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Date: Fri, 6 Oct 2017 09:36:06 -0500
From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: x86@kernel.org, Juergen Gross <jgross@suse.com>,
        Rusty Russell <rusty@rustcorp.com.au>, xen-devel@lists.xenproject.org,
        Peter Zijlstra <peterz@infradead.org>, Jiri Slaby <jslaby@suse.cz>,
        Boris Ostrovsky <boris.ostrovsky@oracle.com>,
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        Alok Kataria <akataria@vmware.com>,
        virtualization@lists.linux-foundation.org,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Ingo Molnar <mingo@kernel.org>
Subject: Re: [Xen-devel] [PATCH 00/13] x86/paravirt: Make pv ops code
 generation more closely match reality
Message-ID: <20171006143606.tbv4y2te6jvqoach@treble>
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On Fri, Oct 06, 2017 at 09:35:16AM +0200, Vitaly Kuznetsov wrote:
> Josh Poimboeuf <jpoimboe@redhat.com> writes:
> 
> > - For the most common runtime cases (everything except Xen and vSMP),
> >   vmlinux disassembly now matches what the actual runtime code looks
> >   like.  This improves debuggability and kernel developer sanity (a
> >   precious resource).
> >
> > ...
> >
> > - It's hopefully a first step in simplifying paravirt patching by
> >   getting rid of .parainstructions, pv ops, and apply_paravirt()
> >   completely.  (I think Xen can be changed to set CPU feature bits to
> >   specify which ops it needs during early boot, then those ops can be
> >   patched in using early alternatives.)
> 
> JFYI starting 4.14 Xen PV is not the only user of pv_mmu_ops, Hyper-V
> uses it for TLB shootdown now.

Yeah, I saw that.  It should be fine because the pv_alternatives get
patched before the Hyper-V code sets up pv_mmu_ops.

-- 
Josh