[PATCH] X86: don't print a warning when MTRR are blank andrunning in KVM

From: Joerg Roedel
Date: Thu Feb 21 2008 - 09:50:48 EST


Inside a KVM virtual machine the MTRRs are usually blank. This confuses Linux
and causes a warning message at boot. This patch removes that warning message
when running Linux as a KVM guest.

Signed-off-by: Joerg Roedel <joerg.roedel@xxxxxxx>
---
arch/x86/kernel/cpu/mtrr/main.c | 7 +++++--
1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c
index b6e136f..47e624c 100644
--- a/arch/x86/kernel/cpu/mtrr/main.c
+++ b/arch/x86/kernel/cpu/mtrr/main.c
@@ -43,6 +43,7 @@
#include <asm/uaccess.h>
#include <asm/processor.h>
#include <asm/msr.h>
+#include <asm/kvm_para.h>
#include "mtrr.h"

u32 num_var_ranges = 0;
@@ -687,12 +688,14 @@ int __init mtrr_trim_uncached_memory(unsigned long end_pfn)
}

/* kvm/qemu doesn't have mtrr set right, don't trim them all */
- if (!highest_pfn) {
+ if (!highest_pfn && !kvm_para_available()) {
printk(KERN_WARNING "WARNING: strange, CPU MTRRs all blank?\n");
WARN_ON(1);
- return 0;
}

+ if (!highest_pfn)
+ return 0;
+
if (highest_pfn < end_pfn) {
printk(KERN_WARNING "WARNING: BIOS bug: CPU MTRRs don't cover"
" all of memory, losing %luMB of RAM.\n",
--
1.5.3.7



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