Paolo, I find the following links related to the discussions here along with one example feature called GENPROTRANGE.
https://csrc.nist.gov/CSRC/media/Presentations/The-Whole-is-Greater/images-media/day1_trusted-computing_200-250.pdf https://cansecwest.com/slides/2017/CSW2017_Cuauhtemoc-Rene_CPU_Hot-Add_flow.pdf https://www.mouser.com/ds/2/612/5520-5500-chipset-ioh-datasheet-1131292.pdf Best regards, Mike > -----Original Message----- > From: Paolo Bonzini [mailto:pbonz...@redhat.com] > Sent: Thursday, August 22, 2019 4:12 PM > To: Kinney, Michael D <michael.d.kin...@intel.com>; > Laszlo Ersek <ler...@redhat.com>; r...@edk2.groups.io; > Yao, Jiewen <jiewen....@intel.com> > Cc: Alex Williamson <alex.william...@redhat.com>; > devel@edk2.groups.io; qemu devel list <qemu- > de...@nongnu.org>; Igor Mammedov <imamm...@redhat.com>; > Chen, Yingwen <yingwen.c...@intel.com>; Nakajima, Jun > <jun.nakaj...@intel.com>; Boris Ostrovsky > <boris.ostrov...@oracle.com>; Joao Marcal Lemos Martins > <joao.m.mart...@oracle.com>; Phillip Goerl > <phillip.go...@oracle.com> > Subject: Re: [edk2-rfc] [edk2-devel] CPU hotplug using > SMM with QEMU+OVMF > > On 23/08/19 00:32, Kinney, Michael D wrote: > > Paolo, > > > > It is my understanding that real HW hot plug uses the > SDM defined > > methods. Meaning the initial SMI is to 3000:8000 and > they rebase to > > TSEG in the first SMI. They must have chipset specific > methods to > > protect 3000:8000 from DMA. > > It would be great if you could check. > > > Can we add a chipset feature to prevent DMA to 64KB > range from > > 0x30000-0x3FFFF and the UEFI Memory Map and ACPI > content can be > > updated so the Guest OS knows to not use that range for > DMA? > > If real hardware does it at the chipset level, we will > probably use Igor's suggestion of aliasing A-seg to > 3000:0000. Before starting the new CPU, the SMI handler > can prepare the SMBASE relocation trampoline at > A000:8000 and the hot-plugged CPU will find it at > 3000:8000 when it receives the initial SMI. Because this > is backed by RAM at 0xA0000-0xAFFFF, DMA cannot access it > and would still go through to RAM at 0x30000. > > Paolo -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#46248): https://edk2.groups.io/g/devel/message/46248 Mute This Topic: https://groups.io/mt/32979681/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
