| Message ID | cover.1705534719.git.alison.schofield@intel.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | Support poison list retrieval | expand |
alison.schofield@ wrote: > From: Alison Schofield <alison.schofield@intel.com> > > Changes since v5: > - Use a private parser for cxl_poison events. (Dan) > Previously used the default parser and re-parsed per the cxl-list > needs. Replace that with a private parsing method for cxl_poison. > - Add a private context to support private parsers. > - Add helpers to use with the cxl_poison parser. > - cxl list json: drop nr_records field (Dan) > - cxl list option: replace "poison" w "media-errors" (Dan) > - cxl list json: replace "poison" w "media_errors" (Dan) > - Link to v5: https://lore.kernel.org/linux-cxl/cover.1700615159.git.alison.schofield@intel.com/ > > > Begin cover letter: > > Add the option to add a memory devices poison list to the cxl-list > json output. Offer the option by memdev and by region. Sample usage: > > # cxl list -m mem1 --media-errors > [ > { > "memdev":"mem1", > "pmem_size":1073741824, > "ram_size":1073741824, > "serial":1, > "numa_node":1, > "host":"cxl_mem.1", > "media_errors":[ > { > "dpa":0, > "dpa_length":64, > "source":"Injected" > }, > { > "region":"region5", It feels odd to list the region here. I feel like what really matters is to list the endpoint decoder and if someone wants to associate endpoint decoder to region, or endpoint decoder to memdev there are other queries for that. Then this format does not change between the "region" listing and "memdev" listing, they both just output the endpoint decoder and leave the rest to follow-on queries. For example I expect operations software has already recorded the endpoint decoder to region mapping, so when this data comes in the endpoint decoder is a key to make that association. Otherwise: cxl list -RT -e $endpoint_decoder ...can answer follow up questions about what is impacted by a given media error record. > "dpa":1073741824, > "dpa_length":64, The dpa_length is also the hpa_length, right? So maybe just call the field "length". > "hpa":1035355557888, > "source":"Injected" > }, > { > "region":"region5", > "dpa":1073745920, > "dpa_length":64, > "hpa":1035355566080, > "source":"Injected" This "source" field feels like debug data. In production nobody is going to be doing poison injection, and if the administrator injected it then its implied they know that status. Otherwise a media-error is a media-error regardless of the source. > } > ] > } > ] > > # cxl list -r region5 --media-errors > [ > { > "region":"region5", > "resource":1035355553792, > "size":2147483648, > "type":"pmem", > "interleave_ways":2, > "interleave_granularity":4096, > "decode_state":"commit", > "media_errors":[ > { > "memdev":"mem1", > "dpa":1073741824, > "dpa_length":64, > "hpa":1035355557888, > "source":"Injected" > }, > { > "memdev":"mem1", > "dpa":1073745920, > "dpa_length":64, > "hpa":1035355566080, > "source":"Injected" > } > ] > } > ] > > Alison Schofield (7): > libcxl: add interfaces for GET_POISON_LIST mailbox commands > cxl: add an optional pid check to event parsing > cxl/event_trace: add a private context for private parsers > cxl/event_trace: add helpers get_field_[string|data]() > cxl/list: collect and parse media_error records > cxl/list: add --media-errors option to cxl list > cxl/test: add cxl-poison.sh unit test > > Documentation/cxl/cxl-list.txt | 71 +++++++++++ > cxl/event_trace.c | 53 +++++++- > cxl/event_trace.h | 9 +- > cxl/filter.h | 3 + > cxl/json.c | 218 +++++++++++++++++++++++++++++++++ > cxl/lib/libcxl.c | 47 +++++++ > cxl/lib/libcxl.sym | 6 + > cxl/libcxl.h | 2 + > cxl/list.c | 2 + > test/cxl-poison.sh | 133 ++++++++++++++++++++ > test/meson.build | 2 + > 11 files changed, 543 insertions(+), 3 deletions(-) > create mode 100644 test/cxl-poison.sh > > > base-commit: a871e6153b11fe63780b37cdcb1eb347b296095c > -- > 2.37.3 > >
