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.
>
>> >> It looks like some other IRQs cause the coalescing, because also
>> >> looking at RTC code, it seems it's not possible for RTC to raise the
>> >> IRQ (except update IRQ, alarm etc.) without calling
>> >> apic_reset_irq_delivered().
>> >>
>> >> I've attached my test program. Compile:
>> >> gcc -m32 -o coalescing coalescing.S -ffreestanding -nostdlib -Wl,-T
>> >> coalescing.ld -g && objcopy -Obinary coalescing coalescing.bin
>> >>
>> >> Run:
>> >> qemu -L . -bios coalescing.bin -no-hpet -rtc-td-hack
>> >>
>> > The application does not work for me. Looks like it fails to enter
>> > protected mode. $pc jumps from 0x00000000fffffff0 to 0x00000000000f003e
>> > and back.
>>
>> Strange. Here's a working binary.
>>
> Your binary works here too. What compiler are you using?

Using built-in specs.
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian
4.3.2-1.1' --with-bugurl=file:///usr/share/doc/gcc-4.3/README.Bugs
--enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr
--enable-shared --with-system-zlib --libexecdir=/usr/lib
--without-included-gettext --enable-threads=posix --enable-nls
--with-gxx-include-dir=/usr/include/c++/4.3 --program-suffix=-4.3
--enable-clocale=gnu --enable-libstdcxx-debug --enable-objc-gc
--enable-mpfr --enable-cld --enable-checking=release
--build=x86_64-linux-gnu --host=x86_64-linux-gnu
--target=x86_64-linux-gnu
Thread model: posix
gcc version 4.3.2 (Debian 4.3.2-1.1)