File 0033-linux-user-reserve-4GB-of-vmem-for-32-on-6... of Package qemu

Overview Repositories Revisions Requests Users Attributes Meta

File 0033-linux-user-reserve-4GB-of-vmem-for-32-on-64.patch of Package qemu (Revision 68a258807f7ca2d035244c960c780f34)

Currently displaying revision 68a258807f7ca2d035244c960c780f34 , Show latest

From ac233b323ad7e498c665e8c74df7e44de4a542c0 Mon Sep 17 00:00:00 2001
From: Alexander Graf <agraf@suse.de>
Date: Wed, 14 Dec 2011 00:33:28 +0100
Subject: [PATCH] linux-user: reserve 4GB of vmem for 32-on-64

When running 32-on-64 bit guests, we should always reserve as much
virtual memory as we possibly can for the guest process, so it can
never overlap with QEMU address space.

Fortunately we already have the infrastructure for that. All that's
missing is some sane default value to also make use of it!

Signed-off-by: Alexander Graf <agraf@suse.de>
---
 linux-user/main.c |   11 +++++++++++
 1 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/linux-user/main.c b/linux-user/main.c
index 788ff98..3ffee40 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -48,8 +48,19 @@ unsigned long mmap_min_addr;
 #if defined(CONFIG_USE_GUEST_BASE)
 unsigned long guest_base;
 int have_guest_base;
+#if (TARGET_LONG_BITS == 32) && (HOST_LONG_BITS == 64)
+/*
+ * When running 32-on-64 we should make sure we can fit all of the possible
+ * guest address space into a contiguous chunk of virtual host memory.
+ *
+ * This way we will never overlap with our own libraries or binaries or stack
+ * or anything else that QEMU maps.
+ */
+unsigned long reserved_va = 0xf7000000;
+#else
 unsigned long reserved_va;
 #endif
+#endif
 
 static void usage(void);
 extern int use_stopflag;
-- 
1.6.0.2

Places

File 0033-linux-user-reserve-4GB-of-vmem-for-32-on-64.patch of Package qemu (Revision 68a258807f7ca2d035244c960c780f34)

Places