kernel/drivers/s390/crypto/zcrypt_error.h, branch linux-6.9.y

s390/zcrypt: improve zcrypt retry behavior

2024-03-07T13:41:15Z

This patch reworks and improves the zcrypt retry behavior: - The zcrypt_rescan_req counter has been removed. This counter variable has been increased on some transport errors and was used as a gatekeeper for AP bus rescans. - Rework of the zcrypt_process_rescan() function to not use the above counter variable any more. Instead now always the ap_bus_force_rescan() function is called (as this has been improved with a previous patch). - As the zcrpyt_process_rescan() function is called in all cprb send functions in case of the first attempt to send failed with ENODEV now before the next attempt to send an cprb is started. - Introduce a define ZCRYPT_WAIT_BINDINGS_COMPLETE_MS for the amount of milliseconds to have the zcrypt API wait for AP bindings complete. This amount has been reduced to 30s (was 60s). Some playing around showed that 30s is a really fair limit. The result of the above together with the patches to improve the AP scan bus functions is that after the first loop of cprb send retries when the result is a ENODEV the AP bus scan is always triggered (synchronous). If the AP bus scan detects changes in the configuration, all the send functions now retry when the first attempt was failing with ENODEV in the hope that now a suitable device has appeared. About concurrency: The ap_bus_force_rescan() uses a mutex to ensure only one active AP bus scan is running. Another caller of this function is blocked as long as the scan is running but does not cause yet another scan. Instead the result of the 'other' scan is used. This affects only tasks which run into an initial ENODEV. Tasks with successful delivery of cprbs will never invoke the bus scan and thus never get blocked by the mutex. Signed-off-by: Harald Freudenberger Reviewed-by: Holger Dengler Signed-off-by: Heiko Carstens

s390/ap: show APFS value on error reply 0x8B

2023-10-16T11:04:09Z

With Secure Execution the error reply RX 0x8B now carries an APFS value indicating why the request has been filtered by a lower layer of the firmware. So display this value as a warning line in the s390 debug feature trace. Signed-off-by: Harald Freudenberger Reviewed-by: Holger Dengler Signed-off-by: Vasily Gorbik

s390/zcrypt: code cleanup

2022-04-25T11:54:14Z

This patch tries to fix as much as possible of the checkpatch.pl --strict findings: CHECK: Logical continuations should be on the previous line CHECK: No space is necessary after a cast CHECK: Alignment should match open parenthesis CHECK: 'useable' may be misspelled - perhaps 'usable'? WARNING: Possible repeated word: 'is' CHECK: spaces preferred around that '*' (ctx:VxV) CHECK: Comparison to NULL could be written "!msg" CHECK: Prefer kzalloc(sizeof(*zc)...) over kzalloc(sizeof(struct...)...) CHECK: Unnecessary parentheses around resp_type->work CHECK: Avoid CamelCase: There is no functional change comming with this patch, only code cleanup, renaming, whitespaces, indenting, ... but no semantic change in any way. Also the API (zcrypt and pkey header file) is semantically unchanged. Signed-off-by: Harald Freudenberger Reviewed-by: Jürgen Christ Signed-off-by: Heiko Carstens

s390/zcrypt: rework of debug feature messages

2021-10-26T13:21:27Z

This patch reworks all the debug feature invocations to be more uniform. All invocations now use the macro with the level already part of the macro name. All messages now start with %s filled with __func__ (well there are still some exceptions), and some message text has been shortened or reworked. There is no functional code touched with this patch. Signed-off-by: Harald Freudenberger Signed-off-by: Vasily Gorbik

