From 61fad0cef2ed50a900717d11aab2e5e0ef121894 Mon Sep 17 00:00:00 2001
From: David Gibson <dgibson@redhat.com>
Date: Thu, 16 Nov 2017 03:07:29 +0100
Subject: [PATCH 25/30] memory: Create FlatView directly

RH-Author: David Gibson <dgibson@redhat.com>
Message-id: <20171116030732.8560-20-dgibson@redhat.com>
Patchwork-id: 77703
O-Subject: [PATCH 19/22] memory: Create FlatView directly
Bugzilla: 1481593
RH-Acked-by: Thomas Huth <thuth@redhat.com>
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>
RH-Acked-by: Eduardo Habkost <ehabkost@redhat.com>
RH-Acked-by: Laurent Vivier <lvivier@redhat.com>

From: Alexey Kardashevskiy <aik@ozlabs.ru>

This avoids usual memory_region_transaction_commit() which rebuilds
all FVs.

On POWER8 with 255 CPUs, 255 virtio-net, 40 PCI bridges guest this brings
down the boot time from 25s to 20s and reduces the amount of temporary FVs
allocated during machine constructon (~800000 -> ~640000) and amount of
temporary dispatch trees (~370000 -> ~300000), the total memory footprint
goes down (18G -> 17G).

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Message-Id: <20170921085110.25598-18-aik@ozlabs.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 202fc01b05572ecb258fdf4c5bd56cf6de8140c7)

Signed-off-by: David Gibson <dgibson@redhat.com>
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 memory.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/memory.c b/memory.c
index 00d5788..93b4221 100644
--- a/memory.c
+++ b/memory.c
@@ -1009,6 +1009,17 @@ static void address_space_set_flatview(AddressSpace *as)
     }
 }
 
+static void address_space_update_topology(AddressSpace *as)
+{
+    MemoryRegion *physmr = memory_region_get_flatview_root(as->root);
+
+    flatviews_init();
+    if (!g_hash_table_lookup(flat_views, physmr)) {
+        generate_memory_topology(physmr);
+    }
+    address_space_set_flatview(as);
+}
+
 void memory_region_transaction_begin(void)
 {
     qemu_flush_coalesced_mmio_buffer();
@@ -2720,7 +2731,6 @@ void memory_region_invalidate_mmio_ptr(MemoryRegion *mr, hwaddr offset,
 void address_space_init(AddressSpace *as, MemoryRegion *root, const char *name)
 {
     memory_region_ref(root);
-    memory_region_transaction_begin();
     as->root = root;
     as->current_map = NULL;
     as->ioeventfd_nb = 0;
@@ -2728,8 +2738,8 @@ void address_space_init(AddressSpace *as, MemoryRegion *root, const char *name)
     QTAILQ_INIT(&as->listeners);
     QTAILQ_INSERT_TAIL(&address_spaces, as, address_spaces_link);
     as->name = g_strdup(name ? name : "anonymous");
-    memory_region_update_pending |= root->enabled;
-    memory_region_transaction_commit();
+    address_space_update_topology(as);
+    address_space_update_ioeventfds(as);
 }
 
 static void do_address_space_destroy(AddressSpace *as)
-- 
1.8.3.1