Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: [PATCH v8 26/33] x86/fred: allow single-step trap and NMI when starting a new thread | Date | Mon, 05 Jun 2023 15:52:02 +0200 |
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On Mon, Jun 05 2023 at 15:50, Thomas Gleixner wrote:
> On Mon, Apr 10 2023 at 01:14, Xin Li wrote: >> Allow single-step trap and NMI when starting a new thread, thus once >> the new thread returns to ring3, single-step trap and NMI are both >> enabled immediately. >> >> High-order 48 bits above the lowest 16 bit CS are discarded by the >> legacy IRET instruction, thus can be set unconditionally, even when >> FRED is not enabled. > > I assume this has been validated to be true on _all_ CPU incarnations of > _all_ x86 vendors.
It's also ensured that VMMs do not get confused by this, right?
> If so, then please document it. If not, then go back to the drawing > board. > > Thanks, > > tglx
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