Merge git://github.com/rustyrussell/linuxHEADmaster

* git://github.com/rustyrussell/linux:
  lguest: move process freezing before pending signals check
  lguest: don't allow KVM-detection cpuid.
  lguest: Allow running under paravirt-enabled KVM.

2 files changed, 18 insertions, 8 deletions

diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c
index 13ee258442ae2b..f63da5ef217c40 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.
diff --git a/drivers/lguest/core.c b/drivers/lguest/core.c
index 2535933c49f83c..b5fdcb78a75b86 100644
--- a/drivers/lguest/core.c
+++ b/drivers/lguest/core.c
@@ -232,6 +232,13 @@ int run_guest(struct lg_cpu *cpu, unsigned long __user *user)
 			}
 		}
 
+		/*
+		 * All long-lived kernel loops need to check with this horrible
+		 * thing called the freezer.  If the Host is trying to suspend,
+		 * it stops us.
+		 */
+		try_to_freeze();
+
 		/* Check for signals */
 		if (signal_pending(current))
 			return -ERESTARTSYS;
@@ -246,13 +253,6 @@ int run_guest(struct lg_cpu *cpu, unsigned long __user *user)
 			try_deliver_interrupt(cpu, irq, more);
 
 		/*
-		 * All long-lived kernel loops need to check with this horrible
-		 * thing called the freezer.  If the Host is trying to suspend,
-		 * it stops us.
-		 */
-		try_to_freeze();
-
-		/*
 		 * Just make absolutely sure the Guest is still alive.  One of
 		 * those hypercalls could have been fatal, for example.
 		 */
@@ -313,7 +313,7 @@ static int __init init(void)
 	int err;
 
 	/* Lguest can't run under Xen, VMI or itself.  It does Tricky Stuff. */
-	if (paravirt_enabled()) {
+	if (get_kernel_rpl() != 0) {
 		printk("lguest is afraid of being a guest\n");
 		return -EPERM;
 	}