On 1/12/24 21:07, Borislav Petkov wrote: > On Fri, Jan 12, 2024 at 12:00:01PM -0800, Dave Hansen wrote: >> On 12/30/23 08:19, Michael Roth wrote: >> > If the kernel uses a 2MB directmap mapping to write to an address, and >> > that 2MB range happens to contain a 4KB page that set to private in the >> > RMP table, that will also lead to a page-fault exception. >> >> I thought we agreed long ago to just demote the whole direct map to 4k >> on kernels that might need to act as SEV-SNP hosts. That should be step >> one and this can be discussed as an optimization later. > > What would be the disadvantage here? Higher TLB pressure when running > kernel code I guess... Yeah and last LSF/MM we concluded that it's not as a big disadvantage as we previously thought https://lwn.net/Articles/931406/
