KVM: MMU: Introduce and use spte_to_page()

Encapsulate the pte mask'n'shift in a function.

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

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index dd4b95b..6fc3421 100644 (file)
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -240,6 +240,13 @@ static int is_rmap_pte(u64 pte)
        return is_shadow_present_pte(pte);
 }
 
+static struct page *spte_to_page(u64 pte)
+{
+       hfn_t hfn = (pte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
+
+       return pfn_to_page(hfn);
+}
+
 static gfn_t pse36_gfn_delta(u32 gpte)
 {
        int shift = 32 - PT32_DIR_PSE36_SHIFT - PAGE_SHIFT;
@@ -541,7 +548,7 @@ static void rmap_remove(struct kvm *kvm, u64 *spte)
        if (!is_rmap_pte(*spte))
                return;
        sp = page_header(__pa(spte));
-       page = pfn_to_page((*spte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT);
+       page = spte_to_page(*spte);
        mark_page_accessed(page);
        if (is_writeble_pte(*spte))
                kvm_release_page_dirty(page);
@@ -630,7 +637,7 @@ static void rmap_write_protect(struct kvm *kvm, u64 gfn)
                struct page *page;
 
                spte = rmap_next(kvm, rmapp, NULL);
-               page = pfn_to_page((*spte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT);
+               page = spte_to_page(*spte);
                SetPageDirty(page);
        }
 
@@ -1033,7 +1040,6 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte,
        u64 spte;
        int was_rmapped = 0;
        int was_writeble = is_writeble_pte(*shadow_pte);
-       hfn_t host_pfn = (*shadow_pte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
 
        pgprintk("%s: spte %llx access %x write_fault %d"
                 " user_fault %d gfn %lx\n",
@@ -1051,9 +1057,10 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte,
 
                        child = page_header(pte & PT64_BASE_ADDR_MASK);
                        mmu_page_remove_parent_pte(child, shadow_pte);
-               } else if (host_pfn != page_to_pfn(page)) {
+               } else if (page != spte_to_page(*shadow_pte)) {
                        pgprintk("hfn old %lx new %lx\n",
-                                host_pfn, page_to_pfn(page));
+                                page_to_pfn(spte_to_page(*shadow_pte)),
+                                page_to_pfn(page));
                        rmap_remove(vcpu->kvm, shadow_pte);
                } else {
                        if (largepage)