From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52978) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZhSqo-00065W-Mv for qemu-devel@nongnu.org; Wed, 30 Sep 2015 21:40:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZhSqn-0005mP-Id for qemu-devel@nongnu.org; Wed, 30 Sep 2015 21:40:02 -0400 Date: Thu, 1 Oct 2015 10:43:05 +1000 From: David Gibson Message-ID: <20151001004305.GH23574@voom> References: <1443584920-23015-1-git-send-email-david@gibson.dropbear.id.au> <1443584920-23015-4-git-send-email-david@gibson.dropbear.id.au> <560BAC75.5060209@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="+Z7/5fzWRHDJ0o7Q" Content-Disposition: inline In-Reply-To: <560BAC75.5060209@redhat.com> Subject: Re: [Qemu-devel] [PATCH 3/4] spapr_iommu: Provide a function to switch a TCE table to allowing VFIO List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Laurent Vivier Cc: thuth@redhat.com, aik@ozlabs.ru, mdroth@linux.vnet.ibm.com, qemu-devel@nongnu.org, alex.williamson@redhat.com, qemu-ppc@nongnu.org --+Z7/5fzWRHDJ0o7Q Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Sep 30, 2015 at 11:33:41AM +0200, Laurent Vivier wrote: >=20 >=20 > On 30/09/2015 05:48, David Gibson wrote: > > Because of the way non-VFIO guest IOMMU operations are KVM accelerated,= not > > all TCE tables (guest IOMMU contexts) can support VFIO devices. Curren= tly, > > this is decided at creation time. > >=20 > > To support hotplug of VFIO devices, we need to allow a TCE table which > > previously didn't allow VFIO devices to be switched so that it can. Th= is > > patch adds an spapr_tce_set_need_vfio() function to do this, by > > reallocating the table in userspace if necessary. > >=20 > > Currently this doesn't allow the KVM acceleration to be re-enabled if a= ll > > the VFIO devices are removed. That's an optimization for another time. > >=20 > > Signed-off-by: David Gibson > > --- > > hw/ppc/spapr_iommu.c | 32 ++++++++++++++++++++++++++++++++ > > include/hw/ppc/spapr.h | 2 ++ > > 2 files changed, 34 insertions(+) > >=20 > > diff --git a/hw/ppc/spapr_iommu.c b/hw/ppc/spapr_iommu.c > > index 5166cde..8d60f8b 100644 > > --- a/hw/ppc/spapr_iommu.c > > +++ b/hw/ppc/spapr_iommu.c > > @@ -168,6 +168,38 @@ static int spapr_tce_table_realize(DeviceState *de= v) > > return 0; > > } > > =20 > > +void spapr_tce_set_need_vfio(sPAPRTCETable *tcet, bool need_vfio) > > +{ > > + size_t table_size =3D tcet->nb_table * sizeof(uint64_t); > > + void *newtable; > > + > > + if (need_vfio =3D=3D tcet->need_vfio) { > > + /* Nothing to do */ > > + return; > > + } > > + > > + if (!need_vfio) { > > + /* FIXME: We don't support transition back to KVM accelerated > > + * TCEs yet */ >=20 > Report some warnings ? I don't see much value in it. At present nothing calls this function with need_vfio =3D=3D false anyway. Switching back is harmless, just not optimal. >=20 > > + return; > > + } > > + > > + tcet->need_vfio =3D true; > > + > > + if (tcet->fd < 0) { > > + /* Table is already in userspace, nothing to be do */ > > + return; > > + } > > + > > + newtable =3D g_malloc0(table_size); > > + memcpy(newtable, tcet->table, table_size); > > + > > + kvmppc_remove_spapr_tce(tcet->table, tcet->fd, tcet->nb_table); > > + > > + tcet->fd =3D -1; > > + tcet->table =3D newtable; > > +} > > + > > sPAPRTCETable *spapr_tce_new_table(DeviceState *owner, uint32_t liobn, > > uint64_t bus_offset, > > uint32_t page_shift, > > diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h > > index 27d65d5..5baa906 100644 > > --- a/include/hw/ppc/spapr.h > > +++ b/include/hw/ppc/spapr.h > > @@ -589,6 +589,8 @@ sPAPRTCETable *spapr_tce_new_table(DeviceState *own= er, uint32_t liobn, > > uint32_t page_shift, > > uint32_t nb_table, > > bool need_vfio); > > +void spapr_tce_set_need_vfio(sPAPRTCETable *tcet, bool need_vfio); > > + > > MemoryRegion *spapr_tce_get_iommu(sPAPRTCETable *tcet); > > int spapr_dma_dt(void *fdt, int node_off, const char *propname, > > uint32_t liobn, uint64_t window, uint32_t size); > >=20 >=20 > Reviewed-by: Laurent Vivier >=20 --=20 David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson --+Z7/5fzWRHDJ0o7Q Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJWDIGZAAoJEGw4ysog2bOSHLoP+gMRAGBXa4Lzhrx5pRKcPU7B Dn+Lbskt92L5lgxFzdSSpOnXZW6fCZp1xmaifWi49niQ0M4GplrmX94yTdQNyhT+ iiZLT0JX/HdnIuPi+h18woifApUmUMRQLCIrgSMDrIUH4YiBFHugEUT2cGUPaB56 xX+Yort50nFbe/fiCsQP41oID4q6/g3EhtHs9dF0tM4uvKcfnVRLTCH9E0T+w02k +n04BAud/Jju+zI9MAJFBOE0Jr7CNZiDx7s0zOUXocUuNpIE8juDwfYFEsJuz+Un qAbyBeLwkt5FO/ZdOeI7D6q7tly9gb+HLXqZyXiZLLOFuZIy98bPz+9yz9cX2fdO JzHxvFP1fpBLgelaD3lonWwtRub33+XWmTkBQi2+iAmgEiwQ2oHx5nGKoli2iKao Q1z/B7QRWkv9rY64SJdGO/Qoo6Uyvmtonp4Fr6stzDmmkcSqapPP3ru6JmxGPL/8 7XBjbPc26vpMoZKSxuux8MDI/vQQiZxum7ic8Qndy/G2XFudlxPoXL1oyh0D8uTu fdToTCPmoJ0bXq8vyrEGGPzn/bzrzN9JxOh+oMbxvb/K1lLw/ua4kQ9SiN9fdzAC PAG1Sk3nawfgIq3rLmv8dv1ds74/AtgAMjrOnd108APuI6GXzQ4zC35VjsB1sKdB dIt/rwo26HGERSZ3xiRJ =74gh -----END PGP SIGNATURE----- --+Z7/5fzWRHDJ0o7Q--