On Thu, Jan 18, 2024 at 01:56:51PM -0800, Dan Williams wrote: > alison.schofield@ wrote: > > From: Alison Schofield <alison.schofield@intel.com> > > > > Changes since v5: > > - Use a private parser for cxl_poison events. (Dan) > > Previously used the default parser and re-parsed per the cxl-list > > needs. Replace that with a private parsing method for cxl_poison. > > - Add a private context to support private parsers. > > - Add helpers to use with the cxl_poison parser. > > - cxl list json: drop nr_records field (Dan) > > - cxl list option: replace "poison" w "media-errors" (Dan) > > - cxl list json: replace "poison" w "media_errors" (Dan) > > - Link to v5: https://lore.kernel.org/linux-cxl/cover.1700615159.git.alison.schofield@intel.com/ > > > > > > Begin cover letter: > > > > Add the option to add a memory devices poison list to the cxl-list > > json output. Offer the option by memdev and by region. Sample usage: > > > > # cxl list -m mem1 --media-errors > > [ > > { > > "memdev":"mem1", > > "pmem_size":1073741824, > > "ram_size":1073741824, > > "serial":1, > > "numa_node":1, > > "host":"cxl_mem.1", > > "media_errors":[ > > { > > "dpa":0, > > "dpa_length":64, > > "source":"Injected" > > }, > > { > > "region":"region5", > > It feels odd to list the region here. I feel like what really matters is > to list the endpoint decoder and if someone wants to associate endpoint > decoder to region, or endpoint decoder to memdev there are other queries > for that. > > Then this format does not change between the "region" listing and > "memdev" listing, they both just output the endpoint decoder and leave > the rest to follow-on queries. > > For example I expect operations software has already recorded the > endpoint decoder to region mapping, so when this data comes in the > endpoint decoder is a key to make that association. Otherwise: > > cxl list -RT -e $endpoint_decoder > > ...can answer follow up questions about what is impacted by a given > media error record. I see it as a convenience offering, but I'm starting to see that your stance is probably that a cxl-list option should only list additional info provided by the option, and not include info that can be retrieved elsewhere w cxl-list. I plan to make this change to endpoint as you suggest. > > > "dpa":1073741824, > > "dpa_length":64, > > The dpa_length is also the hpa_length, right? So maybe just call the > field "length". > No, the length only refers to the device address space. I don't think the hpa is guaranteed to be contiguous, so only the starting hpa addr is offered. hmm..should we call it 'size' because that seems to imply less contiguous-ness than length? Which should it be 'dpa_length' or 'size' (or 'length') > > "hpa":1035355557888, > > "source":"Injected" > > }, > > { > > "region":"region5", > > "dpa":1073745920, > > "dpa_length":64, > > "hpa":1035355566080, > > "source":"Injected" > > This "source" field feels like debug data. In production nobody is going > to be doing poison injection, and if the administrator injected it then > its implied they know that status. Otherwise a media-error is a > media-error regardless of the source. From CXL Spec Tabel 8-140 Sources can be: Unknown. External. Poison received from a source external to the device. Internal. The device generated poison from an internal source. Injected. The error was injected into the device for testing purposes. Vendor Specific. On the v5 review, Erwin commented: >> This is how I would use source. >> "external" = don't expect to see a cxl media error, look elsewhere like a UCNA or a mem_data error in the RP's CXL.CM RAS. >> "internal" = expect to see a media error for more information. >> "injected" = somebody injected the error, no service action needed except to maybe tighten up your security. >> "vendor" = see vendor If it's not presented here, user can look it up in the cxl_poison trace event directly. I think we should keep this as is. > > > } > > ] > > } > > ] > > > > # cxl list -r region5 --media-errors > > [ > > { > > "region":"region5", > > "resource":1035355553792, > > "size":2147483648, > > "type":"pmem", > > "interleave_ways":2, > > "interleave_granularity":4096, > > "decode_state":"commit", > > "media_errors":[ > > { > > "memdev":"mem1", > > "dpa":1073741824, > > "dpa_length":64, > > "hpa":1035355557888, > > "source":"Injected" > > }, > > { > > "memdev":"mem1", > > "dpa":1073745920, > > "dpa_length":64, > > "hpa":1035355566080, > > "source":"Injected" > > } > > ] > > } > > ] > > > > Alison