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GET /api/patches/908462/?format=api
HTTP 200 OK
Allow: GET, PUT, PATCH, HEAD, OPTIONS
Content-Type: application/json
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{
    "id": 908462,
    "url": "http://patchwork.ozlabs.org/api/patches/908462/?format=api",
    "web_url": "http://patchwork.ozlabs.org/project/qemu-devel/patch/20180504030811.28111-5-peterx@redhat.com/",
    "project": {
        "id": 14,
        "url": "http://patchwork.ozlabs.org/api/projects/14/?format=api",
        "name": "QEMU Development",
        "link_name": "qemu-devel",
        "list_id": "qemu-devel.nongnu.org",
        "list_email": "qemu-devel@nongnu.org",
        "web_url": "",
        "scm_url": "",
        "webscm_url": "",
        "list_archive_url": "",
        "list_archive_url_format": "",
        "commit_url_format": ""
    },
    "msgid": "<20180504030811.28111-5-peterx@redhat.com>",
    "list_archive_url": null,
    "date": "2018-05-04T03:08:05",
    "name": "[v2,04/10] intel-iommu: only do page walk for MAP notifiers",
    "commit_ref": null,
    "pull_url": null,
    "state": "new",
    "archived": false,
    "hash": "a59509a04a2ce7a7b3c1c7226fee1294f4d08e97",
    "submitter": {
        "id": 67717,
        "url": "http://patchwork.ozlabs.org/api/people/67717/?format=api",
        "name": "Peter Xu",
        "email": "peterx@redhat.com"
    },
    "delegate": null,
    "mbox": "http://patchwork.ozlabs.org/project/qemu-devel/patch/20180504030811.28111-5-peterx@redhat.com/mbox/",
    "series": [
        {
            "id": 42502,
            "url": "http://patchwork.ozlabs.org/api/series/42502/?format=api",
            "web_url": "http://patchwork.ozlabs.org/project/qemu-devel/list/?series=42502",
            "date": "2018-05-04T03:08:01",
            "name": "intel-iommu: nested vIOMMU, cleanups, bug fixes",
            "version": 2,
            "mbox": "http://patchwork.ozlabs.org/series/42502/mbox/"
        }
    ],
    "comments": "http://patchwork.ozlabs.org/api/patches/908462/comments/",
    "check": "pending",
    "checks": "http://patchwork.ozlabs.org/api/patches/908462/checks/",
    "tags": {},
    "related": [],
    "headers": {
        "Return-Path": "<qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org>",
        "X-Original-To": "incoming@patchwork.ozlabs.org",
        "Delivered-To": "patchwork-incoming@bilbo.ozlabs.org",
        "Authentication-Results": [
            "ozlabs.org;\n\tspf=pass (mailfrom) smtp.mailfrom=nongnu.org\n\t(client-ip=2001:4830:134:3::11; helo=lists.gnu.org;\n\tenvelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org;\n\treceiver=<UNKNOWN>)",
            "ozlabs.org;\n\tdmarc=fail (p=none dis=none) header.from=redhat.com"
        ],
        "Received": [
            "from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11])\n\t(using TLSv1 with cipher AES256-SHA (256/256 bits))\n\t(No client certificate requested)\n\tby ozlabs.org (Postfix) with ESMTPS id 40ccST2NYYz9s35\n\tfor <incoming@patchwork.ozlabs.org>;\n\tFri,  4 May 2018 13:09:45 +1000 (AEST)",
            "from localhost ([::1]:60164 helo=lists.gnu.org)\n\tby lists.gnu.org with esmtp (Exim 4.71) (envelope-from\n\t<qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org>)\n\tid 1fER6M-0001jw-W4\n\tfor incoming@patchwork.ozlabs.org; Thu, 03 May 2018 23:09:43 -0400",
            "from eggs.gnu.org ([2001:4830:134:3::10]:33271)\n\tby lists.gnu.org with esmtp (Exim 4.71)\n\t(envelope-from <peterx@redhat.com>) id 1fER5W-0001iD-9c\n\tfor qemu-devel@nongnu.org; Thu, 03 May 2018 23:08:51 -0400",
            "from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)\n\t(envelope-from <peterx@redhat.com>) id 1fER5V-0005YP-3o\n\tfor qemu-devel@nongnu.org; Thu, 03 May 2018 23:08:50 -0400",
