Patchwork [15/15] qtest: add rtc-test test-case

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Submitter Anthony Liguori
Date Jan. 10, 2012, 7:10 p.m.
Message ID <1326222656-26588-15-git-send-email-aliguori@us.ibm.com>
Download mbox | patch
Permalink /patch/135284/
State New
Headers show

Comments

Anthony Liguori - Jan. 10, 2012, 7:10 p.m.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
---
 tests/Makefile   |    2 +-
 tests/rtc-test.c |  222 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 223 insertions(+), 1 deletions(-)
 create mode 100644 tests/rtc-test.c
Paolo Bonzini - Jan. 10, 2012, 7:59 p.m.
On 01/10/2012 08:10 PM, Anthony Liguori wrote:
> +    sec = cmos_read(0x00);
> +    min = cmos_read(0x02);
> +    hour = cmos_read(0x04);
> +    mday = cmos_read(0x07);
> +    mon = cmos_read(0x08);
> +    year = cmos_read(0x09);

Please use identifiers for register numbers.

> +    /*
> +     * This check assumes a few things.  First, we cannot guarantee that we get
> +     * a consistent reading from the wall clock because we may hit an edge of
> +     * the clock while reading.  To work around this, we read four clock readings
> +     * such that at least two of them should match.  We need to assume that one
> +     * reading is corrupt so we need four readings to ensure that we have at
> +     * least two consecutive identical readings
> +     *
> +     * It's also possible that we'll cross an edge reading the host clock so
> +     * simply check to make sure that the clock reading is within the period of
> +     * when we expect it to be.
> +     */

This seems broken to me.  The right thing to do would be to run the test 
with vm_clock for the rtc_clock, add a way for the qtest machine to bump 
the vm_clock to the next event, and busy loop running that method using 
UIP like you would do on hardware.

Paolo
Anthony Liguori - Jan. 11, 2012, 5:06 p.m.
On 01/10/2012 01:59 PM, Paolo Bonzini wrote:
> On 01/10/2012 08:10 PM, Anthony Liguori wrote:
>> + sec = cmos_read(0x00);
>> + min = cmos_read(0x02);
>> + hour = cmos_read(0x04);
>> + mday = cmos_read(0x07);
>> + mon = cmos_read(0x08);
>> + year = cmos_read(0x09);
>
> Please use identifiers for register numbers.
>
>> + /*
>> + * This check assumes a few things. First, we cannot guarantee that we get
>> + * a consistent reading from the wall clock because we may hit an edge of
>> + * the clock while reading. To work around this, we read four clock readings
>> + * such that at least two of them should match. We need to assume that one
>> + * reading is corrupt so we need four readings to ensure that we have at
>> + * least two consecutive identical readings
>> + *
>> + * It's also possible that we'll cross an edge reading the host clock so
>> + * simply check to make sure that the clock reading is within the period of
>> + * when we expect it to be.
>> + */
>
> This seems broken to me.

It's not broken, although it may be ugly.

> The right thing to do would be to run the test with
> vm_clock for the rtc_clock, add a way for the qtest machine to bump the vm_clock
> to the next event,

I actually was looking at this yesterday.  Just bumping to the next event is not 
enough, you want to be able to control how time progresses.  I was thinking of 
adding another qtest_clock and allowing the rtc to use the qtest_clock.

What's nice about that is that you can simulate long periods of time (2 years) 
in a short period of time and do long term drift testing.

I know the math in the rtc is broken right now because we assume that there's a 
rational conversion from RTC cycle frequency to nanoseconds which is not the 
case.  We need a more sophisticated approach that can maintain an irrational 
conversion factor (in the form of a fractional multiplier).

