On 9/20/23 05:42, Duan, Zhenzhong wrote:
-----Original Message-----
From: Cédric Le Goater <clg@redhat.com>
Sent: Wednesday, September 20, 2023 1:08 AM
Subject: Re: [PATCH v1 15/22] Add iommufd configure option
On 8/30/23 12:37, Zhenzhong Duan wrote:
This adds "--enable-iommufd/--disable-iommufd" to enable or disable
iommufd support, enabled by default.
Why would someone want to disable support at compile time ? It might
For those users who only want to support legacy container feature?
Let me know if you still prefer to drop this patch, I'm fine with that.
I think it is too early.
have been useful for dev but now QEMU should self-adjust at runtime
depending only on the host capabilities AFAIUI. Am I missing something ?
IOMMUFD doesn't support all features of legacy container, so QEMU
doesn't self-adjust at runtime by checking if host supports IOMMUFD.
We need to specify it explicitly to use IOMMUFD as below:
-object iommufd,id=iommufd0
-device vfio-pci,host=0000:02:00.0,iommufd=iommufd0
OK. I am not sure this is the correct interface yet. At first glance,
I wouldn't introduce a new object for a simple backend depending on a
kernel interface. I would tend to prefer a "iommu-something" property
of the vfio-pci device with string values: "legacy", "iommufd", "default"
and define the various interfaces (the ops you proposed) for each
depending on the user preference and the capabilities of the host and
possibly the device.