On Mon, Jun 20, 2011 at 11:29:47PM +0900, Takuya Yoshikawa wrote: > From: Takuya Yoshikawa <[email protected]> > > Avoid two step jump to the error handling part. This eliminates the use > of the variables present and rsvd_fault. > > We also use the const type qualifier to show that write/user/fetch_fault > do not change in the function. > > Both of these were suggested by Ingo Molnar. > > Cc: Ingo Molnar <[email protected]> > Signed-off-by: Takuya Yoshikawa <[email protected]> > --- > v2-v3: only changelog update > > arch/x86/kvm/paging_tmpl.h | 64 +++++++++++++++++++------------------------ > 1 files changed, 28 insertions(+), 36 deletions(-) > > diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h > index 1caeb4d..137aa45 100644 > --- a/arch/x86/kvm/paging_tmpl.h > +++ b/arch/x86/kvm/paging_tmpl.h > @@ -125,18 +125,17 @@ static int FNAME(walk_addr_generic)(struct guest_walker > *walker, > gfn_t table_gfn; > unsigned index, pt_access, uninitialized_var(pte_access); > gpa_t pte_gpa; > - bool eperm, present, rsvd_fault; > - int offset, write_fault, user_fault, fetch_fault; > - > - write_fault = access & PFERR_WRITE_MASK; > - user_fault = access & PFERR_USER_MASK; > - fetch_fault = access & PFERR_FETCH_MASK; > + bool eperm; > + int offset; > + const int write_fault = access & PFERR_WRITE_MASK; > + const int user_fault = access & PFERR_USER_MASK; > + const int fetch_fault = access & PFERR_FETCH_MASK; > + u16 errcode = 0; > > trace_kvm_mmu_pagetable_walk(addr, write_fault, user_fault, > fetch_fault); > walk: > - present = true; > - eperm = rsvd_fault = false; > + eperm = false; > walker->level = mmu->root_level; > pte = mmu->get_cr3(vcpu); > > @@ -145,7 +144,7 @@ walk: > pte = kvm_pdptr_read_mmu(vcpu, mmu, (addr >> 30) & 3); > trace_kvm_mmu_paging_element(pte, walker->level); > if (!is_present_gpte(pte)) { > - present = false; > + errcode |= PFERR_PRESENT_MASK; > goto error; > } > --walker->level; > @@ -171,34 +170,34 @@ walk: > real_gfn = mmu->translate_gpa(vcpu, gfn_to_gpa(table_gfn), > PFERR_USER_MASK|PFERR_WRITE_MASK); > if (unlikely(real_gfn == UNMAPPED_GVA)) { > - present = false; > - break; > + errcode |= PFERR_PRESENT_MASK; > + goto error; > } > real_gfn = gpa_to_gfn(real_gfn); > > host_addr = gfn_to_hva(vcpu->kvm, real_gfn); > if (unlikely(kvm_is_error_hva(host_addr))) { > - present = false; > - break; > + errcode |= PFERR_PRESENT_MASK; > + goto error; > } > > ptep_user = (pt_element_t __user *)((void *)host_addr + offset); > if (unlikely(__copy_from_user(&pte, ptep_user, sizeof(pte)))) { > - present = false; > - break; > + errcode |= PFERR_PRESENT_MASK; > + goto error; > } > > trace_kvm_mmu_paging_element(pte, walker->level); > > if (unlikely(!is_present_gpte(pte))) { > - present = false; > - break; > + errcode |= PFERR_PRESENT_MASK; > + goto error; > }
Assignment of PFERR_PRESENT_MASK is inverted. -- 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
