From 6a2046866f4e057da661d496fc8014e5bca0d44e Mon Sep 17 00:00:00 2001
From: Gerd Hoffmann <kraxel@redhat.com>
Date: Thu, 16 Jan 2014 10:25:59 +0100
Subject: [PATCH 03/14] q35: gigabyle alignment for ram

RH-Author: Gerd Hoffmann <kraxel@redhat.com>
Message-id: <1389867959-12463-5-git-send-email-kraxel@redhat.com>
Patchwork-id: 56746
O-Subject: [RHEL-7 qemu-kvm PATCH 4/4] q35: gigabyle alignment for ram
Bugzilla: 1026548
RH-Acked-by: Laszlo Ersek <lersek@redhat.com>
RH-Acked-by: Igor Mammedov <imammedo@redhat.com>
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>

Map 2G of memory below 4G, so the two RAM pieces are nicely
aligned to gigabyte borders.

Keep old memory layout for in case all memory fits below 4G and
thus we don't have to split RAM into pieces in the first place.

upstream: Not yet.  Planned, but want sort mmconf bar issues first.
          Put into rhel7 nevertheless to make life simpler for rhel8
          (i.e. no need to support gigabyte alignment the rhel6 way).

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 hw/i386/pc_q35.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 hw/i386/pc_q35.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index 232c62d..7e46799 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -51,6 +51,7 @@
 static bool smbios_type1_defaults = true;
 static bool has_pci_info;
 static bool has_acpi_build = true;
+static bool gigabyte_align = true;
 
 /* PC hardware initialisation */
 static void pc_q35_init(QEMUMachineInitArgs *args)
@@ -87,8 +88,9 @@ static void pc_q35_init(QEMUMachineInitArgs *args)
     kvmclock_create();
 
     if (args->ram_size >= 0xb0000000) {
-        above_4g_mem_size = args->ram_size - 0xb0000000;
-        below_4g_mem_size = 0xb0000000;
+        ram_addr_t lowmem = gigabyte_align ? 0x80000000 : 0xb0000000;
+        above_4g_mem_size = args->ram_size - lowmem;
+        below_4g_mem_size = lowmem;
     } else {
         above_4g_mem_size = 0;
         below_4g_mem_size = args->ram_size;
-- 
1.7.1