xen: branch for v5.17-rc1

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Merge tag 'for-linus-5.17-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen updates from Juergen Gross:

 - a fix for the Xen gntdev driver

 - a fix for running as Xen dom0 booted via EFI and the EFI framebuffer
   being located above 4GB

 - a series for support of mapping other guest's memory by using zone
   device when running as Xen guest on Arm

* tag 'for-linus-5.17-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  dt-bindings: xen: Clarify "reg" purpose
  arm/xen: Read extended regions from DT and init Xen resource
  xen/unpopulated-alloc: Add mechanism to use Xen resource
  xen/balloon: Bring alloc(free)_xenballooned_pages helpers back
  arm/xen: Switch to use gnttab_setup_auto_xlat_frames() for DT
  xen/unpopulated-alloc: Drop check for virt_addr_valid() in fill_list()
  xen/x86: obtain upper 32 bits of video frame buffer address for Dom0
  xen/gntdev: fix unmap notification order

Documentation/devicetree/bindings/arm/xen.txt

@@ -7,15 +7,17 @@ the following properties:
 	compatible = "xen,xen-<version>", "xen,xen";
   where <version> is the version of the Xen ABI of the platform.
 
-- reg: specifies the base physical address and size of a region in
-  memory where the grant table should be mapped to, using an
-  HYPERVISOR_memory_op hypercall. The memory region is large enough to map
-  the whole grant table (it is larger or equal to gnttab_max_grant_frames()).
-  This property is unnecessary when booting Dom0 using ACPI.
+- reg: specifies the base physical address and size of the regions in memory
+  where the special resources should be mapped to, using an HYPERVISOR_memory_op
+  hypercall.
+  Region 0 is reserved for mapping grant table, it must be always present.
+  The memory region is large enough to map the whole grant table (it is larger
+  or equal to gnttab_max_grant_frames()).
+  Regions 1...N are extended regions (unused address space) for mapping foreign
+  GFNs and grants, they might be absent if there is nothing to expose.
 
 - interrupts: the interrupt used by Xen to inject event notifications.
   A GIC node is also required.
-  This property is unnecessary when booting Dom0 using ACPI.
 
 To support UEFI on Xen ARM virtual platforms, Xen populates the FDT "uefi" node
 under /hypervisor with following parameters:

arch/arm/xen/enlighten.c

@@ -59,6 +59,10 @@ unsigned long xen_released_pages;
 struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata;
 
 static __read_mostly unsigned int xen_events_irq;
+static __read_mostly phys_addr_t xen_grant_frames;
+
+#define GRANT_TABLE_INDEX   0
+#define EXT_REGION_INDEX    1
 
 uint32_t xen_start_flags;
 EXPORT_SYMBOL(xen_start_flags);
@@ -300,9 +304,115 @@ static void __init xen_acpi_guest_init(void)
 #endif
 }
 
