gpa_t pte_gpa[PT_MAX_FULL_LEVELS];
pt_element_t __user *ptep_user[PT_MAX_FULL_LEVELS];
bool pte_writable[PT_MAX_FULL_LEVELS];
- unsigned pt_access;
- unsigned pte_access;
+ unsigned int pt_access[PT_MAX_FULL_LEVELS];
+ unsigned int pte_access;
gfn_t gfn;
struct x86_exception fault;
};
return pkeys;
}
+static inline bool FNAME(is_last_gpte)(struct kvm_mmu *mmu,
+ unsigned int level, unsigned int gpte)
+{
+ /*
+ * For EPT and PAE paging (both variants), bit 7 is either reserved at
+ * all level or indicates a huge page (ignoring CR3/EPTP). In either
+ * case, bit 7 being set terminates the walk.
+ */
+#if PTTYPE == 32
+ /*
+ * 32-bit paging requires special handling because bit 7 is ignored if
+ * CR4.PSE=0, not reserved. Clear bit 7 in the gpte if the level is
+ * greater than the last level for which bit 7 is the PAGE_SIZE bit.
+ *
+ * The RHS has bit 7 set iff level < (2 + PSE). If it is clear, bit 7
+ * is not reserved and does not indicate a large page at this level,
+ * so clear PT_PAGE_SIZE_MASK in gpte if that is the case.
+ */
+ gpte &= level - (PT32_ROOT_LEVEL + mmu->mmu_role.ext.cr4_pse);
+#endif
+ /*
+ * PG_LEVEL_4K always terminates. The RHS has bit 7 set
+ * iff level <= PG_LEVEL_4K, which for our purpose means
+ * level == PG_LEVEL_4K; set PT_PAGE_SIZE_MASK in gpte then.
+ */
+ gpte |= level - PG_LEVEL_4K - 1;
+
+ return gpte & PT_PAGE_SIZE_MASK;
+}
/*
* Fetch a guest pte for a guest virtual address, or for an L2's GPA.
*/
}
walker->ptes[walker->level - 1] = pte;
- } while (!is_last_gpte(mmu, walker->level, pte));
+
+ /* Convert to ACC_*_MASK flags for struct guest_walker. */
+ walker->pt_access[walker->level - 1] = FNAME(gpte_access)(pt_access ^ walk_nx_mask);
+ } while (!FNAME(is_last_gpte)(mmu, walker->level, pte));
pte_pkey = FNAME(gpte_pkeys)(vcpu, pte);
accessed_dirty = have_ad ? pte_access & PT_GUEST_ACCESSED_MASK : 0;
/* Convert to ACC_*_MASK flags for struct guest_walker. */
- walker->pt_access = FNAME(gpte_access)(pt_access ^ walk_nx_mask);
walker->pte_access = FNAME(gpte_access)(pte_access ^ walk_nx_mask);
errcode = permission_fault(vcpu, mmu, walker->pte_access, pte_pkey, access);
if (unlikely(errcode))
}
pgprintk("%s: pte %llx pte_access %x pt_access %x\n",
- __func__, (u64)pte, walker->pte_access, walker->pt_access);
+ __func__, (u64)pte, walker->pte_access,
+ walker->pt_access[walker->level - 1]);
return 1;
error:
errcode |= write_fault | user_fault;
- if (fetch_fault && (mmu->nx ||
- kvm_read_cr4_bits(vcpu, X86_CR4_SMEP)))
+ if (fetch_fault && (is_efer_nx(mmu) || is_cr4_smep(mmu)))
errcode |= PFERR_FETCH_MASK;
walker->fault.vector = PF_VECTOR;
bool huge_page_disallowed = exec && nx_huge_page_workaround_enabled;
struct kvm_mmu_page *sp = NULL;
struct kvm_shadow_walk_iterator it;
- unsigned direct_access, access = gw->pt_access;
+ unsigned int direct_access, access;
int top_level, level, req_level, ret;
gfn_t base_gfn = gw->gfn;
sp = NULL;
if (!is_shadow_present_pte(*it.sptep)) {
table_gfn = gw->table_gfn[it.level - 2];
+ access = gw->pt_access[it.level - 2];
sp = kvm_mmu_get_page(vcpu, table_gfn, addr, it.level-1,
false, access);
}
bool self_changed = false;
if (!(walker->pte_access & ACC_WRITE_MASK ||
- (!is_write_protection(vcpu) && !user_fault)))
+ (!is_cr0_wp(vcpu->arch.mmu) && !user_fault)))
return false;
for (level = walker->level; level <= walker->max_level; level++) {
* we will cache the incorrect access into mmio spte.
*/
if (write_fault && !(walker.pte_access & ACC_WRITE_MASK) &&
- !is_write_protection(vcpu) && !user_fault &&
- !is_noslot_pfn(pfn)) {
+ !is_cr0_wp(vcpu->arch.mmu) && !user_fault && !is_noslot_pfn(pfn)) {
walker.pte_access |= ACC_WRITE_MASK;
walker.pte_access &= ~ACC_USER_MASK;
* then we should prevent the kernel from executing it
* if SMEP is enabled.
*/
- if (kvm_read_cr4_bits(vcpu, X86_CR4_SMEP))
+ if (is_cr4_smep(vcpu->arch.mmu))
walker.pte_access &= ~ACC_EXEC_MASK;
}
*/
static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
{
+ union kvm_mmu_page_role mmu_role = vcpu->arch.mmu->mmu_role.base;
int i, nr_present = 0;
bool host_writable;
gpa_t first_pte_gpa;
int set_spte_ret = 0;
- /* direct kvm_mmu_page can not be unsync. */
- BUG_ON(sp->role.direct);
+ /*
+ * Ignore various flags when verifying that it's safe to sync a shadow
+ * page using the current MMU context.
+ *
+ * - level: not part of the overall MMU role and will never match as the MMU's
+ * level tracks the root level
+ * - access: updated based on the new guest PTE
+ * - quadrant: not part of the overall MMU role (similar to level)
+ */
+ const union kvm_mmu_page_role sync_role_ign = {
+ .level = 0xf,
+ .access = 0x7,
+ .quadrant = 0x3,
+ };
+
+ /*
+ * Direct pages can never be unsync, and KVM should never attempt to
+ * sync a shadow page for a different MMU context, e.g. if the role
+ * differs then the memslot lookup (SMM vs. non-SMM) will be bogus, the
+ * reserved bits checks will be wrong, etc...
+ */
+ if (WARN_ON_ONCE(sp->role.direct ||
+ (sp->role.word ^ mmu_role.word) & ~sync_role_ign.word))
+ return 0;
first_pte_gpa = FNAME(get_level1_sp_gpa)(sp);
projects / linux-2.6-microblaze.git / blobdiff