KVM: MMU: Move set_pte() into guest paging mode independent code

As set_pte() no longer references either a gpte or the guest walker, we can
move it out of paging mode dependent code (which compiles twice and is
generally nasty).

Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 83 insertions, 0 deletions

diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c
index cace1e41b683..a91e05b42345 100644
--- a/drivers/kvm/mmu.c
+++ b/drivers/kvm/mmu.c
@@ -879,6 +879,89 @@ struct page *gva_to_page(struct kvm_vcpu *vcpu, gva_t gva)
         return gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT);
 }
 
+static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte,
+                         unsigned pt_access, unsigned pte_access,
+                         int user_fault, int write_fault, int dirty,
+                         int *ptwrite, gfn_t gfn)
+{
+        u64 spte;
+        int was_rmapped = is_rmap_pte(*shadow_pte);
+        struct page *page;
+
+        pgprintk("%s: spte %llx gpte %llx access %x write_fault %d"
+                 " user_fault %d gfn %lx\n",
+                 __FUNCTION__, *shadow_pte, (u64)gpte, pt_access,
+                 write_fault, user_fault, gfn);
+
+        /*
+         * We don't set the accessed bit, since we sometimes want to see
+         * whether the guest actually used the pte (in order to detect
+         * demand paging).
+         */
+        spte = PT_PRESENT_MASK | PT_DIRTY_MASK;
+        if (!dirty)
+                pte_access &= ~ACC_WRITE_MASK;
+        if (!(pte_access & ACC_EXEC_MASK))
+                spte |= PT64_NX_MASK;
+
+        page = gfn_to_page(vcpu->kvm, gfn);
+
+        spte |= PT_PRESENT_MASK;
+        if (pte_access & ACC_USER_MASK)
+                spte |= PT_USER_MASK;
+
+        if (is_error_page(page)) {
+                set_shadow_pte(shadow_pte,
+                               shadow_trap_nonpresent_pte | PT_SHADOW_IO_MARK);
+                kvm_release_page_clean(page);
+                return;
+        }
+
+        spte |= page_to_phys(page);
+
+        if ((pte_access & ACC_WRITE_MASK)
+            || (write_fault && !is_write_protection(vcpu) && !user_fault)) {
+                struct kvm_mmu_page *shadow;
+
+                spte |= PT_WRITABLE_MASK;
+                if (user_fault) {
+                        mmu_unshadow(vcpu->kvm, gfn);
+                        goto unshadowed;
+                }
+
+                shadow = kvm_mmu_lookup_page(vcpu->kvm, gfn);
+                if (shadow) {
+                        pgprintk("%s: found shadow page for %lx, marking ro\n",
+                                 __FUNCTION__, gfn);
+                        pte_access &= ~ACC_WRITE_MASK;
+                        if (is_writeble_pte(spte)) {
+                                spte &= ~PT_WRITABLE_MASK;
+                                kvm_x86_ops->tlb_flush(vcpu);
+                        }
+                        if (write_fault)
+                                *ptwrite = 1;
+                }
+        }
+
+unshadowed:
+
+        if (pte_access & ACC_WRITE_MASK)
+                mark_page_dirty(vcpu->kvm, gfn);
+
+        pgprintk("%s: setting spte %llx\n", __FUNCTION__, spte);
+        set_shadow_pte(shadow_pte, spte);
+        page_header_update_slot(vcpu->kvm, shadow_pte, gfn);
+        if (!was_rmapped) {
+                rmap_add(vcpu, shadow_pte, gfn);
+                if (!is_rmap_pte(*shadow_pte))
+                        kvm_release_page_clean(page);
+        }
+        else
+                kvm_release_page_clean(page);
+        if (!ptwrite || !*ptwrite)
+                vcpu->last_pte_updated = shadow_pte;
+}
+
 static void nonpaging_new_cr3(struct kvm_vcpu *vcpu)
 {
 }