From: "Lendacky, Thomas" <thomas.lendacky@amd.com>
To: "Xu, Min M" <min.m.xu@intel.com>,
"devel@edk2.groups.io" <devel@edk2.groups.io>,
"Ni, Ray" <ray.ni@intel.com>
Cc: "Yao, Jiewen" <jiewen.yao@intel.com>,
Gerd Hoffmann <kraxel@redhat.com>,
Anthony Perard <anthony.perard@citrix.com>,
Julien Grall <julien@xen.org>, "Dong, Eric" <eric.dong@intel.com>
Subject: Re: [edk2-devel] [PATCH V7 36/37] UefiCpuPkg: Setting initial-count register as the last step
Date: Wed, 11 May 2022 09:06:11 -0500 [thread overview]
Message-ID: <0389cf2a-e9ba-0ba2-ac90-73ae402f7a08@amd.com> (raw)
In-Reply-To: <PH0PR11MB50643E3F369F8154733514B4C5C89@PH0PR11MB5064.namprd11.prod.outlook.com>
On 5/10/22 21:00, Xu, Min M wrote:
> On May 11, 2022 4:30 AM, Tom Lendacky wrote:
>> On 2/28/22 01:21, Min Xu via groups.io wrote:
>>> BZ: https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbugzilla.tianocore.org%2Fshow_bug.cgi%3Fid%3D3711&data=05%7C01%7Cthomas.lendacky%40amd.com%7Cce8cd76e1b054fe277d808da32f20976%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637878312370633666%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=C%2F0BMTV%2FoZdUxLwRbqzjNVdlMvEKfl20z6RwKeMzr2c%3D&reserved=0
>>>
>>> Per SDM, changing the mode of APIC timer (from one-shot to periodic or
>>> vice versa) by writing to the timer LVT entry does not start the timer.
>>> To start the timer, it is necessary to write to the initial-count
>>> register.
>>>
>>> If initial-count is wrote before mode change, it's possible that timer
>>> expired before the mode change. Thus failing the periodic mode.
>>
>> I'm replying to this patch since I can't find patch V12 46/47 anywhere in my
>> email.
>>
>> I've bisected a regression in the Linux kernel to this patch when an SEV-SNP
>> guest is booted. The following message is issued in the kernel for every AP
>> being brought online:
>>
>> APIC: Stale IRR:
>> 00000000,00000000,00000000,00000000,00000000,00000000,00000000,000
>> 00020 ISR:
>> 00000000,00000000,00000000,00000000,00000000,00000000,00000000,000
>> 00000
>>
>> Possibly a timing issue involving the mode switch with the interrupt
>> unmasked. If I leave the interrupt masked and only un-mask it after the
>> programming of the init-count, then the message goes away.
>
> Do you mean in InitializeApicTimer, it should follow below steps:
> 1. mask LvtTimer. (set LvtTimer.Bits.Mask = 1)
> 2. Do other stuff, including programing the init-count register.
> 3. un-mask LvtTimer (set LvtTimer.Bit.Mask = 0)
Yes, I believe so. I'm not an expert on the APIC timer, but that seems
reasonable to me.
Thanks,
Tom
>
> Thanks
> Min
>
next prev parent reply other threads:[~2022-05-11 14:06 UTC|newest]
Thread overview: 72+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-28 7:20 [PATCH V7 00/37] Enable Intel TDX in OvmfPkg (Config-A) Min Xu
2022-02-28 7:20 ` [PATCH V7 01/37] MdePkg: Add Tdx.h Min Xu
2022-02-28 7:20 ` [PATCH V7 02/37] MdePkg: Introduce basic Tdx functions in BaseLib Min Xu
2022-02-28 7:20 ` [PATCH V7 03/37] MdePkg: Add TdxLib to wrap Tdx operations Min Xu
2022-02-28 7:20 ` [PATCH V7 04/37] UefiCpuPkg: Extend VmgExitLibNull to handle #VE exception Min Xu
2022-03-15 7:15 ` [edk2-devel] [PATCH V7 04/37] UefiCpuPkg: Extend VmgExitLibNull to handle #VE exception #ve Ni, Ray
2022-02-28 7:20 ` [PATCH V7 05/37] OvmfPkg: Extend VmgExitLib to handle #VE exception Min Xu
2022-02-28 7:20 ` [PATCH V7 06/37] UefiCpuPkg/CpuExceptionHandler: Add base support for the " Min Xu
2022-03-15 7:17 ` [edk2-devel] [PATCH V7 06/37] UefiCpuPkg/CpuExceptionHandler: Add base support for the #VE exception #ve Ni, Ray
2022-03-15 7:37 ` Min Xu
2022-02-28 7:20 ` [PATCH V7 07/37] MdePkg: Add helper functions for Tdx guest in BaseIoLibIntrinsic Min Xu
2022-02-28 7:20 ` [PATCH V7 08/37] MdePkg: Support mmio " Min Xu
