lguest: make pending notifications per-vcpu

this patch makes the pending_notify field, used to control
pending notifications, per-vcpu, instead of per-guest
Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

drivers/lguest/core.c

@@ -186,10 +186,10 @@ int run_guest(struct lg_cpu *cpu, unsigned long __user *user)
 
 		/* It's possible the Guest did a NOTIFY hypercall to the
 		 * Launcher, in which case we return from the read() now. */
-		if (lg->pending_notify) {
-			if (put_user(lg->pending_notify, user))
+		if (cpu->pending_notify) {
+			if (put_user(cpu->pending_notify, user))
 				return -EFAULT;
-			return sizeof(lg->pending_notify);
+			return sizeof(cpu->pending_notify);
 		}
 
 		/* Check for signals */

drivers/lguest/hypercalls.c

@@ -91,7 +91,7 @@ static void do_hcall(struct lg_cpu *cpu, struct hcall_args *args)
 		cpu->halted = 1;
 		break;
 	case LHCALL_NOTIFY:
-		lg->pending_notify = args->arg1;
+		cpu->pending_notify = args->arg1;
 		break;
 	default:
 		/* It should be an architecture-specific hypercall. */
@@ -154,7 +154,7 @@ static void do_async_hcalls(struct lg_cpu *cpu)
 
 		/* Stop doing hypercalls if they want to notify the Launcher:
 		 * it needs to service this first. */
-		if (lg->pending_notify)
+		if (cpu->pending_notify)
 			break;
 	}
 }
@@ -219,7 +219,7 @@ void do_hypercalls(struct lg_cpu *cpu)
 	/* If we stopped reading the hypercall ring because the Guest did a
 	 * NOTIFY to the Launcher, we want to return now.  Otherwise we do
 	 * the hypercall. */
-	if (!cpu->lg->pending_notify) {
+	if (!cpu->pending_notify) {
 		do_hcall(cpu, cpu->hcall);
 		/* Tricky point: we reset the hcall pointer to mark the
 		 * hypercall as "done".  We use the hcall pointer rather than

drivers/lguest/lg.h

@@ -51,6 +51,8 @@ struct lg_cpu {
 	u32 esp1;
 	u8 ss1;
 
+	unsigned long pending_notify; /* pfn from LHCALL_NOTIFY */
+
 	/* At end of a page shared mapped over lguest_pages in guest.  */
 	unsigned long regs_page;
 	struct lguest_regs *regs;
@@ -95,7 +97,6 @@ struct lguest
 	struct pgdir pgdirs[4];
 
 	unsigned long noirq_start, noirq_end;
-	unsigned long pending_notify; /* pfn from LHCALL_NOTIFY */
 
 	unsigned int stack_pages;
 	u32 tsc_khz;

drivers/lguest/lguest_user.c

@@ -89,8 +89,8 @@ static ssize_t read(struct file *file, char __user *user, size_t size,loff_t*o)
 
 	/* If we returned from read() last time because the Guest notified,
 	 * clear the flag. */
-	if (lg->pending_notify)
-		lg->pending_notify = 0;
+	if (cpu->pending_notify)
+		cpu->pending_notify = 0;
 
 	/* Run the Guest until something interesting happens. */
 	return run_guest(cpu, (unsigned long __user *)user);