aboutsummaryrefslogtreecommitdiffstats
path: root/arch/x86/lguest
diff options
context:
space:
mode:
authorRusty Russell <rusty@rustcorp.com.au>2011-10-27 10:56:17 +1030
committerRusty Russell <rusty@rustcorp.com.au>2011-10-27 10:56:17 +1030
commit89cfc99177c9270c5c6d429f6c5177ab3428ad57 (patch)
treef8336b3a477325305746cc425181d5d12361d7f7 /arch/x86/lguest
parentb56e3215d4331bff9b6d5e5f68bc1ec5cb01e650 (diff)
lguest: don't allow KVM-detection cpuid.
Host might be running under KVM, but we shouldn't allow Guest to think it can use KVM hypercalls (it can't, and it will embarrass itself if it tries). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'arch/x86/lguest')
-rw-r--r--arch/x86/lguest/boot.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c
index 13ee258442ae..f63da5ef217c 100644
--- a/arch/x86/lguest/boot.c
+++ b/arch/x86/lguest/boot.c
@@ -70,6 +70,7 @@
#include <asm/i387.h>
#include <asm/stackprotector.h>
#include <asm/reboot.h> /* for struct machine_ops */
+#include <asm/kvm_para.h>
/*G:010
* Welcome to the Guest!
@@ -455,6 +456,15 @@ static void lguest_cpuid(unsigned int *ax, unsigned int *bx,
*ax &= 0xFFFFF0FF;
*ax |= 0x00000500;
break;
+
+ /*
+ * This is used to detect if we're running under KVM. We might be,
+ * but that's a Host matter, not us. So say we're not.
+ */
+ case KVM_CPUID_SIGNATURE:
+ *bx = *cx = *dx = 0;
+ break;
+
/*
* 0x80000000 returns the highest Extended Function, so we futureproof
* like we do above by limiting it to known fields.

Privacy Policy