From: "Gerd Hoffmann" <kraxel@redhat.com>
To: devel@edk2.groups.io, min.m.xu@intel.com
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>,
"Justen, Jordan L" <jordan.l.justen@intel.com>,
Brijesh Singh <brijesh.singh@amd.com>,
Erdem Aktas <erdemaktas@google.com>,
James Bottomley <jejb@linux.ibm.com>,
"Yao, Jiewen" <jiewen.yao@intel.com>,
Tom Lendacky <thomas.lendacky@amd.com>
Subject: Re: [edk2-devel] [PATCH V2 28/28] OvmfPkg: Add LocalApicTimerDxe
Date: Mon, 25 Oct 2021 13:27:50 +0200 [thread overview]
Message-ID: <20211025112750.mytcbe3yawtidj7q@sirius.home.kraxel.org> (raw)
In-Reply-To: <PH0PR11MB50644452AFE73525B2D30A12C5839@PH0PR11MB5064.namprd11.prod.outlook.com>
On Mon, Oct 25, 2021 at 07:37:33AM +0000, Min Xu wrote:
> On October 12, 2021 9:02 PM, Gerd Hoffmann wrote:
> > On Tue, Oct 05, 2021 at 11:39:39AM +0800, Min Xu wrote:
> > > RFC： https://bugzilla.tianocore.org/show_bug.cgi?id=3429
> > >
> > > TDX guest supports LocalApicTimer. But in current OvmfPkg the
> > > supported timer is 8254TimerDxe. So
> > > gUefiOvmfPkgTokenSpaceGuid.PcdTimerSelector
> > > is introduced to select the running Timer. The Timer driver will check
> > > the TimerSelector in its entry point. The default Timer is 8254.
> >
> > Hmm.
> >
> > We already have a local apic timer implementation (XenTimerDxe). Works fine
> > with kvm, microvm already uses that. See commit 76602f45dcd9
> > ("OvmfPkg/Microvm: use XenTimerDxe (lapic timer)").
> >
> > So, first I'd suggest to just use that (maybe rename the thing to avoid confusion
> > as it isn't really Xen specific).
>
> Thanks for reminder. We can use XenTimerDxe as the LocalApicTimerDxe in Tdx guest. There will be a separate patch to rename XenTimerDxe to LocalApicTimerDxe in the next version.
You can also split this off into a separate patch series as it
shouldn't have any tdx dependency.
> I am not quite sure if there will be any side effect if we switch ovmf
> (X64) from 8254 to lapic unconditionally. Quick smoke test does show
> no obvious problems (EDK2 CI shows no error either). But since 8254
> timer has already been used in OvmfPkgX64, then there always a reason
> why 8254 is used.
Note that 8254TimerDxe was not written for OVMF, it was moved over
from PcAtChipsetPkg to OvmfPkg in 2019. Probably because OVMF was
the only user left.
Most likely the reason OVMF used 8254TimerDxe initially was that it
could just use the existing driver in PcAtChipsetPkg. And it simply
hasn't been changed ever.
Hmm, CSM support was moved in 2019 too, checking ...
Yes, CSM support depends on 8254 (and 8259) drivers.
> I am thinking if it is a more secure way to introduce PcdTimerSelector
> (to select timer in run-time) this time. We can revisit this proposal
> (switch ovmf from 8254 to lapic unconditionally) when we are pretty
> sure there is no side effect in the future.
