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From:   "Wang, Wei W" <wei.w.wang@intel.com>
To:     "Christopherson,, Sean" <seanjc@google.com>,
        Uros Bizjak <ubizjak@gmail.com>
CC:     "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>
Subject: RE: [PATCH] KVM/VMX: Do not declare vmread_error asmlinkage
Thread-Topic: [PATCH] KVM/VMX: Do not declare vmread_error asmlinkage
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Date:   Tue, 6 Sep 2022 07:28:22 +0000
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On Thursday, September 1, 2022 11:37 PM, Sean Christopherson wrote:
> > > And vmread_error() isn't the only case where asmlinkage appears to be=
 a
> burden, e.g.
> > > schedule_tail_wrapper() =3D> schedule_tail() seems to exist purely to
> > > deal with the side affect of asmlinkage generating -regparm=3D0 on 32=
-bit
> kernels.
> >
> > schedule_tail is external to the x86 arch directory, and for some
> > reason marked asmlinkage. So, the call from asm must follow asmlinkage
> > ABI.
>=20
> Ahhh, it's a common helper that's called from assembly on other architect=
ures.
> That makes sense.

I still doubt the necessity. The compilation is architecture specific, and =
we don't
build one architecture-agnostic kernel binary to run on different architect=
ures,
right?

Thanks,
Wei