s390/ap/zcrypt: revisit ap and zcrypt error handling

2020-10-07T19:50:01Z

Revisit the ap queue error handling: Based on discussions and evaluatios with the firmware folk here is now a rework of the response code handling for all the AP instructions. The idea is to distinguish between failures because of some kind of invalid request where a retry does not make any sense and a failure where another attempt to send the very same request may succeed. The first case is handled by returning EINVAL to the userspace application. The second case results in retries within the zcrypt API controlled by a per message retry counter. Revisit the zcrpyt error handling: Similar here, based on discussions with the firmware people here comes a rework of the handling of all the reply codes. Main point here is that there are only very few cases left, where a zcrypt device queue is switched to offline. It should never be the case that an AP reply message is 'unknown' to the device driver as it indicates a total mismatch between device driver and crypto card firmware. In all other cases, the code distinguishes between failure because of invalid message (see above - EINVAL) or failures of the infrastructure (see above - EAGAIN). Signed-off-by: Harald Freudenberger Signed-off-by: Vasily Gorbik

s390/zcrypt: code beautification and struct field renames

2020-07-03T08:49:34Z

Some beautifications related to the internal only used struct ap_message and related code. Instead of one int carrying only the special flag now a u32 flags field is used. At struct CPRBX the pointers to additional data are now marked with __user. This caused some changes needed on code, where these structs are also used within the zcrypt misc functions. The ica_rsa_* structs now use the generic types __u8, __u32, ... instead of char, unsigned int. zcrypt_msg6 and zcrypt_msg50 use min_t() instead of min(). Signed-off-by: Harald Freudenberger Signed-off-by: Heiko Carstens

s390/zcrypt: handle new reply code FILTERED_BY_HYPERVISOR

2019-11-30T09:52:44Z

This patch introduces support for a new architectured reply code 0x8B indicating that a hypervisor layer (if any) has rejected an ap message. Linux may run as a guest on top of a hypervisor like zVM or KVM. So the crypto hardware seen by the ap bus may be restricted by the hypervisor for example only a subset like only clear key crypto requests may be supported. Other requests will be filtered out - rejected by the hypervisor. The new reply code 0x8B will appear in such cases and needs to get recognized by the ap bus and zcrypt device driver zoo. Signed-off-by: Harald Freudenberger Signed-off-by: Vasily Gorbik

s390/zcrypt: improve special ap message cmd handling

2018-11-30T06:22:05Z

There exist very few ap messages which need to have the 'special' flag enabled. This flag tells the firmware layer to do some pre- and maybe postprocessing. However, it may happen that this special flag is enabled but the firmware is unable to deal with this kind of message and thus returns with reply code 0x41. For example older firmware may not know the newest messages triggered by the zcrypt device driver and thus react with reject and the named reply code. Unfortunately this reply code is not known to the zcrypt error routines and thus default behavior is to switch the ap queue offline. This patch now makes the ap error routine aware of the reply code and so userspace is informed about the bad processing result but the queue is not switched to offline state any more. Signed-off-by: Harald Freudenberger Signed-off-by: Martin Schwidefsky

s390/zcrypt: provide apfs failure code on type 86 error reply

2018-10-09T09:21:36Z

The apfs field (AP final status) is set on transport protocol failures (reply code 0x90) for type 86 replies. For CCA cprbs this value is copied into the xcrb status field which gives userspace a hint for the failure reason. However, for EP11 cprbs there is no such status field in the xcrb struct. So now regardless of the request type, if a reply type 86 with transport protocol failure is seen, the apfs value is printed as part of the debug message. So the user has a chance to see the apfs value without using a special build kernel. Signed-off-by: Harald Freudenberger Signed-off-by: Martin Schwidefsky

s390/zcrypt: zcrypt device driver cleanup

2018-10-09T09:21:35Z

Some cleanup in the s390 zcrypt device driver: - Removed fragments of pcixx crypto card code. This code can't be reached anymore because the hardware detection function does not recognize crypto cards < CEX2 since commit f56545430736 ("s390/zcrypt: Introduce QACT support for AP bus devices.") - Rename of some files and driver names which where still reflecting pcixx support to cex2a/cex2c. - Removed all the zcrypt version strings in the file headers. There is only one place left - the zcrypt.h header file is now the only place for zcrypt device driver version info. - Zcrypt version pump up from 2.2.0 to 2.2.1. Signed-off-by: Harald Freudenberger Signed-off-by: Martin Schwidefsky