Schofield (7): > > libcxl: add interfaces for GET_POISON_LIST mailbox commands > > cxl: add an optional pid check to event parsing > > cxl/event_trace: add a private context for private parsers > > cxl/event_trace: add helpers get_field_[string|data]() > > cxl/list: collect and parse media_error records > > cxl/list: add --media-errors option to cxl list > > cxl/test: add cxl-poison.sh unit test > > > > Documentation/cxl/cxl-list.txt | 71 +++++++++++ > > cxl/event_trace.c | 53 +++++++- > > cxl/event_trace.h | 9 +- > > cxl/filter.h | 3 + > > cxl/json.c | 218 +++++++++++++++++++++++++++++++++ > > cxl/lib/libcxl.c | 47 +++++++ > > cxl/lib/libcxl.sym | 6 + > > cxl/libcxl.h | 2 + > > cxl/list.c | 2 + > > test/cxl-poison.sh | 133 ++++++++++++++++++++ > > test/meson.build | 2 + > > 11 files changed, 543 insertions(+), 3 deletions(-) > > create mode 100644 test/cxl-poison.sh > > > > > > base-commit: a871e6153b11fe63780b37cdcb1eb347b296095c > > -- > > 2.37.3 > > > > > >
Alison Schofield wrote: [..] > > > "dpa":1073741824, > > > "dpa_length":64, > > > > The dpa_length is also the hpa_length, right? So maybe just call the > > field "length". > > > > No, the length only refers to the device address space. I don't think > the hpa is guaranteed to be contiguous, so only the starting hpa addr > is offered. > > hmm..should we call it 'size' because that seems to imply less > contiguous-ness than length? The only way the length could be discontiguous in HPA space is if the error length is greater than the interleave granularity. Given poison is tracked in cachelines and the smallest granularity is 4 cachelines it is unlikely to hit the mutiple HPA case. However, I think the kernel side should aim to preclude that from happening. Given that this is relying on the kernel's translation I would make it so that the kernel never leaves the impacted HPAs as ambiguous. For example, if the interleave_granularity of the region is 256 and the DPA length is 512, it would be helpful if the *kernel* split that into multiple trace events to communicate the multiple impacted HPAs rather than leave it as an exercise to userspace. > Which should it be 'dpa_length' or 'size' (or 'length') I recall we used "length" for the number of badblocks in "ndctl list --media-errors", might as well keep in consistent. > > > "hpa":1035355557888, > > > "source":"Injected" > > > }, > > > { > > > "region":"region5", > > > "dpa":1073745920, > > > "dpa_length":64, > > > "hpa":1035355566080, > > > "source":"Injected" > > > > This "source" field feels like debug data. In production nobody is going > > to be doing poison injection, and if the administrator injected it then > > its implied they know that status. Otherwise a media-error is a > > media-error regardless of the source. > > From CXL Spec Tabel 8-140 Sources can be: > > Unknown. > External. Poison received from a source external to the device. > Internal. The device generated poison from an internal source. > Injected. The error was injected into the device for testing purposes. > Vendor Specific. > > On the v5 review, Erwin commented: > >> This is how I would use source. > >> "external" = don't expect to see a cxl media error, look elsewhere like a UCNA or a mem_data error in the RP's CXL.CM RAS. > >> "internal" = expect to see a media error for more information. > >> "injected" = somebody injected the error, no service action needed except to maybe tighten up your security. > >> "vendor" = see vendor > > If it's not presented here, user can look it up in the cxl_poison trace > event directly. > > I think we should keep this as is. Ah, I had forgotten Erwin's comment, yeah, showing "external" vs "internal" looks useful, "injected" gets to come along for the ride, and if any vendor actually ships that "vendor" status that's a good indication to the end user to go shopping for a device that plays better with open standards. Might be useful to capture Erwin's analysis of how to use that field in the man page, if it's not there already.
