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

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

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

2018-04-04 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

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

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

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