Re: [Qemu-devel] [PATCH] PPC: Fix large page support in TCG

["Andreas Färber" <afaerber@suse.de>]

Am 03.03.2012 17:39, schrieb Nathan Whitehorn:
> Fix large page support in TCG. The old code would overwrite the large
> page table entry with the fake 4 KB
> one generated here whenever the ref/change bits were updated, causing it
> to point to the wrong area of memory. Instead of creating a fake PTE,
> just update the real address at the end.
> 
> Signed-off-by: Nathan Whitehorn <nwhitehorn@freebsd.org>

cc'ing Alex and qemu-ppc.

/-F

> ---
>  target-ppc/helper.c |   11 +++++------
>  1 files changed, 5 insertions(+), 6 deletions(-)
> 
> diff --git a/target-ppc/helper.c b/target-ppc/helper.c
> index 928fbcf..0f5ad2e 100644
> --- a/target-ppc/helper.c
> +++ b/target-ppc/helper.c
> @@ -597,12 +597,6 @@ static inline int _find_pte(CPUState *env,
> mmu_ctx_t *ctx,
> int is_64b, int h,
>                  pte1 = ldq_phys(env->htab_base + pteg_off + (i * 16) + 8);
>              }
> 
> -            /* We have a TLB that saves 4K pages, so let's
> -             * split a huge page to 4k chunks */
> -            if (target_page_bits != TARGET_PAGE_BITS)
> -                pte1 |= (ctx->eaddr & (( 1 << target_page_bits ) - 1))
> - & TARGET_PAGE_MASK;
> -
>              r = pte64_check(ctx, pte0, pte1, h, rw, type);
>              LOG_MMU("Load pte from " TARGET_FMT_lx " => " TARGET_FMT_lx
> " "
>                      TARGET_FMT_lx " %d %d %d " TARGET_FMT_lx "\n",
> @@ -678,6 +672,11 @@ static inline int _find_pte(CPUState *env,
> mmu_ctx_t *ctx,
> int is_64b, int h,
>          }
>      }
> 
> +    /* We have a TLB that saves 4K pages, so let's
> +     * split a huge page to 4k chunks */
> +    if (target_page_bits != TARGET_PAGE_BITS)
> +       ctx->raddr |= (ctx->eaddr & (( 1 << target_page_bits ) - 1))
> + & TARGET_PAGE_MASK;
>      return ret;
>  }
> 
> -- 
> 1.7.9

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