On Thu, Jan 18, 2024 at 03:55:00PM -0800, Dan Williams wrote: > Alison Schofield wrote: > [..] > > > > "dpa":1073741824, > > > > "dpa_length":64, > > > > > > The dpa_length is also the hpa_length, right? So maybe just call the > > > field "length". > > > > > > > No, the length only refers to the device address space. I don't think > > the hpa is guaranteed to be contiguous, so only the starting hpa addr > > is offered. > > > > hmm..should we call it 'size' because that seems to imply less > > contiguous-ness than length? > > The only way the length could be discontiguous in HPA space is if the > error length is greater than the interleave granularity. Given poison is > tracked in cachelines and the smallest granularity is 4 cachelines it is > unlikely to hit the mutiple HPA case. Hi Dan, Circling back to this issue, as I'm posting an udpated rev. I'm not getting how *only* an error length greater that IG can lead to discontigous HPA. If the poison starts on the last 64 bytes of an IG and has a length greater than 64 bytes, we go beyond the endpoints mapping, even if that length is less than IG. In the layout below, if the device underlying endpoint2 reports ^poison^ as shown, it is discontinguous in HPA space. HPA 0..........................................................N ep1 .......... .......... .......... ep2 .......... .......... .......... bad ^poison^ good ^po ison^ 'bad' is what happens today if length is applied to HPA 'good' is what is right Am I missing something wrt cachelines you mention? > > However, I think the kernel side should aim to preclude that from > happening. Given that this is relying on the kernel's translation I > would make it so that the kernel never leaves the impacted HPAs as > ambiguous. For example, if the interleave_granularity of the region is > 256 and the DPA length is 512, it would be helpful if the *kernel* split > that into multiple trace events to communicate the multiple impacted > HPAs rather than leave it as an exercise to userspace. > That's a familiar plan that we rejected in the driver implementation, As defined, a cxl_poison event reports a starting dpa, a dpa_length, and the starting hpa if the address is mapped. That left userspace to do the HPA translation work. We can move that work to the driver independent of this ndctl work. > > Might be useful to capture Erwin's analysis of how to use that field in > the man page, if it's not there already. The man page now has the definitions of the source field and a spec reference. I don't see the cxl list man page as the place to offer media-error trouble-shooting tips.
From: Alison Schofield <alison.schofield@intel.com> Changes since v5: - Use a private parser for cxl_poison events. (Dan) Previously used the default parser and re-parsed per the cxl-list needs. Replace that with a private parsing method for cxl_poison. - Add a private context to support private parsers. - Add helpers to use with the cxl_poison parser. - cxl list json: drop nr_records field (Dan) - cxl list option: replace "poison" w "media-errors" (Dan) - cxl list json: replace "poison" w "media_errors" (Dan) - Link to v5: https://lore.kernel.org/linux-cxl/cover.1700615159.git.alison.schofield@intel.com/ Begin cover letter: Add the option to add a memory devices poison list to the cxl-list json output. Offer the option by memdev and by region. Sample usage: # cxl list -m mem1 --media-errors [ { "memdev":"mem1", "pmem_size":1073741824, "ram_size":1073741824, "serial":1, "numa_node":1, "host":"cxl_mem.1", "media_errors":[ { "dpa":0, "dpa_length":64, "source":"Injected" }, { "region":"region5", "dpa":1073741824, "dpa_length":64, "hpa":1035355557888, "source":"Injected" }, { "region":"region5", "dpa":1073745920, "dpa_length":64, "hpa":1035355566080, "source":"Injected" } ] } ] # cxl list -r region5 --media-errors [ { "region":"region5", "resource":1035355553792, "size":2147483648, "type":"pmem", "interleave_ways":2, "interleave_granularity":4096, "decode_state":"commit", "media_errors":[ { "memdev":"mem1", "dpa":1073741824, "dpa_length":64, "hpa":1035355557888, "source":"Injected" }, { "memdev":"mem1", "dpa":1073745920, "dpa_length":64, "hpa":1035355566080, "source":"Injected" } ] } ] Alison Schofield (7): libcxl: add interfaces for GET_POISON_LIST mailbox commands cxl: add an optional pid check to event parsing cxl/event_trace: add a private context for private parsers cxl/event_trace: add helpers get_field_[string|data]() cxl/list: collect and parse media_error records cxl/list: add --media-errors option to cxl list cxl/test: add cxl-poison.sh unit test Documentation/cxl/cxl-list.txt | 71 +++++++++++ cxl/event_trace.c | 53 +++++++- cxl/event_trace.h | 9 +- cxl/filter.h | 3 + cxl/json.c | 218 +++++++++++++++++++++++++++++++++ cxl/lib/libcxl.c | 47 +++++++ cxl/lib/libcxl.sym | 6 + cxl/libcxl.h | 2 + cxl/list.c | 2 + test/cxl-poison.sh | 133 ++++++++++++++++++++ test/meson.build | 2 + 11 files changed, 543 insertions(+), 3 deletions(-) create mode 100644 test/cxl-poison.sh base-commit: a871e6153b11fe63780b37cdcb1eb347b296095c