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authorGautham R. Shenoy <ego@linux.vnet.ibm.com>2015-08-07 17:41:20 +0530
committerPaul Mackerras <paulus@samba.org>2015-09-03 16:08:34 +1000
commit06554d9f6cc8f0b5ec903db19726a15dfc7b09d6 (patch)
tree03f6337869ec9bdbe95b4fab3886418c9a4f5d05 /arch/powerpc/kvm
parent7f23532866f931be626e69ff55caf39e54516047 (diff)
downloadop-kernel-dev-06554d9f6cc8f0b5ec903db19726a15dfc7b09d6.zip
op-kernel-dev-06554d9f6cc8f0b5ec903db19726a15dfc7b09d6.tar.gz
KVM: PPC: Book3S HV: Exit on H_DOORBELL if HOST_IPI is set
The code that handles the case when we receive a H_DOORBELL interrupt has a comment which says "Hypervisor doorbell - exit only if host IPI flag set". However, the current code does not actually check if the host IPI flag is set. This is due to a comparison instruction that got missed. As a result, the current code performs the exit to host only if some sibling thread or a sibling sub-core is exiting to the host. This implies that, an IPI sent to a sibling core in (subcores-per-core != 1) mode will be missed by the host unless the sibling core is on the exit path to the host. This patch adds the missing comparison operation which will ensure that when HOST_IPI flag is set, we unconditionally exit to the host. Fixes: 66feed61cdf6 Cc: stable@vger.kernel.org # v4.1+ Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/powerpc/kvm')
-rw-r--r--arch/powerpc/kvm/book3s_hv_rmhandlers.S1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index b07f045..2273dca 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -1213,6 +1213,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
cmpwi r12, BOOK3S_INTERRUPT_H_DOORBELL
bne 3f
lbz r0, HSTATE_HOST_IPI(r13)
+ cmpwi r0, 0
beq 4f
b guest_exit_cont
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