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Date:   Tue, 13 Jul 2021 20:39:06 +0000
From:   Sean Christopherson <seanjc@google.com>
To:     Paolo Bonzini <pbonzini@redhat.com>
Cc:     isaku.yamahata@intel.com, Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        "H . Peter Anvin" <hpa@zytor.com>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        Wanpeng Li <wanpengli@tencent.com>,
        Jim Mattson <jmattson@google.com>,
        Joerg Roedel <joro@8bytes.org>, erdemaktas@google.com,
        Connor Kuehl <ckuehl@redhat.com>, x86@kernel.org,
        linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
        isaku.yamahata@gmail.com,
        Sean Christopherson <sean.j.christopherson@intel.com>,
        Xiaoyao Li <xiaoyao.li@intel.com>
Subject: Re: [RFC PATCH v2 22/69] KVM: x86: Add vm_type to differentiate
 legacy VMs from protected VMs
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References: <cover.1625186503.git.isaku.yamahata@intel.com>
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 <e2270f66-abd8-db17-c3bd-b6d9459624ec@redhat.com>
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On Tue, Jul 06, 2021, Paolo Bonzini wrote:
> On 03/07/21 00:04, isaku.yamahata@intel.com wrote:
> >   struct kvm_arch {
> > +	unsigned long vm_type;
> 
> Also why not just int or u8?

Heh, because kvm_dev_ioctl_create_vm() takes an "unsigned long" for the type and
it felt wrong to store it as something else.  Storing it as a smaller field should
be fine, I highly doubt we'll get to 256 types anytime soon :-)

I think kvm_x86_ops.is_vm_type_supported() should take the full size though.