Hi Julien, > -----Original Message----- > Subject: [PATCH v7 2/5] xen/arm64: Rework the memory layout > > From: Julien Grall <jgr...@amazon.com> > > Xen is currently not fully compliant with the Arm Arm because it will > switch the TTBR with the MMU on. > > In order to be compliant, we need to disable the MMU before > switching the TTBR. The implication is the page-tables should > contain an identity mapping of the code switching the TTBR. > > In most of the case we expect Xen to be loaded in low memory. I am aware > of one platform (i.e AMD Seattle) where the memory start above 512GB. > To give us some slack, consider that Xen may be loaded in the first 2TB > of the physical address space. > > The memory layout is reshuffled to keep the first four slots of the zeroeth > level free. All the regions currently in L0 slot 0 will not be part of > slot 4 (2TB). This requires a slight tweak of the boot code because > XEN_VIRT_START (2TB + 2MB) cannot be used as an immediate. > > This reshuffle will make trivial to create a 1:1 mapping when Xen is > loaded below 2TB. > > Lastly, take the opportunity to check a compile time if any of the > regions may overlap with the reserved area for identity mapping. > > Signed-off-by: Julien Grall <jgr...@amazon.com>
This time I used our CI to test this series patch by patch on top of staging today (Apr 17), so that we can see if the qemu issue reported by Bertrand in v6 still persists. I can confirm all boards including the qemu-arm64 passed this time, so: Tested-by: Henry Wang <henry.w...@arm.com> Kind regards, Henry
