summaryrefslogtreecommitdiffstats
path: root/arch/x86
diff options
context:
space:
mode:
authorKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2011-03-09 22:03:16 -0500
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2011-03-11 11:01:45 -0500
commit86b32122fd54addc9af01f8b919c65d3f49090a3 (patch)
treeb441a0cd5ff7875672502777386eb97b5111f5a9 /arch/x86
parent2f14ddc3a7146ea4cd5a3d1ecd993f85f2e4f948 (diff)
downloadlinux-86b32122fd54addc9af01f8b919c65d3f49090a3.tar.bz2
xen/e820: Don't mark balloon memory as E820_UNUSABLE when running as guest and fix overflow.
If we have a guest that asked for: memory=1024 maxmem=2048 Which means we want 1GB now, and create pagetables so that we can expand up to 2GB, we would have this E820 layout: [ 0.000000] BIOS-provided physical RAM map: [ 0.000000] Xen: 0000000000000000 - 00000000000a0000 (usable) [ 0.000000] Xen: 00000000000a0000 - 0000000000100000 (reserved) [ 0.000000] Xen: 0000000000100000 - 0000000080800000 (usable) Due to patch: "xen/setup: Inhibit resource API from using System RAM E820 gaps as PCI mem gaps." we would mark the memory past the 1GB mark as unusuable resulting in: [ 0.000000] BIOS-provided physical RAM map: [ 0.000000] Xen: 0000000000000000 - 00000000000a0000 (usable) [ 0.000000] Xen: 00000000000a0000 - 0000000000100000 (reserved) [ 0.000000] Xen: 0000000000100000 - 0000000040000000 (usable) [ 0.000000] Xen: 0000000040000000 - 0000000080800000 (unusable) which meant that we could not balloon up anymore. We could balloon the guest down. The fix is to run the code introduced by the above mentioned patch only for the initial domain. We will have to revisit this once we start introducing a modified E820 for PCI passthrough so that we can utilize the P2M identity code. We also fix an overflow by having UL instead of ULL on 32-bit machines. [v2: Ian pointed to the overflow issue] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/xen/setup.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 2a4add9634ce..010ba2e62de5 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -200,7 +200,8 @@ char * __init xen_memory_setup(void)
* used as potential resource for I/O address (happens
* when 'allocate_resource' is called).
*/
- if (delta && end < 0x100000000UL)
+ if (delta &&
+ (xen_initial_domain() && end < 0x100000000ULL))
e820_add_region(end, delta, E820_UNUSABLE);
}