The Documentation/arm64/memory.txt says: When using KVM, the hypervisor maps kernel pages in EL2, at a fixed offset from the kernel VA (top 24bits of the kernel VA set to zero): In fact, kernel addresses are transleted to HYP with kern_hyp_va macro, which has more options, and none of them assumes clearing of top 24bits of the kernel VA. Signed-off-by: Yury Norov <ynorov@xxxxxxxxxxxxxxxxxx> --- Documentation/arm64/memory.txt | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/Documentation/arm64/memory.txt b/Documentation/arm64/memory.txt index d7273a5f6456..c39895d7e3a2 100644 --- a/Documentation/arm64/memory.txt +++ b/Documentation/arm64/memory.txt @@ -86,9 +86,12 @@ Translation table lookup with 64KB pages: +-------------------------------------------------> [63] TTBR0/1 -When using KVM, the hypervisor maps kernel pages in EL2, at a fixed -offset from the kernel VA (top 24bits of the kernel VA set to zero): - -Start End Size Use ------------------------------------------------------------------------ -0000004000000000 0000007fffffffff 256GB kernel objects mapped in HYP +When using KVM without Virtualization Host Extensions, the hypervisor maps +kernel pages in EL2, at a fixed offset from the kernel VA. Namely, top 16 +or 25 bits of the kernel VA set to zero depending on ARM64_VA_BITS_48 or +ARM64_VA_BITS_39 config option selected; or top 17 or 26 bits of the kernel +VA set to zero if CPU has Reduced HYP mapping offset capability. See +kern_hyp_va macro. + +When using KVM with Virtualization Host Extensions, no additional mappings +created as host kernel already operates in EL2. -- 2.11.0
