[Qemu-devel] vIOMMU Posted-interrupt implementation - atomic operation?

[Jintack Lim]

Hi,

I'm implementing Posted-interrupt functionality in vIOMMU. According
to Vt-d spec 5.2.3, IOMMU performs a coherent atomic read-modify-write
operation of the posted-interrupt descriptor. I wonder how can we
achieve this considering the guest can modify the same
posted-interrupt descriptor anytime. Is there any existing mechanism
that I can use in QEMU?

Thanks,
Jintack