Eric W. Biederman wrote: >>>> svm can writeback into memory at odd times if we don't do this, and the cost >> is >>>> small - clear a bit in EFER. There's no reason to be lazy. >>>> >>> Especially if we can clear that bit unconditionally (when >>> EFER is present) I'm all for it. >>> >> That is the case. > > Cool. I forget if we have to test for EFER on 32bit, or if we can just wrmsr > and be done with it. Regardless that sounds easy to do on the kexec path. I'm pretty sure you have to test for it first; pre-64 bit x86 hardware doesn't have the EFER register, so you'll fault on access. On the other hand pre-64 bit x86 hardware doesn't usually (ever?) have VT extensions either. -- Chris Lalancette
