Allow to specify different time-of-day clock offsets for HVM guests.

There are some usage scenarios in which differing user domains want
to be using different base TOD clocks. This patch adds the ability
to specify the base TOD time difference.  The patch also adds a
hook point to notify another entity when the domain changes this
offset. This might occur, for instance, on a Linux domain using
hwclock -w.

Signed-off-by: Ben Thomas <ben@virtualiron.com>

diff --git a/tools/ioemu/hw/mc146818rtc.c b/tools/ioemu/hw/mc146818rtc.c
index 9d4cbed90bfe39d854c38b31ab0cc652344118f2..cf0f2c029ef84668851b9516c18889f6859b2640 100644 (file)
--- a/tools/ioemu/hw/mc146818rtc.c
+++ b/tools/ioemu/hw/mc146818rtc.c
@@ -178,10 +178,27 @@ static inline int from_bcd(RTCState *s, int a)
     }
 }
 
+static void send_timeoffset_msg(time_t delta)
+{
+
+/* This routine is used to inform another entity that the
+   base time offset has changed. For instance, if you
+   were using xenstore, you might want to write to the store
+   at this point.  Or, you might use some other method.
+   Whatever you might choose, here's a hook point to implement it.
+
+   One item of note is that this delta is in addition to
+   any existing offset you might be already using. */
+
+    return;
+}
+
 static void rtc_set_time(RTCState *s)
 {
     struct tm *tm = &s->current_tm;
-
+    time_t before, after;
+    
+    before = mktime(tm);
     tm->tm_sec = from_bcd(s, s->cmos_data[RTC_SECONDS]);
     tm->tm_min = from_bcd(s, s->cmos_data[RTC_MINUTES]);
     tm->tm_hour = from_bcd(s, s->cmos_data[RTC_HOURS] & 0x7f);
@@ -193,6 +210,12 @@ static void rtc_set_time(RTCState *s)
     tm->tm_mday = from_bcd(s, s->cmos_data[RTC_DAY_OF_MONTH]);
     tm->tm_mon = from_bcd(s, s->cmos_data[RTC_MONTH]) - 1;
     tm->tm_year = from_bcd(s, s->cmos_data[RTC_YEAR]) + 100;
+
+    /* Compute, and send, the additional time delta
+       We could compute the total time delta, but this is
+       sufficient, and simple. */
+    after = mktime(tm);
+    send_timeoffset_msg(after-before);
 }
 
 static void rtc_copy_date(RTCState *s)

diff --git a/tools/ioemu/hw/pc.c b/tools/ioemu/hw/pc.c
index 08106fc75a8b87317e9aea717745b33b93e8c6eb..d762f0e9ee1c976cae83e013403cb90e56ae0881 100644 (file)
--- a/tools/ioemu/hw/pc.c
+++ b/tools/ioemu/hw/pc.c
@@ -118,7 +118,7 @@ static void cmos_init_hd(int type_ofs, int info_ofs, BlockDriverState *hd)
 }
 
 /* hd_table must contain 4 block drivers */
-static void cmos_init(uint64_t ram_size, int boot_device, BlockDriverState **hd_table)
+static void cmos_init(uint64_t ram_size, int boot_device, BlockDriverState **hd_table, time_t timeoffset)
 {
     RTCState *s = rtc_state;
     int val;
@@ -129,6 +129,7 @@ static void cmos_init(uint64_t ram_size, int boot_device, BlockDriverState **hd_
 
     /* set the CMOS date */
     time(&ti);
+    ti += timeoffset;
     if (rtc_utc)
         tm = gmtime(&ti);
     else
@@ -381,7 +382,7 @@ extern int acpi_init(unsigned int base);
 void pc_init(uint64_t ram_size, int vga_ram_size, int boot_device,
              DisplayState *ds, const char **fd_filename, int snapshot,
              const char *kernel_filename, const char *kernel_cmdline,
-             const char *initrd_filename)
+             const char *initrd_filename, time_t timeoffset)
 {
     SerialState *sp;
     char buf[1024];
@@ -577,7 +578,7 @@ void pc_init(uint64_t ram_size, int vga_ram_size, int boot_device,
 
     floppy_controller = fdctrl_init(6, 2, 0, 0x3f0, fd_table);
 
