From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:46472 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753147AbbIQF0Z (ORCPT ); Thu, 17 Sep 2015 01:26:25 -0400 Subject: Patch "KVM: PPC: Book3S HV: Exit on H_DOORBELL if HOST_IPI is set" has been added to the 4.2-stable tree To: ego@linux.vnet.ibm.com, david@gibson.dropbear.id.au, gregkh@linuxfoundation.org, paulus@samba.org Cc: , From: Date: Wed, 16 Sep 2015 22:25:51 -0700 Message-ID: <144246755111762@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled KVM: PPC: Book3S HV: Exit on H_DOORBELL if HOST_IPI is set to the 4.2-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: kvm-ppc-book3s-hv-exit-on-h_doorbell-if-host_ipi-is-set.patch and it can be found in the queue-4.2 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 06554d9f6cc8f0b5ec903db19726a15dfc7b09d6 Mon Sep 17 00:00:00 2001 From: "Gautham R. Shenoy" Date: Fri, 7 Aug 2015 17:41:20 +0530 Subject: KVM: PPC: Book3S HV: Exit on H_DOORBELL if HOST_IPI is set From: "Gautham R. Shenoy" commit 06554d9f6cc8f0b5ec903db19726a15dfc7b09d6 upstream. 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 Signed-off-by: Gautham R. Shenoy Reviewed-by: David Gibson Signed-off-by: Paul Mackerras Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/kvm/book3s_hv_rmhandlers.S | 1 + 1 file changed, 1 insertion(+) --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -1127,6 +1127,7 @@ 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 3: Patches currently in stable-queue which might be from ego@linux.vnet.ibm.com are queue-4.2/kvm-ppc-book3s-hv-exit-on-h_doorbell-if-host_ipi-is-set.patch