On 4/1/23 21:12, Bernhard Beschow wrote:
Am 4. Januar 2023 16:35:57 UTC schrieb "Philippe Mathieu-Daudé"
<phi...@linaro.org>:
On 4/1/23 17:01, Bernhard Beschow wrote:
Am 4. Januar 2023 14:37:29 UTC schrieb "Philippe Mathieu-Daudé"
<phi...@linaro.org>:
On 21/12/22 17:59, Bernhard Beschow wrote:
Having a proxy PIC allows for ISA PICs to be created and wired up in
southbridges. This is especially useful for PIIX3 for two reasons:
First, the southbridge doesn't need to care about the virtualization
technology used (KVM, TCG, Xen) due to in-IRQs (where devices get
attached) and out-IRQs (which will trigger the IRQs of the respective
virtzalization technology) are separated. Second, since the in-IRQs are
Typo "virtualization".
Fixed...
Why restrict to 16 and not use a class property and allocate
on the heap? See TYPE_SPLIT_IRQ for example.
TYPE_SPLIT_IRQ doesn't allocate on the heap and instead has a hardcoded limit
of MAX_SPLIT_LINES which equals 16 ;)
I was unsure on when to free the memory and how to dispose the elements so I
went with this solution for simplicity. I'll look for inspitation in other
device models and respin.
Oh indeed. Well this model as is is OK, but it could be more useful
if able to proxy any range of IRQs.
I've responded with a new, single patch to this patch. Is that okay or shall I
respin the whole series? Is anything missing? IIUC we can make the proxy-pic
dynamic in a follow-up?
I think we are good :) If you can point me to a branch with all your
patches, I could verify everything is properly applied locally.
I have the feeling we are cycling around this IRQ proxy:
22ec3283ef ("irq: introduce qemu_irq_proxy()")
078778c5a5 ("piix4: Add an i8259 Interrupt Controller as specified in
datasheet")
fc531e7cab ("Revert "irq: introduce qemu_irq_proxy()"")
What is our problem? IRQ lines connect 2 devices in a fixed direction.
Current model expects one edge to be wired to a device before wiring
the other device, so device composition with IRQs in middle is
impossible? If so, this doesn't scale with dynamic machine creation.
My PIIX consolidation series and even more so my effort to make the VT82xx
south bridges work with the PC machine are indeed bottom-up explorations of
dynamic/flexible machine creation.
Yeah (I have been there too...). Also Mark Cave-Ayland confirmed
elsewhere in this thread that yourv effort points toward the right
direction :)
Regards,
Phil.
