Hi Baolu, > -----Original Message----- > From: Lu Baolu <[email protected]> > Sent: Thursday, May 28, 2020 6:52 PM > To: Prakhya, Sai Praneeth <[email protected]>; > [email protected] > Cc: [email protected]; Christoph Hellwig <[email protected]>; Joerg Roedel > <[email protected]>; Raj, Ashok <[email protected]>; Will Deacon > <[email protected]>; Mehta, Sohil <[email protected]>; Robin > Murphy <[email protected]>; Jacob Pan <[email protected]> > Subject: Re: [PATCH V3 0/3] iommu: Add support to change default domain of > an iommu > > Hi Sai, > > On 5/29/20 3:23 AM, Sai Praneeth Prakhya wrote: > > Presently, the default domain of a iommu group is allocated during > > boot time and it cannot be changed later. So, the device would > > typically be either in identity > > (pass_through) mode or the device would be in DMA mode as long as the > > system is up and running. There is no way to change the default domain > > type dynamically i.e. after booting, a device cannot switch between identity > mode and DMA mode. > > > > Assume a use case wherein the privileged user would want to use the > > device in pass-through mode when the device is used for host so that > > it would be high performing. Presently, this is not supported. Hence > > add support to change the default domain of an iommu group dynamically. > > > > Support this by writing to a sysfs file, namely > > "/sys/kernel/iommu_groups/<grp_id>/type". > > The email subject > > [PATCH V3 0/3] iommu: Add support to change default domain of an iommu > > probably should be changed to > > [PATCH V3 0/3] iommu: Add support to change default domain of an iommu > group
Oops.. my bad. I have it in the patches that I have on my dev machine. I added "group" to a new line because the subject line crossed 80 character limit. Probably, I will just put it in the same line for the next version. Thanks for bringing this up. Regards, Sai _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