+#ifdef CONFIG_XEN_UNPOPULATED_ALLOC
+/*
+ * A type-less specific Xen resource which contains extended regions
+ * (unused regions of guest physical address space provided by the hypervisor).
+ */
+static struct resource xen_resource = {
+	.name = "Xen unused space",
+};
+
+int __init arch_xen_unpopulated_init(struct resource **res)
+{
+	struct device_node *np;
+	struct resource *regs, *tmp_res;
+	uint64_t min_gpaddr = -1, max_gpaddr = 0;
+	unsigned int i, nr_reg = 0;
+	int rc;
+
+	if (!xen_domain())
+		return -ENODEV;
+
+	if (!acpi_disabled)
+		return -ENODEV;
+
+	np = of_find_compatible_node(NULL, NULL, "xen,xen");
+	if (WARN_ON(!np))
+		return -ENODEV;
+
+	/* Skip region 0 which is reserved for grant table space */
+	while (of_get_address(np, nr_reg + EXT_REGION_INDEX, NULL, NULL))
+		nr_reg++;
+
+	if (!nr_reg) {
+		pr_err("No extended regions are found\n");
+		return -EINVAL;
+	}
+
+	regs = kcalloc(nr_reg, sizeof(*regs), GFP_KERNEL);
+	if (!regs)
+		return -ENOMEM;
+
+	/*
+	 * Create resource from extended regions provided by the hypervisor to be
+	 * used as unused address space for Xen scratch pages.
+	 */
+	for (i = 0; i < nr_reg; i++) {
+		rc = of_address_to_resource(np, i + EXT_REGION_INDEX, &regs[i]);
+		if (rc)
+			goto err;
+
+		if (max_gpaddr < regs[i].end)
+			max_gpaddr = regs[i].end;
+		if (min_gpaddr > regs[i].start)
+			min_gpaddr = regs[i].start;
+	}
+
+	xen_resource.start = min_gpaddr;
+	xen_resource.end = max_gpaddr;
+
+	/*
+	 * Mark holes between extended regions as unavailable. The rest of that
+	 * address space will be available for the allocation.
+	 */
+	for (i = 1; i < nr_reg; i++) {
+		resource_size_t start, end;
+
+		/* There is an overlap between regions */
+		if (regs[i - 1].end + 1 > regs[i].start) {
+			rc = -EINVAL;
+			goto err;
+		}
+
+		/* There is no hole between regions */
+		if (regs[i - 1].end + 1 == regs[i].start)
+			continue;
+
+		start = regs[i - 1].end + 1;
+		end = regs[i].start - 1;
+
+		tmp_res = kzalloc(sizeof(*tmp_res), GFP_KERNEL);
+		if (!tmp_res) {
+			rc = -ENOMEM;
+			goto err;
+		}
+
+		tmp_res->name = "Unavailable space";
+		tmp_res->start = start;
+		tmp_res->end = end;
+
+		rc = insert_resource(&xen_resource, tmp_res);
+		if (rc) {
+			pr_err("Cannot insert resource %pR (%d)\n", tmp_res, rc);
+			kfree(tmp_res);
+			goto err;
+		}
+	}
+
+	*res = &xen_resource;
+
+err:
+	kfree(regs);
+
+	return rc;
+}
+#endif
+
 static void __init xen_dt_guest_init(void)
 {
 	struct device_node *xen_node;
+	struct resource res;
 
 	xen_node = of_find_compatible_node(NULL, NULL, "xen,xen");
 	if (!xen_node) {
@@ -311,13 +421,19 @@ static void __init xen_dt_guest_init(void)
 	}
 
 	xen_events_irq = irq_of_parse_and_map(xen_node, 0);
+
+	if (of_address_to_resource(xen_node, GRANT_TABLE_INDEX, &res)) {
+		pr_err("Xen grant table region is not found\n");
+		return;
+	}
+	xen_grant_frames = res.start;
 }
 
 static int __init xen_guest_init(void)
 {
 	struct xen_add_to_physmap xatp;
 	struct shared_info *shared_info_page = NULL;
-	int cpu;
+	int rc, cpu;
 
 	if (!xen_domain())
 		return 0;
@@ -370,12 +486,16 @@ static int __init xen_guest_init(void)
 	for_each_possible_cpu(cpu)
 		per_cpu(xen_vcpu_id, cpu) = cpu;
 
-	xen_auto_xlat_grant_frames.count = gnttab_max_grant_frames();
-	if (xen_xlate_map_ballooned_pages(&xen_auto_xlat_grant_frames.pfn,
-					  &xen_auto_xlat_grant_frames.vaddr,
-					  xen_auto_xlat_grant_frames.count)) {
+	if (!xen_grant_frames) {
+		xen_auto_xlat_grant_frames.count = gnttab_max_grant_frames();
+		rc = xen_xlate_map_ballooned_pages(&xen_auto_xlat_grant_frames.pfn,
+										   &xen_auto_xlat_grant_frames.vaddr,
+										   xen_auto_xlat_grant_frames.count);
+	} else
+		rc = gnttab_setup_auto_xlat_frames(xen_grant_frames);
+	if (rc) {
 		free_percpu(xen_vcpu_info);
-		return -ENOMEM;
+		return rc;
 	}
 	gnttab_init();
 

arch/x86/xen/vga.c

@@ -62,14 +62,18 @@ void __init xen_init_vga(const struct dom0_vga_console_info *info, size_t size)
 			break;
 		}
 
