Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

Pull fw_cfg, vhost updates from Michael Tsirkin:
 "This cleans up the qemu fw cfg device driver.

  On top of this, vmcore is dumped there on crash to help debugging
  with kASLR enabled.

  Also included are some fixes in vhost"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  vhost: add vsock compat ioctl
  vhost: fix vhost ioctl signature to build with clang
  fw_cfg: write vmcoreinfo details
  crash: export paddr_vmcoreinfo_note()
  fw_cfg: add DMA register
  fw_cfg: add a public uapi header
  fw_cfg: handle fw_cfg_read_blob() error
  fw_cfg: remove inline from fw_cfg_read_blob()
  fw_cfg: fix sparse warnings around FW_CFG_FILE_DIR read
  fw_cfg: fix sparse warning reading FW_CFG_ID
  fw_cfg: fix sparse warnings with fw_cfg_file
  fw_cfg: fix sparse warnings in fw_cfg_sel_endianness()
  ptr_ring: fix build

8 files changed, 348 insertions, 64 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index 5e929acb5a82..83f5a6fd7de3 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11464,6 +11464,7 @@ M:	"Michael S. Tsirkin" <mst@redhat.com>
 L:	qemu-devel@nongnu.org
 S:	Maintained
 F:	drivers/firmware/qemu_fw_cfg.c
+F:	include/uapi/linux/qemu_fw_cfg.h
 
 QIB DRIVER
 M:	Dennis Dalessandro <dennis.dalessandro@intel.com>
diff --git a/drivers/firmware/qemu_fw_cfg.c b/drivers/firmware/qemu_fw_cfg.c
index a41b572eeeb1..14fedbeca724 100644
--- a/drivers/firmware/qemu_fw_cfg.c
+++ b/drivers/firmware/qemu_fw_cfg.c
@@ -10,20 +10,21 @@
  * and select subsets of aarch64), a Device Tree node (on arm), or using
  * a kernel module (or command line) parameter with the following syntax:
  *
- *      [qemu_fw_cfg.]ioport=<size>@<base>[:<ctrl_off>:<data_off>]
+ *      [qemu_fw_cfg.]ioport=<size>@<base>[:<ctrl_off>:<data_off>[:<dma_off>]]
  * or
- *      [qemu_fw_cfg.]mmio=<size>@<base>[:<ctrl_off>:<data_off>]
+ *      [qemu_fw_cfg.]mmio=<size>@<base>[:<ctrl_off>:<data_off>[:<dma_off>]]
  *
  * where:
  *      <size>     := size of ioport or mmio range
  *      <base>     := physical base address of ioport or mmio range
  *      <ctrl_off> := (optional) offset of control register
  *      <data_off> := (optional) offset of data register
+ *      <dma_off> := (optional) offset of dma register
  *
  * e.g.:
- *      qemu_fw_cfg.ioport=2@0x510:0:1		(the default on x86)
+ *      qemu_fw_cfg.ioport=12@0x510:0:1:4	(the default on x86)
  * or
- *      qemu_fw_cfg.mmio=0xA@0x9020000:8:0	(the default on arm)
+ *      qemu_fw_cfg.mmio=16@0x9020000:8:0:16	(the default on arm)
  */
 
 #include <linux/module.h>
@@ -32,29 +33,17 @@
 #include <linux/slab.h>
 #include <linux/io.h>
 #include <linux/ioport.h>
+#include <uapi/linux/qemu_fw_cfg.h>
+#include <linux/delay.h>
+#include <linux/crash_dump.h>
+#include <linux/crash_core.h>
 
 MODULE_AUTHOR("Gabriel L. Somlo <somlo@cmu.edu>");
 MODULE_DESCRIPTION("QEMU fw_cfg sysfs support");
 MODULE_LICENSE("GPL");
 
