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| author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2016-07-24 09:32:10 +1000 |
|---|---|---|
| committer | Stewart Smith <stewart@linux.vnet.ibm.com> | 2016-10-17 10:33:28 +1100 |
| commit | 0279d8951ead549fdebce93130a2f6c673081862 (patch) | |
| tree | b0fee12867dbf0a4796ec98b3d4b12907d604ab0 /include/config.h | |
| parent | 8110b0595f0de2df18a06e8e9aff66db45872fa7 (diff) | |
| download | skiboot-0279d8951ead549fdebce93130a2f6c673081862.zip skiboot-0279d8951ead549fdebce93130a2f6c673081862.tar.gz skiboot-0279d8951ead549fdebce93130a2f6c673081862.tar.bz2 | |
Fast reboot for P8
This is an experimental patch that implements "Fast reboot" on P8
machines.
The basic idea is that when the OS calls OPAL reboot, we gather all
the threads in the system using a combination of patching the reset
vector and soft-resetting them, then cleanup a few bits of hardware
(we do re-probe PCIe for example), and reload & restart the bootloader.
For Trusted Boot, this means we *add* measurements to the TPM, so you
will get *different* PCR values as compared to a full IPL. This makes
sense as if you want to be sure you are running something known then,
well, do a full IPL as soft reset should never be trusted to clear any
malicious code.
This is very experimental and needs a lot of testing and also auditing
code for other bits of HW that might need to be cleaned up.
BenH TODO: I also need to check if we are properly PERST'ing PCI devices.
This is partially based on old code I had to do that on P7. I only
support it on P8 though as there are issues with the PSI interrupts
on P7 that cannot be reliably solved.
Even though this should be considered somewhat experimental, we've had
a lot of success on a variety of machines. Dozens/hundreds of reboots
across Tuleta, Garrison and Habanero.
Currently, we've hidden it behind a NVRAM config option, which *is*
liable to change in the future (to ensure that only those who know
what they're doing enable it)
You can enable the experimental support via nvram option:
nvram -p ibm,skiboot --update-config experimental-fast-reset=feeling-lucky
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[stewart@linux.vnet.ibm.com: hide behind nvram option, include Mambo fixes
from Mikey]
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>
Diffstat (limited to 'include/config.h')
| -rw-r--r-- | include/config.h | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/include/config.h b/include/config.h index 2524570..f6572b0 100644 --- a/include/config.h +++ b/include/config.h @@ -72,9 +72,6 @@ */ //#define FORCE_DUMMY_CONSOLE 1 -/* Enable this to do fast resets. Currently unreliable... */ -//#define ENABLE_FAST_RESET 1 - /* Enable this to make fast reboot clear memory */ //#define FAST_REBOOT_CLEARS_MEMORY 1 |