Re: [Xen-devel] [PATCH] x86/hvm: Fix mapping corner case during task switching.

2018-08-30 Thread Jan Beulich
>>> On 28.08.18 at 20:17, wrote: > hvm_map_entry() can fail for a number of reasons, including for a misaligned > LDT/GDT access which crosses a 4K boundary. Architecturally speaking, this > should be fixed, but Long Mode doesn't support task switches, and no 32bit OS > is going to misalign its L

[Xen-devel] [PATCH] x86/hvm: Fix mapping corner case during task switching.

2018-08-28 Thread Andrew Cooper
hvm_map_entry() can fail for a number of reasons, including for a misaligned LDT/GDT access which crosses a 4K boundary. Architecturally speaking, this should be fixed, but Long Mode doesn't support task switches, and no 32bit OS is going to misalign its LDT/GDT base, which is why this task isn't