-		if (size >= offsetof(struct dom0_vga_console_info,
-				     u.vesa_lfb.gbl_caps)
-		    + sizeof(info->u.vesa_lfb.gbl_caps))
-			screen_info->capabilities = info->u.vesa_lfb.gbl_caps;
 		if (size >= offsetof(struct dom0_vga_console_info,
 				     u.vesa_lfb.mode_attrs)
 		    + sizeof(info->u.vesa_lfb.mode_attrs))
 			screen_info->vesa_attributes = info->u.vesa_lfb.mode_attrs;
+
+		if (size >= offsetof(struct dom0_vga_console_info,
+				     u.vesa_lfb.ext_lfb_base)
+		    + sizeof(info->u.vesa_lfb.ext_lfb_base)
+		    && info->u.vesa_lfb.ext_lfb_base) {
+			screen_info->ext_lfb_base = info->u.vesa_lfb.ext_lfb_base;
+			screen_info->capabilities |= VIDEO_CAPABILITY_64BIT_BASE;
+		}
 		break;
 	}
 }

drivers/xen/Kconfig

@@ -327,7 +327,7 @@ config XEN_FRONT_PGDIR_SHBUF
 
 config XEN_UNPOPULATED_ALLOC
 	bool "Use unpopulated memory ranges for guest mappings"
-	depends on X86 && ZONE_DEVICE
+	depends on ZONE_DEVICE
 	default XEN_BACKEND || XEN_GNTDEV || XEN_DOM0
 	help
 	  Use unpopulated memory ranges in order to create mappings for guest

drivers/xen/balloon.c

@@ -581,7 +581,6 @@ void balloon_set_new_target(unsigned long target)
 }
 EXPORT_SYMBOL_GPL(balloon_set_new_target);
 
-#ifndef CONFIG_XEN_UNPOPULATED_ALLOC
 static int add_ballooned_pages(unsigned int nr_pages)
 {
 	enum bp_state st;
@@ -610,12 +609,12 @@ static int add_ballooned_pages(unsigned int nr_pages)
 }
 
 /**
- * xen_alloc_unpopulated_pages - get pages that have been ballooned out
+ * xen_alloc_ballooned_pages - get pages that have been ballooned out
  * @nr_pages: Number of pages to get
  * @pages: pages returned
  * @return 0 on success, error otherwise
  */
-int xen_alloc_unpopulated_pages(unsigned int nr_pages, struct page **pages)
+int xen_alloc_ballooned_pages(unsigned int nr_pages, struct page **pages)
 {
 	unsigned int pgno = 0;
 	struct page *page;
@@ -652,23 +651,23 @@ int xen_alloc_unpopulated_pages(unsigned int nr_pages, struct page **pages)
 	return 0;
  out_undo:
 	mutex_unlock(&balloon_mutex);
-	xen_free_unpopulated_pages(pgno, pages);
+	xen_free_ballooned_pages(pgno, pages);
 	/*
-	 * NB: free_xenballooned_pages will only subtract pgno pages, but since
+	 * NB: xen_free_ballooned_pages will only subtract pgno pages, but since
 	 * target_unpopulated is incremented with nr_pages at the start we need
 	 * to remove the remaining ones also, or accounting will be screwed.
 	 */
 	balloon_stats.target_unpopulated -= nr_pages - pgno;
 	return ret;
 }
-EXPORT_SYMBOL(xen_alloc_unpopulated_pages);
+EXPORT_SYMBOL(xen_alloc_ballooned_pages);
 
 /**
- * xen_free_unpopulated_pages - return pages retrieved with get_ballooned_pages
+ * xen_free_ballooned_pages - return pages retrieved with get_ballooned_pages
  * @nr_pages: Number of pages
  * @pages: pages to return
  */
-void xen_free_unpopulated_pages(unsigned int nr_pages, struct page **pages)
+void xen_free_ballooned_pages(unsigned int nr_pages, struct page **pages)
 {
 	unsigned int i;
 
@@ -687,9 +686,9 @@ void xen_free_unpopulated_pages(unsigned int nr_pages, struct page **pages)
 
 	mutex_unlock(&balloon_mutex);
 }
-EXPORT_SYMBOL(xen_free_unpopulated_pages);
+EXPORT_SYMBOL(xen_free_ballooned_pages);
 
