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GET /api/patches/810923/?format=api
{ "id": 810923, "url": "http://patchwork.ozlabs.org/api/patches/810923/?format=api", "web_url": "http://patchwork.ozlabs.org/project/qemu-devel/patch/20170907092010.3605-4-aik@ozlabs.ru/", "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": "<20170907092010.3605-4-aik@ozlabs.ru>", "list_archive_url": null, "date": "2017-09-07T09:20:09", "name": "[RFC,qemu,3/4] memory: Share flat views and dispatch trees between address spaces", "commit_ref": null, "pull_url": null, "state": "new", "archived": false, "hash": "1d3fb65dc916abdc558785a5acb5ab1bb5833186", "submitter": { "id": 7621, "url": "http://patchwork.ozlabs.org/api/people/7621/?format=api", "name": "Alexey Kardashevskiy", "email": "aik@ozlabs.ru" }, "delegate": null, "mbox": "http://patchwork.ozlabs.org/project/qemu-devel/patch/20170907092010.3605-4-aik@ozlabs.ru/mbox/", "series": [ { "id": 1955, "url": "http://patchwork.ozlabs.org/api/series/1955/?format=api", "web_url": "http://patchwork.ozlabs.org/project/qemu-devel/list/?series=1955", "date": "2017-09-07T09:20:10", "name": "memory: Reduce memory use", "version": 1, "mbox": "http://patchwork.ozlabs.org/series/1955/mbox/" } ], "comments": "http://patchwork.ozlabs.org/api/patches/810923/comments/", "check": "pending", "checks": "http://patchwork.ozlabs.org/api/patches/810923/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>)", "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 3xnw2q4C6pz9sNV\n\tfor <incoming@patchwork.ozlabs.org>;\n\tThu, 7 Sep 2017 19:22:27 +1000 (AEST)", "from localhost ([::1]:39514 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 1dpt0y-0001wf-H2\n\tfor incoming@patchwork.ozlabs.org; Thu, 07 Sep 2017 05:22:24 -0400", "from eggs.gnu.org ([2001:4830:134:3::10]:57255)\n\tby lists.gnu.org with esmtp (Exim 4.71)\n\t(envelope-from <aik@ozlabs.ru>) id 1dpszb-0001H1-6g\n\tfor qemu-devel@nongnu.org; Thu, 07 Sep 2017 05:21:05 -0400", "from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)\n\t(envelope-from <aik@ozlabs.ru>) id 1dpszY-0007jF-Nu\n\tfor qemu-devel@nongnu.org; Thu, 07 Sep 2017 05:20:59 -0400", "from ozlabs.ru ([107.173.13.209]:51600)\n\tby eggs.gnu.org with esmtp (Exim 4.71)\n\t(envelope-from <aik@ozlabs.ru>) id 1dpszY-0007j2-95\n\tfor qemu-devel@nongnu.org; Thu, 07 Sep 2017 05:20:56 -0400", "from vpl1.ozlabs.ibm.com (localhost [IPv6:::1])\n\tby ozlabs.ru (Postfix) with ESMTP id CE94D3A604D3;\n\tThu, 7 Sep 2017 05:21:35 -0400 (EDT)" ], "From": "Alexey Kardashevskiy <aik@ozlabs.ru>", "To": "qemu-devel@nongnu.org", "Date": "Thu, 7 Sep 2017 19:20:09 +1000", "Message-Id": "<20170907092010.3605-4-aik@ozlabs.ru>", "X-Mailer": "git-send-email 2.11.0", "In-Reply-To": "<20170907092010.3605-1-aik@ozlabs.ru>", "References": "<20170907092010.3605-1-aik@ozlabs.ru>", "X-detected-operating-system": "by eggs.gnu.org: GNU/Linux 3.x [fuzzy]", "X-Received-From": "107.173.13.209", "Subject": "[Qemu-devel] [RFC PATCH qemu 3/4] memory: Share flat views and\n\tdispatch trees between address spaces", "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": "Alexey Kardashevskiy <aik@ozlabs.ru>, Paolo Bonzini <pbonzini@redhat.com>,\n\tStefan Hajnoczi <stefanha@gmail.com>,\n\tPeter Maydell <peter.maydell@linaro.org>,\n\tDavid Gibson <david@gibson.dropbear.id.au>", "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": "This allows sharing flat views between address spaces when the same root\nmemory region is used when creating a new address space.