Subject: Re: [RFC PATCH v3 2/2] KVM: x86: Allow Qemu/KVM to use PVH entry
 point
To: Juergen Gross <jgross@suse.com>,
        Maran Wilson <maran.wilson@oracle.com>, boris.ostrovsky@oracle.com,
        roger.pau@citrix.com, andrew.cooper3@citrix.com, hch@infradead.org,
        JBeulich@suse.com, x86@kernel.org, xen-devel@lists.xenproject.org,
        linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com,
        rkrcmar@redhat.com
References: <1513122151-5371-1-git-send-email-maran.wilson@oracle.com>
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From: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <72846976-b3c3-ceca-8168-d50bcad5993e@redhat.com>
Date: Fri, 15 Dec 2017 18:25:34 +0100
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On 15/12/2017 16:55, Juergen Gross wrote:
> I'm fine with the general idea.
> 
> I'm wondering whether you really want to require CONFIG_XEN for the
> KVM case, though.
> 
> Wouldn't it be better to rename arch/x86/xen/enlighten_pvh.c to
> arch/x86/pvh.c and arch/x86/xen/xen-pvh.S to arch/x86/pvh-head.S,

Yes, sounds good.

> put both under CONFIG_PVH umbrella and select this from CONFIG_XEN_PVH
> and KVM_PVH (or what you like to call it)?

CONFIG_KVM_GUEST will be good enough.

> In the two moved source files you can make Xen/KVM-specific parts
> optional via their CONFIG_ options.
> 
> And you might want to add an own ELF note for the KVM case?

As long as it's compatible with Xen, it's not needed.  Only the startup
code changes between a KVM "PVH" kernel and a KVM "HVM" kernel.

Paolo