Re: [PATCH RFC 00/15] Add VFIO mediated device support and IMS support for the idxd driver.

From: Jason Wang
Date: Fri Apr 24 2020 - 02:32:13 EST



On 2020/4/22 äå7:54, Jason Gunthorpe wrote:
The mdev utilizes Interrupt Message Store or IMS[3] instead of MSIX for
interrupts for the guest. This preserves MSIX for host usages and also allows a
significantly larger number of interrupt vectors for guest usage.
I never did get a reply to my earlier remarks on the IMS patches.

The concept of a device specific addr/data table format for MSI is not
Intel specific. This should be general code. We have a device that can
use this kind of kernel capability today.

Jason


+1.

Another example is to extend virtio MMIO to support MSI[1].

Thanks

[1] https://lkml.org/lkml/2020/2/10/127