diff options
| author | Nicholas Piggin <npiggin@gmail.com> | 2021-11-23 19:51:47 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-11-24 21:08:57 +1100 |
| commit | 46f9caf1a246a5c0622fa8cc7e673658e925f97e (patch) | |
| tree | 588a28905c70adcd36e135af702a8e4293b20288 /arch/powerpc/kernel/dt_cpu_ftrs.c | |
| parent | eacc818864bb01828280f4d64334c4e5ae6a4daf (diff) | |
| download | linux-46f9caf1a246a5c0622fa8cc7e673658e925f97e.tar.bz2 | |
powerpc/64s: Keep AMOR SPR a constant ~0 at runtime
This register controls supervisor SPR modifications, and as such is only
relevant for KVM. KVM always sets AMOR to ~0 on guest entry, and never
restores it coming back out to the host, so it can be kept constant and
avoid the mtSPR in KVM guest entry.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211123095231.1036501-10-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc/kernel/dt_cpu_ftrs.c')
| -rw-r--r-- | arch/powerpc/kernel/dt_cpu_ftrs.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/dt_cpu_ftrs.c b/arch/powerpc/kernel/dt_cpu_ftrs.c index ba527fb52993..de59971319ab 100644 --- a/arch/powerpc/kernel/dt_cpu_ftrs.c +++ b/arch/powerpc/kernel/dt_cpu_ftrs.c @@ -80,6 +80,7 @@ static void __restore_cpu_cpufeatures(void) mtspr(SPRN_LPCR, system_registers.lpcr); if (hv_mode) { mtspr(SPRN_LPID, 0); + mtspr(SPRN_AMOR, ~0); mtspr(SPRN_HFSCR, system_registers.hfscr); mtspr(SPRN_PCR, system_registers.pcr); } @@ -216,6 +217,7 @@ static int __init feat_enable_hv(struct dt_cpu_feature *f) } mtspr(SPRN_LPID, 0); + mtspr(SPRN_AMOR, ~0); lpcr = mfspr(SPRN_LPCR); lpcr &= ~LPCR_LPES0; /* HV external interrupts */ |