Re: Consuming PCI device in PV kernel

[Simon Martin <furryfuttock@gmail.com>]

Hello Ian,

> IIRC from the guest PoV you just need to read the BAR values from the
> CFG space and then use them without worrying about where they point,
> i.e. by creating virtual address mappings of whatever MMIO address the
> BAR gives you.

I  thought that I was mapping the BAR memory correctly, however when I
fixed  a  bug in my software I started getting errors and I eventually
tracked it down to mapping the MMIO memory.

I     have     tried     calling    HYPERCALL_update_va_mapping    and
HYPERCALL_mmu_update  and  they both fail. HYPERCALL_update_va_mapping
gives me the following in xl dmesg:

(XEN) mm.c:1700:d292v0 Bad L1 flags 400000

Looking at the code I can't see where bit 22 is being set!

Reading  the qemu PCI mapping code, it seems to call xc_domctl. I have
traced   down   through  this  into  the xen source and it seems to do
many  things that I don't have access to via straight hypercalls.

Google doesn't seem to help much on this one either.

Any idea on how to proceed with this?

-- 
Best regards,
 Simon                            mailto:furryfuttock@gmail.com