Merge tag 'for-linus-4.19-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen updates from Juergen Gross:

 - add dma-buf functionality to Xen grant table handling

 - fix for booting the kernel as Xen PVH dom0

 - fix for booting the kernel as a Xen PV guest with
   CONFIG_DEBUG_VIRTUAL enabled

 - other minor performance and style fixes

* tag 'for-linus-4.19-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/balloon: fix balloon initialization for PVH Dom0
  xen: don't use privcmd_call() from xen_mc_flush()
  xen/pv: Call get_cpu_address_sizes to set x86_virt/phys_bits
  xen/biomerge: Use true and false for boolean values
  xen/gntdev: don't dereference a null gntdev_dmabuf on allocation failure
  xen/spinlock: Don't use pvqspinlock if only 1 vCPU
  xen/gntdev: Implement dma-buf import functionality
  xen/gntdev: Implement dma-buf export functionality
  xen/gntdev: Add initial support for dma-buf UAPI
  xen/gntdev: Make private routines/structures accessible
  xen/gntdev: Allow mappings for DMA buffers
  xen/grant-table: Allow allocating buffers suitable for DMA
  xen/balloon: Share common memory reservation routines
  xen/grant-table: Make set/clear page private code shared

3 files changed, 186 insertions, 0 deletions

diff --git a/include/uapi/xen/gntdev.h b/include/uapi/xen/gntdev.h
index 6d1163456c03..fe4423e518c6 100644
--- a/include/uapi/xen/gntdev.h
+++ b/include/uapi/xen/gntdev.h
@@ -5,6 +5,7 @@
  * Interface to /dev/xen/gntdev.
  * 
  * Copyright (c) 2007, D G Murray
+ * Copyright (c) 2018, Oleksandr Andrushchenko, EPAM Systems Inc.
  * 
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License version 2
@@ -200,4 +201,109 @@ struct ioctl_gntdev_grant_copy {
 /* Send an interrupt on the indicated event channel */
 #define UNMAP_NOTIFY_SEND_EVENT 0x2
 
+/*
+ * Flags to be used while requesting memory mapping's backing storage
+ * to be allocated with DMA API.
+ */
+
+/*
+ * The buffer is backed with memory allocated with dma_alloc_wc.
+ */
+#define GNTDEV_DMA_FLAG_WC		(1 << 0)
+
+/*
+ * The buffer is backed with memory allocated with dma_alloc_coherent.
+ */
+#define GNTDEV_DMA_FLAG_COHERENT	(1 << 1)
+
+/*
+ * Create a dma-buf [1] from grant references @refs of count @count provided
+ * by the foreign domain @domid with flags @flags.
+ *
+ * By default dma-buf is backed by system memory pages, but by providing
+ * one of the GNTDEV_DMA_FLAG_XXX flags it can also be created as
+ * a DMA write-combine or coherent buffer, e.g. allocated with dma_alloc_wc/
+ * dma_alloc_coherent.
+ *
+ * Returns 0 if dma-buf was successfully created and the corresponding
+ * dma-buf's file descriptor is returned in @fd.
+ *
+ * [1] Documentation/driver-api/dma-buf.rst
+ */
+
+#define IOCTL_GNTDEV_DMABUF_EXP_FROM_REFS \
+	_IOC(_IOC_NONE, 'G', 9, \
+	     sizeof(struct ioctl_gntdev_dmabuf_exp_from_refs))
+struct ioctl_gntdev_dmabuf_exp_from_refs {
+	/* IN parameters. */
+	/* Specific options for this dma-buf: see GNTDEV_DMA_FLAG_XXX. */
+	__u32 flags;
+	/* Number of grant references in @refs array. */
+	__u32 count;
+	/* OUT parameters. */
+	/* File descriptor of the dma-buf. */
+	__u32 fd;
+	/* The domain ID of the grant references to be mapped. */
+	__u32 domid;
+	/* Variable IN parameter. */
+	/* Array of grant references of size @count. */
+	__u32 refs[1];
+};
+
+/*
+ * This will block until the dma-buf with the file descriptor @fd is
+ * released. This is only valid for buffers created with
+ * IOCTL_GNTDEV_DMABUF_EXP_FROM_REFS.
+ *
+ * If within @wait_to_ms milliseconds the buffer is not released
+ * then -ETIMEDOUT error is returned.
+ * If the buffer with the file descriptor @fd does not exist or has already
+ * been released, then -ENOENT is returned. For valid file descriptors
+ * this must not be treated as error.
+ */
+#define IOCTL_GNTDEV_DMABUF_EXP_WAIT_RELEASED \
+	_IOC(_IOC_NONE, 'G', 10, \
+	     sizeof(struct ioctl_gntdev_dmabuf_exp_wait_released))
+struct ioctl_gntdev_dmabuf_exp_wait_released {
+	/* IN parameters */
+	__u32 fd;
+	__u32 wait_to_ms;
+};
+
+/*
+ * Import a dma-buf with file descriptor @fd and export granted references
+ * to the pages of that dma-buf into array @refs of size @count.
+ */
+#define IOCTL_GNTDEV_DMABUF_IMP_TO_REFS \
+	_IOC(_IOC_NONE, 'G', 11, \
+	     sizeof(struct ioctl_gntdev_dmabuf_imp_to_refs))
+struct ioctl_gntdev_dmabuf_imp_to_refs {
+	/* IN parameters. */
+	/* File descriptor of the dma-buf. */
+	__u32 fd;
+	/* Number of grant references in @refs array. */
+	__u32 count;
+	/* The domain ID for which references to be granted. */
+	__u32 domid;
+	/* Reserved - must be zero. */
+	__u32 reserved;
+	/* OUT parameters. */
+	/* Array of grant references of size @count. */
+	__u32 refs[1];
+};
+
+/*
+ * This will close all references to the imported buffer with file descriptor
+ * @fd, so it can be released by the owner. This is only valid for buffers
+ * created with IOCTL_GNTDEV_DMABUF_IMP_TO_REFS.
+ */
+#define IOCTL_GNTDEV_DMABUF_IMP_RELEASE \
+	_IOC(_IOC_NONE, 'G', 12, \
+	     sizeof(struct ioctl_gntdev_dmabuf_imp_release))
+struct ioctl_gntdev_dmabuf_imp_release {
+	/* IN parameters */
+	__u32 fd;
+	__u32 reserved;
+};
+
 #endif /* __LINUX_PUBLIC_GNTDEV_H__ */
diff --git a/include/xen/grant_table.h b/include/xen/grant_table.h
index 2e37741f6b8d..9bc5bc07d4d3 100644
--- a/include/xen/grant_table.h
+++ b/include/xen/grant_table.h
@@ -198,6 +198,27 @@ void gnttab_free_auto_xlat_frames(void);
 int gnttab_alloc_pages(int nr_pages, struct page **pages);
 void gnttab_free_pages(int nr_pages, struct page **pages);
 
