[PATCH v1 6/8]: PVH ballooning and grant changes

[Mukesh Rathor <mukesh.rathor@oracle.com>]

---
 drivers/xen/balloon.c     |   35 ++++++++++++++++++++++++++++-------
 drivers/xen/gntdev.c      |    3 ++-
 drivers/xen/grant-table.c |   25 +++++++++++++++++++++----
 3 files changed, 51 insertions(+), 12 deletions(-)

diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index 31ab82f..85a6917 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -358,10 +358,21 @@ static enum bp_state increase_reservation(unsigned long nr_pages)
 		BUG_ON(!xen_feature(XENFEAT_auto_translated_physmap) &&
 		       phys_to_machine_mapping_valid(pfn));
 
-		set_phys_to_machine(pfn, frame_list[i]);
+		if (xen_pv_domain() && 
+		    xen_feature(XENFEAT_auto_translated_physmap)) {
+			/* PVH: we just need to update native page table */
+			pte_t *ptep;
+			unsigned int level;
+			void *addr = __va(pfn << PAGE_SHIFT);
+			ptep = lookup_address((unsigned long)addr, &level);
+			set_pte(ptep, pfn_pte(pfn, PAGE_KERNEL));
+		} else
+			set_phys_to_machine(pfn, frame_list[i]);
 
 		/* Link back into the page tables if not highmem. */
-		if (xen_pv_domain() && !PageHighMem(page)) {
+		if (xen_pv_domain() && !PageHighMem(page) && 
+		    !xen_feature(XENFEAT_auto_translated_physmap)) {
+
 			int ret;
 			ret = HYPERVISOR_update_va_mapping(
 				(unsigned long)__va(pfn << PAGE_SHIFT),
@@ -418,12 +429,21 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp)
 		scrub_page(page);
 
 		if (xen_pv_domain() && !PageHighMem(page)) {
-			ret = HYPERVISOR_update_va_mapping(
-				(unsigned long)__va(pfn << PAGE_SHIFT),
-				__pte_ma(0), 0);
-			BUG_ON(ret);
+			if (xen_feature(XENFEAT_auto_translated_physmap)) {
+				unsigned int level;
+				pte_t *ptep;
+				void *addr = __va(pfn << PAGE_SHIFT);
+				ptep = lookup_address((unsigned long)addr, 
+							&level);
+				set_pte(ptep, __pte(0));
+
+			} else {
+				ret = HYPERVISOR_update_va_mapping(
+					(unsigned long)__va(pfn << PAGE_SHIFT),
+					__pte_ma(0), 0);
+				BUG_ON(ret);
+			}
 		}
-
 	}
 
 	/* Ensure that ballooned highmem pages don't have kmaps. */
@@ -433,6 +453,7 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp)
 	/* No more mappings: invalidate P2M and add to balloon. */
 	for (i = 0; i < nr_pages; i++) {
 		pfn = mfn_to_pfn(frame_list[i]);
+		/* PVH note: following will noop for auto translated */
 		__set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
 		balloon_append(pfn_to_page(pfn));
 	}
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 1ffd03b..35d1e3c 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -802,7 +802,8 @@ static int __init gntdev_init(void)
 	if (!xen_domain())
 		return -ENODEV;
 
-	use_ptemod = xen_pv_domain();
+	use_ptemod = xen_pv_domain() && 
+		     !xen_feature(XENFEAT_auto_translated_physmap);
 
 	err = misc_register(&gntdev_miscdev);
 	if (err != 0) {
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index 0bfc1ef..d831d52 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -974,14 +974,19 @@ static void gnttab_unmap_frames_v2(void)
 static int gnttab_map(unsigned int start_idx, unsigned int end_idx)
 {
 	struct gnttab_setup_table setup;
-	unsigned long *frames;
+	unsigned long *frames, start_gpfn;
 	unsigned int nr_gframes = end_idx + 1;
 	int rc;
 
-	if (xen_hvm_domain()) {
+	if (xen_hvm_domain() || xen_feature(XENFEAT_auto_translated_physmap)) {
 		struct xen_add_to_physmap xatp;
 		unsigned int i = end_idx;
 		rc = 0;
+
+		if (xen_hvm_domain())
+			start_gpfn = xen_hvm_resume_frames >> PAGE_SHIFT;
+		else
+			start_gpfn = virt_to_pfn(gnttab_shared.addr);
 		/*
 		 * Loop backwards, so that the first hypercall has the largest
 		 * index, ensuring that the table will grow only once.
@@ -990,7 +995,7 @@ static int gnttab_map(unsigned int start_idx, unsigned int end_idx)
 			xatp.domid = DOMID_SELF;
 			xatp.idx = i;
 			xatp.space = XENMAPSPACE_grant_table;
-			xatp.gpfn = (xen_hvm_resume_frames >> PAGE_SHIFT) + i;
+			xatp.gpfn = start_gpfn + i;
 			rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp);
 			if (rc != 0) {
 				printk(KERN_WARNING
@@ -1053,7 +1058,7 @@ static void gnttab_request_version(void)
 	int rc;
 	struct gnttab_set_version gsv;
 
-	if (xen_hvm_domain())
+	if (xen_hvm_domain() || xen_feature(XENFEAT_auto_translated_physmap))
 		gsv.version = 1;
 	else
 		gsv.version = 2;
@@ -1081,12 +1086,24 @@ static void gnttab_request_version(void)
 int gnttab_resume(void)
 {
 	unsigned int max_nr_gframes;
+	char *kmsg="Failed to kmalloc pages for pv in hvm grant frames\n";
 
 	gnttab_request_version();
 	max_nr_gframes = gnttab_max_grant_frames();
 	if (max_nr_gframes < nr_grant_frames)
 		return -ENOSYS;
 
+	/* PVH note: xen will free existing kmalloc'd mfn in 
+	 * XENMEM_add_to_physmap */
+	if (xen_pv_domain() && xen_feature(XENFEAT_auto_translated_physmap) && 
+	    !gnttab_shared.addr) {
+		gnttab_shared.addr =
+			kmalloc(max_nr_gframes * PAGE_SIZE, GFP_KERNEL);
+		if ( !gnttab_shared.addr ) {
+			printk(KERN_WARNING "%s", kmsg);
+			return -ENOMEM;
+		}
+	}
 	if (xen_pv_domain())
 		return gnttab_map(0, nr_grant_frames - 1);
 
-- 
1.7.2.3