On Wed, Jul 01, 2020 at 04:11:49PM +0800, Jason Wang wrote:
On 2020/6/30 下午11:20, Peter Xu wrote:
On Tue, Jun 30, 2020 at 05:23:31PM +0800, Jason Wang wrote:
Ok, we had a dedicated mr for interrupt:
memory_region_add_subregion_overlap(MEMORY_REGION(&vtd_dev_as->iommu),
VTD_INTERRUPT_ADDR_FIRST,
&vtd_dev_as->iommu_ir, 1);
So it should be fine. I guess the reason that I'm asking is that I thought
"IR" means "Interrupt remapping" but in fact it means "Interrupt Region"?
I was meaning "interrupt remapping", and of course it's the interrupt region
too when IR enabled...
Right.
But I'm still not clear about the invalidation part for interrupt region,
maybe you can elaborate a little more on this.
Btw, I think guest can trigger the assert in vtd_do_iommu_translate() if we
teach vhost to DMA to that region:
Why would we want to?
I meant a buggy(malicious) guest driver.
Yes seems possible. Do you want to post a patch? Let me know if you want me
to... Thanks,
Yes please.
Oh wait... Actually the comment above explains...
/*
* We have standalone memory region for interrupt addresses, we
* should never receive translation requests in this region.
*/
assert(!vtd_is_interrupt_addr(addr));
I overlooked myself that the IR region will be there even if ir=off.