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From:   Pavel Tatashin <pasha.tatashin@soleen.com>
Date:   Wed, 4 Dec 2019 12:55:31 -0500
Message-ID: <CA+CK2bDV5pUYb5c-mkA9heE-CMg1MZdC=zz6zkDJDUZuuUpOmA@mail.gmail.com>
Subject: Re: [Xen-devel] [PATCH 1/3] arm/arm64/xen: use C inlines for privcmd_call
To:     Andrew Cooper <andrew.cooper3@citrix.com>
Cc:     Julien Grall <julien@xen.org>, James Morris <jmorris@namei.org>,
        Sasha Levin <sashal@kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>, steve.capper@arm.com,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        Marc Zyngier <marc.zyngier@arm.com>,
        James Morse <james.morse@arm.com>,
        Vladimir Murzin <vladimir.murzin@arm.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        allison@lohutok.net, info@metux.net, alexios.zavras@intel.com,
        Stefano Stabellini <sstabellini@kernel.org>,
        boris.ostrovsky@oracle.com, jgross@suse.com,
        Stefan Agner <stefan@agner.ch>,
        Masahiro Yamada <yamada.masahiro@socionext.com>,
        xen-devel@lists.xenproject.org,
        Russell King - ARM Linux admin <linux@armlinux.org.uk>
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On Fri, Nov 29, 2019 at 10:10 AM Andrew Cooper
<andrew.cooper3@citrix.com> wrote:
>
> On 29/11/2019 15:05, Julien Grall wrote:
> > Hi,
> >
> > On 27/11/2019 18:44, Pavel Tatashin wrote:
> >> diff --git a/arch/arm64/include/asm/xen/hypercall.h
> >> b/arch/arm64/include/asm/xen/hypercall.h
> >> index 3522cbaed316..1a74fb28607f 100644
> >> --- a/arch/arm64/include/asm/xen/hypercall.h
> >> +++ b/arch/arm64/include/asm/xen/hypercall.h
> >> @@ -1 +1,29 @@
> >> +#ifndef _ASM_ARM64_XEN_HYPERCALL_H
> >> +#define _ASM_ARM64_XEN_HYPERCALL_H
> >>   #include <xen/arm/hypercall.h>
> >> +#include <linux/uaccess.h>
> >> +
> >> +static inline long privcmd_call(unsigned int call, unsigned long a1,
> >> +                unsigned long a2, unsigned long a3,
> >> +                unsigned long a4, unsigned long a5)
> >
> > I realize that privcmd_call is the only hypercall using Software PAN
> > at the moment. However, dm_op needs the same as hypercall will be
> > issued from userspace as well.
>
> And dm_op() won't be the only example as we continue in cleaning up the
> gaping hole that is privcmd.
>
> > So I was wondering whether we should create a generic function (e.g.
> > do_xen_hypercall() or do_xen_user_hypercall()) to cover the two
> > hypercalls?
>
> Probably a good idea.

It sounds good to me, but let's keep it outside of this series.

Thank you,
Pasha