Re: [Xen-devel] [PATCH] xen/pvh: Fix segment selector ABI

2020-02-10 Thread Jan Beulich
On 10.02.2020 15:06, Andrew Cooper wrote: > On 10/02/2020 14:00, Jan Beulich wrote: >> On 10.02.2020 14:56, Andrew Cooper wrote: >>> On 10/02/2020 13:47, Jan Beulich wrote: On 10.02.2020 14:29, Andrew Cooper wrote: > On 10/02/2020 13:22, Jan Beulich wrote: >> On 08.02.2020 16:19, Andre

Re: [Xen-devel] [PATCH] xen/pvh: Fix segment selector ABI

2020-02-10 Thread Andrew Cooper
On 10/02/2020 14:00, Jan Beulich wrote: > On 10.02.2020 14:56, Andrew Cooper wrote: >> On 10/02/2020 13:47, Jan Beulich wrote: >>> On 10.02.2020 14:29, Andrew Cooper wrote: On 10/02/2020 13:22, Jan Beulich wrote: > On 08.02.2020 16:19, Andrew Cooper wrote: >> --- a/docs/misc/pvh.pandoc

Re: [Xen-devel] [PATCH] xen/pvh: Fix segment selector ABI

2020-02-10 Thread Jan Beulich
On 10.02.2020 14:56, Andrew Cooper wrote: > On 10/02/2020 13:47, Jan Beulich wrote: >> On 10.02.2020 14:29, Andrew Cooper wrote: >>> On 10/02/2020 13:22, Jan Beulich wrote: On 08.02.2020 16:19, Andrew Cooper wrote: > --- a/docs/misc/pvh.pandoc > +++ b/docs/misc/pvh.pandoc > @@ -23,

Re: [Xen-devel] [PATCH] xen/pvh: Fix segment selector ABI

2020-02-10 Thread Andrew Cooper
On 10/02/2020 13:47, Jan Beulich wrote: > On 10.02.2020 14:29, Andrew Cooper wrote: >> On 10/02/2020 13:22, Jan Beulich wrote: >>> On 08.02.2020 16:19, Andrew Cooper wrote: --- a/docs/misc/pvh.pandoc +++ b/docs/misc/pvh.pandoc @@ -23,7 +23,7 @@ following machine state: * `cs`:

Re: [Xen-devel] [PATCH] xen/pvh: Fix segment selector ABI

2020-02-10 Thread Jan Beulich
On 10.02.2020 14:29, Andrew Cooper wrote: > On 10/02/2020 13:22, Jan Beulich wrote: >> On 08.02.2020 16:19, Andrew Cooper wrote: >>> --- a/docs/misc/pvh.pandoc >>> +++ b/docs/misc/pvh.pandoc >>> @@ -23,7 +23,7 @@ following machine state: >>> * `cs`: must be a 32-bit read/execute code segment with

Re: [Xen-devel] [PATCH] xen/pvh: Fix segment selector ABI

2020-02-10 Thread Andrew Cooper
On 10/02/2020 13:22, Jan Beulich wrote: > On 08.02.2020 16:19, Andrew Cooper wrote: >> --- a/docs/misc/pvh.pandoc >> +++ b/docs/misc/pvh.pandoc >> @@ -23,7 +23,7 @@ following machine state: >> * `cs`: must be a 32-bit read/execute code segment with a base of ‘0’ >> and a limit of ‘0x’

Re: [Xen-devel] [PATCH] xen/pvh: Fix segment selector ABI

2020-02-10 Thread Jan Beulich
On 08.02.2020 16:19, Andrew Cooper wrote: > --- a/docs/misc/pvh.pandoc > +++ b/docs/misc/pvh.pandoc > @@ -23,7 +23,7 @@ following machine state: > * `cs`: must be a 32-bit read/execute code segment with a base of ‘0’ > and a limit of ‘0x’. The selector value is unspecified. > > - *

Re: [Xen-devel] [PATCH] xen/pvh: Fix segment selector ABI

2020-02-10 Thread Roger Pau Monné
On Sat, Feb 08, 2020 at 03:19:39PM +, Andrew Cooper wrote: > The written ABI states that %es will be set up, but libxc doesn't do so. In > practice, it breaks `rep movs` inside guests before they reload %es. > > The written ABI doesn't mention %ss, but libxc does set it up. Having %ds > diff

Re: [Xen-devel] [PATCH] xen/pvh: Fix segment selector ABI

2020-02-08 Thread Wei Liu
On Sat, Feb 08, 2020 at 03:19:39PM +, Andrew Cooper wrote: > The written ABI states that %es will be set up, but libxc doesn't do so. In > practice, it breaks `rep movs` inside guests before they reload %es. > > The written ABI doesn't mention %ss, but libxc does set it up. Having %ds > diff

[Xen-devel] [PATCH] xen/pvh: Fix segment selector ABI

2020-02-08 Thread Andrew Cooper
The written ABI states that %es will be set up, but libxc doesn't do so. In practice, it breaks `rep movs` inside guests before they reload %es. The written ABI doesn't mention %ss, but libxc does set it up. Having %ds different to %ss is obnoxous to work with, as different registers have differ