Merge tag 'stable/for-linus-3.20-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen features and fixes from David Vrabel:

 - Reworked handling for foreign (grant mapped) pages to simplify the
   code, enable a number of additional use cases and fix a number of
   long-standing bugs.

 - Prefer the TSC over the Xen PV clock when dom0 (and the TSC is
   stable).

 - Assorted other cleanup and minor bug fixes.

* tag 'stable/for-linus-3.20-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (25 commits)
  xen/manage: Fix USB interaction issues when resuming
  xenbus: Add proper handling of XS_ERROR from Xenbus for transactions.
  xen/gntdev: provide find_special_page VMA operation
  xen/gntdev: mark userspace PTEs as special on x86 PV guests
  xen-blkback: safely unmap grants in case they are still in use
  xen/gntdev: safely unmap grants in case they are still in use
  xen/gntdev: convert priv->lock to a mutex
  xen/grant-table: add a mechanism to safely unmap pages that are in use
  xen-netback: use foreign page information from the pages themselves
  xen: mark grant mapped pages as foreign
  xen/grant-table: add helpers for allocating pages
  x86/xen: require ballooned pages for grant maps
  xen: remove scratch frames for ballooned pages and m2p override
  xen/grant-table: pre-populate kernel unmap ops for xen_gnttab_unmap_refs()
  mm: add 'foreign' alias for the 'pinned' page flag
  mm: provide a find_special_page vma operation
  x86/xen: cleanup arch/x86/xen/mmu.c
  x86/xen: add some __init annotations in arch/x86/xen/mmu.c
  x86/xen: add some __init and static annotations in arch/x86/xen/setup.c
  x86/xen: use correct types for addresses in arch/x86/xen/setup.c
  ...

5 files changed, 68 insertions, 1 deletions

diff --git a/include/linux/mm.h b/include/linux/mm.h
index dd5ea3016fc4..237b3ba29225 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -290,6 +290,14 @@ struct vm_operations_struct {
         /* called by sys_remap_file_pages() to populate non-linear mapping */
         int (*remap_pages)(struct vm_area_struct *vma, unsigned long addr,
                            unsigned long size, pgoff_t pgoff);
+
+        /*
+         * Called by vm_normal_page() for special PTEs to find the
+         * page for @addr.  This is useful if the default behavior
+         * (using pte_page()) would not find the correct page.
+         */
+        struct page *(*find_special_page)(struct vm_area_struct *vma,
+                                          unsigned long addr);
 };
 
 struct mmu_gather;
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index e1f5fcd79792..5ed7bdaf22d5 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -121,8 +121,12 @@ enum pageflags {
         PG_fscache = PG_private_2,      /* page backed by cache */
 
         /* XEN */
+        /* Pinned in Xen as a read-only pagetable page. */
         PG_pinned = PG_owner_priv_1,
+        /* Pinned as part of domain save (see xen_mm_pin_all()). */
         PG_savepinned = PG_dirty,
+        /* Has a grant mapping of another (foreign) domain's page. */
+        PG_foreign = PG_owner_priv_1,
 
         /* SLOB */
         PG_slob_free = PG_private,
@@ -215,6 +219,7 @@ __PAGEFLAG(Slab, slab)
 PAGEFLAG(Checked, checked)              /* Used by some filesystems */
 PAGEFLAG(Pinned, pinned) TESTSCFLAG(Pinned, pinned)     /* Xen */
 PAGEFLAG(SavePinned, savepinned);                       /* Xen */
+PAGEFLAG(Foreign, foreign);                             /* Xen */
 PAGEFLAG(Reserved, reserved) __CLEARPAGEFLAG(Reserved, reserved)
 PAGEFLAG(SwapBacked, swapbacked) __CLEARPAGEFLAG(SwapBacked, swapbacked)
         __SETPAGEFLAG(SwapBacked, swapbacked)
diff --git a/include/xen/grant_table.h b/include/xen/grant_table.h
index 3387465b9caa..143ca5ffab7a 100644
--- a/include/xen/grant_table.h
+++ b/include/xen/grant_table.h
@@ -45,6 +45,8 @@
 #include <asm/xen/hypervisor.h>
 
 #include <xen/features.h>
+#include <linux/mm_types.h>
+#include <linux/page-flags.h>
 
