From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53131) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dr7pl-0003IP-Lk for qemu-devel@nongnu.org; Sun, 10 Sep 2017 15:23:58 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dr7pi-0003r5-HN for qemu-devel@nongnu.org; Sun, 10 Sep 2017 15:23:57 -0400 Received: from 5.mo3.mail-out.ovh.net ([87.98.178.36]:57902) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dr7pi-0003p9-BJ for qemu-devel@nongnu.org; Sun, 10 Sep 2017 15:23:54 -0400 Received: from player758.ha.ovh.net (b6.ovh.net [213.186.33.56]) by mo3.mail-out.ovh.net (Postfix) with ESMTP id BBEDB150369 for ; Sun, 10 Sep 2017 21:23:49 +0200 (CEST) References: <20170908143344.12960-1-clg@kaod.org> <20170908143344.12960-3-clg@kaod.org> <20170910031731.GY2735@umbus.fritz.box> From: =?UTF-8?Q?C=c3=a9dric_Le_Goater?= Message-ID: <093c41a2-abaa-ce97-a93c-e4b475b67e2d@kaod.org> Date: Sun, 10 Sep 2017 21:23:42 +0200 MIME-Version: 1.0 In-Reply-To: <20170910031731.GY2735@umbus.fritz.box> Content-Type: text/plain; charset=windows-1252 Content-Language: en-US Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH 2/3] spapr: fix CAS-generated reset List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: David Gibson Cc: qemu-ppc@nongnu.org, qemu-devel@nongnu.org, Michael Roth , Sam Bobroff On 09/10/2017 05:17 AM, David Gibson wrote: > On Fri, Sep 08, 2017 at 04:33:43PM +0200, C=E9dric Le Goater wrote: >> The OV5_MMU_RADIX_300 requires special handling in the CAS negotiation >> process. It is cleared from the option vector of the guest before >> evaluating the changes and re-added later. But, when testing for a >> possible CAS reset : >> >> spapr->cas_reboot =3D spapr_ovec_diff(ov5_updates, >> ov5_cas_old, spapr->ov5_cas); >> >> the bit OV5_MMU_RADIX_300 will each time be seen as removed from the >> previous OV5 set, hence generating a reset loop. >> >> Fix this problem by also clearing the same bit in the ov5_cas_old set. >> >> Signed-off-by: C=E9dric Le Goater >=20 > Kind of an ugly hack, =20 yes. I lack context to fully understand why the guest radix option is handled that way.=20 > but probably the easiest fix for now. Applied to ppc-for-2.11. Thanks, C. >=20 >> --- >> hw/ppc/spapr_hcall.c | 7 +++++++ >> 1 file changed, 7 insertions(+) >> >> diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c >> index 07b3da8dc4cd..92f1e21358b8 100644 >> --- a/hw/ppc/spapr_hcall.c >> +++ b/hw/ppc/spapr_hcall.c >> @@ -1575,6 +1575,13 @@ static target_ulong h_client_architecture_suppo= rt(PowerPCCPU *cpu, >> * to worry about this for now. >> */ >> ov5_cas_old =3D spapr_ovec_clone(spapr->ov5_cas); >> + >> + /* also clear the radix/hash bit from the current ov5_cas bits to >> + * be in sync with the newly ov5 bits. Else the radix bit will be >> + * seen as being removed and this will generate a reset loop >> + */ >> + spapr_ovec_clear(ov5_cas_old, OV5_MMU_RADIX_300); >> + >> /* full range of negotiated ov5 capabilities */ >> spapr_ovec_intersect(spapr->ov5_cas, spapr->ov5, ov5_guest); >> spapr_ovec_cleanup(ov5_guest); >=20