ACK/Cmnt: [SRU][Xenial][PULL] Guests using IBRS incur a large performance penalty (LP: #1764956)

[Kleber Souza]

On 1/8/19 2:43 PM, Stefan Bader wrote:
> On 19.12.18 11:03, Juerg Haefliger wrote:
>> git://git.launchpad.net/~juergh/+git/xenial-linux lp1764956-v2
>
> Glancing over the changes I noticed that "UBUNTU: SAUCE: x86/speculation:
> Cleanup IBPB runtime control handling" adds use of spec_ctrl_mutex but only
> "UBUNTU: SAUCE: x86/speculation: Cleanup IBRS runtime control handling" which
> follows next actually seems to declare it. In the end that does not matter only
> could make bisection a pain.
>
> Minor pedantic nitbit: is not "UBUNTU: SAUCE: x86/speculation: Move RSB_CTXSW
> hunk" moving the hunk further down?

The mentioned commits, although they are on that branch, are not part of
this PR (which is only
d0b9a387cf1d68745c558d04fd3aa980497d1529..7ad0e9a99c1466f8fee92cba5ffeaa0af83f6622).
They seem to have been sent as part of an earlier thread titled
"[SRU][Xenial][PATCH v2 0/4] Cleanups for CVE-2017-5715 (Spectre v2)".

Should we treat these patches as separated requests or as a single PR?