 #define GNTTAB_RESERVED_XENSTORE 1
 
@@ -58,6 +60,22 @@ struct gnttab_free_callback {
         u16 count;
 };
 
+struct gntab_unmap_queue_data;
+
+typedef void (*gnttab_unmap_refs_done)(int result, struct gntab_unmap_queue_data *data);
+
+struct gntab_unmap_queue_data
+{
+        struct delayed_work     gnttab_work;
+        void *data;
+        gnttab_unmap_refs_done  done;
+        struct gnttab_unmap_grant_ref *unmap_ops;
+        struct gnttab_unmap_grant_ref *kunmap_ops;
+        struct page **pages;
+        unsigned int count;
+        unsigned int age;
+};
+
 int gnttab_init(void);
 int gnttab_suspend(void);
 int gnttab_resume(void);
@@ -163,12 +181,17 @@ void gnttab_free_auto_xlat_frames(void);
 
 #define gnttab_map_vaddr(map) ((void *)(map.host_virt_addr))
 
+int gnttab_alloc_pages(int nr_pages, struct page **pages);
+void gnttab_free_pages(int nr_pages, struct page **pages);
+
 int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
                     struct gnttab_map_grant_ref *kmap_ops,
                     struct page **pages, unsigned int count);
 int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
-                      struct gnttab_map_grant_ref *kunmap_ops,
+                      struct gnttab_unmap_grant_ref *kunmap_ops,
                       struct page **pages, unsigned int count);
+void gnttab_unmap_refs_async(struct gntab_unmap_queue_data* item);
+
 
 /* Perform a batch of grant map/copy operations. Retry every batch slot
  * for which the hypervisor returns GNTST_eagain. This is typically due
@@ -182,4 +205,22 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
 void gnttab_batch_map(struct gnttab_map_grant_ref *batch, unsigned count);
 void gnttab_batch_copy(struct gnttab_copy *batch, unsigned count);
 
+
+struct xen_page_foreign {
+        domid_t domid;
+        grant_ref_t gref;
+};
+
+static inline struct xen_page_foreign *xen_page_foreign(struct page *page)
+{
+        if (!PageForeign(page))
+                return NULL;
+#if BITS_PER_LONG < 64
+        return (struct xen_page_foreign *)page->private;
+#else
+        BUILD_BUG_ON(sizeof(struct xen_page_foreign) > BITS_PER_LONG);
+        return (struct xen_page_foreign *)&page->private;
+#endif
+}
+
 #endif /* __ASM_GNTTAB_H__ */
diff --git a/include/xen/interface/features.h b/include/xen/interface/features.h
index 131a6ccdba25..6ad3d110bb81 100644
--- a/include/xen/interface/features.h
+++ b/include/xen/interface/features.h
@@ -41,6 +41,12 @@
 /* x86: Does this Xen host support the MMU_PT_UPDATE_PRESERVE_AD hypercall? */
 #define XENFEAT_mmu_pt_update_preserve_ad  5
 
+/*
+ * If set, GNTTABOP_map_grant_ref honors flags to be placed into guest kernel
+ * available pte bits.
+ */
+#define XENFEAT_gnttab_map_avail_bits      7
+
 /* x86: Does this Xen host support the HVM callback vector type? */
 #define XENFEAT_hvm_callback_vector        8
 
diff --git a/include/xen/interface/grant_table.h b/include/xen/interface/grant_table.h
index bcce56439d64..56806bc90c2f 100644
--- a/include/xen/interface/grant_table.h
+++ b/include/xen/interface/grant_table.h
@@ -526,6 +526,13 @@ DEFINE_GUEST_HANDLE_STRUCT(gnttab_cache_flush);
 #define GNTMAP_contains_pte     (1<<_GNTMAP_contains_pte)
 
 /*
+ * Bits to be placed in guest kernel available PTE bits (architecture
+ * dependent; only supported when XENFEAT_gnttab_map_avail_bits is set).
+ */
+#define _GNTMAP_guest_avail0    (16)
+#define GNTMAP_guest_avail_mask ((uint32_t)~0 << _GNTMAP_guest_avail0)
+
+/*
  * Values for error status returns. All errors are -ve.
  */
 #define GNTST_okay             (0)  /* Normal return.                        */