Today X86 CpuMp PEIM enables the paging in 32bit and 64bit mode for protection of: 1. Stack overflow 2. Avoid accessing SPI flash after NEM tear down
We could either producing a 32bit PPI for above needs (DxeIpl should not call this PPI for DxeCore protection in mixed 32PEI+64DXE env) or separating above protection logic into separate 32bit/64bit functions. For the latter case, 32bit function could use existing logic, 64bit function could use the new PPI. Thanks, Ray > -----Original Message----- > From: Kinney, Michael D <michael.d.kin...@intel.com> > Sent: Wednesday, May 24, 2023 12:48 AM > To: devel@edk2.groups.io; a...@kernel.org > Cc: ler...@redhat.com; Ni, Ray <ray...@intel.com>; Yao, Jiewen > <jiewen....@intel.com>; Gerd Hoffmann <kra...@redhat.com>; Taylor Beebe > <t...@taylorbeebe.com>; Oliver Smith-Denny <o...@smith-denny.com>; Kinney, > Michael D <michael.d.kin...@intel.com> > Subject: RE: [edk2-devel] managing memory attributes in PEI > > Hi Ard, > > Thanks. I agree with your plan. > > In the future, if we think there is value in enabling paging in 32-bit PEI, we > could add the PPI at that time. > > Mike > > > -----Original Message----- > > From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Ard > > Biesheuvel > > Sent: Tuesday, May 23, 2023 8:51 AM > > To: devel@edk2.groups.io; Kinney, Michael D > > <michael.d.kin...@intel.com> > > Cc: ler...@redhat.com; Ni, Ray <ray...@intel.com>; Yao, Jiewen > > <jiewen....@intel.com>; Gerd Hoffmann <kra...@redhat.com>; Taylor > > Beebe <t...@taylorbeebe.com>; Oliver Smith-Denny <o...@smith-denny.com> > > Subject: Re: [edk2-devel] managing memory attributes in PEI > > > > On Tue, 23 May 2023 at 17:15, Michael D Kinney > > <michael.d.kin...@intel.com> wrote: > > > > > > > > > > > > > -----Original Message----- > > > > From: Ard Biesheuvel <a...@kernel.org> > > > > Sent: Tuesday, May 23, 2023 7:59 AM > > > > To: Kinney, Michael D <michael.d.kin...@intel.com> > > > > Cc: devel@edk2.groups.io; ler...@redhat.com; Ni, Ray > > <ray...@intel.com>; > > > > Yao, Jiewen <jiewen....@intel.com>; Gerd Hoffmann > > > > <kra...@redhat.com>; Taylor Beebe <t...@taylorbeebe.com>; Oliver > > Smith- > > > > Denny <o...@smith-denny.com> > > > > Subject: Re: [edk2-devel] managing memory attributes in PEI > > > > > > > > On Tue, 23 May 2023 at 16:49, Kinney, Michael D > > > > <michael.d.kin...@intel.com> wrote: > > > > > > > > > > Ard, > > > > > > > > > > I would prefer to keep the IA32 PEI support for OVMF. > > > > > > > > > > > > > Sure. But does that imply that all enhancements regarding memory > > > > protections should be introduced there as well? > > > > > > I would prefer to not support these protections in IA32 PEI. Same > > > for IA32 DXE. Can the proposed PPI do nothing for IA32? > > > > > > > Absolutely. I was just trying to narrow down whether your 'keeping > > IA32' meant just keeping it in working order, or have it keep up with > > future enhancements. > > > > My intent is to implement an optional PPI that will be used by the PEI > > image loader to map PE code and data sections with the appropriate > > permissions if they are suitably aligned. Only the DXE core would > > generally fit this description, but there is no reason to disallow > > this for shadowed PEIMs that happen to be built as PE32 binaries with > > 4k section alignment (although I'm not convinced of the value add > > there) > > > > If the PPI is not exposed (for any reason) things should just keep > > working as they do today. > > > > Given that OVMF no longer functionally depends on IA32 PEI, we simply > > won't bother to implement the PPI at all for IA32. > > > > > > > > -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#105213): https://edk2.groups.io/g/devel/message/105213 Mute This Topic: https://groups.io/mt/99062463/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/leave/9847357/21656/1706620634/xyzzy [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
