From bd84e2f7c81c917d9b39dac98c11e87ae1b30f5e Mon Sep 17 00:00:00 2001 From: Christian Ehrhardt <94231383+chrehrhardt@users.noreply.github.com> Date: Tue, 4 Feb 2025 16:12:05 +0100 Subject: [PATCH] cheripte: Make PTE bits reserved in guest page tables (#515) The base hypervisor spec says that the format for guest page table PTEs is the same as for normal PTEs and reserves bits (e.g. the G bit) that don't have a meaning for guest address translation (yet). Do the same for the cheripte bits. Co-authored-by: Christian Ehrhardt --- src/cheri-pte-ext.adoc | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/src/cheri-pte-ext.adoc b/src/cheri-pte-ext.adoc index ca1666b9..fdcb13bb 100644 --- a/src/cheri-pte-ext.adoc +++ b/src/cheri-pte-ext.adoc @@ -82,7 +82,9 @@ Generation (CRG), are added to leaf PTEs in Sv39, Sv48 and Sv57 as shown in xref:sv39pte[xrefstyle=short], xref:sv48pte[xrefstyle=short] and xref:sv57pte[xrefstyle=short] respectively. For non-leaf PTEs these bits remain reserved and must be cleared by software for forward compatibility, -or else a page-fault exception is raised. +or else a page-fault exception is raised. Additionally, if the hypervisor +extension is enabled these bits remain reserved for leaf and non-leaf PTEs +used in guest address translation. .Sv39 page table entry [#sv39pte]