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Date:   Tue, 13 Dec 2022 05:52:20 +0000
From:   Sean Christopherson <seanjc@google.com>
To:     Yu Zhang <yu.c.zhang@linux.intel.com>
Cc:     pbonzini@redhat.com, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] KVM: X86: Use the common definition - 'GPA_INVALID' for
 X86
Message-ID: <Y5gTFPxUTXDsQb5p@google.com>
References: <20221209023622.274715-1-yu.c.zhang@linux.intel.com>
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On Fri, Dec 09, 2022, Yu Zhang wrote:
> KVM already has a 'GPA_INVALID' defined as (~(gpa_t)0) in
> kvm_types.h, and it is used by ARM and X86 xen code. We do
> not need a replicated 'INVALID_GPA' for X86 specifically.
> Just replace it with the common one.
> 
> Tested by rebuilding KVM.
> 
> No functional change intended.
> 
> Signed-off-by: Yu Zhang <yu.c.zhang@linux.intel.com>
> ---
>  arch/x86/include/asm/kvm_host.h |  2 -
>  arch/x86/kvm/hyperv.c           |  2 +-
>  arch/x86/kvm/mmu/paging_tmpl.h  |  6 +--
>  arch/x86/kvm/svm/nested.c       |  4 +-
>  arch/x86/kvm/svm/svm.c          |  4 +-
>  arch/x86/kvm/vmx/nested.c       | 66 ++++++++++++++++-----------------
>  arch/x86/kvm/vmx/sgx.c          |  2 +-
>  arch/x86/kvm/vmx/vmx.c          |  6 +--
>  arch/x86/kvm/x86.c              | 18 ++++-----
>  9 files changed, 54 insertions(+), 56 deletions(-)

What if we rename GPA_INVALID to INVALID_GPA and modify _those_ users?  I have
a slight preference for INVALID_GPA, and we also have INVALID_PAGE.  It'll also
yield a smaller diff.

EVMPTR_INVALID is the counter argument, but that's more of an error code than a
semi-arbitrary value, e.g. there's also EVMPTR_MAP_PENDING.

$ git grep GPA_INVALID | wc -l
17
$ git grep INVALID_GPA | wc -l
55