Re: [Xen-devel] [PATCH v4 1/8] x86: NOP out XPTI entry/exit code when it's not in use

2018-04-09 Thread Juergen Gross
On 09/04/18 10:28, Jan Beulich wrote: On 04.04.18 at 08:07, wrote: >> On 03/04/18 19:48, Juergen Gross wrote: >>> On 19/03/18 14:37, Jan Beulich wrote: Introduce a synthetic feature flag to use alternative instruction patching to NOP out all code on entry/exit paths. Having NOPs her

Re: [Xen-devel] [PATCH v4 1/8] x86: NOP out XPTI entry/exit code when it's not in use

2018-04-09 Thread Jan Beulich
>>> On 04.04.18 at 08:07, wrote: > On 03/04/18 19:48, Juergen Gross wrote: >> On 19/03/18 14:37, Jan Beulich wrote: >>> Introduce a synthetic feature flag to use alternative instruction >>> patching to NOP out all code on entry/exit paths. Having NOPs here is >>> generally better than using condit

Re: [Xen-devel] [PATCH v4 1/8] x86: NOP out XPTI entry/exit code when it's not in use

2018-04-03 Thread Juergen Gross
On 03/04/18 19:48, Juergen Gross wrote: > On 19/03/18 14:37, Jan Beulich wrote: >> Introduce a synthetic feature flag to use alternative instruction >> patching to NOP out all code on entry/exit paths. Having NOPs here is >> generally better than using conditional branches. >> >> Also change the li

Re: [Xen-devel] [PATCH v4 1/8] x86: NOP out XPTI entry/exit code when it's not in use

2018-04-03 Thread Juergen Gross
On 19/03/18 14:37, Jan Beulich wrote: > Introduce a synthetic feature flag to use alternative instruction > patching to NOP out all code on entry/exit paths. Having NOPs here is > generally better than using conditional branches. > > Also change the limit on the number of bytes we can patch in one

Re: [Xen-devel] [PATCH v4 1/8] x86: NOP out XPTI entry/exit code when it's not in use

2018-03-22 Thread Wei Liu
On Mon, Mar 19, 2018 at 07:37:54AM -0600, Jan Beulich wrote: > Introduce a synthetic feature flag to use alternative instruction > patching to NOP out all code on entry/exit paths. Having NOPs here is > generally better than using conditional branches. > > Also change the limit on the number of by

Re: [Xen-devel] [PATCH v4 1/8] x86: NOP out XPTI entry/exit code when it's not in use

2018-03-21 Thread Juergen Gross
On 19/03/18 14:37, Jan Beulich wrote: > Introduce a synthetic feature flag to use alternative instruction > patching to NOP out all code on entry/exit paths. Having NOPs here is > generally better than using conditional branches. > > Also change the limit on the number of bytes we can patch in one

[Xen-devel] [PATCH v4 1/8] x86: NOP out XPTI entry/exit code when it's not in use

2018-03-19 Thread Jan Beulich
Introduce a synthetic feature flag to use alternative instruction patching to NOP out all code on entry/exit paths. Having NOPs here is generally better than using conditional branches. Also change the limit on the number of bytes we can patch in one go to that resulting from the encoding in struc