On Thu, May 04, 2023 at 05:36:32PM +0200, Ard Biesheuvel wrote: > On Thu, 4 May 2023 at 17:13, Jean-Philippe Brucker > <jean-phili...@linaro.org> wrote: > > > > Hello, > > > > On Tue, Apr 25, 2023 at 05:03:58PM +0100, Sami Mujawar wrote: > > > We are happy to announce an early RFC version of the Arm Confidential > > > Compute Architecture (CCA) support for the Kvmtool guest firmware. > > > The intention is to seek early feedback in the following areas: > > > * Integration of the Arm CCA in ArmVirtPkg > > > * Generalise the operations wherever possible with other Confidential > > > Compute solutions and Virtual Machine Managers (VMMs) > > > > Experimental support for ArmVirtQemu is available at [1]. Most of it > > simply includes Sami's libraries into ArmVirtQemu, but there are a few > > things specific to QEMU, one of which I still haven't figured out. > > > > The early debug support in PEI is problematic. A realm must access the > > emulated serial port through unprotected Intermediate Physical Address > > (IPA aka GPA) which is the upper half of the IPA space. The IPA address > > must have the most significant bit set. Once the MMU is enabled and > > ArmCcaConfigureMmio() runs, the page tables point to the right IPA so > > there is no problem. Before that however, EarlyFdtPL011SerialPortLib would > > need to access the device using the unprotected IPA address. So far I > > haven't managed to implement this, so the early serial debug is just > > disabled. > > > > Did you spot the changes I made recently for booting at EL1 with hard > coded [initial] page tables in flash? It seems to me that mapping the > serial port in there shouldn't be that hard.
Ah I did but I had misunderstood your change, it does set a TTBR right at the beginning in ArmPlatformPeiBootAction. Although we can't hardcode the serial port mapping (because its address in a Realm depends on the IPA width which varies across VM configurations), I can probably patch it early enough. Thanks, Jean -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#104109): https://edk2.groups.io/g/devel/message/104109 Mute This Topic: https://groups.io/mt/98496036/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
