mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-15 23:25:07 +00:00
5706340a33
Currently the kernel doesn't use transaction memory. And there is an issue for privileged state in the guest that: tbegin/tsuspend/tresume/tabort TM instructions can impact MSR TM bits without trapping into the PR host. So following code will lead to a false mfmsr result: tbegin <- MSR bits update to Transaction active. beq <- failover handler branch mfmsr <- still read MSR bits from magic page with transaction inactive. It is not an issue for non-privileged guest state since its mfmsr is not patched with magic page and will always trap into the PR host. This patch will always fail tbegin attempt for privileged state in the guest, so that the above issue is prevented. It is benign since currently (guest) kernel doesn't initiate a transaction. Test case: https://github.com/justdoitqd/publicFiles/blob/master/test_tbegin_pr.c Signed-off-by: Simon Guo <wei.guo.simon@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> |
||
|---|---|---|
| .. | ||
| alpha | ||
| arc | ||
| arm | ||
| arm64 | ||
| c6x | ||
| h8300 | ||
| hexagon | ||
| ia64 | ||
| m68k | ||
| microblaze | ||
| mips | ||
| nds32 | ||
| nios2 | ||
| openrisc | ||
| parisc | ||
| powerpc | ||
| riscv | ||
| s390 | ||
| sh | ||
| sparc | ||
| um | ||
| unicore32 | ||
| x86 | ||
| xtensa | ||
| .gitignore | ||
| Kconfig | ||