From 073cbf6bb0a1ceddf3c7974d04608ca10062951e Mon Sep 17 00:00:00 2001 From: Stewart Smith Date: Mon, 16 Oct 2017 19:32:41 +1100 Subject: skiboot 5.9-rc2 release notes Signed-off-by: Stewart Smith --- doc/release-notes/skiboot-5.9-rc2.rst | 246 ++++++++++++++++++++++++++++++++++ 1 file changed, 246 insertions(+) create mode 100644 doc/release-notes/skiboot-5.9-rc2.rst diff --git a/doc/release-notes/skiboot-5.9-rc2.rst b/doc/release-notes/skiboot-5.9-rc2.rst new file mode 100644 index 0000000..ab97b08 --- /dev/null +++ b/doc/release-notes/skiboot-5.9-rc2.rst @@ -0,0 +1,246 @@ +.. _skiboot-5.9-rc2: + +skiboot-5.9-rc2 +=============== + +skiboot v5.9-rc2 was released on Monday October 16th 2017. It is the second +release candidate of skiboot 5.9, which will become the new stable release +of skiboot following the 5.8 release, first released August 31st 2017. + +skiboot v5.9-rc2 contains all bug fixes as of :ref:`skiboot-5.4.8` +and :ref:`skiboot-5.1.21` (the currently maintained stable releases). We +do not currently expect to do any 5.8.x stable releases. + +For how the skiboot stable releases work, see :ref:`stable-rules` for details. + +The current plan is to cut the final 5.9 by October 17th, with skiboot 5.9 +being for all POWER8 and POWER9 platforms in op-build v1.20 (Due October 18th). +This release will be targetted to early POWER9 systems. + +Over :ref:`skiboot-5.9-rc1`, we have the following changes: + +- opal-prd: Fix memory leak +- hdata/i2c: update the list of known i2c devs + + This updates the list of known i2c devices - as of HDAT spec v10.5e - so + that they can be properly identified during the hdat parsing. +- hdata/i2c: log unknown i2c devices + + An i2c device is unknown if either the i2c device list is outdated or + the device is marked as unknown (0xFF) in the hdat. + +- opal/cpu: Mark the core as bad while disabling threads of the core. + + If any of the core fails to sync its TB during chipTOD initialization, + all the threads of that core are disabled. But this does not make + linux kernel to ignore the core/cpus. It crashes while bringing them up + with below backtrace: :: + + [ 38.883898] kexec_core: Starting new kernel + cpu 0x0: Vector: 300 (Data Access) at [c0000003f277b730] + pc: c0000000001b9890: internal_create_group+0x30/0x304 + lr: c0000000001b9880: internal_create_group+0x20/0x304 + sp: c0000003f277b9b0 + msr: 900000000280b033 + dar: 40 + dsisr: 40000000 + current = 0xc0000003f9f41000 + paca = 0xc00000000fe00000 softe: 0 irq_happened: 0x01 + pid = 2572, comm = kexec + Linux version 4.13.2-openpower1 (jenkins@p89) (gcc version 6.4.0 (Buildroot 2017.08-00006-g319c6e1)) #1 SMP Wed Sep 20 05:42:11 UTC 2017 + enter ? for help + [c0000003f277b9b0] c0000000008a8780 (unreliable) + [c0000003f277ba50] c00000000041c3ac topology_add_dev+0x2c/0x40 + [c0000003f277ba70] c00000000006b078 cpuhp_invoke_callback+0x88/0x170 + [c0000003f277bac0] c00000000006b22c cpuhp_up_callbacks+0x54/0xb8 + [c0000003f277bb10] c00000000006bc68 cpu_up+0x11c/0x168 + [c0000003f277bbc0] c00000000002f0e0 default_machine_kexec+0x1fc/0x274 + [c0000003f277bc50] c00000000002e2d8 machine_kexec+0x50/0x58 + [c0000003f277bc70] c0000000000de4e8 kernel_kexec+0x98/0xb4 + [c0000003f277bce0] c00000000008b0f0 SyS_reboot+0x1c8/0x1f4 + [c0000003f277be30] c00000000000b118 system_call+0x58/0x6c + +- hw/imc: pause microcode at boot + + IMC nest counters has both in-band (ucode access) and out of + band access to it. Since not all nest counter configurations + are supported by ucode, out of band tools are used to characterize + other configuration. + + So it is prefer to pause the nest microcode at boot to aid the + nest out of band tools. If the ucode not paused and OS does not + have IMC driver support, then out to band tools will race with + ucode and end up getting undesirable values. Patch to check and + pause the ucode at boot. + + OPAL provides APIs to control IMC counters. OPAL_IMC_COUNTERS_INIT + is used to initialize these counters at boot. OPAL_IMC_COUNTERS_START + and OPAL_IMC_COUNTERS_STOP API calls should be used to start and pause + these IMC engines. `doc/opal-api/opal-imc-counters.rst` details the + OPAL APIs and their usage. +- xive: Fix VP free block group mode false-positive parameter check + + The check to ensure the buddy allocation idx is aligned to its + allocation order was not taking into account the allocation split. + This would result in opal_xive_free_vp_block failures despite + giving the same value as returned by opal_xive_alloc_vp_block. + + E.g., starting then stopping 4 KVM guests gives the following pattern + in the host: :: + + opal_xive_alloc_vp_block(5)=0x45000020 + opal_xive_alloc_vp_block(5)=0x45000040 + opal_xive_alloc_vp_block(5)=0x45000060 + opal_xive_alloc_vp_block(5)=0x45000080 + opal_xive_free_vp_block(0x45000020)=-1 + opal_xive_free_vp_block(0x45000040)=0 + opal_xive_free_vp_block(0x45000060)=-1 + opal_xive_free_vp_block(0x45000080)=0 +- hw/p8-i2c: Fix deadlock in p9_i2c_bus_owner_change + + When debugging a system where Linux was taking soft lockup errors with + two CPUs stuck in OPAL: + + ======================= ============== + CPU0 CPU1 + ======================= ============== + lock + p8_i2c_recover + opal_handle_interrupt + sync_timer + cancel_timer + p9_i2c_bus_owner_change + occ_p9_interrupt + xive_source_interrupt + opal_handle_interrupt + ======================= ============== + + p8_i2c_recover() is a timer, and is stuck trying to take master->lock. + p9_i2c_bus_owner_change() has taken master->lock, but then is stuck waiting + for all timers to complete. We deadlock. + + Fix this by using cancel_timer_async(). + +- FSP/CONSOLE: Limit number of error logging + + Commit c8a7535f (FSP/CONSOLE: Workaround for unresponsive ipmi daemon) added + error logging when buffer is full. In some corner cases kernel may call this + function multiple time and we may endup logging error again and again. + + This patch fixes it by generating error log only once. + +- FSP/CONSOLE: Fix fsp_console_write_buffer_space() call + + Kernel calls fsp_console_write_buffer_space() to check console buffer space + availability. If there is enough buffer space to write data, then kernel will + call fsp_console_write() to write actual data. + + In some extreme corner cases (like one explained in commit c8a7535f) + console becomes full and this function returns 0 to kernel (or space available + in console buffer < next incoming data size). Kernel will continue retrying + until it gets enough space. So we will start seeing RCU stalls. + + This patch keeps track of previous available space. If previous space is same + as current means not enough space in console buffer to write incoming data. + It may be due to very high console write operation and slow response from FSP + -OR- FSP has stopped processing data (ex: because of ipmi daemon died). At this + point we will start timer with timeout of SER_BUFFER_OUT_TIMEOUT (10 secs). + If situation is not improved within 10 seconds means something went bad. Lets + return OPAL_RESOURCE so that kernel can drop console write and continue. +- FSP/CONSOLE: Close SOL session during R/R + + Presently we are not closing SOL and FW console sessions during R/R. Host will + continue to write to SOL buffer during FSP R/R. If there is heavy console write + operation happening during FSP R/R (like running `top` command inside console), + then at some point console buffer becomes full. fsp_console_write_buffer_space() + returns 0 (or less than required space to write data) to host. While one thread + is busy writing to console, if some other threads tries to write data to console + we may see RCU stalls (like below) in kernel. :: + + [ 2082.828363] INFO: rcu_sched detected stalls on CPUs/tasks: { 32} (detected by 16, t=6002 jiffies, g=23154, c=23153, q=254769) + [ 2082.828365] Task dump for CPU 32: + [ 2082.828368] kworker/32:3 R running task 0 4637 2 0x00000884 + [ 2082.828375] Workqueue: events dump_work_fn + [ 2082.828376] Call Trace: + [ 2082.828382] [c000000f1633fa00] [c00000000013b6b0] console_unlock+0x570/0x600 (unreliable) + [ 2082.828384] [c000000f1633fae0] [c00000000013ba34] vprintk_emit+0x2f4/0x5c0 + [ 2082.828389] [c000000f1633fb60] [c00000000099e644] printk+0x84/0x98 + [ 2082.828391] [c000000f1633fb90] [c0000000000851a8] dump_work_fn+0x238/0x250 + [ 2082.828394] [c000000f1633fc60] [c0000000000ecb98] process_one_work+0x198/0x4b0 + [ 2082.828396] [c000000f1633fcf0] [c0000000000ed3dc] worker_thread+0x18c/0x5a0 + [ 2082.828399] [c000000f1633fd80] [c0000000000f4650] kthread+0x110/0x130 + [ 2082.828403] [c000000f1633fe30] [c000000000009674] ret_from_kernel_thread+0x5c/0x68 + + Hence lets close SOL (and FW console) during FSP R/R. +- FSP/CONSOLE: Do not associate unavailable console + + Presently OPAL sends associate/unassociate MBOX command for all + FSP serial console (like below OPAL message). We have to check + console is available or not before sending this message. :: + + [ 5013.227994012,7] FSP: Reassociating HVSI console 1 + [ 5013.227997540,7] FSP: Reassociating HVSI console 2 +- FSP: Disable PSI link whenever FSP tells OPAL about impending R/R + + Commit 42d5d047 fixed scenario where DPO has been initiated, but FSP went + into reset before the CEC power down came in. But this is generic issue + that can happen in normal shutdown path as well. + + Hence disable PSI link as soon as we detect FSP impending R/R. + +- fsp: return OPAL_BUSY_EVENT on failure sending FSP_CMD_POWERDOWN_NORM + Also, return OPAL_BUSY_EVENT on failure sending FSP_CMD_REBOOT / DEEP_REBOOT. + + We had a race condition between FSP Reset/Reload and powering down + the system from the host: + + Roughly: + + == ======================== ========================================================== + # FSP Host + == ======================== ========================================================== + 1 Power on + 2 Power on + 3 (inject EPOW) + 4 (trigger FSP R/R) + 5 Processes EPOW event, starts shutting down + 6 calls OPAL_CEC_POWER_DOWN + 7 (is still in R/R) + 8 gets OPAL_INTERNAL_ERROR, spins in opal_poll_events + 9 (FSP comes back) + 10 spinning in opal_poll_events + 11 (thinks host is running) + == ======================== ========================================================== + + The call to OPAL_CEC_POWER_DOWN is only made once as the reset/reload + error path for fsp_sync_msg() is to return -1, which means we give + the OS OPAL_INTERNAL_ERROR, which is fine, except that our own API + docs give us the opportunity to return OPAL_BUSY when trying again + later may be successful, and we're ambiguous as to if you should retry + on OPAL_INTERNAL_ERROR. + + For reference, the linux code looks like this: :: + + static void __noreturn pnv_power_off(void) + { + long rc = OPAL_BUSY; + + pnv_prepare_going_down(); + + while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) { + rc = opal_cec_power_down(0); + if (rc == OPAL_BUSY_EVENT) + opal_poll_events(NULL); + else + mdelay(10); + } + for (;;) + opal_poll_events(NULL); + } + + Which means that *practically* our only option is to return OPAL_BUSY + or OPAL_BUSY_EVENT. + + We choose OPAL_BUSY_EVENT for FSP systems as we do want to ensure we're + running pollers to communicate with the FSP and do the final bits of + Reset/Reload handling before we power off the system. -- cgit v1.1