From: Xiaoyao Li <xiaoyao.li@intel.com>
To: Gerd Hoffmann <kraxel@redhat.com>
Cc: "Xu, Min M" <min.m.xu@intel.com>,
Dionna Amalie Glaze <dionnaglaze@google.com>,
"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>,
"Lendacky, Thomas" <Thomas.Lendacky@amd.com>,
"Yao, Jiewen" <jiewen.yao@intel.com>,
"Aktas, Erdem" <erdemaktas@google.com>,
"Yamahata, Isaku" <isaku.yamahata@intel.com>
Subject: Re: New "IndustryStandard" fw_cfg?
Date: Thu, 16 Jun 2022 13:49:11 +0800 [thread overview]
Message-ID: <6c2f350c-61eb-825d-36b7-86c913e610b3@intel.com> (raw)
In-Reply-To: <20220616053741.strgwe3mx3adxzui@sirius.home.kraxel.org>
On 6/16/2022 1:37 PM, Gerd Hoffmann wrote:
> Hi,
>
>> Per my understanding, Unaccepted Memory in UEFI is introduced for
>> confidential VMs, i.e., for Intel TDX and AMD SEV-SNP. The only reason
>> UEFI/OVMF reports "Unaccepted Memory" to OS, is a confidential VM is
>> desired.
>
> No. Reporting "Unaccepted Memory" to the OS is not a hard requirement
> for confidential VMs, it only optimizes boot times. Instead of doing
> that time-consuming process in the firmware for all memory we tell the
> guest OS which memory is accepted already and which is not. So the
> guest OS can go accept the remaining memory in a background process.
But for non-confidential VMs, even a range of memory is reported as
unaccepted nothing prevents it from being accessed without accepting it,
and it's not time-consuming. Did I miss anything?
> take care,
> Gerd
>
next prev parent reply other threads:[~2022-06-16 5:52 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-14 18:08 New "IndustryStandard" fw_cfg? Dionna Amalie Glaze
[not found] ` <PH0PR11MB50643B5AEE5A399EB8AFB000C5AD9@PH0PR11MB5064.namprd11.prod.outlook.com>
2022-06-15 7:33 ` Gerd Hoffmann
2022-06-15 19:23 ` Dionna Amalie Glaze
2022-06-15 15:19 ` Xiaoyao Li
2022-06-15 16:51 ` Tom Lendacky
2022-06-16 5:37 ` Gerd Hoffmann
2022-06-16 5:49 ` Xiaoyao Li [this message]
2022-06-16 6:00 ` Gerd Hoffmann
2022-06-16 6:33 ` Xiaoyao Li
2022-06-16 8:28 ` Gerd Hoffmann
2022-06-17 2:53 ` Xiaoyao Li
2022-06-17 19:57 ` Dionna Amalie Glaze
2022-06-20 10:42 ` Gerd Hoffmann
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