Fri, May 26, 2023 at 06:00:06PM +0100, Jonathan Cameron wrote:
> v8: Formatting fixes for QMP docs from Markus Armbruster (thanks!)

This and other patches add a bunch of over-80 chars lines.  I'm not
going to intervene here as cxl has lots of them but maybe scan over cxl
codebase and shorten where appropriate.
Thanks!

-- 
MST

Re: [PATCH v8 0/4] hw/cxl: Poison get, inject, clear

[Jonathan Cameron via]

On Fri, 23 Jun 2023 02:59:44 -0400
"Michael S. Tsirkin" <mst@redhat.com> wrote:

> On Fri, May 26, 2023 at 06:00:06PM +0100, Jonathan Cameron wrote:
> > v8: Formatting fixes for QMP docs from Markus Armbruster (thanks!)  
> 
> This and other patches add a bunch of over-80 chars lines.  I'm not
> going to intervene here as cxl has lots of them but maybe scan over cxl
> codebase and shorten where appropriate.
> Thanks!

Will add it to the todo list and will pay more attention to this for
future series.

Some annoyingly complex register names make it tricky but I'm sure we
can do better if not necessarily perfectly!

Jonathan

> 

Re: [PATCH v8 0/4] hw/cxl: Poison get, inject, clear

[Peter Maydell]

On Fri, 23 Jun 2023 at 13:07, Jonathan Cameron via
<qemu-devel@nongnu.org> wrote:
>
> On Fri, 23 Jun 2023 02:59:44 -0400
> "Michael S. Tsirkin" <mst@redhat.com> wrote:
>
> > On Fri, May 26, 2023 at 06:00:06PM +0100, Jonathan Cameron wrote:
> > > v8: Formatting fixes for QMP docs from Markus Armbruster (thanks!)
> >
> > This and other patches add a bunch of over-80 chars lines.  I'm not
> > going to intervene here as cxl has lots of them but maybe scan over cxl
> > codebase and shorten where appropriate.
> > Thanks!
>
> Will add it to the todo list and will pay more attention to this for
> future series.
>
> Some annoyingly complex register names make it tricky but I'm sure we
> can do better if not necessarily perfectly!

The coding style says:

# Lines should be 80 characters; try not to make them longer.
#
# Sometimes it is hard to do, especially when dealing with QEMU subsystems
# that use long function or symbol names. If wrapping the line at 80 columns
# is obviously less readable and more awkward, prefer not to wrap it; better
# to have an 85 character line than one which is awkwardly wrapped.
#
# Even in that case, try not to make lines much longer than 80 characters.

so if it would be obviously worse to wrap the line you can
make it longer than 80 chars.

-- PMM