Re: [Xen-devel] Bug: Windows 2003 fails to install on xen-unstable tip

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 19.04.13 at 15:51, George Dunlap <george.dunlap@xxxxxxxxxxxxx> wrote:
> (XEN) HVM1: Booting from DVD/CD...
> (XEN) HVM1: Booting from 0000:7c00
> (XEN) HVM1: pnp call arg1=0
> [   75.071460] xenbr0: port 3(vif1.0-emu) entering forwarding state
> (XEN) pt on: 10
> (XEN) B=42 [A:2a B:02 C:50 pt:10/0]
> (XEN) C=50 pt=10/0
> (XEN) C=c0 pt=10/0
> (XEN) C=00 pt=10/0
> (XEN) C=c0 pt=10/0
> (XEN) C=00 pt=10/0
> (XEN) pt off @87

Odd - both the fact that apparently two to four interrupt instances
arrive, and the fact that REG_C gets read two times when
supposedly there was no interrupt. The latter may be indicative of
a re-read near the end of the interrupt handler (i.e. checking
whether more work is to do), which is why I added time stamps in
the new version of the patch.

The time stamps should also help understanding whether turning
off the periodic timer really happens with due distance to the last
interrupt instance (also increasing the gap from 10 to 250). Plus
the patch now adds tracking of when the last RTC interrupt got
triggered.

I also retained the NetBSD fixes in here, as I don't think they
would harm Windows, and ultimately we want them committed
unless we need to do some sort of revert.

Jan

--- a/xen/arch/x86/hvm/rtc.c
+++ b/xen/arch/x86/hvm/rtc.c
@@ -50,6 +50,23 @@ static void rtc_set_time(RTCState *s);
 static inline int from_bcd(RTCState *s, int a);
 static inline int convert_hour(RTCState *s, int hour);
 
+#include <xen/symbols.h>//temp
+#define LOGIDX_MASK 0xf//temp
+static struct {//temp
+ s_time_t time;
+ void*caller;
+} log[LOGIDX_MASK + 1];
+static unsigned logidx;//temp
+static void pt_off(int line) {//temp
+ unsigned i, idx = logidx;
+ printk("pt off #%d @%"PRIx64"\n", line, NOW());
+ for(i = idx; i <= idx + LOGIDX_MASK; ++i) {
+  if(!log[i & LOGIDX_MASK].caller) continue;
+  printk("pt irq @%"PRIx64, log[i & LOGIDX_MASK].time);
+  print_symbol(" (%s)\n", (unsigned long)log[i & LOGIDX_MASK].caller);
+ }
+}
+
 static void rtc_update_irq(RTCState *s)
 {
     struct domain *d = vrtc_domain(s);
@@ -68,6 +85,7 @@ static void rtc_update_irq(RTCState *s)
 
     hvm_isa_irq_deassert(d, RTC_IRQ);
     if ( irqf )
+log[logidx & LOGIDX_MASK].time = NOW(), log[logidx++ & LOGIDX_MASK].caller = 
__builtin_return_address(0),//temp
         hvm_isa_irq_assert(d, RTC_IRQ);
 }
 
@@ -81,12 +99,14 @@ void rtc_periodic_interrupt(void *opaque
         s->hw.cmos_data[RTC_REG_C] |= RTC_PF;
         rtc_update_irq(s);
     }
-    else if ( ++(s->pt_dead_ticks) >= 10 )
+    else if ( ++(s->pt_dead_ticks) >= 250 )
     {
         /* VM is ignoring its RTC; no point in running the timer */
+pt_off(__LINE__);//temp
         destroy_periodic_time(&s->pt);
         s->pt_code = 0;
     }
+else if(s->pt_code) rtc_update_irq(s);//todo?
     spin_unlock(&s->lock);
 }
 
@@ -114,6 +134,7 @@ static void rtc_timer_update(RTCState *s
         {
             if ( period_code != s->pt_code )
             {
+printk("pt on: %d @%"PRIx64"\n", period_code, NOW());//temp
                 s->pt_code = period_code;
                 period = 1 << (period_code - 1); /* period in 32 Khz cycles */
                 period = DIV_ROUND(period * 1000000000ULL, 32768); /* in ns */
@@ -125,6 +146,7 @@ static void rtc_timer_update(RTCState *s
         }
         /* fall through */
     default:
+pt_off(__LINE__);//temp
         destroy_periodic_time(&s->pt);
         s->pt_code = 0;
         break;
@@ -451,6 +473,9 @@ static int rtc_ioport_write(void *opaque
             rtc_timer_update(s);
         break;
     case RTC_REG_B:
+printk("B=%02x [A:%02x B:%02x C:%02x pt:%d/%d] @%"PRIx64"\n",//temp
+       data, s->hw.cmos_data[RTC_REG_A], orig, 
s->hw.cmos_data[RTC_REG_C],//temp
+       s->pt_code, s->pt_dead_ticks, NOW());//temp
         if ( data & RTC_SET )
         {
             /* set mode: reset UIP mode */
@@ -474,6 +499,7 @@ static int rtc_ioport_write(void *opaque
          */
         rtc_update_irq(s);
         s->hw.cmos_data[RTC_REG_B] = data;
+if((data & RTC_PIE) && !(orig & RTC_PIE)) rtc_timer_update(s);//todo?
         if ( (data ^ orig) & RTC_SET )
             check_update_timer(s);
         if ( (data ^ orig) & (RTC_24H | RTC_DM_BINARY | RTC_SET) )
@@ -629,6 +655,7 @@ static uint32_t rtc_ioport_read(RTCState
     case RTC_REG_C:
         ret = s->hw.cmos_data[s->hw.cmos_index];
         s->hw.cmos_data[RTC_REG_C] = 0x00;
+printk("C=%02x pt=%d/%d @%"PRIx64"\n", ret, s->pt_code, s->pt_dead_ticks, 
NOW());//temp
         rtc_update_irq(s);
         check_update_timer(s);
         alarm_timer_update(s);
@@ -730,6 +757,8 @@ void rtc_reset(struct domain *d)
     destroy_periodic_time(&s->pt);
     s->pt_code = 0;
     s->pt.source = PTSRC_isa;
+s->hw.cmos_data[RTC_REG_B] &= ~(RTC_PIE|RTC_AIE|RTC_UIE);//todo?
+s->hw.cmos_data[RTC_REG_C] = 0;//todo?
 }
 
 void rtc_init(struct domain *d)

Attachment: x86-HVM-RTC.patch
Description: Text document

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