From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (bilbo.ozlabs.org [103.22.144.67]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3z314n6qQwzF06l for ; Fri, 22 Dec 2017 18:54:49 +1100 (AEDT) Date: Fri, 22 Dec 2017 18:54:30 +1100 From: Paul Mackerras To: Michael Ellerman Cc: Laurent Vivier , =?iso-8859-1?Q?C=E9dric?= Le Goater , kvm-ppc@vger.kernel.org, Benjamin Herrenschmidt , linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH] KVM: PPC: Book3S: fix XIVE migration of pending interrupts Message-ID: <20171222075430.GB6945@fergus.ozlabs.ibm.com> References: <20171212120204.6799-1-clg@kaod.org> <4be897d4-2d54-305b-8416-b32384de73a9@redhat.com> <878tdvpeib.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 In-Reply-To: <878tdvpeib.fsf@concordia.ellerman.id.au> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, Dec 22, 2017 at 03:34:20PM +1100, Michael Ellerman wrote: > Laurent Vivier writes: > > > On 12/12/2017 13:02, Cédric Le Goater wrote: > >> When restoring a pending interrupt, we are setting the Q bit to force > >> a retrigger in xive_finish_unmask(). But we also need to force an EOI > >> in this case to reach the same initial state : P=1, Q=0. > >> > >> This can be done by not setting 'old_p' for pending interrupts which > >> will inform xive_finish_unmask() that an EOI needs to be sent. > >> > >> Suggested-by: Benjamin Herrenschmidt > >> Signed-off-by: Cédric Le Goater > >> --- > >> > >> Tested with a guest running iozone. > >> > >> arch/powerpc/kvm/book3s_xive.c | 4 ++-- > >> 1 file changed, 2 insertions(+), 2 deletions(-) > > > > We really need this patch to fix VM migration on POWER9. > > When will it be merged? > > Paul is away, so I'll merge it via the powerpc tree. > > I'll mark it: > > Fixes: 5af50993850a ("KVM: PPC: Book3S HV: Native usage of the XIVE interrupt controller") > Cc: stable@vger.kernel.org # v4.12+ Thanks for doing that. If you felt like merging Alexey's patch "KVM: PPC: Book3S PR: Fix WIMG handling under pHyp" with my acked-by, that would be fine too. The commit message needs a little work - the reason for using HPTE_R_M is not just because it seems to work, but because current POWER processors require M set on mappings for normal pages, and pHyp enforces that. Cheers, Paul. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Mackerras Date: Fri, 22 Dec 2017 07:54:30 +0000 Subject: Re: [PATCH] KVM: PPC: Book3S: fix XIVE migration of pending interrupts Message-Id: <20171222075430.GB6945@fergus.ozlabs.ibm.com> List-Id: References: <20171212120204.6799-1-clg@kaod.org> <4be897d4-2d54-305b-8416-b32384de73a9@redhat.com> <878tdvpeib.fsf@concordia.ellerman.id.au> In-Reply-To: <878tdvpeib.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To: Michael Ellerman Cc: Laurent Vivier , =?iso-8859-1?Q?C=E9dric?= Le Goater , kvm-ppc@vger.kernel.org, Benjamin Herrenschmidt , linuxppc-dev@lists.ozlabs.org On Fri, Dec 22, 2017 at 03:34:20PM +1100, Michael Ellerman wrote: > Laurent Vivier writes: >=20 > > On 12/12/2017 13:02, C=E9dric Le Goater wrote: > >> When restoring a pending interrupt, we are setting the Q bit to force > >> a retrigger in xive_finish_unmask(). But we also need to force an EOI > >> in this case to reach the same initial state : P=3D1, Q=3D0. > >>=20 > >> This can be done by not setting 'old_p' for pending interrupts which > >> will inform xive_finish_unmask() that an EOI needs to be sent. > >>=20 > >> Suggested-by: Benjamin Herrenschmidt > >> Signed-off-by: C=E9dric Le Goater > >> --- > >>=20 > >> Tested with a guest running iozone. > >>=20 > >> arch/powerpc/kvm/book3s_xive.c | 4 ++-- > >> 1 file changed, 2 insertions(+), 2 deletions(-) > > > > We really need this patch to fix VM migration on POWER9. > > When will it be merged? >=20 > Paul is away, so I'll merge it via the powerpc tree. >=20 > I'll mark it: >=20 > Fixes: 5af50993850a ("KVM: PPC: Book3S HV: Native usage of the XIVE int= errupt controller") > Cc: stable@vger.kernel.org # v4.12+ Thanks for doing that. If you felt like merging Alexey's patch "KVM: PPC: Book3S PR: Fix WIMG handling under pHyp" with my acked-by, that would be fine too. The commit message needs a little work - the reason for using HPTE_R_M is not just because it seems to work, but because current POWER processors require M set on mappings for normal pages, and pHyp enforces that. Cheers, Paul.