Jan Beulich
2008-Sep-16 14:53 UTC
[Xen-devel] [PATCH] x86-64: enforce memory limits imposed by virtual memory layout
... which currently means:
- The 1:1 map cannot deal with more than 1Tb.
- The m2p table can handle at most 8Tb.
- The page_info array can cover up to e.g. 1.6Gb (<= 64 CPUs) or
1Tb (193-256 CPUs).
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Index: 2008-09-01/xen/arch/x86/e820.c
==================================================================---
2008-09-01.orig/xen/arch/x86/e820.c 2008-09-05 16:14:11.000000000 +0200
+++ 2008-09-01/xen/arch/x86/e820.c 2008-09-16 16:47:24.000000000 +0200
@@ -4,6 +4,7 @@
#include <xen/compat.h>
#include <xen/dmi.h>
#include <asm/e820.h>
+#include <asm/mm.h>
#include <asm/page.h>
/* opt_mem: Limit of physical RAM. Any RAM beyond this point is ignored. */
@@ -327,7 +328,7 @@ static void __init clip_to_limit(uint64_
continue;
if ( warnmsg )
{
- snprintf(_warnmsg, sizeof(_warnmsg), warnmsg,
(int)(limit>>30));
+ snprintf(_warnmsg, sizeof(_warnmsg), warnmsg,
(long)(limit>>30));
printk("WARNING: %s\n", _warnmsg);
}
printk("Truncating memory map to %lukB\n",
@@ -366,8 +367,25 @@ static void __init machine_specific_memo
#ifdef __i386__
clip_to_limit((1ULL << 30) * MACHPHYS_MBYTES,
- "Only the first %u GB of the physical memory map "
+ "Only the first %lu GB of the physical memory map "
"can be accessed by Xen in 32-bit mode.");
+#else
+ {
+ unsigned long limit, mpt_limit, pft_limit;
+
+ limit = DIRECTMAP_VIRT_END - DIRECTMAP_VIRT_START;
+ mpt_limit = ((RDWR_MPT_VIRT_END - RDWR_MPT_VIRT_START)
+ / sizeof(unsigned long)) << PAGE_SHIFT;
+ pft_limit = ((FRAMETABLE_VIRT_END - FRAMETABLE_VIRT_START)
+ / sizeof(struct page_info)) << PAGE_SHIFT;
+ if ( limit > mpt_limit )
+ limit = mpt_limit;
+ if ( limit > pft_limit )
+ limit = pft_limit;
+ clip_to_limit(limit,
+ "Only the first %lu GB of the physical "
+ "memory map can be accessed by Xen.");
+ }
#endif
reserve_dmi_region();
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