\n\nThis adds a global list of flat views and a list of attached address\nspaces per a flat view. Each address space references a flat view.\n\nThis hard codes the dispatch tree building instead of doing so via\na memory listener.\n\nSigned-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>\n---\n\nThis was suggested by Paolo in\nhttps://lists.gnu.org/archive/html/qemu-devel/2017-08/msg05011.html\n\nI am not putting \"Suggested-by\" as I want to make sure that this is doing\nwhat was actually suggested.\n---\n include/exec/memory-internal.h | 6 +-\n include/exec/memory.h | 9 +-\n exec.c | 58 ++--------\n hw/pci/pci.c | 3 +-\n memory.c | 253 +++++++++++++++++++++++++++--------------\n 5 files changed, 187 insertions(+), 142 deletions(-)", "diff": "diff --git a/include/exec/memory-internal.h b/include/exec/memory-internal.h\nindex fb467acdba..8516e0b48f 100644\n--- a/include/exec/memory-internal.h\n+++ b/include/exec/memory-internal.h\n@@ -22,9 +22,11 @@\n #ifndef CONFIG_USER_ONLY\n typedef struct AddressSpaceDispatch AddressSpaceDispatch;\n \n-void address_space_init_dispatch(AddressSpace *as);\n void address_space_unregister(AddressSpace *as);\n-void address_space_destroy_dispatch(AddressSpace *as);\n+void address_space_dispatch_free(AddressSpaceDispatch *d);\n+AddressSpaceDispatch *mem_begin(void);\n+void mem_commit(AddressSpaceDispatch *d);\n+void mem_add(AddressSpaceDispatch *d, MemoryRegionSection *section);\n \n extern const MemoryRegionOps unassigned_mem_ops;\n \ndiff --git a/include/exec/memory.h b/include/exec/memory.h\nindex 83e82e90d5..41ab165302 100644\n--- a/include/exec/memory.h\n+++ b/include/exec/memory.h\n@@ -27,6 +27,7 @@\n #include \"qemu/rcu.h\"\n #include \"hw/qdev-core.h\"\n \n+typedef struct AddressSpaceDispatch AddressSpaceDispatch;\n #define RAM_ADDR_INVALID (~(ram_addr_t)0)\n \n #define MAX_PHYS_ADDR_SPACE_BITS 62\n@@ -312,6 +313,7 @@ struct MemoryListener {\n };\n \n AddressSpaceDispatch *address_space_to_dispatch(AddressSpace *as);\n+MemoryRegion *address_space_root(AddressSpace *as);\n \n /**\n * AddressSpace: describes a mapping of addresses to #MemoryRegion objects\n@@ -320,20 +322,17 @@ struct AddressSpace {\n /* All fields are private. */\n struct rcu_head rcu;\n char *name;\n- MemoryRegion *root;\n- int ref_count;\n- bool malloced;\n \n /* Accessed via RCU. */\n struct FlatView *current_map;\n \n int ioeventfd_nb;\n struct MemoryRegionIoeventfd *ioeventfds;\n- struct AddressSpaceDispatch *dispatch;\n- struct AddressSpaceDispatch *next_dispatch;\n+\n MemoryListener dispatch_listener;\n QTAILQ_HEAD(memory_listeners_as, MemoryListener) listeners;\n QTAILQ_ENTRY(AddressSpace) address_spaces_link;\n+ QTAILQ_ENTRY(AddressSpace) flat_view_link;\n };\n \n /**\ndiff --git a/exec.c b/exec.c\nindex 66f01f5fce..51243f57f4 100644\n--- a/exec.c\n+++ b/exec.c\n@@ -188,15 +188,12 @@ typedef struct PhysPageMap {\n } PhysPageMap;\n \n struct AddressSpaceDispatch {\n- struct rcu_head rcu;\n-\n MemoryRegionSection *mru_section;\n /* This is a multi-level map on the physical address space.\n * The bottom level has pointers to MemoryRegionSections.