I still think we don't need a runtime switch. Continue using
8254TimerDxe for CSM_ENABLE=TRUE builds should be enough.
take care,
Gerd
next prev parent reply other threads:[~2021-10-25 11:27 UTC|newest]
Thread overview: 91+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-05 3:39 [PATCH V2 00/28] Enable Intel TDX in OvmfPkg (Config-A) Min Xu
2021-10-05 3:39 ` [PATCH V2 01/28] OvmfPkg: Copy Main.asm from UefiCpuPkg to OvmfPkg's ResetVector Min Xu
2021-10-05 3:39 ` [PATCH V2 02/28] OvmfPkg: Enable TDX in ResetVector Min Xu
2021-10-05 3:39 ` [PATCH V2 03/28] OvmfPkg: Merge TEMP_MEM entries in Tdx metadata Min Xu
2021-10-05 3:39 ` [PATCH V2 04/28] MdePkg: Add Tdx.h Min Xu
2021-10-12 7:48 ` [edk2-devel] " Gerd Hoffmann
2021-10-05 3:39 ` [PATCH V2 05/28] MdePkg: Add TdxLib to wrap Tdx operations Min Xu
2021-10-12 8:22 ` [edk2-devel] " Gerd Hoffmann
2021-10-13 12:13 ` Min Xu
2021-10-14 5:30 ` Gerd Hoffmann
2021-10-22 2:06 ` Min Xu
2021-10-05 3:39 ` [PATCH V2 06/28] MdePkg: Update BaseIoLibIntrinsicSev to support Tdx Min Xu
2021-10-12 10:05 ` [edk2-devel] " Gerd Hoffmann
2021-10-13 13:40 ` Min Xu
2021-10-14 5:37 ` Gerd Hoffmann
2021-10-14 6:24 ` Min Xu
2021-10-14 9:03 ` Gerd Hoffmann
2021-10-22 5:23 ` Min Xu
2021-10-05 3:39 ` [PATCH V2 07/28] UefiCpuPkg: Support TDX in BaseXApicX2ApicLib Min Xu
2021-10-12 10:15 ` [edk2-devel] " Gerd Hoffmann
2021-10-13 14:06 ` Min Xu
2021-10-13 5:30 ` Ni, Ray
2021-10-14 7:58 ` Min Xu
2021-10-05 3:39 ` [PATCH V2 08/28] UefiCpuPkg: Add VmTdExitLibNull Min Xu
2021-10-05 3:39 ` [PATCH V2 09/28] UefiPayloadPkg: Prepare UefiPayloadPkg to use the VmTdExitLib library Min Xu
2021-10-05 3:39 ` [PATCH V2 10/28] OvmfPkg: Prepare OvmfPkg " Min Xu
2021-10-05 3:39 ` [PATCH V2 11/28] OvmfPkg: Implement library support for VmTdExitLib in Ovmf Min Xu
2021-10-05 3:39 ` [PATCH V2 12/28] UefiCpuPkg/CpuExceptionHandler: Add base support for the #VE exception Min Xu
2021-10-12 10:27 ` [edk2-devel] " Gerd Hoffmann
2021-10-26 5:06 ` Min Xu
2021-10-26 6:11 ` Gerd Hoffmann
2021-10-26 8:23 ` Min Xu
2021-10-26 10:24 ` Gerd Hoffmann
2021-10-26 12:09 ` Min Xu
2021-10-27 7:19 ` Gerd Hoffmann
2021-10-28 1:59 ` Yao, Jiewen
2021-10-28 15:35 ` Brijesh Singh
2021-10-28 15:52 ` Yao, Jiewen
2021-10-28 18:28 ` Lendacky, Thomas
2021-10-29 0:17 ` Yao, Jiewen
2021-10-29 4:52 ` Gerd Hoffmann
2021-10-29 7:51 ` Min Xu
2021-10-29 11:40 ` Gerd Hoffmann
2021-11-01 13:54 ` Sami Mujawar
2021-11-01 13:57 ` Yao, Jiewen
[not found] ` <16B2583BF2C9DB9C.5572@groups.io>
2021-10-29 0:20 ` Yao, Jiewen
2021-10-29 0:25 ` Brijesh Singh
[not found] ` <16B20F4407499229.28171@groups.io>