-/* selector key values for "well-known" fw_cfg entries */
-#define FW_CFG_SIGNATURE  0x00
-#define FW_CFG_ID         0x01
-#define FW_CFG_FILE_DIR   0x19
-
-/* size in bytes of fw_cfg signature */
-#define FW_CFG_SIG_SIZE 4
-
-/* fw_cfg "file name" is up to 56 characters (including terminating nul) */
-#define FW_CFG_MAX_FILE_PATH 56
-
-/* fw_cfg file directory entry type */
-struct fw_cfg_file {
-	u32 size;
-	u16 select;
-	u16 reserved;
-	char name[FW_CFG_MAX_FILE_PATH];
-};
+/* fw_cfg revision attribute, in /sys/firmware/qemu_fw_cfg top-level dir. */
+static u32 fw_cfg_rev;
 
 /* fw_cfg device i/o register addresses */
 static bool fw_cfg_is_mmio;
@@ -63,19 +52,83 @@ static resource_size_t fw_cfg_p_size;
 static void __iomem *fw_cfg_dev_base;
 static void __iomem *fw_cfg_reg_ctrl;
 static void __iomem *fw_cfg_reg_data;
+static void __iomem *fw_cfg_reg_dma;
 
 /* atomic access to fw_cfg device (potentially slow i/o, so using mutex) */
 static DEFINE_MUTEX(fw_cfg_dev_lock);
 
 /* pick appropriate endianness for selector key */
-static inline u16 fw_cfg_sel_endianness(u16 key)
+static void fw_cfg_sel_endianness(u16 key)
+{
+	if (fw_cfg_is_mmio)
+		iowrite16be(key, fw_cfg_reg_ctrl);
+	else
+		iowrite16(key, fw_cfg_reg_ctrl);
+}
+
+#ifdef CONFIG_CRASH_CORE
+static inline bool fw_cfg_dma_enabled(void)
+{
+	return (fw_cfg_rev & FW_CFG_VERSION_DMA) && fw_cfg_reg_dma;
+}
+
+/* qemu fw_cfg device is sync today, but spec says it may become async */
+static void fw_cfg_wait_for_control(struct fw_cfg_dma_access *d)
 {
-	return fw_cfg_is_mmio ? cpu_to_be16(key) : cpu_to_le16(key);
+	for (;;) {
+		u32 ctrl = be32_to_cpu(READ_ONCE(d->control));
+
+		/* do not reorder the read to d->control */
+		rmb();
+		if ((ctrl & ~FW_CFG_DMA_CTL_ERROR) == 0)
+			return;
+
+		cpu_relax();
+	}
+}
+
+static ssize_t fw_cfg_dma_transfer(void *address, u32 length, u32 control)
+{
+	phys_addr_t dma;
+	struct fw_cfg_dma_access *d = NULL;
+	ssize_t ret = length;
+
+	d = kmalloc(sizeof(*d), GFP_KERNEL);
+	if (!d) {
+		ret = -ENOMEM;
+		goto end;
+	}
+
+	/* fw_cfg device does not need IOMMU protection, so use physical addresses */
+	*d = (struct fw_cfg_dma_access) {
+		.address = cpu_to_be64(address ? virt_to_phys(address) : 0),
+		.length = cpu_to_be32(length),
+		.control = cpu_to_be32(control)
+	};
+
+	dma = virt_to_phys(d);
+
+	iowrite32be((u64)dma >> 32, fw_cfg_reg_dma);
+	/* force memory to sync before notifying device via MMIO */
+	wmb();
+	iowrite32be(dma, fw_cfg_reg_dma + 4);
+
+	fw_cfg_wait_for_control(d);
+
+	if (be32_to_cpu(READ_ONCE(d->control)) & FW_CFG_DMA_CTL_ERROR) {
+		ret = -EIO;
+	}
+
+end:
+	kfree(d);
+
+	return ret;
 }
+#endif
 
 /* read chunk of given fw_cfg blob (caller responsible for sanity-check) */
-static inline void fw_cfg_read_blob(u16 key,
-				    void *buf, loff_t pos, size_t count)
+static ssize_t fw_cfg_read_blob(u16 key,
+				void *buf, loff_t pos, size_t count)
 {
 	u32 glk = -1U;
 	acpi_status status;
@@ -88,18 +141,60 @@ static inline void fw_cfg_read_blob(u16 key,
 		/* Should never get here */
 		WARN(1, "fw_cfg_read_blob: Failed to lock ACPI!\n");
 		memset(buf, 0, count);
-		return;
+		return -EINVAL;
 	}
 
