[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH] fix bits 39:32 of the final physical address wh
From: |
Luiz Capitulino |
Subject: |
Re: [Qemu-devel] [PATCH] fix bits 39:32 of the final physical address when using 4M page |
Date: |
Mon, 7 Jan 2013 11:40:08 -0200 |
On Mon, 07 Jan 2013 14:10:46 +0100
Andreas Färber <address@hidden> wrote:
> Am 07.01.2013 13:06, schrieb Markus Armbruster:
> > Wen Congyang <address@hidden> writes:
> >
> >> ((pde & 0x1fe000) << 19) is the bits 39:32 of the final physical address,
> >> and
> >> we shouldn't use unit32_t to calculate it. Convert the type to hwaddr to
> >> fix
> >> this problem.
> >
> > Spotted by Coverity.
> >
> >> Signed-off-by: Wen Congyang <address@hidden>
> >>
> >> ---
> >> target-i386/arch_memory_mapping.c | 11 ++++++++---
> >> 1 file changed, 8 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/target-i386/arch_memory_mapping.c
> >> b/target-i386/arch_memory_mapping.c
> >> index c6c7874..844893f 100644
> >> --- a/target-i386/arch_memory_mapping.c
> >> +++ b/target-i386/arch_memory_mapping.c
> >> @@ -115,7 +115,7 @@ static void walk_pde2(MemoryMappingList *list,
> >> hwaddr pde_start_addr, int32_t a20_mask,
> >> bool pse)
> >> {
> >> - hwaddr pde_addr, pte_start_addr, start_paddr;
> >> + hwaddr pde_addr, pte_start_addr, start_paddr, high_paddr;
> >> uint32_t pde;
> >> target_ulong line_addr, start_vaddr;
> >> int i;
> >> @@ -130,8 +130,13 @@ static void walk_pde2(MemoryMappingList *list,
> >>
> >> line_addr = (((unsigned int)i & 0x3ff) << 22);
> >> if ((pde & PG_PSE_MASK) && pse) {
> >> - /* 4 MB page */
> >> - start_paddr = (pde & ~0x3fffff) | ((pde & 0x1fe000) << 19);
> >> + /*
> >> + * 4 MB page:
> >> + * bits 39:32 are bits 20:13 of the PDE
> >> + * bit3 31:22 are bits 31:22 of the PDE
> >> + */
> >> + high_paddr = ((hwaddr)(pde & 0x1fe000) << 19);
> >> + start_paddr = (pde & ~0x3fffff) | high_paddr;
> >> if (cpu_physical_memory_is_io(start_paddr)) {
> >> /* I/O region */
> >> continue;
> >
> > Extra points for extending the comment.
>
> ...and a "target-i386: " prefix in the subject would be appreciated,
> since it does not seem to fix a general issue.
I can do that myself when I apply the patch (which will take a little bit,
as I'm just back from vacation).
>
> Andreas
>
> >
> > Reviewed-by: Markus Armbruster <address@hidden>
> >
>
>