Re: [Xen-devel] [PATCH 2/5] x86emul: limit-check branch targets

2016-02-17 Thread Andrew Cooper
On 17/02/16 16:35, Jan Beulich wrote: > All branches need to #GP when their target violates the segment limit > (in 16- and 32-bit modes) or is non-canonical (in 64-bit mode). For > near branches facilitate this via a zero-byte instruction fetch from > the target address (resulting in address trans

[Xen-devel] [PATCH 2/5] x86emul: limit-check branch targets

2016-02-17 Thread Jan Beulich
All branches need to #GP when their target violates the segment limit (in 16- and 32-bit modes) or is non-canonical (in 64-bit mode). For near branches facilitate this via a zero-byte instruction fetch from the target address (resulting in address translation and validation without an actual read f