-    cmos_init(ram_size, boot_device, bs_table);
+    cmos_init(ram_size, boot_device, bs_table, timeoffset);
     acpi_init(0x8000);
 
     /* must be done after all PCI devices are instanciated */

diff --git a/tools/ioemu/vl.c b/tools/ioemu/vl.c
index 54ec0967fcf115176de3508d713e5cdbd65c4f4c..08e38449bb76a7e963ce7c57183bc1bef9b81926 100644 (file)
--- a/tools/ioemu/vl.c
+++ b/tools/ioemu/vl.c
@@ -147,6 +147,7 @@ int repeat_key = 1;
 TextConsole *vga_console;
 CharDriverState *serial_hds[MAX_SERIAL_PORTS];
 int xc_handle;
+time_t timeoffset = 0;
 
 /***********************************************************/
 /* x86 ISA bus support */
@@ -2247,9 +2248,10 @@ void help(void)
            "-s              wait gdb connection to port %d\n"
            "-p port         ioreq port for xen\n"
            "-d domain       domain that we're serving\n"
-           "-domain-namn    domain name that we're serving\n"
+           "-domain-name    domain name that we're serving\n"
            "-hdachs c,h,s   force hard disk 0 geometry (usually qemu can guess it)\n"
            "-L path         set the directory for the BIOS and VGA BIOS\n"
+          "-timeoffset     time offset (in seconds) from local time (Xen)\n"
 #ifdef USE_CODE_COPY
            "-no-code-copy   disable code copy acceleration\n"
 #endif
@@ -2347,6 +2349,7 @@ enum {
     QEMU_OPTION_monitor,
     QEMU_OPTION_domainname,
     QEMU_OPTION_serial,
+    QEMU_OPTION_timeoffset,
     QEMU_OPTION_loadvm,
     QEMU_OPTION_full_screen,
     QEMU_OPTION_vgaacc,
@@ -2420,6 +2423,7 @@ const QEMUOption qemu_options[] = {
     { "std-vga", 0, QEMU_OPTION_std_vga },
     { "monitor", 1, QEMU_OPTION_monitor },
     { "domain-name", 1, QEMU_OPTION_domainname },
+    { "timeoffset", HAS_ARG, QEMU_OPTION_timeoffset },
     { "serial", 1, QEMU_OPTION_serial },
     { "loadvm", HAS_ARG, QEMU_OPTION_loadvm },
     { "full-screen", 0, QEMU_OPTION_full_screen },
@@ -2936,7 +2940,10 @@ int main(int argc, char **argv)
             case QEMU_OPTION_domainname:
                 strncat(domain_name, optarg, sizeof(domain_name) - 20);
                 break;
-
+           case QEMU_OPTION_timeoffset:
+                timeoffset = strtol(optarg, NULL, 0);
+               break;
+ 
             }
         }
     }
@@ -3227,7 +3234,7 @@ int main(int argc, char **argv)
 #if defined(TARGET_I386)
     pc_init(ram_size, vga_ram_size, boot_device,
             ds, fd_filename, snapshot,
-            kernel_filename, kernel_cmdline, initrd_filename);
+            kernel_filename, kernel_cmdline, initrd_filename, timeoffset);
 #elif defined(TARGET_PPC)
     ppc_init(ram_size, vga_ram_size, boot_device,
             ds, fd_filename, snapshot,

diff --git a/tools/ioemu/vl.h b/tools/ioemu/vl.h
index 5b6b4ce3430ff1506a20fa7fe4f878dc0e5f59b4..54a84c6bd433905f463f4992301f2e9dbd16f196 100644 (file)
--- a/tools/ioemu/vl.h
+++ b/tools/ioemu/vl.h
@@ -679,7 +679,7 @@ int pit_get_out(PITState *pit, int channel, int64_t current_time);
 void pc_init(uint64_t ram_size, int vga_ram_size, int boot_device,
              DisplayState *ds, const char **fd_filename, int snapshot,
              const char *kernel_filename, const char *kernel_cmdline,
-             const char *initrd_filename);
+             const char *initrd_filename, time_t timeoffset);
 
 /* ppc.c */
 void ppc_init (int ram_size, int vga_ram_size, int boot_device,