From: Takuya Yoshikawa <[email protected]> The address of the gpte was already calculated and stored in ptep_user before entering cmpxchg_gpte().
This patch makes cmpxchg_gpte() to use that to make it clear that we are using the same address during walk_addr_generic(). Signed-off-by: Takuya Yoshikawa <[email protected]> --- Note: I tested this but could not see cmpxchg_gpte() being called. Is there any good test case? arch/x86/kvm/paging_tmpl.h | 32 +++++++++++--------------------- 1 files changed, 11 insertions(+), 21 deletions(-) diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index 52450a6..73cdf98 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -79,20 +79,16 @@ static gfn_t gpte_to_gfn_lvl(pt_element_t gpte, int lvl) } static int FNAME(cmpxchg_gpte)(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, - gfn_t table_gfn, unsigned index, - pt_element_t orig_pte, pt_element_t new_pte) + pt_element_t __user *ptep_user, unsigned index, + pt_element_t orig_pte, pt_element_t new_pte) { + int npages; pt_element_t ret; pt_element_t *table; struct page *page; - gpa_t gpa; - gpa = mmu->translate_gpa(vcpu, table_gfn << PAGE_SHIFT, - PFERR_USER_MASK|PFERR_WRITE_MASK); - if (gpa == UNMAPPED_GVA) - return -EFAULT; - - page = gfn_to_page(vcpu->kvm, gpa_to_gfn(gpa)); + npages = get_user_pages_fast((unsigned long)ptep_user, 1, 1, &page); + BUG_ON(npages != 1); table = kmap_atomic(page, KM_USER0); ret = CMPXCHG(&table[index], orig_pte, new_pte); @@ -234,12 +230,9 @@ walk: int ret; trace_kvm_mmu_set_accessed_bit(table_gfn, index, sizeof(pte)); - ret = FNAME(cmpxchg_gpte)(vcpu, mmu, table_gfn, - index, pte, pte|PT_ACCESSED_MASK); - if (ret < 0) { - present = false; - break; - } else if (ret) + ret = FNAME(cmpxchg_gpte)(vcpu, mmu, ptep_user, index, + pte, pte|PT_ACCESSED_MASK); + if (ret) goto walk; mark_page_dirty(vcpu->kvm, table_gfn); @@ -293,12 +286,9 @@ walk: int ret; trace_kvm_mmu_set_dirty_bit(table_gfn, index, sizeof(pte)); - ret = FNAME(cmpxchg_gpte)(vcpu, mmu, table_gfn, index, pte, - pte|PT_DIRTY_MASK); - if (ret < 0) { - present = false; - goto error; - } else if (ret) + ret = FNAME(cmpxchg_gpte)(vcpu, mmu, ptep_user, index, + pte, pte|PT_DIRTY_MASK); + if (ret) goto walk; mark_page_dirty(vcpu->kvm, table_gfn); -- 1.7.1 -- 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
