On Fri, 19 May 2023 15:18:01 +0100 Jonathan Cameron <jonathan.came...@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.schofi...@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...@samsung.com> > Reviewed-by: Ira Weiny <ira.we...@intel.com> > Signed-off-by: Jonathan Cameron <jonathan.came...@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: > #