2022-02-28 7:20 ` [PATCH V7 09/37] MdePkg: Support IoFifo " Min Xu
2022-02-28 7:20 ` [PATCH V7 10/37] MdePkg: Support IoRead/IoWrite " Min Xu
2022-02-28 7:20 ` [PATCH V7 11/37] UefiCpuPkg: Support TDX in BaseXApicX2ApicLib Min Xu
2022-03-15 7:44 ` [edk2-devel] " Ni, Ray
2022-02-28 7:20 ` [PATCH V7 12/37] MdePkg: Add macro to check SEV / TDX guest Min Xu
2022-02-28 7:20 ` [PATCH V7 13/37] UefiCpuPkg: Enable Tdx support in MpInitLib Min Xu
2022-02-28 7:20 ` [PATCH V7 14/37] OvmfPkg: Add IntelTdx.h in OvmfPkg/Include/IndustryStandard Min Xu
2022-02-28 7:20 ` [PATCH V7 15/37] OvmfPkg: Add TdxMailboxLib Min Xu
2022-02-28 7:20 ` [PATCH V7 16/37] MdePkg: Add EFI_RESOURCE_ATTRIBUTE_ENCRYPTED in PiHob.h Min Xu
2022-02-28 7:20 ` [PATCH V7 17/37] OvmfPkg: Create initial version of PlatformInitLib Min Xu
2022-03-01 12:32 ` Gerd Hoffmann
2022-02-28 7:20 ` [PATCH V7 18/37] OvmfPkg/PlatformInitLib: Add hob functions Min Xu
2022-03-01 12:33 ` Gerd Hoffmann
2022-02-28 7:20 ` [PATCH V7 19/37] OvmfPkg/PlatformInitLib: Add memory functions Min Xu
2022-03-01 13:09 ` Gerd Hoffmann
2022-03-02 1:05 ` Min Xu
2022-03-02 6:56 ` [edk2-devel] " Gerd Hoffmann
2022-03-08 2:39 ` Min Xu
2022-02-28 7:20 ` [PATCH V7 20/37] OvmfPkg/PlatformInitLib: Add platform functions Min Xu
2022-02-28 7:20 ` [PATCH V7 21/37] OvmfPkg: Update PlatformInitLib to process Tdx hoblist Min Xu
2022-02-28 7:20 ` [PATCH V7 22/37] OvmfPkg/Sec: Declare local variable as volatile in SecCoreStartupWithStack Min Xu
2022-02-28 7:20 ` [PATCH V7 23/37] OvmfPkg: Update Sec to support Tdx Min Xu
2022-03-01 13:11 ` Gerd Hoffmann
2022-02-28 7:20 ` [PATCH V7 24/37] OvmfPkg: Check Tdx in QemuFwCfgPei to avoid DMA operation Min Xu
2022-02-28 7:20 ` [PATCH V7 25/37] MdeModulePkg: EFER should not be changed in TDX Min Xu
2022-03-03 3:11 ` Wang, Jian J
2022-03-04 0:18 ` Min Xu
2022-03-04 1:36 ` Wang, Jian J
2022-02-28 7:20 ` [PATCH V7 26/37] MdeModulePkg: Add PcdTdxSharedBitMask Min Xu
2022-03-03 3:27 ` Wang, Jian J
2022-03-04 1:34 ` Min Xu
2022-02-28 7:20 ` [PATCH V7 27/37] UefiCpuPkg: Update AddressEncMask in CpuPageTable Min Xu
2022-03-15 8:03 ` [edk2-devel] " Ni, Ray
2022-03-16 5:35 ` Min Xu
2022-02-28 7:21 ` [PATCH V7 28/37] OvmfPkg: Update PlatformInitLib for Tdx guest to publish ram regions Min Xu
2022-03-01 13:12 ` Gerd Hoffmann
2022-02-28 7:21 ` [PATCH V7 29/37] OvmfPkg: Update PlatformPei to support Tdx guest Min Xu
2022-03-01 13:13 ` Gerd Hoffmann
2022-02-28 7:21 ` [PATCH V7 30/37] OvmfPkg: Update AcpiPlatformDxe to alter MADT table Min Xu
2022-02-28 7:21 ` [PATCH V7 31/37] OvmfPkg/BaseMemEncryptTdxLib: Add TDX helper library Min Xu
2022-02-28 7:21 ` [PATCH V7 32/37] OvmfPkg: Add TdxDxe driver Min Xu
2022-02-28 7:21 ` [PATCH V7 33/37] OvmfPkg/QemuFwCfgLib: Support Tdx in QemuFwCfgDxe Min Xu
2022-02-28 7:21 ` [PATCH V7 34/37] OvmfPkg: Update IoMmuDxe to support TDX Min Xu
2022-02-28 7:21 ` [PATCH V7 35/37] OvmfPkg: Rename XenTimerDxe to LocalApicTimerDxe Min Xu
2022-02-28 7:21 ` [PATCH V7 36/37] UefiCpuPkg: Setting initial-count register as the last step Min Xu
2022-03-15 8:07 ` [edk2-devel] " Ni, Ray
2022-05-10 20:30 ` Lendacky, Thomas
2022-05-11 2:00 ` Min Xu
2022-05-11 14:06 ` Lendacky, Thomas [this message]
2022-05-12 0:52 ` Min Xu
2022-05-13 22:12 ` Lendacky, Thomas
2022-05-19 21:54 ` Henz, Patrick
2022-05-20 3:50 ` Jeff Fan
2022-02-28 7:21 ` [PATCH V7 37/37] OvmfPkg: Switch timer in build time for OvmfPkg Min Xu
2022-03-01 2:19 ` 回复: [edk2-devel] [PATCH V7 00/37] Enable Intel TDX in OvmfPkg (Config-A) gaoliming
2022-03-01 6:39 ` Min Xu
2022-03-01 6:53 ` Yao, Jiewen
2022-03-10 6:21 ` Min Xu
2022-03-11 3:19 ` 回复: " gaoliming
2022-03-11 7:17 ` Min Xu
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=0389cf2a-e9ba-0ba2-ac90-73ae402f7a08@amd.com \
--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