Regards,

Anthony Liguori

> and busy loop running that method using UIP like you would do
> on hardware.
>
> Paolo
>
>
Paolo Bonzini - Jan. 11, 2012, 7:27 p.m.
On 01/11/2012 06:06 PM, Anthony Liguori wrote:
>
>> The right thing to do would be to run the test with
>> vm_clock for the rtc_clock, add a way for the qtest machine to bump
>> the vm_clock
>> to the next event,
>
> I actually was looking at this yesterday.  Just bumping to the next
> event is not enough, you want to be able to control how time
> progresses.  I was thinking of adding another qtest_clock and allowing
> the rtc to use the qtest_clock.

Yes, that's right.  Only remark, I think it makes sense to reuse the 
vm_clock, so that you can reuse the icount infrastructure in -icount 0. 
  qemu_icount is then simply your nanosecond count.

This requires you not to set env->halted, though.

Paolo

Patch

diff --git a/tests/Makefile b/tests/Makefile
index 63b835d..a90eaff 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -2,7 +2,7 @@  CHECKS = check-qdict check-qfloat check-qint check-qstring check-qlist
 CHECKS += check-qjson test-qmp-output-visitor test-qmp-input-visitor
 CHECKS += test-coroutine
 
-HW_TESTS=
+HW_TESTS=tests/rtc-test
 
 TARGETS=$(patsubst %-softmmu,%, $(filter %-softmmu,$(TARGET_DIRS)))
 