            "from mx3-rdu2.redhat.com ([66.187.233.73]:48264\n\thelo=mx1.redhat.com)\n\tby eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32)\n\t(Exim 4.71) (envelope-from <peterx@redhat.com>) id 1fER5U-0005Xj-UX\n\tfor qemu-devel@nongnu.org; Thu, 03 May 2018 23:08:49 -0400",
            "from smtp.corp.redhat.com\n\t(int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3])\n\t(using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits))\n\t(No client certificate requested)\n\tby mx1.redhat.com (Postfix) with ESMTPS id 9DFB240858C9;\n\tFri,  4 May 2018 03:08:48 +0000 (UTC)",
            "from xz-mi.redhat.com (ovpn-12-46.pek2.redhat.com [10.72.12.46])\n\tby smtp.corp.redhat.com (Postfix) with ESMTP id 49CCD11166E0;\n\tFri,  4 May 2018 03:08:44 +0000 (UTC)"
        ],
        "From": "Peter Xu <peterx@redhat.com>",
        "To": "qemu-devel@nongnu.org",
        "Date": "Fri,  4 May 2018 11:08:05 +0800",
        "Message-Id": "<20180504030811.28111-5-peterx@redhat.com>",
        "In-Reply-To": "<20180504030811.28111-1-peterx@redhat.com>",
        "References": "<20180504030811.28111-1-peterx@redhat.com>",
        "X-Scanned-By": "MIMEDefang 2.78 on 10.11.54.3",
        "X-Greylist": [
            "Sender IP whitelisted, not delayed by milter-greylist-4.5.16\n\t(mx1.redhat.com [10.11.55.5]);\n\tFri, 04 May 2018 03:08:48 +0000 (UTC)",
            "inspected by milter-greylist-4.5.16 (mx1.redhat.com\n\t[10.11.55.5]); \n\tFri, 04 May 2018 03:08:48 +0000 (UTC) for IP:'10.11.54.3'\n\tDOMAIN:'int-mx03.intmail.prod.int.rdu2.redhat.com'\n\tHELO:'smtp.corp.redhat.com' FROM:'peterx@redhat.com' RCPT:''"
        ],
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        "X-Received-From": "66.187.233.73",
        "Subject": "[Qemu-devel] [PATCH v2 04/10] intel-iommu: only do page walk for\n\tMAP notifiers",
        "X-BeenThere": "qemu-devel@nongnu.org",
        "X-Mailman-Version": "2.1.21",
        "Precedence": "list",
        "List-Id": "<qemu-devel.nongnu.org>",
        "List-Unsubscribe": "<https://lists.nongnu.org/mailman/options/qemu-devel>,\n\t<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>",
        "List-Archive": "<http://lists.nongnu.org/archive/html/qemu-devel/>",
        "List-Post": "<mailto:qemu-devel@nongnu.org>",
        "List-Help": "<mailto:qemu-devel-request@nongnu.org?subject=help>",
        "List-Subscribe": "<https://lists.nongnu.org/mailman/listinfo/qemu-devel>,\n\t<mailto:qemu-devel-request@nongnu.org?subject=subscribe>",
        "Cc": "Tian Kevin <kevin.tian@intel.com>, \"Michael S . Tsirkin\" <mst@redhat.com>,\n\tJason Wang <jasowang@redhat.com>, peterx@redhat.com,\n\tAlex Williamson <alex.williamson@redhat.com>,\n\tJintack Lim <jintack@cs.columbia.edu>",
        "Errors-To": "qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org",
        "Sender": "\"Qemu-devel\"\n\t<qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org>"
    },
    "content": "For UNMAP-only IOMMU notifiers, we don't really need to walk the page\ntables.  Fasten that procedure by skipping the page table walk.  That\nshould boost performance for UNMAP-only notifiers like vhost.\n\nSigned-off-by: Peter Xu <peterx@redhat.com>\n---\n include/hw/i386/intel_iommu.h |  2 ++\n hw/i386/intel_iommu.c         | 43 +++++++++++++++++++++++++++++++----\n 2 files changed, 40 insertions(+), 5 deletions(-)",
