Re: [Qemu-devel] Re: [RFT][PATCH 07/15] qemu_irq: Add IRQ handlers with delivery feedback

[Blue Swirl]

On Sun, May 30, 2010 at 1:49 PM, Gleb Natapov <address@hidden> wrote:
> On Sun, May 30, 2010 at 12:56:26PM +0000, Blue Swirl wrote:
>> >> Well, I'd like to get the test program also trigger it. Now I'm getting:
>> >> apic: write: 00000350 = 00000000
>> >> apic: apic_reset_irq_delivered: old coalescing 0
>> >> apic: apic_local_deliver: vector 3 delivery mode 0
>> >> apic: apic_set_irq: coalescing 1
>> >> apic: apic_get_irq_delivered: returning coalescing 1
>> >> apic: apic_reset_irq_delivered: old coalescing 1
>> >> apic: apic_local_deliver: vector 3 delivery mode 0
>> >> apic: apic_set_irq: coalescing 0
>> >> apic: apic_get_irq_delivered: returning coalescing 0
>> >> apic: apic_reset_irq_delivered: old coalescing 0
>> >> apic: apic_local_deliver: vector 3 delivery mode 0
>> >> apic: apic_set_irq: coalescing 0
>> >>
> So interrupt is _alway_ coalesced. If apic_get_irq_delivered() returns
> 0 it means the interrupt was not delivered.

That seems strange. I changed the program so that the handler gets
executed, also output a dot to serial from the handler. I changed the
frequency to 2Hz.

Now, if I leave out -rtc-td-hack, I get the dots at 2Hz as expected.
With -rtc-td-hack, the dots come out much faster. I added
DEBUG_COALESCING also to RTC, with that enabled I get:
qemu -L . -bios coalescing.bin -d in_asm,int -no-hpet -rtc-td-hack -serial stdio
cmos: coalesced irqs scaled to 0
cmos: coalesced irqs increased to 1
cmos: injecting on ack
.cmos: injecting on ack
.cmos: injecting on ack
.cmos: injecting on ack
.cmos: injecting on ack
.cmos: injecting on ack
.cmos: injecting on ack
.cmos: injecting on ack
.cmos: injecting on ack
.cmos: injecting on ack
.cmos: injecting on ack
.cmos: injecting on ack
.cmos: injecting on ack
.cmos: injecting on ack
.cmos: injecting on ack
.cmos: injecting on ack
.cmos: injecting on ack
.cmos: injecting on ack
.cmos: injecting on ack
.cmos: injecting on ack
..cmos: injecting from timer
.cmos: coalesced irqs increased to 2
cmos: injecting on ack

So, there are bogus injections.

coalescing.S
Description: Binary data

coalescing.bin.bz2
Description: BZip2 compressed data