diff mbox series

[v5,01/33] powerpc: Turn off CPU_FTR_P9_TM_HV_ASSIST in non-hypervisor mode

Message ID 1538976679-1363-2-git-send-email-paulus@ozlabs.org (mailing list archive)
State New, archived
Headers show
Series KVM: PPC: Book3S HV: Nested HV virtualization | expand

Commit Message

Paul Mackerras Oct. 8, 2018, 5:30 a.m. UTC 
When doing nested virtualization, it is only necessary to do the
transactional memory hypervisor assist at level 0, that is, when
we are in hypervisor mode.  Nested hypervisors can just use the TM
facilities as architected.  Therefore we should clear the
CPU_FTR_P9_TM_HV_ASSIST bit when we are not in hypervisor mode,
along with the CPU_FTR_HVMODE bit.

Doing this will not change anything at this stage because the only
code that tests CPU_FTR_P9_TM_HV_ASSIST is in HV KVM, which currently
can only be used when when CPU_FTR_HVMODE is set.

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
---
 arch/powerpc/kernel/cpu_setup_power.S | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/arch/powerpc/kernel/cpu_setup_power.S b/arch/powerpc/kernel/cpu_setup_power.S
index 458b928..c317080 100644
--- a/arch/powerpc/kernel/cpu_setup_power.S
+++ b/arch/powerpc/kernel/cpu_setup_power.S
@@ -147,8 +147,8 @@  __init_hvmode_206:
 	rldicl.	r0,r3,4,63
 	bnelr
 	ld	r5,CPU_SPEC_FEATURES(r4)
-	LOAD_REG_IMMEDIATE(r6,CPU_FTR_HVMODE)
-	xor	r5,r5,r6
+	LOAD_REG_IMMEDIATE(r6,CPU_FTR_HVMODE | CPU_FTR_P9_TM_HV_ASSIST)
+	andc	r5,r5,r6
 	std	r5,CPU_SPEC_FEATURES(r4)
 	blr