Hi, Josh, On Fri, Dec 17, 2021 at 02:57:06PM -0800, Josh Poimboeuf wrote: > On Fri, Dec 17, 2021 at 10:01:35PM +0000, Fenghua Yu wrote: > > The ENQCMD implicitly accesses the PASID_MSR to fill in the pasid field > > of the descriptor being submitted to an accelerator. But there is no > > precise (and stable across kernel changes) point at which the PASID_MSR > > is updated from the value for one task to the next. > > > > Kernel code that uses accelerators must always use the ENQCMDS instruction > > which does not access the PASID_MSR. > > > > Check for use of the ENQCMD instruction in the kernel and warn on its > > usage. > > > > Signed-off-by: Fenghua Yu <[email protected]> > > Reviewed-by: Tony Luck <[email protected]> > > --- > > v2: > > - Simplify handling ENQCMD (PeterZ and Josh) > > Acked-by: Josh Poimboeuf <[email protected]>
Thank you! -Fenghua _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
