KVM: MMU: cleanup FNAME(page_fault)

Let it return emulate state instead of spte like __direct_map

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 13 insertions, 19 deletions

diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 045d31ae8eb3..c5555329c735 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -427,21 +427,21 @@ static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, struct guest_walker *gw,
 
 /*
  * Fetch a shadow pte for a specific level in the paging hierarchy.
+ * If the guest tries to write a write-protected page, we need to
+ * emulate this operation, return 1 to indicate this case.
  */
-static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
+static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
                          struct guest_walker *gw,
                          int user_fault, int write_fault, int hlevel,
-                         int *emulate, pfn_t pfn, bool map_writable,
-                         bool prefault)
+                         pfn_t pfn, bool map_writable, bool prefault)
 {
-        unsigned access = gw->pt_access;
         struct kvm_mmu_page *sp = NULL;
-        int top_level;
-        unsigned direct_access;
         struct kvm_shadow_walk_iterator it;
+        unsigned direct_access, access = gw->pt_access;
+        int top_level, emulate = 0;
 
         if (!is_present_gpte(gw->ptes[gw->level - 1]))
-                return NULL;
+                return 0;
 
         direct_access = gw->pte_access;
 
@@ -505,17 +505,17 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
 
         clear_sp_write_flooding_count(it.sptep);
         mmu_set_spte(vcpu, it.sptep, access, gw->pte_access,
-                     user_fault, write_fault, emulate, it.level,
+                     user_fault, write_fault, &emulate, it.level,
                      gw->gfn, pfn, prefault, map_writable);
         FNAME(pte_prefetch)(vcpu, gw, it.sptep);
 
-        return it.sptep;
+        return emulate;
 
 out_gpte_changed:
         if (sp)
                 kvm_mmu_put_page(sp, it.sptep);
         kvm_release_pfn_clean(pfn);
-        return NULL;
+        return 0;
 }
 
 /*
@@ -538,8 +538,6 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code,
         int write_fault = error_code & PFERR_WRITE_MASK;
         int user_fault = error_code & PFERR_USER_MASK;
         struct guest_walker walker;
-        u64 *sptep;
-        int emulate = 0;
         int r;
         pfn_t pfn;
         int level = PT_PAGE_TABLE_LEVEL;
@@ -601,17 +599,13 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code,
         kvm_mmu_free_some_pages(vcpu);
         if (!force_pt_level)
                 transparent_hugepage_adjust(vcpu, &walker.gfn, &pfn, &level);
-        sptep = FNAME(fetch)(vcpu, addr, &walker, user_fault, write_fault,
-                             level, &emulate, pfn, map_writable, prefault);
-        (void)sptep;
-        pgprintk("%s: shadow pte %p %llx emulate %d\n", __func__,
-                 sptep, *sptep, emulate);
-
+        r = FNAME(fetch)(vcpu, addr, &walker, user_fault, write_fault,
+                         level, pfn, map_writable, prefault);
         ++vcpu->stat.pf_fixed;
         kvm_mmu_audit(vcpu, AUDIT_POST_PAGE_FAULT);
         spin_unlock(&vcpu->kvm->mmu_lock);
 
-        return emulate;
+        return r;
 
 out_unlock:
         spin_unlock(&vcpu->kvm->mmu_lock);