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authorIan Campbell <ian.campbell@citrix.com>2009-02-07 04:09:48 +0100
committerJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>2010-10-22 21:57:27 +0200
commit35ae11fd146384d222f3bb1f17eed1970cc92c36 (patch)
tree5d8298d9e8c41525f501003cc3c4ed18ac23ace2 /arch/x86/xen/setup.c
parentxen: don't map missing memory (diff)
downloadlinux-35ae11fd146384d222f3bb1f17eed1970cc92c36.tar.xz
linux-35ae11fd146384d222f3bb1f17eed1970cc92c36.zip
xen: Use host-provided E820 map
Rather than simply using a flat memory map from Xen, use its provided E820 map. This allows the domain builder to tell the domain to reserve space for more pages than those initially provided at domain-build time. It also allows the host to specify holes in the address space (for PCI-passthrough, for example). Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Diffstat (limited to 'arch/x86/xen/setup.c')
-rw-r--r--arch/x86/xen/setup.c38
1 files changed, 36 insertions, 2 deletions
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 328b00305426..dd2eb2a9303f 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -19,6 +19,7 @@
#include <xen/page.h>
#include <xen/interface/callback.h>
+#include <xen/interface/memory.h>
#include <xen/interface/physdev.h>
#include <xen/interface/memory.h>
#include <xen/features.h>
@@ -107,13 +108,46 @@ static unsigned long __init xen_return_unused_memory(unsigned long max_pfn,
char * __init xen_memory_setup(void)
{
+ static struct e820entry map[E820MAX] __initdata;
+
unsigned long max_pfn = xen_start_info->nr_pages;
+ unsigned long long mem_end;
+ int rc;
+ struct xen_memory_map memmap;
+ int i;
max_pfn = min(MAX_DOMAIN_PAGES, max_pfn);
+ mem_end = PFN_PHYS(max_pfn);
+
+ memmap.nr_entries = E820MAX;
+ set_xen_guest_handle(memmap.buffer, map);
+
+ rc = HYPERVISOR_memory_op(XENMEM_memory_map, &memmap);
+ if (rc == -ENOSYS) {
+ memmap.nr_entries = 1;
+ map[0].addr = 0ULL;
+ map[0].size = mem_end;
+ /* 8MB slack (to balance backend allocations). */
+ map[0].size += 8ULL << 20;
+ map[0].type = E820_RAM;
+ rc = 0;
+ }
+ BUG_ON(rc);
e820.nr_map = 0;
-
- e820_add_region(0, PFN_PHYS((u64)max_pfn), E820_RAM);
+ for (i = 0; i < memmap.nr_entries; i++) {
+ unsigned long long end = map[i].addr + map[i].size;
+ if (map[i].type == E820_RAM) {
+ if (map[i].addr > mem_end)
+ continue;
+ if (end > mem_end) {
+ /* Truncate region to max_mem. */
+ map[i].size -= end - mem_end;
+ }
+ }
+ if (map[i].size > 0)
+ e820_add_region(map[i].addr, map[i].size, map[i].type);
+ }
/*
* Even though this is normal, usable memory under Xen, reserve