Re: [Xen-devel] [PATCH v3 2/2] x86/hvm: Don't intercept #UD exceptions in general

2016-02-01 Thread Tian, Kevin
> From: Andrew Cooper [mailto:andrew.coop...@citrix.com] > Sent: Saturday, January 30, 2016 3:18 AM > > c/s 0f1cb96e "x86 hvm: Allow cross-vendor migration" caused HVM domains to > unconditionally intercept #UD exceptions. While cross-vendor migration is > cool as a demo, it is extremely niche. >

Re: [Xen-devel] [PATCH v3 2/2] x86/hvm: Don't intercept #UD exceptions in general

2016-02-01 Thread Jan Beulich
>>> On 29.01.16 at 20:17, wrote: > c/s 0f1cb96e "x86 hvm: Allow cross-vendor migration" caused HVM domains to > unconditionally intercept #UD exceptions. While cross-vendor migration is > cool as a demo, it is extremely niche. > > Intercepting #UD allows userspace code in a multi-vcpu guest to e

[Xen-devel] [PATCH v3 2/2] x86/hvm: Don't intercept #UD exceptions in general

2016-01-29 Thread Andrew Cooper
c/s 0f1cb96e "x86 hvm: Allow cross-vendor migration" caused HVM domains to unconditionally intercept #UD exceptions. While cross-vendor migration is cool as a demo, it is extremely niche. Intercepting #UD allows userspace code in a multi-vcpu guest to execute arbitrary instructions in the x86 emu