diff options
| -rw-r--r-- | arch/x86/kvm/paging_tmpl.h | 28 | ||||
| -rw-r--r-- | include/linux/kvm_host.h | 2 | ||||
| -rw-r--r-- | virt/kvm/kvm_main.c | 20 |
3 files changed, 38 insertions, 12 deletions
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index 7f83f5557d5e..136a65d72b0a 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -316,10 +316,12 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, metaphysical, access, shadow_ent, &new_page); if (new_page && !metaphysical) { + int r; pt_element_t curr_pte; - kvm_read_guest(vcpu->kvm, walker->pte_gpa[level - 2], - &curr_pte, sizeof(curr_pte)); - if (curr_pte != walker->ptes[level - 2]) + r = kvm_read_guest_atomic(vcpu->kvm, + walker->pte_gpa[level - 2], + &curr_pte, sizeof(curr_pte)); + if (r || curr_pte != walker->ptes[level - 2]) return NULL; } shadow_addr = __pa(shadow_page->spt); @@ -429,9 +431,8 @@ static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr) static void FNAME(prefetch_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) { - int i, offset = 0; - pt_element_t *gpt; - struct page *page; + int i, offset = 0, r = 0; + pt_element_t pt; if (sp->role.metaphysical || (PTTYPE == 32 && sp->role.level > PT_PAGE_TABLE_LEVEL)) { @@ -441,15 +442,18 @@ static void FNAME(prefetch_page)(struct kvm_vcpu *vcpu, if (PTTYPE == 32) offset = sp->role.quadrant << PT64_LEVEL_BITS; - page = gfn_to_page(vcpu->kvm, sp->gfn); - gpt = kmap_atomic(page, KM_USER0); - for (i = 0; i < PT64_ENT_PER_PAGE; ++i) - if (is_present_pte(gpt[offset + i])) + + for (i = 0; i < PT64_ENT_PER_PAGE; ++i) { + gpa_t pte_gpa = gfn_to_gpa(sp->gfn); + pte_gpa += (i+offset) * sizeof(pt_element_t); + + r = kvm_read_guest_atomic(vcpu->kvm, pte_gpa, &pt, + sizeof(pt_element_t)); + if (r || is_present_pte(pt)) sp->spt[i] = shadow_trap_nonpresent_pte; else sp->spt[i] = shadow_notrap_nonpresent_pte; - kunmap_atomic(gpt, KM_USER0); - kvm_release_page_clean(page); + } } #undef pt_element_t diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 9ff5904c5072..a020fb280540 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -167,6 +167,8 @@ void kvm_release_page_clean(struct page *page); void kvm_release_page_dirty(struct page *page); int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset, int len); +int kvm_read_guest_atomic(struct kvm *kvm, gpa_t gpa, void *data, + unsigned long len); int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len); int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, const void *data, int offset, int len); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 678e80561b74..8d0b7c16c2f7 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -541,6 +541,26 @@ int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len) } EXPORT_SYMBOL_GPL(kvm_read_guest); +int kvm_read_guest_atomic(struct kvm *kvm, gpa_t gpa, void *data, + unsigned long len) +{ + int r; + unsigned long addr; + gfn_t gfn = gpa >> PAGE_SHIFT; + int offset = offset_in_page(gpa); + + addr = gfn_to_hva(kvm, gfn); + if (kvm_is_error_hva(addr)) + return -EFAULT; + pagefault_disable(); + r = __copy_from_user_inatomic(data, (void __user *)addr + offset, len); + pagefault_enable(); + if (r) + return -EFAULT; + return 0; +} +EXPORT_SYMBOL(kvm_read_guest_atomic); + int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, const void *data, int offset, int len) { |