commit b4231d61807cac8d9d257eb6979c1685fa9a171f
author Izik Eidus <izike@localhost.localdomain> Tue Nov 20 11:49:33 2007 +0200
committer Avi Kivity <avi@qumranet.com> Wed Jan 30 17:53:09 2008 +0200
tree 36b2064c0df4a2b2e11c5d9a2221c097bb0c7be9
parent 2065b3727ecdb64450597d70f7e13af00b85dbd8

KVM: MMU: Selectively set PageDirty when releasing guest memory

Improve dirty bit setting for pages that kvm release, until now every page
that we released we marked dirty, from now only pages that have potential
to get dirty we mark dirty.

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

drivers/kvm/mmu.c

diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c
index 8add4d5..4624f37 100644
--- a/drivers/kvm/mmu.c
+++ b/drivers/kvm/mmu.c
@@ -420,14 +420,18 @@
 	struct kvm_rmap_desc *desc;
 	struct kvm_rmap_desc *prev_desc;
 	struct kvm_mmu_page *page;
+	struct page *release_page;
 	unsigned long *rmapp;
 	int i;
 
 	if (!is_rmap_pte(*spte))
 		return;
 	page = page_header(__pa(spte));
-	kvm_release_page(pfn_to_page((*spte & PT64_BASE_ADDR_MASK) >>
-			 PAGE_SHIFT));
+	release_page = pfn_to_page((*spte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT);
+	if (is_writeble_pte(*spte))
+		kvm_release_page_dirty(release_page);
+	else
+		kvm_release_page_clean(release_page);
 	rmapp = gfn_to_rmap(kvm, page->gfns[spte - page->spt]);
 	if (!*rmapp) {
 		printk(KERN_ERR "rmap_remove: %p %llx 0->BUG\n", spte, *spte);
@@ -893,7 +897,9 @@
 {
 	int level = PT32E_ROOT_LEVEL;
 	hpa_t table_addr = vcpu->mmu.root_hpa;
+	struct page *page;
 
+	page = pfn_to_page(p >> PAGE_SHIFT);
 	for (; ; level--) {
 		u32 index = PT64_INDEX(v, level);
 		u64 *table;
@@ -908,7 +914,7 @@
 			pte = table[index];
 			was_rmapped = is_rmap_pte(pte);
 			if (is_shadow_present_pte(pte) && is_writeble_pte(pte)) {
-				kvm_release_page(pfn_to_page(p >> PAGE_SHIFT));
+				kvm_release_page_clean(page);
 				return 0;
 			}
 			mark_page_dirty(vcpu->kvm, v >> PAGE_SHIFT);
@@ -918,7 +924,8 @@
 			if (!was_rmapped)
 				rmap_add(vcpu, &table[index], v >> PAGE_SHIFT);
 			else
-				kvm_release_page(pfn_to_page(p >> PAGE_SHIFT));
+				kvm_release_page_clean(page);
+
 			return 0;
 		}
 
@@ -933,7 +940,7 @@
 						     1, 3, &table[index]);
 			if (!new_table) {
 				pgprintk("nonpaging_map: ENOMEM\n");
-				kvm_release_page(pfn_to_page(p >> PAGE_SHIFT));
+				kvm_release_page_clean(page);
 				return -ENOMEM;
 			}
 
@@ -1049,8 +1056,8 @@
 	paddr = gpa_to_hpa(vcpu->kvm, addr & PT64_BASE_ADDR_MASK);
 
 	if (is_error_hpa(paddr)) {
-		kvm_release_page(pfn_to_page((paddr & PT64_BASE_ADDR_MASK)
-				 >> PAGE_SHIFT));
+		kvm_release_page_clean(pfn_to_page((paddr & PT64_BASE_ADDR_MASK)
+				       >> PAGE_SHIFT));
 		return 1;
 	}
 
@@ -1580,7 +1587,7 @@
 				       " valid guest gva %lx\n", audit_msg, va);
 			page = pfn_to_page((gpa & PT64_BASE_ADDR_MASK)
 					   >> PAGE_SHIFT);
-			kvm_release_page(page);
+			kvm_release_page_clean(page);
 
 		}
 	}