Re: [PATCH v2 0/5] TDX host: kexec/kdump support

["Huang, Kai" <kai.huang@intel.com>]

On Wed, 2025-05-14 at 07:37 -0500, Tom Lendacky wrote:
> On 5/10/25 06:20, Kai Huang wrote:
> > Hi Dave,
> > 
> > This series is the latest attempt to support kexec on TDX host following
> > your suggestion to use a percpu boolean to control WBINVD during kexec.
> > I appreciate if you can help to review.
> > 
> > The last attempt was to have one patch to make TDX and kexec mutually
> > exclusive at runtime while allowing them to be both enabled in Kconfig,
> > but it turns out to be overkill.  Dave proposed another option of using
> > a percpu boolean to track the need for flushing:
> > 
> > https://lore.kernel.org/lkml/20250416230259.97989-1-kai.huang@intel.com/
> > 
> > One advantage of the percpu boolean is for TDX we could do optimization
> > to do:
> > 
> > 	wbinvd();
> > 	percpu(boolean) = 0;
> > 
> > for all CPUs at early stage to avoid having to do WBINVD in
> > stop_this_cpu() at kexec time.  I made a RFC patch to show the idea:
> > 
> > https://github.com/intel/tdx/commit/d9f0123b1d63ba24f472da6971181939ce53d2e3
> > 
> > I'll also reply this RFC patch to this coverletter in case anyone wants
> > to have a discussion.  Nevertheless, my exception is this series can be
> > merged first w/o the RFC patch.  We can follow up the optimizations
> > later.
> > 
> > This series is tagged v2, since it's a closer follow on to the RFC
> > patchset, which was posted before the single patch:
> > 
> > https://lore.kernel.org/all/cover.1741778537.git.kai.huang@intel.com/
> > 
> > This series is based on today's tip/master.
> 
> I'm on PTO for the next few days, so I'll try to review/test the SME
> related changes when I return.
> 

Hi Tom,

I hope you had a good time off? :-)

I appreciate if you can help to review/test.  This series can still be applied
cleanly on today's tip/master. :-)