\n */\n PhysPageEntry phys_map;\n PhysPageMap map;\n- AddressSpace *as;\n };\n \n typedef struct AddressSpaceDispatch AddressSpaceDispatch;\n@@ -240,11 +237,6 @@ struct DirtyBitmapSnapshot {\n unsigned long dirty[];\n };\n \n-AddressSpaceDispatch *address_space_to_dispatch(AddressSpace *as)\n-{\n- return atomic_rcu_read(&as->dispatch);\n-}\n-\n #endif\n \n #if !defined(CONFIG_USER_ONLY)\n@@ -1354,10 +1346,8 @@ static void register_multipage(AddressSpaceDispatch *d,\n phys_page_set(d, start_addr >> TARGET_PAGE_BITS, num_pages, section_index);\n }\n \n-static void mem_add(MemoryListener *listener, MemoryRegionSection *section)\n+void mem_add(AddressSpaceDispatch *d, MemoryRegionSection *section)\n {\n- AddressSpace *as = container_of(listener, AddressSpace, dispatch_listener);\n- AddressSpaceDispatch *d = as->next_dispatch;\n MemoryRegionSection now = *section, remain = *section;\n Int128 page_size = int128_make64(TARGET_PAGE_SIZE);\n \n@@ -2680,9 +2670,8 @@ static void io_mem_init(void)\n NULL, UINT64_MAX);\n }\n \n-static void mem_begin(MemoryListener *listener)\n+AddressSpaceDispatch *mem_begin(void)\n {\n- AddressSpace *as = container_of(listener, AddressSpace, dispatch_listener);\n AddressSpaceDispatch *d = g_new0(AddressSpaceDispatch, 1);\n uint16_t n;\n \n@@ -2696,27 +2685,19 @@ static void mem_begin(MemoryListener *listener)\n assert(n == PHYS_SECTION_WATCH);\n \n d->phys_map = (PhysPageEntry) { .ptr = PHYS_MAP_NODE_NIL, .skip = 1 };\n- as->next_dispatch = d;\n+\n+ return d;\n }\n \n-static void address_space_dispatch_free(AddressSpaceDispatch *d)\n+void address_space_dispatch_free(AddressSpaceDispatch *d)\n {\n phys_sections_free(&d->map);\n g_free(d);\n }\n \n-static void mem_commit(MemoryListener *listener)\n+void mem_commit(AddressSpaceDispatch *d)\n {\n- AddressSpace *as = container_of(listener, AddressSpace, dispatch_listener);\n- AddressSpaceDispatch *cur = as->dispatch;\n- AddressSpaceDispatch *next = as->next_dispatch;\n-\n- phys_page_compact_all(next, next->map.nodes_nb);\n-\n- atomic_rcu_set(&as->dispatch, next);\n- if (cur) {\n- call_rcu(cur, address_space_dispatch_free, rcu);\n- }\n+ phys_page_compact_all(d, d->map.nodes_nb);\n }\n \n static void tcg_commit(MemoryListener *listener)\n@@ -2732,39 +2713,16 @@ static void tcg_commit(MemoryListener *listener)\n * We reload the dispatch pointer now because cpu_reloading_memory_map()\n * may have split the RCU critical section.\n */\n- d = atomic_rcu_read(&cpuas->as->dispatch);\n+ d = address_space_to_dispatch(cpuas->as);\n atomic_rcu_set(&cpuas->memory_dispatch, d);\n tlb_flush(cpuas->cpu);\n }\n \n-void address_space_init_dispatch(AddressSpace *as)\n-{\n- as->dispatch = NULL;\n- as->dispatch_listener = (MemoryListener) {\n- .begin = mem_begin,\n- .commit = mem_commit,\n- .region_add = mem_add,\n- .region_nop = mem_add,\n- .priority = 0,\n- };\n- memory_listener_register(&as->dispatch_listener, as);\n-}\n-\n void address_space_unregister(AddressSpace *as)\n {\n memory_listener_unregister(&as->dispatch_listener);\n }\n \n-void address_space_destroy_dispatch(AddressSpace *as)\n-{\n- AddressSpaceDispatch *d = as->dispatch;\n-\n- atomic_rcu_set(&as->dispatch, NULL);\n- if (d) {\n- call_rcu(d, address_space_dispatch_free, rcu);\n- }\n-}\n-\n static void memory_map_init(void)\n {\n system_memory = g_malloc(sizeof(*system_memory));\ndiff --git