The following patch implements a solution to the bug occuring on Arm with Linux with KPTI enabled during a context switch from user mode: (XEN) p2m.c:1890: d1v0: Failed to walk page-table va 0xffffff837ebe0cd0
This is an answer to the discussion started here: https://lists.xenproject.org/archives/html/xen-devel/2020-05/msg00735.html and a modification of the patches submitted here: https://lists.xenproject.org/archives/html/xen-devel/2019-05/msg02320.html This is submitted as an RFC as the solution is only working on Arm and I would need some help for the x86 implementation. On x86 this needs at least a solution to implement an equivalent of get_page_from_gva (see #error in domain.c) and implementation of the different runstate_update functions. Any help or suggestion on that would be nice. I also added some XXX in different places as part of the code of the original patch I started from are not completely clear to me. Bertrand Marquis (1): xen: Use a global mapping for runstate xen/arch/arm/domain.c | 32 +++++++++------- xen/arch/x86/domain.c | 51 ++++++++++++++----------- xen/common/domain.c | 84 ++++++++++++++++++++++++++++++++++------- xen/include/xen/sched.h | 11 ++++-- 4 files changed, 124 insertions(+), 54 deletions(-) -- 2.17.1
