On Thu, Mar 21, 2019 at 11:27 AM Peter Zijlstra <pet...@infradead.org> wrote: > > On Thu, Mar 21, 2019 at 11:05:06AM -0700, Andy Lutomirski wrote: > > > Ugh. > > > > I certainly agree in principle that sticking the CR2 read into the asm > > is the right solution. But this patch makes the spaghetti even more > > tangled. Maybe we can rearrange the code a bit so that the entry > > sequence saves at least one register before calling error_entry, so we > > can do it the obvious way. > > What is the obvious way? Note that with all the Xen/paravirt-me-harder > bits on, we need to clobber at least RAX to get CR2. > > And most of the patch was munging the paravirt bits to make that happen. > > Another thing I did notices is that CLAC and CLD are not next to one > another in these paths.
The thing I really don't like is all the EBX crud to try to get everything in to the right order.
