Re: [Xen-devel] [PATCH 5/5] x86: drop failsafe callback invocation from assembly

2016-02-17 Thread Andrew Cooper
On 17/02/16 16:38, Jan Beulich wrote: > Afaict this was never necessary on a 64-bit hypervisor, and was instead > just blindly cloned over from 32-bit code: We don't fiddle with (and > hence don't reload) any of DS, ES, FS, or GS, and an exception on IRET > itself can equally well be reported to th

[Xen-devel] [PATCH 5/5] x86: drop failsafe callback invocation from assembly

2016-02-17 Thread Jan Beulich
Afaict this was never necessary on a 64-bit hypervisor, and was instead just blindly cloned over from 32-bit code: We don't fiddle with (and hence don't reload) any of DS, ES, FS, or GS, and an exception on IRET itself can equally well be reported to the guest as that very exception on the target o