Ping? On Wed, Sep 13, 2017 at 09:08:30PM +0300, Yury Norov wrote: > 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
