Re: [Xen-devel] [PATCH] x86emul: correct segment override decode for 64-bit mode

2019-12-12 Thread Andrew Cooper
On 12/12/2019 10:04, Jan Beulich wrote: > On 11.12.2019 21:51, Andrew Cooper wrote: >> On 11/12/2019 09:27, Jan Beulich wrote: >>> The legacy / compatibility mode ES, CS, SS, and DS overrides are null >>> prefixes in 64-bit mode, i.e. they in particular don't cancel an >>> earlier FS or GS one.

Re: [Xen-devel] [PATCH] x86emul: correct segment override decode for 64-bit mode

2019-12-12 Thread Jan Beulich
On 11.12.2019 21:51, Andrew Cooper wrote: > On 11/12/2019 09:27, Jan Beulich wrote: >> The legacy / compatibility mode ES, CS, SS, and DS overrides are null >> prefixes in 64-bit mode, i.e. they in particular don't cancel an >> earlier FS or GS one. >> >> Signed-off-by: Jan Beulich > > null is a

Re: [Xen-devel] [PATCH] x86emul: correct segment override decode for 64-bit mode

2019-12-11 Thread Andrew Cooper
On 11/12/2019 09:27, Jan Beulich wrote: > The legacy / compatibility mode ES, CS, SS, and DS overrides are null > prefixes in 64-bit mode, i.e. they in particular don't cancel an > earlier FS or GS one. > > Signed-off-by: Jan Beulich null is a very overloaded term.  What you mean here is simply

[Xen-devel] [PATCH] x86emul: correct segment override decode for 64-bit mode

2019-12-11 Thread Jan Beulich
The legacy / compatibility mode ES, CS, SS, and DS overrides are null prefixes in 64-bit mode, i.e. they in particular don't cancel an earlier FS or GS one. Signed-off-by: Jan Beulich --- a/xen/arch/x86/x86_emulate/x86_emulate.c +++ b/xen/arch/x86/x86_emulate/x86_emulate.c @@ -2830,14 +2830,17