kvm: Cleanup interrupt timer logic

This patch moves the interrupt timer logic to kvm.c and cleans it up.

Signed-off-by: Pekka Enberg <penberg@kernel.org>

include/kvm/kvm.h

@@ -7,11 +7,13 @@
 
 #include <stdbool.h>
 #include <stdint.h>
+#include <time.h>
 
 struct kvm {
 	int			sys_fd;		/* For system ioctls(), i.e. /dev/kvm */
 	int			vm_fd;		/* For VM ioctls() */
 	int			vcpu_fd;	/* For VCPU ioctls() */
+	timer_t			timerid;	/* Posix timer for interrupts */
 	struct kvm_run		*kvm_run;
 
 	struct disk_image	*disk_image;
@@ -40,6 +42,7 @@ bool kvm__load_kernel(struct kvm *kvm, const char *kernel_filename,
 			const char *initrd_filename, const char *kernel_cmdline);
 void kvm__reset_vcpu(struct kvm *self);
 void kvm__setup_mem(struct kvm *self);
+void kvm__start_timer(struct kvm *self);
 void kvm__run(struct kvm *self);
 void kvm__irq_line(struct kvm *self, int irq, int level);
 bool kvm__emulate_io(struct kvm *self, uint16_t port, void *data, int direction, int size, uint32_t count);

kvm.c

@@ -1,7 +1,7 @@
 #include "kvm/kvm.h"
 
-#include "kvm/interrupt.h"
 #include "kvm/cpufeature.h"
+#include "kvm/interrupt.h"
 #include "kvm/e820.h"
 #include "kvm/util.h"
 
@@ -12,16 +12,18 @@
 #include <sys/ioctl.h>
 #include <inttypes.h>
 #include <sys/mman.h>
+#include <sys/stat.h>
 #include <stdbool.h>
 #include <assert.h>
 #include <limits.h>
+#include <signal.h>
 #include <stdarg.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 #include <stdio.h>
 #include <fcntl.h>
-#include <sys/stat.h>
+#include <time.h>
 
 /*
  * Compatibility code. Remove this when we move to tools/kvm.
@@ -606,6 +608,46 @@ void kvm__setup_mem(struct kvm *self)
 	};
 }
 
+#define TIMER_INTERVAL_NS 1000000	/* 1 msec */
+
+static void alarm_handler(int sig)
+{
+}
+
+/*
+ * This function sets up a timer that's used to inject interrupts from the
+ * userspace hypervisor into the guest at periodical intervals. Please note
+ * that clock interrupt, for example, is not handled here.
+ */
+void kvm__start_timer(struct kvm *self)
+{
+	struct itimerspec its;
+	struct sigaction sa;
+	struct sigevent sev;
+
+	sigfillset(&sa.sa_mask);
+	sa.sa_flags			= 0;
+	sa.sa_handler			= alarm_handler;
+
+	sigaction(SIGALRM, &sa, NULL);
+
+	memset(&sev, 0, sizeof(struct sigevent));
+	sev.sigev_value.sival_int	= 0;
+	sev.sigev_notify		= SIGEV_SIGNAL;
+	sev.sigev_signo			= SIGALRM;
+
+	if (timer_create(CLOCK_REALTIME, &sev, &self->timerid) < 0)
+		die("timer_create()");
+
+	its.it_value.tv_sec		= TIMER_INTERVAL_NS / 1000000000;
+	its.it_value.tv_nsec		= TIMER_INTERVAL_NS % 1000000000;
+	its.it_interval.tv_sec		= its.it_value.tv_sec;
+	its.it_interval.tv_nsec		= its.it_value.tv_nsec;
+
+	if (timer_settime(self->timerid, 0, &its, NULL) < 0)
+		die("timer_settime()");
+}
+
 void kvm__run(struct kvm *self)
 {
 	int err;

main.c

@@ -8,13 +8,12 @@
 
 #include <inttypes.h>
 #include <termios.h>
-#include <unistd.h>
 #include <signal.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unistd.h>
 #include <stdio.h>
-#include <time.h>
 
 extern bool ioport_debug;
 
@@ -91,46 +90,6 @@ static bool option_matches(char *arg, const char *option)
 	return !strncmp(arg, option, strlen(option));
 }
 
-#define TIMER_INTERVAL_NS 1000000	/* 1 msec */
-
-static void alarm_handler(int sig)
-{
-}
-
-/*
- * This function sets up a timer that's used to inject interrupts from the
- * userspace hypervisor into the guest at periodical intervals. Please note
- * that clock interrupt, for example, is not handled here.
- */
-static void setup_timer(void)
-{
-	struct itimerspec its;
-	struct sigaction sa;
-	struct sigevent sev;
-	timer_t timerid;
-
-	sigfillset(&sa.sa_mask);
-	sa.sa_flags			= 0;
-	sa.sa_handler			= alarm_handler;
-
-	sigaction(SIGALRM, &sa, NULL);
-
-	memset(&sev, 0, sizeof(struct sigevent));
-	sev.sigev_value.sival_int	= 0;
-	sev.sigev_notify		= SIGEV_SIGNAL;
-	sev.sigev_signo			= SIGALRM;
-
-	its.it_value.tv_sec		= TIMER_INTERVAL_NS / 1000000000;
-	its.it_value.tv_nsec		= TIMER_INTERVAL_NS % 1000000000;
-	its.it_interval.tv_sec		= its.it_value.tv_sec;
-	its.it_interval.tv_nsec		= its.it_value.tv_nsec;
-	if (timer_create(CLOCK_MONOTONIC, &sev, &timerid) < 0)
-		die("timer_create()");
-
-	if (timer_settime(timerid, 0, &its, NULL) < 0)
-		die("timer_settime()");
-}
-
 int main(int argc, char *argv[])
 {
 	const char *kernel_filename = NULL;
@@ -222,7 +181,7 @@ int main(int argc, char *argv[])
 
 	blk_virtio__init(kvm);
 
-	setup_timer();
+	kvm__start_timer(kvm);
 
 	tty_set_canon_flag(fileno(stdin), 1);