a/hw/pci/pci.c b/hw/pci/pci.c\nindex 258fbe51e2..86b9e419fd 100644\n--- a/hw/pci/pci.c\n+++ b/hw/pci/pci.c\n@@ -88,7 +88,8 @@ static void pci_init_bus_master(PCIDevice *pci_dev)\n \n memory_region_init_alias(&pci_dev->bus_master_enable_region,\n OBJECT(pci_dev), \"bus master\",\n- dma_as->root, 0, memory_region_size(dma_as->root));\n+ address_space_root(dma_as), 0,\n+ memory_region_size(address_space_root(dma_as)));\n memory_region_set_enabled(&pci_dev->bus_master_enable_region, false);\n memory_region_add_subregion(&pci_dev->bus_master_container_region, 0,\n &pci_dev->bus_master_enable_region);\ndiff --git a/memory.c b/memory.c\nindex c6904a7deb..385a507511 100644\n--- a/memory.c\n+++ b/memory.c\n@@ -47,6 +47,9 @@ static QTAILQ_HEAD(memory_listeners, MemoryListener) memory_listeners\n static QTAILQ_HEAD(, AddressSpace) address_spaces\n = QTAILQ_HEAD_INITIALIZER(address_spaces);\n \n+static QTAILQ_HEAD(FlatViewList, FlatView) flat_views\n+ = QTAILQ_HEAD_INITIALIZER(flat_views);\n+\n typedef struct AddrRange AddrRange;\n \n /*\n@@ -230,6 +233,11 @@ struct FlatView {\n FlatRange *ranges;\n unsigned nr;\n unsigned nr_allocated;\n+ MemoryRegion *root;\n+ struct AddressSpaceDispatch *dispatch;\n+\n+ QTAILQ_ENTRY(FlatView) flat_views_link;\n+ QTAILQ_HEAD(address_spaces, AddressSpace) address_spaces;\n };\n \n typedef struct AddressSpaceOps AddressSpaceOps;\n@@ -259,12 +267,19 @@ static bool flatrange_equal(FlatRange *a, FlatRange *b)\n && a->readonly == b->readonly;\n }\n \n-static void flatview_init(FlatView *view)\n+static void flatview_ref(FlatView *view);\n+\n+static FlatView *flatview_alloc(MemoryRegion *mr_root)\n {\n+ FlatView *view;\n+\n+ view = g_new0(FlatView, 1);\n view->ref = 1;\n- view->ranges = NULL;\n- view->nr = 0;\n- view->nr_allocated = 0;\n+ view->root = mr_root;\n+ memory_region_ref(mr_root);\n+ QTAILQ_INIT(&view->address_spaces);\n+\n+ return view;\n }\n \n /* Insert a range into a given position. Caller is responsible for maintaining\n@@ -292,6 +307,10 @@ static void flatview_destroy(FlatView *view)\n memory_region_unref(view->ranges[i].mr);\n }\n g_free(view->ranges);\n+ if (view->dispatch) {\n+ address_space_dispatch_free(view->dispatch);\n+ }\n+ memory_region_unref(view->root);\n g_free(view);\n }\n \n@@ -303,7 +322,7 @@ static void flatview_ref(FlatView *view)\n static void flatview_unref(FlatView *view)\n {\n if (atomic_fetch_dec(&view->ref) == 1) {\n- flatview_destroy(view);\n+ call_rcu(view, flatview_destroy, rcu);\n }\n }\n \n@@ -608,7 +627,7 @@ static AddressSpace *memory_region_to_address_space(MemoryRegion *mr)\n mr = mr->container;\n }\n QTAILQ_FOREACH(as, &address_spaces, address_spaces_link) {\n- if (mr == as->root) {\n+ if (mr == as->current_map->root) {\n return as;\n }\n }\n@@ -702,23 +721,6 @@ static void render_memory_region(FlatView *view,\n }\n }\n \n-/* Render a memory topology into a list of disjoint absolute ranges. */\n-static FlatView *generate_memory_topology(MemoryRegion *mr)\n-{\n- FlatView *view;\n-\n- view = g_new(FlatView, 1);\n- flatview_init(view);\n-\n- if (mr) {\n- render_memory_region(view, mr, int128_zero(),\n- addrrange_make(int128_zero(), int128_2_64()), false);\n- }\n- flatview_simplify(view);\n-\n- return view;\n-}\n-\n static void address_space_add_del_ioeventfds(AddressSpace *as,\n MemoryRegionIoeventfd *fds_new,\n