From nobody Mon Apr 29 01:33:33 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1529485949605862.0187415401238; Wed, 20 Jun 2018 02:12:29 -0700 (PDT) Received: from localhost ([::1]:46844 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fVZA6-0006Bm-Uy for importer@patchew.org; Wed, 20 Jun 2018 05:12:22 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40473) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fVZ8i-0005Ar-Lt for qemu-devel@nongnu.org; Wed, 20 Jun 2018 05:10:57 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fVZ8e-0002jl-Al for qemu-devel@nongnu.org; Wed, 20 Jun 2018 05:10:56 -0400 Received: from [107.173.13.209] (port=56058 helo=ozlabs.ru) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fVZ8e-0002hm-0p; Wed, 20 Jun 2018 05:10:52 -0400 Received: from vpl1.ozlabs.ibm.com (localhost [IPv6:::1]) by ozlabs.ru (Postfix) with ESMTP id 7EF37AE80001; Wed, 20 Jun 2018 05:09:08 -0400 (EDT) From: Alexey Kardashevskiy To: qemu-devel@nongnu.org Date: Wed, 20 Jun 2018 19:10:12 +1000 Message-Id: <20180620091013.2224-1-aik@ozlabs.ru> X-Mailer: git-send-email 2.11.0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [fuzzy] X-Received-From: 107.173.13.209 Subject: [Qemu-devel] [PATCH qemu v2] vfio/spapr: Allow backing bigger guest IOMMU pages with smaller physical pages X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Alexey Kardashevskiy , Alex Williamson , qemu-ppc@nongnu.org, David Gibson Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" At the moment the PPC64/pseries guest only supports 4K/64K/16M IOMMU pages and POWER8 CPU supports the exact same set of page size so so far things worked fine. However POWER9 supports different set of sizes - 4K/64K/2M/1G and the last two - 2M and 1G - are not even allowed in the paravirt interface (RTAS DDW) so we always end up using 64K IOMMU pages, although we could back guest's 16MB IOMMU pages with 2MB pages on the host. This stores the supported host IOMMU page sizes in VFIOContainer and uses this later when creating a new DMA window. This uses the system page size (64k normally, 2M/16M/1G if hugepages used) as the upper limit of the IOMMU pagesize. This changes the type of @pagesize to uint64_t as this is what memory_region_iommu_get_min_page_size() returns and clz64() takes. There should be no behavioral changes on platforms other than pseries. The guest will keep using the IOMMU page size selected by the PHB pagesize property as this only changes the underlying hardware TCE table granularity. Signed-off-by: Alexey Kardashevskiy --- Changes: v2: * fixed biggest but smaller page size calculation * limit IOMMU pagesize to the system pagesize --- include/hw/vfio/vfio-common.h | 1 + hw/vfio/common.c | 3 +++ hw/vfio/spapr.c | 21 ++++++++++++++++++++- 3 files changed, 24 insertions(+), 1 deletion(-) diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h index a903692..c20524d 100644 --- a/include/hw/vfio/vfio-common.h +++ b/include/hw/vfio/vfio-common.h @@ -73,6 +73,7 @@ typedef struct VFIOContainer { unsigned iommu_type; int error; bool initialized; + unsigned long pgsizes; /* * This assumes the host IOMMU can support only a single * contiguous IOVA window. We may need to generalize that in diff --git a/hw/vfio/common.c b/hw/vfio/common.c index fb396cf..40f0356 100644 --- a/hw/vfio/common.c +++ b/hw/vfio/common.c @@ -1108,6 +1108,7 @@ static int vfio_connect_container(VFIOGroup *group, A= ddressSpace *as, info.iova_pgsizes =3D 4096; } vfio_host_win_add(container, 0, (hwaddr)-1, info.iova_pgsizes); + container->pgsizes =3D info.iova_pgsizes; } else if (ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_SPAPR_TCE_IOMMU) || ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_SPAPR_TCE_v2_IOMMU)) { struct vfio_iommu_spapr_tce_info info; @@ -1172,6 +1173,7 @@ static int vfio_connect_container(VFIOGroup *group, A= ddressSpace *as, } =20 if (v2) { + container->pgsizes =3D info.ddw.pgsizes; /* * There is a default window in just created container. * To make region_add/del simpler, we better remove this @@ -1186,6 +1188,7 @@ static int vfio_connect_container(VFIOGroup *group, A= ddressSpace *as, } } else { /* The default table uses 4K pages */ + container->pgsizes =3D 0x1000; vfio_host_win_add(container, info.dma32_window_start, info.dma32_window_start + info.dma32_window_size - 1, diff --git a/hw/vfio/spapr.c b/hw/vfio/spapr.c index 259397c..becf71a 100644 --- a/hw/vfio/spapr.c +++ b/hw/vfio/spapr.c @@ -15,6 +15,7 @@ =20 #include "hw/vfio/vfio-common.h" #include "hw/hw.h" +#include "exec/ram_addr.h" #include "qemu/error-report.h" #include "trace.h" =20 @@ -144,9 +145,27 @@ int vfio_spapr_create_window(VFIOContainer *container, { int ret; IOMMUMemoryRegion *iommu_mr =3D IOMMU_MEMORY_REGION(section->mr); - unsigned pagesize =3D memory_region_iommu_get_min_page_size(iommu_mr); + uint64_t pagesize =3D memory_region_iommu_get_min_page_size(iommu_mr); unsigned entries, pages; struct vfio_iommu_spapr_tce_create create =3D { .argsz =3D sizeof(crea= te) }; + long systempagesize =3D qemu_getrampagesize(); + + /* + * The host might not support the guest supported IOMMU page size, + * so we will use smaller physical IOMMU pages to back them. + */ + if (pagesize > systempagesize) { + pagesize =3D systempagesize; + } + pagesize =3D 1ULL << (63 - clz64(container->pgsizes & + (pagesize | (pagesize - 1)))); + if (!pagesize) { + error_report("Host doesn't support page size 0x%"PRIx64 + ", the supported mask is 0x%lx", + memory_region_iommu_get_min_page_size(iommu_mr), + container->pgsizes); + return -EINVAL; + } =20 /* * FIXME: For VFIO iommu types which have KVM acceleration to --=20 2.11.0