On Mon, Sep 06, 2010 at 05:55:53PM +0200, Joerg Roedel wrote:
> This patch uses kvm_read_guest_page_tdp to make the
> walk_addr_generic functions suitable for two-level page
> table walking.
> 
> Signed-off-by: Joerg Roedel <[email protected]>
> ---
>  arch/x86/kvm/paging_tmpl.h |   27 ++++++++++++++++++++-------
>  1 files changed, 20 insertions(+), 7 deletions(-)
> 
> diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
> index cd59af1..a5b5759 100644
> --- a/arch/x86/kvm/paging_tmpl.h
> +++ b/arch/x86/kvm/paging_tmpl.h
> @@ -124,6 +124,8 @@ static int FNAME(walk_addr_generic)(struct guest_walker 
> *walker,
>       unsigned index, pt_access, uninitialized_var(pte_access);
>       gpa_t pte_gpa;
>       bool eperm, present, rsvd_fault;
> +     int offset;
> +     u32 error = 0;
>  
>       trace_kvm_mmu_pagetable_walk(addr, write_fault, user_fault,
>                                    fetch_fault);
> @@ -153,12 +155,13 @@ walk:
>               index = PT_INDEX(addr, walker->level);
>  
>               table_gfn = gpte_to_gfn(pte);
> -             pte_gpa = gfn_to_gpa(table_gfn);
> -             pte_gpa += index * sizeof(pt_element_t);
> +             offset    = index * sizeof(pt_element_t);
> +             pte_gpa   = gfn_to_gpa(table_gfn) + offset;
>               walker->table_gfn[walker->level - 1] = table_gfn;
>               walker->pte_gpa[walker->level - 1] = pte_gpa;
>  
> -             if (kvm_read_guest(vcpu->kvm, pte_gpa, &pte, sizeof(pte))) {
> +             if (kvm_read_guest_page_mmu(vcpu, mmu, table_gfn, &pte, offset,
> +                                         sizeof(pte), &error)) {
>                       present = false;
>                       break;
>               }

If there is failure reading the nested page tables here, you fill
vcpu->arch.fault. But the nested fault error values will be overwritten
at the end of walk_addr() by the original fault values?

> @@ -209,15 +212,25 @@ walk:
>                               is_large_pte(pte) &&
>                               mmu->root_level == PT64_ROOT_LEVEL)) {
>                       int lvl = walker->level;
> +                     gpa_t real_gpa;
> +                     gfn_t gfn;
>  
> -                     walker->gfn = gpte_to_gfn_lvl(pte, lvl);
> -                     walker->gfn += (addr & PT_LVL_OFFSET_MASK(lvl))
> -                                     >> PAGE_SHIFT;
> +                     gfn = gpte_to_gfn_lvl(pte, lvl);
> +                     gfn += (addr & PT_LVL_OFFSET_MASK(lvl)) >> PAGE_SHIFT;
>  
>                       if (PTTYPE == 32 &&
>                           walker->level == PT_DIRECTORY_LEVEL &&
>                           is_cpuid_PSE36())
> -                             walker->gfn += pse36_gfn_delta(pte);
> +                             gfn += pse36_gfn_delta(pte);
> +
> +                     real_gpa = mmu->translate_gpa(vcpu, gfn_to_gpa(gfn),
> +                                                   &error);
> +                     if (real_gpa == UNMAPPED_GVA) {
> +                             walker->error_code = error;
> +                             return 0;
> +                     }
> +
> +                     walker->gfn = real_gpa >> PAGE_SHIFT;
>  
>                       break;
>               }
> -- 
> 1.7.0.4
> 
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to