Hi Julien, > -----Original Message----- > Subject: [PATCH 4/7] xen/arm: page: Consolidate write_pte() and clarify the > documentation > > From: Julien Grall <jgr...@amazon.com> > > The implementation of write_pte() is pretty much the same on arm32 > and arm64. So it would be good to consolidate it as this would help > to clarify the requirements when using the helper. > > Take the opportunity to switch from assembly to call macros. Note there > is a difference on arm32 because the option was not specified. But this > meant 'sy' (system wide). > > Futhermore, the requirements for the ISB is incomplete. Per the Arm Arm, > (Armv7 DDI406C.d A3.8.3 and Armv8 DDI 0487J.a B2.3.12), DSB will only > affect explicit accesses. So an ISB is necessary after DSB to ensure > the completion. Having an ISB after each update to the page-tables is > probably too much, so let the caller add the instruction when it is > convenient. > > Lastly, the barrier in write_pte() may be too restrictive but I haven't > yet find the proper section(s) in the Arm Arm. > > Signed-off-by: Julien Grall <jgr...@amazon.com>
Reviewed-by: Henry Wang <henry.w...@arm.com> I've also tested this patch on top of today's staging by our internal CI, and this patch looks good, so: Tested-by: Henry Wang <henry.w...@arm.com> Kind regards, Henry
