[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v6 00/14] arm/mem_access: Walk guest page tables in SW if mem_access is active
Hi all, The function p2m_mem_access_check_and_get_page is called from the function get_page_from_gva if mem_access is active and the hardware-aided translation of the given guest virtual address (gva) into machine address fails. That is, if the stage-2 translation tables constrain access to the guests's page tables, hardware-assisted translation will fail. The idea of the function p2m_mem_access_check_and_get_page is thus to translate the given gva and check the requested access rights in software. However, as the current implementation of p2m_mem_access_check_and_get_page makes use of the hardware-aided gva to ipa translation, the translation might also fail because of reasons stated above and will become equally relevant for the altp2m implementation on ARM. As such, we provide a software guest translation table walk to address the above mentioned issue. The current version of the implementation supports translation of both the short-descriptor as well as the long-descriptor translation table format on ARMv7 and ARMv8 (AArch32/AArch64). This revised version incorporates the comments of the previous patch series. In this patch we move (i) PAGE_*_* macros to xen/page-defs.h instead of xen/lib.h and (ii) we move the function vgic_access_guest_memory to to guestcopy.c (and asm/guest_access.h) and subsequently rename it to access_guest_memory_by_ipa (as its functionality is not specific to vgic). Some additional changes comprising code readability and correct type usage have been made and stated in the individual commits. The following patch series can be found on Github[0]. Cheers, ~Sergej [0] https://github.com/sergej-proskurin/xen (branch arm-gpt-walk-v6) Sergej Proskurin (14): arm/mem_access: Add and cleanup (TCR_|TTBCR_)* defines arm/mem_access: Move PAGE_*_* macros to xen/page-defs.h arm/mem_access: Add defines supporting PTs with varying page sizes arm/lpae: Introduce lpae_is_page helper arm/mem_access: Add short-descriptor pte typedefs and macros arm/mem_access: Introduce GV2M_EXEC permission arm/mem_access: Introduce BIT_ULL bit operation arm/mem_access: Introduce GENMASK_ULL bit operation arm/guest_access: Move vgic_access_guest_memory to guest_access.h arm/guest_access: Rename vgic_access_guest_memory arm/mem_access: Add software guest-page-table walk arm/mem_access: Add long-descriptor based gpt arm/mem_access: Add short-descriptor based gpt arm/mem_access: Walk the guest's pt in software xen/arch/arm/Makefile | 1 + xen/arch/arm/guest_walk.c | 629 +++++++++++++++++++++++++++++++++++++ xen/arch/arm/guestcopy.c | 50 +++ xen/arch/arm/mem_access.c | 31 +- xen/arch/arm/vgic-v3-its.c | 37 +-- xen/arch/arm/vgic.c | 49 --- xen/include/asm-arm/bitops.h | 1 + xen/include/asm-arm/config.h | 2 + xen/include/asm-arm/guest_access.h | 3 + xen/include/asm-arm/guest_walk.h | 19 ++ xen/include/asm-arm/lpae.h | 67 ++++ xen/include/asm-arm/page.h | 1 + xen/include/asm-arm/processor.h | 69 +++- xen/include/asm-arm/short-desc.h | 130 ++++++++ xen/include/asm-arm/vgic.h | 3 - xen/include/xen/bitops.h | 5 +- xen/include/xen/iommu.h | 15 +- xen/include/xen/page-defs.h | 24 ++ 18 files changed, 1046 insertions(+), 90 deletions(-) create mode 100644 xen/arch/arm/guest_walk.c create mode 100644 xen/include/asm-arm/guest_walk.h create mode 100644 xen/include/asm-arm/short-desc.h create mode 100644 xen/include/xen/page-defs.h -- 2.13.2 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx https://lists.xen.org/xen-devel
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