    "diff": "diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h\nindex ee517704e7..9e0a6c1c6a 100644\n--- a/include/hw/i386/intel_iommu.h\n+++ b/include/hw/i386/intel_iommu.h\n@@ -93,6 +93,8 @@ struct VTDAddressSpace {\n     IntelIOMMUState *iommu_state;\n     VTDContextCacheEntry context_cache_entry;\n     QLIST_ENTRY(VTDAddressSpace) next;\n+    /* Superset of notifier flags that this address space has */\n+    IOMMUNotifierFlag notifier_flags;\n };\n \n struct VTDBus {\ndiff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c\nindex 112971638d..9a418abfb6 100644\n--- a/hw/i386/intel_iommu.c\n+++ b/hw/i386/intel_iommu.c\n@@ -138,6 +138,12 @@ static inline void vtd_iommu_unlock(IntelIOMMUState *s)\n     qemu_mutex_unlock(&s->iommu_lock);\n }\n \n+/* Whether the address space needs to notify new mappings */\n+static inline gboolean vtd_as_notify_mappings(VTDAddressSpace *as)\n+{\n+    return as->notifier_flags & IOMMU_NOTIFIER_MAP;\n+}\n+\n /* GHashTable functions */\n static gboolean vtd_uint64_equal(gconstpointer v1, gconstpointer v2)\n {\n@@ -1433,14 +1439,35 @@ static void vtd_iotlb_page_invalidate_notify(IntelIOMMUState *s,\n     VTDAddressSpace *vtd_as;\n     VTDContextEntry ce;\n     int ret;\n+    hwaddr size = (1 << am) * VTD_PAGE_SIZE;\n \n     QLIST_FOREACH(vtd_as, &(s->notifiers_list), next) {\n         ret = vtd_dev_to_context_entry(s, pci_bus_num(vtd_as->bus),\n                                        vtd_as->devfn, &ce);\n         if (!ret && domain_id == VTD_CONTEXT_ENTRY_DID(ce.hi)) {\n-            vtd_page_walk(&ce, addr, addr + (1 << am) * VTD_PAGE_SIZE,\n-                          vtd_page_invalidate_notify_hook,\n-                          (void *)&vtd_as->iommu, true, s->aw_bits);\n+            if (vtd_as_notify_mappings(vtd_as)) {\n+                /*\n+                 * For MAP-inclusive notifiers, we need to walk the\n+                 * page table to sync the shadow page table.\n+                 */\n+                vtd_page_walk(&ce, addr, addr + size,\n+                              vtd_page_invalidate_notify_hook,\n+                              (void *)&vtd_as->iommu, true, s->aw_bits);\n+            } else {\n+                /*\n+                 * For UNMAP-only notifiers, we don't need to walk the\n+                 * page tables.  We just deliver the PSI down to\n+                 * invalidate caches.\n+                 */\n+                IOMMUTLBEntry entry = {\n+                    .target_as = &address_space_memory,\n+                    .iova = addr,\n+                    .translated_addr = 0,\n+                    .addr_mask = size - 1,\n+                    .perm = IOMMU_NONE,\n+                };\n+                memory_region_notify_iommu(&vtd_as->iommu, entry);\n+            }\n         }\n     }\n }\n@@ -2380,6 +2407,9 @@ static void vtd_iommu_notify_flag_changed(IOMMUMemoryRegion *iommu,\n         exit(1);\n     }\n \n+    /* Update per-address-space notifier flags */\n+    vtd_as->notifier_flags = new;\n+\n     if (old == IOMMU_NOTIFIER_NONE) {\n         /* Insert new ones */\n         QLIST_INSERT_HEAD(&s->notifiers_list, vtd_as, next);\n@@ -2890,8 +2920,11 @@ static void vtd_iommu_replay(IOMMUMemoryRegion *iommu_mr, IOMMUNotifier *n)\n                                   PCI_FUNC(vtd_as->devfn),\n                                   VTD_CONTEXT_ENTRY_DID(ce.hi),\n                                   ce.hi, ce.lo);\n-        vtd_page_walk(&ce, 0, ~0ULL, vtd_replay_hook, (void *)n, false,\n-                      s->aw_bits);\n+        if (vtd_as_notify_mappings(vtd_as)) {\n+            /* This is required only for MAP typed notifiers */\n+            vtd_page_walk(&ce, 0, ~0ULL, vtd_replay_hook, (void *)n, false,\n+                          s->aw_bits);\n+        }\n     } else {\n         trace_vtd_replay_ce_invalid(bus_n, PCI_SLOT(vtd_as->devfn),\n                                     PCI_FUNC(vtd_as->devfn));\n",
    "prefixes": [
        "v2",
        "04/10"
    ]
}