2021-10-28 2:07 ` Yao, Jiewen
2021-10-28 8:24 ` Gerd Hoffmann
2021-10-05 3:39 ` [PATCH V2 13/28] UefiCpuPkg: Enable Tdx support in MpInitLib Min Xu
2021-10-12 10:31 ` [edk2-devel] " Gerd Hoffmann
2021-10-14 0:27 ` Min Xu
2021-10-14 6:04 ` Gerd Hoffmann
2021-10-14 6:31 ` Min Xu
2021-10-14 6:56 ` Gerd Hoffmann
2021-10-13 6:01 ` Ni, Ray
2021-10-14 8:22 ` Min Xu
2021-10-05 3:39 ` [PATCH V2 14/28] OvmfPkg: Update SecEntry.nasm to support Tdx Min Xu
2021-10-12 10:38 ` [edk2-devel] " Gerd Hoffmann
2021-10-14 0:55 ` Min Xu
2021-10-14 6:51 ` Gerd Hoffmann
2021-10-05 3:39 ` [PATCH V2 15/28] OvmfPkg: Add IntelTdx.h in OvmfPkg/Include/IndustryStandard Min Xu
2021-10-05 3:39 ` [PATCH V2 16/28] OvmfPkg: Add TdxMailboxLib Min Xu
2021-10-05 3:39 ` [PATCH V2 17/28] MdePkg: Add EFI_RESOURCE_ATTRIBUTE_ENCRYPTED in PiHob.h Min Xu
2021-10-05 3:39 ` [PATCH V2 18/28] OvmfPkg: Enable Tdx in SecMain.c Min Xu
2021-10-05 3:39 ` [PATCH V2 19/28] OvmfPkg: Check Tdx in QemuFwCfgPei to avoid DMA operation Min Xu
2021-10-05 3:39 ` [PATCH V2 20/28] MdeModulePkg: EFER should not be changed in TDX Min Xu
2021-10-05 3:39 ` [PATCH V2 21/28] OvmfPkg: Update PlatformPei to support TDX Min Xu
2021-10-13 4:49 ` [edk2-devel] " Gerd Hoffmann
2021-10-15 1:31 ` Yao, Jiewen
2021-10-15 5:45 ` Gerd Hoffmann
2021-10-15 6:41 ` Yao, Jiewen
2021-10-05 3:39 ` [PATCH V2 22/28] UefiCpuPkg: Define ConfidentialComputingGuestAttr (Temp) Min Xu
2021-10-05 3:39 ` [PATCH V2 23/28] OvmfPkg: Update AcpiPlatformDxe to alter MADT table Min Xu
2021-10-05 3:39 ` [PATCH V2 24/28] OvmfPkg: Add TdxDxe driver Min Xu
2021-10-12 11:50 ` [edk2-devel] " Gerd Hoffmann
2021-10-18 8:38 ` Min Xu
2021-10-05 3:39 ` [PATCH V2 25/28] OvmfPkg/BaseMemEncryptTdxLib: Add TDX helper library Min Xu
2021-10-12 12:13 ` [edk2-devel] " Gerd Hoffmann
2021-10-05 3:39 ` [PATCH V2 26/28] OvmfPkg/QemuFwCfgLib: Support Tdx in QemuFwCfgDxe Min Xu
2021-10-05 3:39 ` [PATCH V2 27/28] OvmfPkg: Update IoMmuDxe to support TDX Min Xu
2021-10-12 12:15 ` [edk2-devel] " Gerd Hoffmann
2021-10-14 2:11 ` Min Xu
2021-10-05 3:39 ` [PATCH V2 28/28] OvmfPkg: Add LocalApicTimerDxe Min Xu
2021-10-12 13:02 ` [edk2-devel] " Gerd Hoffmann
2021-10-14 5:20 ` Min Xu
2021-10-15 1:21 ` Yao, Jiewen
2021-10-25 7:37 ` Min Xu
2021-10-25 11:27 ` Gerd Hoffmann [this message]
2021-10-26 1:29 ` Min Xu
2021-10-26 5:50 ` Gerd Hoffmann
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-list from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20211025112750.mytcbe3yawtidj7q@sirius.home.kraxel.org \
--to=devel@edk2.groups.io \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox