[Xen-devel] [PATCH] x86/HVM: correct notion of new CPL in task switch emulation

2017-06-01 Thread Jan Beulich
Commit aac1df3d03 ("x86/HVM: introduce hvm_get_cpl() and respective hook") went too far in one aspect: When emulating a task switch we really shouldn't be looking at what hvm_get_cpl() returns, as we're switching all segment registers. However, instead of reverting the relevant parts of that commi

Re: [Xen-devel] [PATCH] x86/HVM: correct notion of new CPL in task switch emulation

2017-06-02 Thread Andrew Cooper
On 01/06/17 13:11, Jan Beulich wrote: > Commit aac1df3d03 ("x86/HVM: introduce hvm_get_cpl() and respective > hook") went too far in one aspect: When emulating a task switch we > really shouldn't be looking at what hvm_get_cpl() returns, as we're > switching all segment registers. > > However, inst

Re: [Xen-devel] [PATCH] x86/HVM: correct notion of new CPL in task switch emulation

2017-06-02 Thread Andrew Cooper
On 02/06/17 21:02, Andrew Cooper wrote: > On 01/06/17 13:11, Jan Beulich wrote: >> Reported-by: Andrew Cooper >> Signed-off-by: Jan Beulich > I have finally managed to reproduce the original vmentry failure with an > XTF test. FWIW, the vmentry failure is quite subtle. %es gets reloaded first.

Re: [Xen-devel] [PATCH] x86/HVM: correct notion of new CPL in task switch emulation

2017-06-05 Thread Andrew Cooper
On 01/06/17 13:11, Jan Beulich wrote: > Commit aac1df3d03 ("x86/HVM: introduce hvm_get_cpl() and respective > hook") went too far in one aspect: When emulating a task switch we > really shouldn't be looking at what hvm_get_cpl() returns, as we're > switching all segment registers. > > However, inst

Re: [Xen-devel] [PATCH] x86/HVM: correct notion of new CPL in task switch emulation

2017-06-05 Thread Jan Beulich
>>> On 05.06.17 at 15:06, wrote: > On 01/06/17 13:11, Jan Beulich wrote: >> Commit aac1df3d03 ("x86/HVM: introduce hvm_get_cpl() and respective >> hook") went too far in one aspect: When emulating a task switch we >> really shouldn't be looking at what hvm_get_cpl() returns, as we're >> switching

Re: [Xen-devel] [PATCH] x86/HVM: correct notion of new CPL in task switch emulation

2017-06-06 Thread Jan Beulich
>>> On 02.06.17 at 22:33, wrote: > On 02/06/17 21:02, Andrew Cooper wrote: >> On 01/06/17 13:11, Jan Beulich wrote: >>> Reported-by: Andrew Cooper >>> Signed-off-by: Jan Beulich >> I have finally managed to reproduce the original vmentry failure with an >> XTF test. > > FWIW, the vmentry failur

Re: [Xen-devel] [PATCH] x86/HVM: correct notion of new CPL in task switch emulation

2017-06-06 Thread Andrew Cooper
On 06/06/17 07:42, Jan Beulich wrote: On 05.06.17 at 15:06, wrote: >> On 01/06/17 13:11, Jan Beulich wrote: >>> Commit aac1df3d03 ("x86/HVM: introduce hvm_get_cpl() and respective >>> hook") went too far in one aspect: When emulating a task switch we >>> really shouldn't be looking at what hv

Re: [Xen-devel] [PATCH] x86/HVM: correct notion of new CPL in task switch emulation

2017-06-06 Thread Andrew Cooper
On 06/06/17 08:06, Jan Beulich wrote: On 02.06.17 at 22:33, wrote: >> On 02/06/17 21:02, Andrew Cooper wrote: >>> On 01/06/17 13:11, Jan Beulich wrote: Reported-by: Andrew Cooper Signed-off-by: Jan Beulich >>> I have finally managed to reproduce the original vmentry failure with a

Re: [Xen-devel] [PATCH] x86/HVM: correct notion of new CPL in task switch emulation

2017-06-06 Thread Julien Grall
Hi Andrew, On 02/06/17 21:02, Andrew Cooper wrote: On 01/06/17 13:11, Jan Beulich wrote: Commit aac1df3d03 ("x86/HVM: introduce hvm_get_cpl() and respective hook") went too far in one aspect: When emulating a task switch we really shouldn't be looking at what hvm_get_cpl() returns, as we're swi