-#if defined(CONFIG_XEN_PV)
+#if defined(CONFIG_XEN_PV) && !defined(CONFIG_XEN_UNPOPULATED_ALLOC)
 static void __init balloon_add_region(unsigned long start_pfn,
 				      unsigned long pages)
 {
@@ -712,7 +711,6 @@ static void __init balloon_add_region(unsigned long start_pfn,
 	balloon_stats.total_pages += extra_pfn_end - start_pfn;
 }
 #endif
-#endif
 
 static int __init balloon_init(void)
 {

drivers/xen/gntdev.c

@@ -250,13 +250,13 @@ void gntdev_put_map(struct gntdev_priv *priv, struct gntdev_grant_map *map)
 	if (!refcount_dec_and_test(&map->users))
 		return;
 
+	if (map->pages && !use_ptemod)
+		unmap_grant_pages(map, 0, map->count);
+
 	if (map->notify.flags & UNMAP_NOTIFY_SEND_EVENT) {
 		notify_remote_via_evtchn(map->notify.event);
 		evtchn_put(map->notify.event);
 	}
-
-	if (map->pages && !use_ptemod)
-		unmap_grant_pages(map, 0, map->count);
 	gntdev_free_map(map);
 }
 

drivers/xen/unpopulated-alloc.c

@@ -8,6 +8,7 @@
 
 #include <asm/page.h>
 
+#include <xen/balloon.h>
 #include <xen/page.h>
 #include <xen/xen.h>
 
@@ -15,13 +16,29 @@ static DEFINE_MUTEX(list_lock);
 static struct page *page_list;
 static unsigned int list_count;
 
+static struct resource *target_resource;
+
+/*
+ * If arch is not happy with system "iomem_resource" being used for
+ * the region allocation it can provide it's own view by creating specific
+ * Xen resource with unused regions of guest physical address space provided
+ * by the hypervisor.
+ */
+int __weak __init arch_xen_unpopulated_init(struct resource **res)
+{
+	*res = &iomem_resource;
+
+	return 0;
+}
+
 static int fill_list(unsigned int nr_pages)
 {
 	struct dev_pagemap *pgmap;
-	struct resource *res;
+	struct resource *res, *tmp_res = NULL;
 	void *vaddr;
 	unsigned int i, alloc_pages = round_up(nr_pages, PAGES_PER_SECTION);
-	int ret = -ENOMEM;
+	struct range mhp_range;
+	int ret;
 
 	res = kzalloc(sizeof(*res), GFP_KERNEL);
 	if (!res)
@@ -30,14 +47,40 @@ static int fill_list(unsigned int nr_pages)
 	res->name = "Xen scratch";
 	res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 
-	ret = allocate_resource(&iomem_resource, res,
-				alloc_pages * PAGE_SIZE, 0, -1,
+	mhp_range = mhp_get_pluggable_range(true);
+
+	ret = allocate_resource(target_resource, res,
+				alloc_pages * PAGE_SIZE, mhp_range.start, mhp_range.end,
 				PAGES_PER_SECTION * PAGE_SIZE, NULL, NULL);
 	if (ret < 0) {
 		pr_err("Cannot allocate new IOMEM resource\n");
 		goto err_resource;
 	}
 
+	/*
+	 * Reserve the region previously allocated from Xen resource to avoid
+	 * re-using it by someone else.
+	 */
+	if (target_resource != &iomem_resource) {
+		tmp_res = kzalloc(sizeof(*tmp_res), GFP_KERNEL);
+		if (!tmp_res) {
+			ret = -ENOMEM;
+			goto err_insert;
+		}
+
+		tmp_res->name = res->name;
+		tmp_res->start = res->start;
+		tmp_res->end = res->end;
+		tmp_res->flags = res->flags;
+
+		ret = request_resource(&iomem_resource, tmp_res);
+		if (ret < 0) {
+			pr_err("Cannot request resource %pR (%d)\n", tmp_res, ret);
+			kfree(tmp_res);
+			goto err_insert;
+		}
+	}
+
 	pgmap = kzalloc(sizeof(*pgmap), GFP_KERNEL);
 	if (!pgmap) {
 		ret = -ENOMEM;
@@ -85,7 +128,6 @@ static int fill_list(unsigned int nr_pages)
 	for (i = 0; i < alloc_pages; i++) {
 		struct page *pg = virt_to_page(vaddr + PAGE_SIZE * i);
 