+#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
+struct gnttab_dma_alloc_args {
+	/* Device for which DMA memory will be/was allocated. */
+	struct device *dev;
+	/* If set then DMA buffer is coherent and write-combine otherwise. */
+	bool coherent;
+
+	int nr_pages;
+	struct page **pages;
+	xen_pfn_t *frames;
+	void *vaddr;
+	dma_addr_t dev_bus_addr;
+};
+
+int gnttab_dma_alloc_pages(struct gnttab_dma_alloc_args *args);
+int gnttab_dma_free_pages(struct gnttab_dma_alloc_args *args);
+#endif
+
+int gnttab_pages_set_private(int nr_pages, struct page **pages);
+void gnttab_pages_clear_private(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);
diff --git a/include/xen/mem-reservation.h b/include/xen/mem-reservation.h
new file mode 100644
index 000000000000..80b52b4945e9
--- /dev/null
+++ b/include/xen/mem-reservation.h
@@ -0,0 +1,59 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Xen memory reservation utilities.
+ *
+ * Copyright (c) 2003, B Dragovic
+ * Copyright (c) 2003-2004, M Williamson, K Fraser
+ * Copyright (c) 2005 Dan M. Smith, IBM Corporation
+ * Copyright (c) 2010 Daniel Kiper
+ * Copyright (c) 2018 Oleksandr Andrushchenko, EPAM Systems Inc.
+ */
+
+#ifndef _XENMEM_RESERVATION_H
+#define _XENMEM_RESERVATION_H
+
+#include <linux/highmem.h>
+
+#include <xen/page.h>
+
+static inline void xenmem_reservation_scrub_page(struct page *page)
+{
+#ifdef CONFIG_XEN_SCRUB_PAGES
+	clear_highpage(page);
+#endif
+}
+
+#ifdef CONFIG_XEN_HAVE_PVMMU
+void __xenmem_reservation_va_mapping_update(unsigned long count,
+					    struct page **pages,
+					    xen_pfn_t *frames);
+
+void __xenmem_reservation_va_mapping_reset(unsigned long count,
+					   struct page **pages);
+#endif
+
+static inline void xenmem_reservation_va_mapping_update(unsigned long count,
+							struct page **pages,
+							xen_pfn_t *frames)
+{
+#ifdef CONFIG_XEN_HAVE_PVMMU
+	if (!xen_feature(XENFEAT_auto_translated_physmap))
+		__xenmem_reservation_va_mapping_update(count, pages, frames);
+#endif
+}
+
+static inline void xenmem_reservation_va_mapping_reset(unsigned long count,
+						       struct page **pages)
+{
+#ifdef CONFIG_XEN_HAVE_PVMMU
+	if (!xen_feature(XENFEAT_auto_translated_physmap))
+		__xenmem_reservation_va_mapping_reset(count, pages);
+#endif
+}
+
+int xenmem_reservation_increase(int count, xen_pfn_t *frames);
+
+int xenmem_reservation_decrease(int count, xen_pfn_t *frames);
+
+#endif