From: Xiaoyao Li <xiaoyao.li@intel.com>
To: Sean Christopherson <seanjc@google.com>
Cc: Rick P Edgecombe <rick.p.edgecombe@intel.com>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"pbonzini@redhat.com" <pbonzini@redhat.com>
Subject: Re: [RFC] TDX module configurability of 0x80000008
Date: Wed, 8 May 2024 15:50:53 +0800 [thread overview]
Message-ID: <193c8685-2bb8-46ec-9e34-72fd70300d15@intel.com> (raw)
In-Reply-To: <Zjpg3dhf0mWetkSE@google.com>
On 5/8/2024 1:11 AM, Sean Christopherson wrote:
> On Wed, May 08, 2024, Xiaoyao Li wrote:
>> On 4/25/2024 12:55 AM, Edgecombe, Rick P wrote:
>>> One of the TDX module features is called MAXPA_VIRT. In short, it is similar to
>>> KVM’s allow_smaller_maxphyaddr. It requires an explicit opt-in by the VMM, and
>>> allows a TD’s 0x80000008.EAX[7:0] to be configured by the VMM. Accesses to
>>> physical addresses above the specified value by the TD will cause the TDX module
>>> to inject a mostly correct #PF with the RSVD error code set. It has to deal with
>>> the same problems as allow_smaller_maxphyaddr for correctly setting the RSVD
>>> bit. I wasn’t thinking to push this feature for KVM due the movement away from
>>> allow_smaller_maxphyaddr and towards 0x80000008.EAX[23:16].
>>>
>>
>> I would like to get your opinion of the MAXPA_VIRT feature of TDX. What is
>> likely the KVM's decision on it? Won't support it due to it has the same
>> limitation of allow_smaller_maxphyaddr?
>
> Not supporting MAXPA_VIRT has my vote. I'm of the opinion that allow_smaller_maxphyaddr
> should die a horrible, fiery death :-)
Thanks for the response. It's good to know your preference.
I'm not sure if there is any user of "allow_smaller_maxphyaddr". On QEMU
side, it doesn't check it nor rely on it. QEMU always allow the user to
configure a smaller PA.
prev parent reply other threads:[~2024-05-08 7:50 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-24 16:55 [RFC] TDX module configurability of 0x80000008 Edgecombe, Rick P
2024-04-25 15:09 ` Xiaoyao Li
2024-04-25 16:31 ` Edgecombe, Rick P
2024-04-25 16:59 ` Sean Christopherson
2024-04-25 18:20 ` Edgecombe, Rick P
2024-04-25 21:39 ` Sean Christopherson
2024-04-25 22:41 ` Edgecombe, Rick P
2024-04-25 22:53 ` Sean Christopherson
2024-04-25 23:08 ` Edgecombe, Rick P
2024-04-25 23:28 ` Sean Christopherson
2024-04-25 23:38 ` Edgecombe, Rick P
2024-05-06 18:40 ` Edgecombe, Rick P
2024-05-07 14:22 ` Chao Gao
2024-05-07 14:49 ` Edgecombe, Rick P
2024-05-07 16:21 ` Sean Christopherson
2024-05-07 16:41 ` Xiaoyao Li
2024-05-07 17:11 ` Sean Christopherson
2024-05-08 7:50 ` Xiaoyao Li [this message]
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