-		BUG_ON(!virt_addr_valid(vaddr + PAGE_SIZE * i));
 		pg->zone_device_data = page_list;
 		page_list = pg;
 		list_count++;
@@ -96,6 +138,11 @@ static int fill_list(unsigned int nr_pages)
 err_memremap:
 	kfree(pgmap);
 err_pgmap:
+	if (tmp_res) {
+		release_resource(tmp_res);
+		kfree(tmp_res);
+	}
+err_insert:
 	release_resource(res);
 err_resource:
 	kfree(res);
@@ -113,6 +160,14 @@ int xen_alloc_unpopulated_pages(unsigned int nr_pages, struct page **pages)
 	unsigned int i;
 	int ret = 0;
 
+	/*
+	 * Fallback to default behavior if we do not have any suitable resource
+	 * to allocate required region from and as the result we won't be able to
+	 * construct pages.
+	 */
+	if (!target_resource)
+		return xen_alloc_ballooned_pages(nr_pages, pages);
+
 	mutex_lock(&list_lock);
 	if (list_count < nr_pages) {
 		ret = fill_list(nr_pages - list_count);
@@ -160,6 +215,11 @@ void xen_free_unpopulated_pages(unsigned int nr_pages, struct page **pages)
 {
 	unsigned int i;
 
+	if (!target_resource) {
+		xen_free_ballooned_pages(nr_pages, pages);
+		return;
+	}
+
 	mutex_lock(&list_lock);
 	for (i = 0; i < nr_pages; i++) {
 		pages[i]->zone_device_data = page_list;
@@ -202,3 +262,20 @@ static int __init init(void)
 }
 subsys_initcall(init);
 #endif
+
+static int __init unpopulated_init(void)
+{
+	int ret;
+
+	if (!xen_domain())
+		return -ENODEV;
+
+	ret = arch_xen_unpopulated_init(&target_resource);
+	if (ret) {
+		pr_err("xen:unpopulated: Cannot initialize target resource\n");
+		target_resource = NULL;
+	}
+
+	return ret;
+}
+early_initcall(unpopulated_init);

include/xen/balloon.h

@@ -26,6 +26,9 @@ extern struct balloon_stats balloon_stats;
 
 void balloon_set_new_target(unsigned long target);
 
+int xen_alloc_ballooned_pages(unsigned int nr_pages, struct page **pages);
+void xen_free_ballooned_pages(unsigned int nr_pages, struct page **pages);
+
 #ifdef CONFIG_XEN_BALLOON
 void xen_balloon_init(void);
 #else

include/xen/interface/xen.h

@@ -722,6 +722,9 @@ struct dom0_vga_console_info {
 			uint32_t gbl_caps;
 			/* Mode attributes (offset 0x0, VESA command 0x4f01). */
 			uint16_t mode_attrs;
+			uint16_t pad;
+			/* high 32 bits of lfb_base */
+			uint32_t ext_lfb_base;
 		} vesa_lfb;
 	} u;
 };

include/xen/xen.h

@@ -52,7 +52,23 @@ bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
 extern u64 xen_saved_max_mem_size;
 #endif
 
+#ifdef CONFIG_XEN_UNPOPULATED_ALLOC
 int xen_alloc_unpopulated_pages(unsigned int nr_pages, struct page **pages);
 void xen_free_unpopulated_pages(unsigned int nr_pages, struct page **pages);
+#include <linux/ioport.h>
+int arch_xen_unpopulated_init(struct resource **res);
+#else
+#include <xen/balloon.h>
+static inline int xen_alloc_unpopulated_pages(unsigned int nr_pages,
+		struct page **pages)
+{
+	return xen_alloc_ballooned_pages(nr_pages, pages);
+}
+static inline void xen_free_unpopulated_pages(unsigned int nr_pages,
+		struct page **pages)
+{
+	xen_free_ballooned_pages(nr_pages, pages);
+}
+#endif
 
 #endif	/* _XEN_XEN_H */