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Date: Mon, 25 Mar 2024 16:59:18 -0700
From: Isaku Yamahata <isaku.yamahata@intel.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, michael.roth@amd.com,
	isaku.yamahata@intel.com, seanjc@google.com,
	isaku.yamahata@linux.intel.com, rick.p.edgecombe@intel.com,
	xiaoyao.li@intel.com, kai.huang@intel.com
Subject: Re: [PATCH v4 05/15] KVM: SEV: publish supported VMSA features
Message-ID: <20240325235918.GR2357401@ls.amr.corp.intel.com>
References: <20240318233352.2728327-1-pbonzini@redhat.com>
 <20240318233352.2728327-6-pbonzini@redhat.com>
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In-Reply-To: <20240318233352.2728327-6-pbonzini@redhat.com>

On Mon, Mar 18, 2024 at 07:33:42PM -0400,
Paolo Bonzini <pbonzini@redhat.com> wrote:

> Compute the set of features to be stored in the VMSA when KVM is
> initialized; move it from there into kvm_sev_info when SEV is initialized,
> and then into the initial VMSA.
> 
> The new variable can then be used to return the set of supported features
> to userspace, via the KVM_GET_DEVICE_ATTR ioctl.

Hi. The current TDX KVM introduces KVM_TDX_CAPABILITIES and struct
kvm_tdx_capabilities for feature enumeration.  I'm wondering if TDX should also
use/switch to KVM_GET_DEVICE_ATTR with its own group.  What do you think?
Something like

#define KVM_DEVICE_ATTR_GROUP_SEV       1
#define KVM_X86_SEV_VMSA_FEATURES       1
#define KVM_X86_SEV_xxx                 ...

#define KVM_DEVICE_ATTR_GROUP_TDX       2
#define KVM_X86_TDX_xxx                 ...

Thanks,
-- 
Isaku Yamahata <isaku.yamahata@intel.com>