On 08.08.2023 17:14, Oleksii Kurochko wrote: > The patch series introduces things necessary to implement identity mapping: > 1. Make identity mapping for the entire Xen. > 2. Enable MMU. > 3. Jump to the virtual address world > 4. Remove identity mapping. > > Also current patch series introduces the calculation of physical offset before > MMU is enabled as access to physical offset will be calculated wrong after > MMU will be enabled because access to phys_off variable is PC-relative and > in the case when linker address != load address, it will cause MMU fault. > > The reason for this patch series can be found here: > https://lore.kernel.org/xen-devel/[email protected]/ > > --- > Changes in V7: > - use srli instruction to be consistent with slli instruction in > turn_on_mmu() > --- > Changes in V6: > - Update calc_phys_offset() after rebase. > - Refactor turn_on_mmu() and a way how an argument of turn_on_mmu() is > calculated. > --- > Changes in V5: > - update the algo of identity mapping removing. > - introduce IDENT_AREA_SIZE. > - introduce turn_on_mmu() function to enable and switch from 1:1 > mapping. > - fix typo in PGTBL_INITIAL_COUNT define. > - update the comment above PGTBL_INITIAL_COUNT. > - update prototype of calc_phys_offset(). now it returns phys_offset. > - declare phys_offset as static. > - save returned value of calc_phys_offset to register s2. > --- > Changes in V4: > - drop patch [PATCH v3 1/3] xen/riscv: add SPDX tag to config.h as > it was > merged to staging > - remove definition of ARRAY_SIZE and ROUNDUP as <xen/macors.h> was > introduced where these macros are located now. > - update definition of PGTBL_INITIAL_COUNT > - update the commit message for patch 'xen/riscv: introduce identity > mapping' > - update the comments in head.S > - update the algo of identity mapping removing > --- > Changes in V3: > - Update the patch series message. > - The following patches were merged to staging so droped from the patch > series: > * xen/riscv: add .sbss section to .bss > * xen/riscv: introduce reset_stack() function > * xen/riscv: move extern of cpu0_boot_stack to header > * xen/riscv: add SPDX tags > - move save/restore of a0/a1 registers from patch 4 to patch 2 ( numbers are > from the previous patch series version ) > - add SPDX tag in config.h > - update definition of PGTBL_INITIAL_COUNT taking into account identity > mapping. > - refactor remove_identity_mapping() function. > - add explanatory comments in xen.lds.S and mm.c. > --- > Changes in V2: > - update the patch series message. > - drop patches from the previous version of the patch series: > * xen/riscv: add __ASSEMBLY__ guards". ( merged ) > * xen/riscv: make sure that identity mapping isn't bigger then page size > ( entire Xen is 1:1 mapped so there is no need for the checks from the > patch ) > - add .sbss.* and put it befor .bss* . > - move out reset_stack() to .text section. > - add '__ro_after_init' for phys_offset variable. > - add '__init' for calc_phys_offset(). > - declaring variable phys_off as non static as it will be used in head.S. > - update definition of PGTBL_INITIAL_COUNT and the comment above. > - code style fixes. > - remove id_addrs array becase entire Xen is mapped. > - reverse condition for cycle inside remove_identity_mapping(). > - fix page table walk in remove_identity_mapping(). > - save hart_id and dtb_addr before call MMU related C functions > - use phys_offset variable instead of doing calcultations to get phys offset > in head.S file. ( it can be easily done as entire Xen is 1:1 mapped now ) > - declare enable_muu() as __init. > - Update SPDX tags. > - Add Review-By/Suggested-By for some patches. > - code style fixes. > > Oleksii Kurochko (2): > xen/riscv: introduce function for physical offset calculation > xen/riscv: introduce identity mapping
Acked-by: Jan Beulich <[email protected]>
