[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH/RFC 3/4] Add support for HPET periodic timer.
From: |
Luca Tettamanti |
Subject: |
[Qemu-devel] [PATCH/RFC 3/4] Add support for HPET periodic timer. |
Date: |
Thu, 16 Aug 2007 22:41:16 +0200 |
Linux operates the HPET timer in legacy replacement mode, which means that
the periodic interrupt of the CMOS RTC is not delivered (qemu won't be able
to use /dev/rtc). Add support for HPET (/dev/hpet) as a replacement for the
RTC; the periodic interrupt is delivered via SIGIO and is handled in the
same way as the RTC timer.
Signed-off-by: Luca Tettamanti <address@hidden>
---
qemu/vl.c | 57 ++++++++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 56 insertions(+), 1 deletions(-)
diff --git a/qemu/vl.c b/qemu/vl.c
index f0b4896..0373beb 100644
--- a/qemu/vl.c
+++ b/qemu/vl.c
@@ -54,6 +54,7 @@
#include <pty.h>
#include <malloc.h>
#include <linux/rtc.h>
+#include <linux/hpet.h>
#include <linux/ppdev.h>
#endif
#endif
@@ -773,6 +774,9 @@ static void unix_stop_timer(struct qemu_alarm_timer *t);
#ifdef __linux__
+static int hpet_start_timer(struct qemu_alarm_timer *t);
+static void hpet_stop_timer(struct qemu_alarm_timer *t);
+
static int rtc_start_timer(struct qemu_alarm_timer *t);
static void rtc_stop_timer(struct qemu_alarm_timer *t);
@@ -782,7 +786,9 @@ static void rtc_stop_timer(struct qemu_alarm_timer *t);
static struct qemu_alarm_timer alarm_timers[] = {
#ifdef __linux__
- /* RTC - if available - is preferred */
+ /* HPET - if available - is preferred */
+ {"hpet", hpet_start_timer, hpet_stop_timer, NULL},
+ /* ...otherwise try RTC */
{"rtc", rtc_start_timer, rtc_stop_timer, NULL},
#endif
#ifndef _WIN32
@@ -1117,6 +1123,55 @@ static void enable_sigio_timer(int fd)
fcntl(fd, F_SETOWN, getpid());
}
+static int hpet_start_timer(struct qemu_alarm_timer *t)
+{
+ struct hpet_info info;
+ int r, fd;
+
+ fd = open("/dev/hpet", O_RDONLY);
+ if (fd < 0)
+ return -1;
+
+ /* Set frequency */
+ r = ioctl(fd, HPET_IRQFREQ, RTC_FREQ);
+ if (r < 0) {
+ fprintf(stderr, "Could not configure '/dev/hpet' to have a 1024Hz
timer. This is not a fatal\n"
+ "error, but for better emulation accuracy type:\n"
+ "'echo 1024 > /proc/sys/dev/hpet/max-user-freq' as root.\n");
+ goto fail;
+ }
+
+ /* Check capabilities */
+ r = ioctl(fd, HPET_INFO, &info);
+ if (r < 0)
+ goto fail;
+
+ /* Enable periodic mode */
+ r = ioctl(fd, HPET_EPI, 0);
+ if (info.hi_flags && (r < 0))
+ goto fail;
+
+ /* Enable interrupt */
+ r = ioctl(fd, HPET_IE_ON, 0);
+ if (r < 0)
+ goto fail;
+
+ enable_sigio_timer(fd);
+ t->priv = (void *)fd;
+
+ return 0;
+fail:
+ close(fd);
+ return -1;
+}
+
+static void hpet_stop_timer(struct qemu_alarm_timer *t)
+{
+ int fd = (int)t->priv;
+
+ close(fd);
+}
+
static int rtc_start_timer(struct qemu_alarm_timer *t)
{
int rtc_fd;
--
1.5.2.4
[Qemu-devel] Re: [kvm-devel] [PATCH/RFC 0/4] Rework alarm timer infrastrucure., Avi Kivity, 2007/08/17