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authorPaul Mackerras <paulus@ozlabs.org>2017-08-25 19:52:12 +1000
committerPaul Mackerras <paulus@ozlabs.org>2017-08-31 12:36:44 +1000
commita4faf2e77a565432278430deaaba2f3295b6a2df (patch)
treef96031bb8a27ddab4a71daf97d25975437812c22 /arch/powerpc
parent0bfa33c7f71e7e9de289582d9652110daa1ec8a1 (diff)
downloadop-kernel-dev-a4faf2e77a565432278430deaaba2f3295b6a2df.zip
op-kernel-dev-a4faf2e77a565432278430deaaba2f3295b6a2df.tar.gz
KVM: PPC: Book3S HV: Fix case where HDEC is treated as 32-bit on POWER9
Commit 2f2724630f7a ("KVM: PPC: Book3S HV: Cope with host using large decrementer mode", 2017-05-22) added code to treat the hypervisor decrementer (HDEC) as a 64-bit value on POWER9 rather than 32-bit. Unfortunately, that commit missed one place where HDEC is treated as a 32-bit value. This fixes it. This bug should not have any user-visible consequences that I can think of, beyond an occasional unnecessary exit to the host kernel. If the hypervisor decrementer has gone negative, then the bottom 32 bits will be negative for about 4 seconds after that, so as long as we get out of the guest within those 4 seconds we won't conclude that the HDEC interrupt is spurious. Reported-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Fixes: 2f2724630f7a ("KVM: PPC: Book3S HV: Cope with host using large decrementer mode") Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/kvm/book3s_hv_rmhandlers.S3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 0bc400f..29ec462 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -1280,7 +1280,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
cmpwi r12,BOOK3S_INTERRUPT_HV_DECREMENTER
bne 2f
mfspr r3,SPRN_HDEC
- cmpwi r3,0
+ EXTEND_HDEC(r3)
+ cmpdi r3,0
mr r4,r9
bge fast_guest_return
2:
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