diff --git a/tests/rtc-test.c b/tests/rtc-test.c
new file mode 100644
index 0000000..ff67e56
--- /dev/null
+++ b/tests/rtc-test.c
@@ -0,0 +1,222 @@ 
+/*
+ * QTest
+ *
+ * Copyright IBM, Corp. 2012
+ *
+ * Authors:
+ *  Anthony Liguori   <aliguori@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+#include "libqtest.h"
+
+#include <glib.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+static uint8_t base = 0x70;
+
+static int bcd2dec(int value)
+{
+    return (((value >> 4) & 0x0F) * 10) + (value & 0x0F);
+}
+
+#if 0
+static int dec2bcd(int value)
+{
+    return ((value / 10) << 4) | (value % 10);
+}
+#endif
+
+static uint8_t cmos_read(uint8_t reg)
+{
+    outb(base + 0, reg);
+    return inb(base + 1);
+}
+
+static void cmos_write(uint8_t reg, uint8_t val)
+{
+    outb(base + 0, reg);
+    outb(base + 1, val);
+}
+
+static int tm_cmp(struct tm *lhs, struct tm *rhs)
+{
+    time_t a, b;
+    struct tm d1, d2;
+
+    memcpy(&d1, lhs, sizeof(d1));
+    memcpy(&d2, rhs, sizeof(d2));
+
+    a = mktime(&d1);
+    b = mktime(&d2);
+
+    if (a < b) {
+        return -1;
+    } else if (a > b) {
+        return 1;
+    }
+
+    return 0;
+}
+
+#if 0
+static void print_tm(struct tm *tm)
+{
+    printf("%04d-%02d-%02d %02d:%02d:%02d\n",
+           tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday, 
+           tm->tm_hour, tm->tm_min, tm->tm_sec, tm->tm_gmtoff);
+}
+#endif
+
+static void cmos_get_date_time(struct tm *date)
+{
+    int base_year = 2000, hour_offset;
+    int sec, min, hour, mday, mon, year;
+    time_t ts;
+    struct tm dummy;
+
+    sec = cmos_read(0x00);
+    min = cmos_read(0x02);
+    hour = cmos_read(0x04);
+    mday = cmos_read(0x07);
+    mon = cmos_read(0x08);
+    year = cmos_read(0x09);
+
+    if ((cmos_read(0x0B) & 4) == 0) {
+        sec = bcd2dec(sec);
+        min = bcd2dec(min);
+        hour = bcd2dec(hour);
+        mday = bcd2dec(mday);
+        mon = bcd2dec(mon);
+        year = bcd2dec(year);
+        hour_offset = 80;
+    } else {
+        hour_offset = 0x80;
+    }
+
+    if ((cmos_read(0x0B) & 2) == 0) {
+        if (hour >= hour_offset) {
+            hour -= hour_offset;
+            hour += 12;
+        }
+    }
+
+    ts = time(NULL);
+    localtime_r(&ts, &dummy);
+
+    date->tm_isdst = dummy.tm_isdst;
+    date->tm_sec = sec;
+    date->tm_min = min;
+    date->tm_hour = hour;
+    date->tm_mday = mday;
+    date->tm_mon = mon - 1;
+    date->tm_year = base_year + year - 1900;
+    date->tm_gmtoff = 0;
+
+    ts = mktime(date);
+}
+
+static void check_time(int wiggle)
+{
+    struct tm start, date[4], end;
+    struct tm *datep;
+    time_t ts;
+
+    /*
+     * This check assumes a few things.  First, we cannot guarantee that we get
+     * a consistent reading from the wall clock because we may hit an edge of
+     * the clock while reading.  To work around this, we read four clock readings
+     * such that at least two of them should match.  We need to assume that one
+     * reading is corrupt so we need four readings to ensure that we have at
+     * least two consecutive identical readings
+     *
+     * It's also possible that we'll cross an edge reading the host clock so
+     * simply check to make sure that the clock reading is within the period of
+     * when we expect it to be.
+     */
+
+    ts = time(NULL);
+    gmtime_r(&ts, &start);
+
+    cmos_get_date_time(&date[0]);
+    cmos_get_date_time(&date[1]);
+    cmos_get_date_time(&date[2]);
+    cmos_get_date_time(&date[3]);
+
+    ts = time(NULL);
+    gmtime_r(&ts, &end);
+
+    if (tm_cmp(&date[0], &date[1]) == 0) {
+        datep = &date[0];
+    } else if (tm_cmp(&date[1], &date[2]) == 0) {
+        datep = &date[1];
+    } else if (tm_cmp(&date[2], &date[3]) == 0) {
+        datep = &date[2];
+    } else {
+        g_assert_not_reached();
+    }
+
+    if (!(tm_cmp(&start, datep) <= 0 && tm_cmp(datep, &end) <= 0)) {
+        time_t t, s;
+
+        start.tm_isdst = datep->tm_isdst;
+
+        t = mktime(datep);
+        s = mktime(&start);
+        if (t < s) {
+            g_test_message("RTC is %ld second(s) behind wall-clock\n", (s - t));
+        } else {
+            g_test_message("RTC is %ld second(s) ahead of wall-clock\n", (t - s));
+        }
+
+        g_assert_cmpint(ABS(t - s), <=, wiggle);
+    }
+}
+
+static int wiggle = 2;
+
+static void bcd_check_time(void)
+{
+    /* Set BCD mode */
+    cmos_write(0x0B, cmos_read(0x0B) | 0x02);
+    check_time(wiggle);
+}
+
+static void dec_check_time(void)
+{
+    /* Set DEC mode */
+    cmos_write(0x0B, cmos_read(0x0B) & ~0x02);
+    check_time(wiggle);
+}
+
+int main(int argc, char **argv)
+{
+    const char *arch;
+    QTestState *s = NULL;
+    int ret;
+
+    g_test_init(&argc, &argv, NULL);
+
+    arch = qtest_get_arch();
+    /* These tests only work on i386 and x86_64 */
+    if (strcmp(arch, "i386") == 0 || strcmp(arch, "x86_64") == 0) {
+        s = qtest_start("-vnc none");
+
+        qtest_add_func("/rtc/bcd/check-time", bcd_check_time);
+        qtest_add_func("/rtc/dec/check-time", dec_check_time);
+    } else {
+        g_test_message("Skipping unsupported arch `%s'\n", arch);
+    }
+
+    ret = g_test_run();
+
+    if (s) {
+        qtest_quit(s);
+    }
+
+    return ret;
+}