unsigned fds_new_nb,\n@@ -769,12 +771,10 @@ static void address_space_add_del_ioeventfds(AddressSpace *as,\n }\n }\n \n-static FlatView *address_space_get_flatview(AddressSpace *as)\n+static FlatView *flatview_get(FlatView *view)\n {\n- FlatView *view;\n-\n rcu_read_lock();\n- view = atomic_rcu_read(&as->current_map);\n+ view = atomic_rcu_read(&view);\n flatview_ref(view);\n rcu_read_unlock();\n return view;\n@@ -789,7 +789,7 @@ static void address_space_update_ioeventfds(AddressSpace *as)\n AddrRange tmp;\n unsigned i;\n \n- view = address_space_get_flatview(as);\n+ view = flatview_get(as->current_map);\n FOR_EACH_FLAT_RANGE(fr, view) {\n for (i = 0; i < fr->mr->ioeventfd_nb; ++i) {\n tmp = addrrange_shift(fr->mr->ioeventfds[i].addr,\n@@ -881,28 +881,89 @@ static void address_space_update_topology_pass(AddressSpace *as,\n }\n }\n \n-\n-static void address_space_update_topology(AddressSpace *as)\n+static FlatView *address_space_update_flatview(FlatView *view)\n {\n- FlatView *old_view = address_space_get_flatview(as);\n- FlatView *new_view = generate_memory_topology(as->root);\n+ AddressSpace *as, *asnext;\n+ FlatView *old_view = flatview_get(view);\n+ MemoryRegion *root = old_view->root;\n+ FlatView *new_view = flatview_alloc(root);\n+ unsigned iold, inew;\n+ FlatRange *frold, *frnew;\n \n- address_space_update_topology_pass(as, old_view, new_view, false);\n- address_space_update_topology_pass(as, old_view, new_view, true);\n+ if (root) {\n+ render_memory_region(new_view, root, int128_zero(),\n+ addrrange_make(int128_zero(), int128_2_64()),\n+ false);\n+ flatview_simplify(new_view);\n+ }\n \n- /* Writes are protected by the BQL. */\n- atomic_rcu_set(&as->current_map, new_view);\n- call_rcu(old_view, flatview_unref, rcu);\n+ new_view->dispatch = mem_begin();\n \n- /* Note that all the old MemoryRegions are still alive up to this\n- * point. This relieves most MemoryListeners from the need to\n- * ref/unref the MemoryRegions they get---unless they use them\n- * outside the iothread mutex, in which case precise reference\n- * counting is necessary.\n+ /*\n+ * FIXME: this is cut-n-paste from address_space_update_topology_pass,\n+ * simplify it\n */\n+ iold = inew = 0;\n+ while (iold < old_view->nr || inew < new_view->nr) {\n+ if (iold < old_view->nr) {\n+ frold = &old_view->ranges[iold];\n+ } else {\n+ frold = NULL;\n+ }\n+ if (inew < new_view->nr) {\n+ frnew = &new_view->ranges[inew];\n+ } else {\n+ frnew = NULL;\n+ }\n+\n+ if (frold\n+ && (!frnew\n+ || int128_lt(frold->addr.start, frnew->addr.start)\n+ || (int128_eq(frold->addr.start, frnew->addr.start)\n+ && !flatrange_equal(frold, frnew)))) {\n+ ++iold;\n+ } else if (frold && frnew && flatrange_equal(frold, frnew)) {\n+ /* In both and unchanged (except logging may have changed) */\n+ MemoryRegionSection mrs = section_from_flat_range(frnew,\n+ new_view->dispatch);\n+\n+ mem_add(new_view->dispatch, &mrs);\n+\n+ ++iold;\n+ ++inew;\n+ } else {\n+ /* In new */\n+ MemoryRegionSection mrs = section_from_flat_range(frnew,\n+ new_view->dispatch);\n+\n+ mem_add(new_view->dispatch, &mrs);\n+\n+ ++inew;\n+ }\n+ }\n+\n+ mem_commit(new_view->dispatch);\n+\n+ QTAILQ_FOREACH(as, &old_view->address_spaces, flat_view_link) {\n+ address_space_update_topology_pass(as, old_view, new_view, false);\n+ address_space_update_topology_pass(as, old_view, new_view, true);\n+ }\n+\n+ QTAILQ_FOREACH_SAFE(as, &old_view->address_spaces, flat_view_link, asnext) {\n+ QTAILQ_REMOVE(&old_view->address_spaces, as, flat_view_link);\n+ flatview_unref(old_view);\n+\n+ atomic_rcu_set(&as->current_map, new_view);\n+\n+ flatview_ref(new_view);\n+ QTAILQ_INSERT_TAIL(&new_view->address_spaces, as, flat_view_link);\n+\n+ address_space_update_ioeventfds(as);\n+ }\n+\n flatview_unref(old_view);\n \n- address_space_update_ioeventfds(as);\n+ return new_view;\n }\n \n void memory_region_transaction_begin(void)\n@@ -921,11 +982,31 @@ void memory_region_transaction_commit(void)\n --memory_region_transaction_depth;\n if (!memory_region_transaction_depth) {\n if (memory_region_update_pending) {\n+ FlatView *view, *vnext;\n+ struct FlatViewList fwstmp = QTAILQ_HEAD_INITIALIZER(fwstmp);\n+\n MEMORY_LISTENER_CALL_GLOBAL(begin, Forward);\n \n- QTAILQ_FOREACH(as, &address_spaces, address_spaces_link) {\n- address_space_update_topology(as);\n+ QTAILQ_FOREACH_SAFE(view, &flat_views, flat_views_link, vnext) {\n+ FlatView *old_view, *new_view;\n+\n+ old_view = flatview_get(view);\n+ new_view = address_space_update_flatview(old_view);\n+\n+ QTAILQ_REMOVE(&flat_views, old_view, flat_views_link);\n+ flatview_unref(old_view);\n+ flatview_unref(old_view);\n+\n+ QTAILQ_INSERT_HEAD(&fwstmp, new_view, flat_views_link);\n+\n+ flatview_unref(new_view);\n }\n+\n+ QTAILQ_FOREACH_SAFE(view, &fwstmp, flat_views_link, vnext) {\n+ QTAILQ_REMOVE(&fwstmp, view, flat_views_link);\n+ QTAILQ_INSERT_HEAD(&flat_views, view, flat_views_link);\n+ }\n+\n memory_region_update_pending = false;\n MEMORY_LISTENER_CALL_GLOBAL(commit, Forward);\n } else if (ioeventfd_update_pending) {\n@@ -1834,7 +1915,7 @@ void memory_region_sync_dirty_bitmap(MemoryRegion *mr)\n continue;\n }\n as = listener->address_space;\n- view = address_space_get_flatview(as);\n+ view = flatview_get(as->current_map);\n FOR_EACH_FLAT_RANGE(fr, view) {\n if (fr->mr == mr) {\n MemoryRegionSection mrs = section_from_flat_range(fr,\n@@ -1938,7 +2019,7 @@ static void memory_region_update_coalesced_range_as(MemoryRegion *mr, AddressSpa\n AddrRange tmp;\n MemoryRegionSection section;\n \n- view = address_space_get_flatview(as);\n+ view = flatview_get(as->current_map);\n FOR_EACH_FLAT_RANGE(fr, view) {\n if (fr->mr == mr) {\n section = (MemoryRegionSection) {\n@@ -2350,7 +2431,7 @@ void memory_global_dirty_log_sync(void)\n continue;\n }\n as = listener->address_space;\n- view = address_space_get_flatview(as);\n+ view = flatview_get(as->current_map);\n FOR_EACH_FLAT_RANGE(fr, view) {\n if (fr->dirty_log_mask) {\n MemoryRegionSection mrs = section_from_flat_range(fr,\n@@ -2436,7 +2517,7 @@ static void listener_add_address_space(MemoryListener *listener,\n }\n }\n \n- view = address_space_get_flatview(as);\n+ view = flatview_get(as->current_map);\n FOR_EACH_FLAT_RANGE(fr, view) {\n MemoryRegionSection section = {\n .mr = fr->mr,\n@@ -2615,67 +2696,72 @@ void memory_region_invalidate_mmio_ptr(MemoryRegion *mr, hwaddr offset,\n \n void address_space_init(AddressSpace *as, MemoryRegion *root, const char *name)\n {\n- memory_region_ref(root);\n- memory_region_transaction_begin();\n- as->ref_count = 1;\n- as->root = root;\n- as->malloced = false;\n- as->current_map = g_new(FlatView, 1);\n- flatview_init(as->current_map);\n+ FlatView *view;\n+\n+ as->current_map = NULL;\n as->ioeventfd_nb = 0;\n as->ioeventfds = NULL;\n QTAILQ_INIT(&as->listeners);\n QTAILQ_INSERT_TAIL(&address_spaces, as, address_spaces_link);\n as->name = g_strdup(name ? name : \"anonymous\");\n- address_space_init_dispatch(as);\n- memory_region_update_pending |= root->enabled;\n- memory_region_transaction_commit();\n+\n+ QTAILQ_FOREACH(view, &flat_views, flat_views_link) {\n+ assert(root);\n+ if (view->root == root) {\n+ as->current_map = flatview_get(view);\n+ break;\n+ }\n+ }\n+\n+ if (!as->current_map) {\n+ as->current_map = flatview_alloc(root);\n+\n+ QTAILQ_INSERT_TAIL(&flat_views, as->current_map, flat_views_link);\n+ }\n+\n+ QTAILQ_INSERT_TAIL(&as->current_map->address_spaces, as, flat_view_link);\n+}\n+\n+MemoryRegion *address_space_root(AddressSpace *as)\n+{\n+ return as->current_map->root;\n+}\n+\n+AddressSpaceDispatch *address_space_to_dispatch(AddressSpace *as)\n+{\n+ return atomic_rcu_read(&as->current_map)->dispatch;\n }\n \n static void do_address_space_destroy(AddressSpace *as)\n {\n- bool do_free = as->malloced;\n+ FlatView *view = flatview_get(as->current_map);\n \n- address_space_destroy_dispatch(as);\n assert(QTAILQ_EMPTY(&as->listeners));\n \n- flatview_unref(as->current_map);\n+ QTAILQ_REMOVE(&view->address_spaces, as, flat_view_link);\n+ flatview_unref(view);\n+\n+ flatview_unref(view);\n+\n g_free(as->name);\n g_free(as->ioeventfds);\n- memory_region_unref(as->root);\n- if (do_free) {\n- g_free(as);\n- }\n+ g_free(as);\n }\n \n AddressSpace *address_space_init_shareable(MemoryRegion *root, const char *name)\n {\n AddressSpace *as;\n \n- QTAILQ_FOREACH(as, &address_spaces, address_spaces_link) {\n- if (root == as->root && as->malloced) {\n- as->ref_count++;\n- return as;\n- }\n- }\n-\n as = g_malloc0(sizeof *as);\n address_space_init(as, root, name);\n- as->malloced = true;\n+\n return as;\n }\n \n void address_space_destroy(AddressSpace *as)\n {\n- MemoryRegion *root = as->root;\n-\n- as->ref_count--;\n- if (as->ref_count) {\n- return;\n- }\n /* Flush out anything from MemoryListeners listening in on this */\n memory_region_transaction_begin();\n- as->root = NULL;\n memory_region_transaction_commit();\n QTAILQ_REMOVE(&address_spaces, as, address_spaces_link);\n address_space_unregister(as);\n@@ -2684,7 +2770,6 @@ void address_space_destroy(AddressSpace *as)\n * entries that the guest should never use. Wait for the old\n * values to expire before freeing the data.\n */\n- as->root = root;\n call_rcu(as, do_address_space_destroy, rcu);\n }\n \n@@ -2816,7 +2901,7 @@ static void mtree_print_mr(fprintf_function mon_printf, void *f,\n static void mtree_print_flatview(fprintf_function p, void *f,\n AddressSpace *as)\n {\n- FlatView *view = address_space_get_flatview(as);\n+ FlatView *view = flatview_get(as->current_map);\n FlatRange *range = &view->ranges[0];\n MemoryRegion *mr;\n int n = view->nr;\n@@ -2873,7 +2958,7 @@ void mtree_info(fprintf_function mon_printf, void *f, bool flatview)\n \n QTAILQ_FOREACH(as, &address_spaces, address_spaces_link) {\n mon_printf(f, \"address-space: %s\\n\", as->name);\n- mtree_print_mr(mon_printf, f, as->root, 1, 0, &ml_head);\n+ mtree_print_mr(mon_printf, f, as->current_map->root, 1, 0, &ml_head);\n mon_printf(f, \"\\n\");\n }\n \n", "prefixes": [ "RFC", "qemu", "3/4" ] }