Hi Mark, On Tue, Sep 01, 2026 at 10:47:01PM +0100, Mark Brown wrote: > GCS introduces a number of system registers, on systems with GCS we need > to context switch them and expose them to VMMs to allow guests to use > GCS. > > In order to allow guests to use GCS we also need to configure > HCRX_EL2.GCSEn, if this is not set GCS instructions will be noops and > CHKFEAT will report GCS as disabled. >
Everything you do seems the correct approach, and all the loads/saves are symmetrical, except for VEL2, for which the reason was made known in v19 discussion. That being said, I may have missed something as I am still not very much used to NV code. So, FWIW: Reviewed-by: Leonardo Bras <[email protected]> Nit: Reading this patch, it feels like it should have been two different patches: one for adding the registers to kvm infra, and the other for loading/saving it in the code (with GCSEn). If you later decide to split it, feel free to add my R-b in both of them. Thanks! Leo
