Re: [PATCH v3 3/3] target/riscv: Fix the translation of physical address

[Zong Li]

On Wed, Jul 22, 2020 at 5:08 PM Alexander Richardson
<Alexander.Richardson@cl.cam.ac.uk> wrote:
>
> On Tue, 21 Jul 2020 at 13:43, Zong Li <zong.li@sifive.com> wrote:
> >
> > The real physical address should add the 12 bits page offset. It also
> > causes the PMP wrong checking due to the minimum granularity of PMP is
> > 4 byte, but we always get the physical address which is 4KB alignment,
> > that means, we always use the start address of the page to check PMP for
> > all addresses which in the same page.
> >
> > Signed-off-by: Zong Li <zong.li@sifive.com>
> > ---
> >  target/riscv/cpu_helper.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> > index 75d2ae3434..08b069f0c9 100644
> > --- a/target/riscv/cpu_helper.c
> > +++ b/target/riscv/cpu_helper.c
> > @@ -543,7 +543,8 @@ restart:
> >              /* for superpage mappings, make a fake leaf PTE for the TLB's
> >                 benefit. */
> >              target_ulong vpn = addr >> PGSHIFT;
> > -            *physical = (ppn | (vpn & ((1L << ptshift) - 1))) << PGSHIFT;
> > +            *physical = ((ppn | (vpn & ((1L << ptshift) - 1))) << PGSHIFT) 
> > |
> > +                        (addr & ~TARGET_PAGE_MASK);
> >
> >              /* set permissions on the TLB entry */
> >              if ((pte & PTE_R) || ((pte & PTE_X) && mxr)) {
> > --
> > 2.27.0
>
> I made the same change for our CHERI fork a few months ago but forgot
> to send the patch upstream (despite marking the commit as a candidate
> for upstreaming). Sorry about the duplicated debugging work!
> (https://github.com/CTSRD-CHERI/qemu/commit/61c8e3f2c0fd4965ec3f316146d1751fae673c12)

No, problem.