Hi liming, This is a bug fix. It is required by 201908 stable tag.
Thanks, Eric > -----Original Message----- > From: Gao, Liming > Sent: Wednesday, August 14, 2019 3:27 PM > To: devel@edk2.groups.io; Dong, Eric <eric.d...@intel.com>; > ler...@redhat.com > Cc: Ni, Ray <ray...@intel.com>; leif.lindh...@linaro.org; af...@apple.com; > Cetola, Stephano <stephano.cet...@intel.com>; Kinney, Michael D > <michael.d.kin...@intel.com> > Subject: RE: [edk2-devel] [Patch v2 0/6] Add "test then write" mechanism. > > Eric: > Is this a bug fix or new feature? Dose it catch to this 201908 stable tag? > > Thanks > Liming > >-----Original Message----- > >From: devel@edk2.groups.io [mailto:devel@edk2.groups.io] On Behalf Of > >Dong, Eric > >Sent: Tuesday, August 13, 2019 10:29 AM > >To: devel@edk2.groups.io; ler...@redhat.com > >Cc: Ni, Ray <ray...@intel.com> > >Subject: Re: [edk2-devel] [Patch v2 0/6] Add "test then write" mechanism. > > > >Hi Laszlo, > > > >Yes, I already checked IA32 build. > > > >As Ray is leaving these days, can you help to review this serial? > > > >Thanks, > >Eric > > > >> -----Original Message----- > >> From: devel@edk2.groups.io [mailto:devel@edk2.groups.io] On Behalf Of > >> Laszlo Ersek > >> Sent: Monday, August 12, 2019 10:15 PM > >> To: Dong, Eric <eric.d...@intel.com>; devel@edk2.groups.io > >> Cc: Ni, Ray <ray...@intel.com> > >> Subject: Re: [edk2-devel] [Patch v2 0/6] Add "test then write" mechanism. > >> > >> On 08/12/19 12:31, Eric Dong wrote: > >> > V2 changes: > >> > 1. Split CR read/write action in to one discrete patch 2. Keep the > >> > old logic which continue the process if error found. > >> > > >> > Below code is current implementation: > >> > if (MsrRegister[ProcessorNumber].Bits.Lock == 0) { > >> > CPU_REGISTER_TABLE_WRITE_FIELD ( > >> > ProcessorNumber, > >> > Msr, > >> > MSR_IA32_FEATURE_CONTROL, > >> > MSR_IA32_FEATURE_CONTROL_REGISTER, > >> > Bits.Lock, > >> > 1 > >> > ); > >> > } > >> > > >> > With below steps, the Bits.Lock bit will lose its value: > >> > 1. Trig normal boot, the Bits.Lock is 0. 1 will be added > >> > into the register table and then will set to the MSR. > >> > 2. Trig warm reboot, MSR value preserves. After normal boot phase, > >> > the Bits.Lock is 1, so it will not be added into the register > >> > table during the warm reboot phase. > >> > 3. Trig S3 then resume, the Bits.Lock change to 0 and Bits.Lock is > >> > not added in register table during normal boot phase. so it's > >> > still 0 after resume. > >> > This is not an expect behavior. The expect result is the value > >> > should always 1 after booting or resuming from S3. > >> > > >> > The root cause for this issue is > >> > 1. driver bases on current value to insert the "set value action" to > >> > the register table. > >> > 2. Some MSRs may reserve their value during warm reboot. So the > insert > >> > action may be skip after warm reboot. > >> > > >> > The solution for this issue is: > >> > 1. Always add "Test then Set" action for above referred MSRs. > >> > 2. Detect current value before set new value. Only set new value when > >> > current value not same as new value. > >> > > >> > Cc: Ray Ni <ray...@intel.com> > >> > Cc: Laszlo Ersek <ler...@redhat.com> > >> > > >> > Eric Dong (6): > >> > UefiCpuPkg/RegisterCpuFeaturesLib: Add "Test Then Write" Macros. > >> > UefiCpuPkg/PiSmmCpuDxeSmm: Combine CR read/write action in one > >> > function. > >> > UefiCpuPkg/PiSmmCpuDxeSmm: Supports test then write new value > >logic. > >> > UefiCpuPkg/RegisterCpuFeaturesLib: Combine CR read/write action > >> > in > >> one > >> > function. > >> > UefiCpuPkg/RegisterCpuFeaturesLib: Supports test then write new > value > >> > logic. > >> > UefiCpuPkg/CpuCommonFeaturesLib: Use new macros. > >> > > >> > UefiCpuPkg/Include/AcpiCpuData.h | 1 + > >> > .../Include/Library/RegisterCpuFeaturesLib.h | 77 +++++++++- > >> > .../CpuCommonFeaturesLib/CpuCommonFeatures.h | 15 -- > >> > .../CpuCommonFeaturesLib.c | 8 +- > >> > .../CpuCommonFeaturesLib/FeatureControl.c | 141 ++++++------------ > >> > .../CpuCommonFeaturesLib/MachineCheck.c | 23 ++- > >> > .../CpuFeaturesInitialize.c | 141 ++++++++++++------ > >> > .../RegisterCpuFeaturesLib.c | 14 +- > >> > UefiCpuPkg/PiSmmCpuDxeSmm/CpuS3.c | 135 +++++++++++---- > -- > >> > 9 files changed, 323 insertions(+), 232 deletions(-) > >> > > >> > >> Please don't forget to build-test this series for IA32 too. > >> > >> Thanks > >> Laszlo > >> > >> > > > > > > -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#45590): https://edk2.groups.io/g/devel/message/45590 Mute This Topic: https://groups.io/mt/32839204/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
