Fix incorrect VM Attributes being applied for mapping frames to x86 EPT#321
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dreamliner787-9 wants to merge 2 commits intoseL4:mainfrom
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Fix incorrect VM Attributes being applied for mapping frames to x86 EPT#321dreamliner787-9 wants to merge 2 commits intoseL4:mainfrom
dreamliner787-9 wants to merge 2 commits intoseL4:mainfrom
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Necessary for rust-sel4 to build with [1] applied to seL4. However, this patch does not need [1] to be merged for everything to work since seL4_X86_EPT_VMAttributes has always existed. [1]: seL4/seL4#1577 Signed-off-by: Ivan Velickovic <i.velickovic@unsw.edu.au>
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x86 EPT support was added to the capDL Initializer in [1], but I've made a mistake of not using EPT VM Attributes when mapping frames to EPT. Since the encoding of EPT and ordinary page table VM Attributes are different. Mapping a frame to EPT as "cached" in the spec would translate to mapping it as uncached. [1] seL4#305 Signed-off-by: Bill Nguyen <bill.nguyen@unsw.edu.au>
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Depends on #317
x86 EPT support was added to the capDL Initializer in [1], but I've made a mistake of not using EPT VM Attributes when mapping frames to EPT. Since the encoding of EPT and ordinary page table VM Attributes are different. Mapping a frame to EPT as "cached" in the spec would translate to mapping it as uncached.
The fix was implemented by adding another parameter
is_x86_ept: boolto bothvm_attributes()andvm_attributes_from_whether_cached_and_exec(). I'm not sure whether this is the best approach as it seems a bit hacky. A another approach would be to define this information in the Frame cap spec object. But then you would have two places that encode this information as the cap would be mapped to an EPT.[1] #305