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riscv / riscv-j-extension

Working Draft of the RISC-V J Extension Specification
https://jira.riscv.org/browse/RVG-128
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Zjpm: Clarification on HLV/HSV instructions #25

Closed deepak0414 closed 1 year ago

deepak0414 commented 1 year ago

H extension defines HLV/HSV instructions to allow hypervisor perform loads/store from HS (or even HU) mode as if that access had been done from V mode (i.e. using guest paging structures and applying G stage translations on them).

Philosophically, pointer masking forms the basis for other technologies like memory tagging, sandboxing, etc and thus it's not actually meaningful to apply pointer masking on HLV/HSV accesses to guest virtual addresses.

Spec should define if pointer masking applies to such accesses or not (if guest had pointer masking enabled).

I would prefer not to apply pointer masking on HLV/HSV originated accesses.

martinmaas commented 1 year ago

Addressed in fd7220807e1405ba9b5de38d9d4ac26e73312128 (Section 2.6)