 	mutex_lock(&fw_cfg_dev_lock);
-	iowrite16(fw_cfg_sel_endianness(key), fw_cfg_reg_ctrl);
+	fw_cfg_sel_endianness(key);
 	while (pos-- > 0)
 		ioread8(fw_cfg_reg_data);
 	ioread8_rep(fw_cfg_reg_data, buf, count);
 	mutex_unlock(&fw_cfg_dev_lock);
 
 	acpi_release_global_lock(glk);
+	return count;
+}
+
+#ifdef CONFIG_CRASH_CORE
+/* write chunk of given fw_cfg blob (caller responsible for sanity-check) */
+static ssize_t fw_cfg_write_blob(u16 key,
+				 void *buf, loff_t pos, size_t count)
+{
+	u32 glk = -1U;
+	acpi_status status;
+	ssize_t ret = count;
+
+	/* If we have ACPI, ensure mutual exclusion against any potential
+	 * device access by the firmware, e.g. via AML methods:
+	 */
+	status = acpi_acquire_global_lock(ACPI_WAIT_FOREVER, &glk);
+	if (ACPI_FAILURE(status) && status != AE_NOT_CONFIGURED) {
+		/* Should never get here */
+		WARN(1, "%s: Failed to lock ACPI!\n", __func__);
+		return -EINVAL;
+	}
+
+	mutex_lock(&fw_cfg_dev_lock);
+	if (pos == 0) {
+		ret = fw_cfg_dma_transfer(buf, count, key << 16
+					  | FW_CFG_DMA_CTL_SELECT
+					  | FW_CFG_DMA_CTL_WRITE);
+	} else {
+		fw_cfg_sel_endianness(key);
+		ret = fw_cfg_dma_transfer(NULL, pos, FW_CFG_DMA_CTL_SKIP);
+		if (ret < 0)
+			goto end;
+		ret = fw_cfg_dma_transfer(buf, count, FW_CFG_DMA_CTL_WRITE);
+	}
+
+end:
+	mutex_unlock(&fw_cfg_dev_lock);
+
+	acpi_release_global_lock(glk);
+
+	return ret;
 }
+#endif /* CONFIG_CRASH_CORE */
 
 /* clean up fw_cfg device i/o */
 static void fw_cfg_io_cleanup(void)
@@ -118,12 +213,14 @@ static void fw_cfg_io_cleanup(void)
 # if (defined(CONFIG_ARM) || defined(CONFIG_ARM64))
 #  define FW_CFG_CTRL_OFF 0x08
 #  define FW_CFG_DATA_OFF 0x00
+#  define FW_CFG_DMA_OFF 0x10
 # elif (defined(CONFIG_PPC_PMAC) || defined(CONFIG_SPARC32)) /* ppc/mac,sun4m */
 #  define FW_CFG_CTRL_OFF 0x00
 #  define FW_CFG_DATA_OFF 0x02
 # elif (defined(CONFIG_X86) || defined(CONFIG_SPARC64)) /* x86, sun4u */
 #  define FW_CFG_CTRL_OFF 0x00
 #  define FW_CFG_DATA_OFF 0x01
+#  define FW_CFG_DMA_OFF 0x04
 # else
 #  error "QEMU FW_CFG not available on this architecture!"
 # endif
@@ -133,7 +230,7 @@ static void fw_cfg_io_cleanup(void)
 static int fw_cfg_do_platform_probe(struct platform_device *pdev)
 {
 	char sig[FW_CFG_SIG_SIZE];
-	struct resource *range, *ctrl, *data;
+	struct resource *range, *ctrl, *data, *dma;
 
 	/* acquire i/o range details */
 	fw_cfg_is_mmio = false;
@@ -170,6 +267,7 @@ static int fw_cfg_do_platform_probe(struct platform_device *pdev)
 	/* were custom register offsets provided (e.g. on the command line)? */
 	ctrl = platform_get_resource_byname(pdev, IORESOURCE_REG, "ctrl");
 	data = platform_get_resource_byname(pdev, IORESOURCE_REG, "data");
+	dma = platform_get_resource_byname(pdev, IORESOURCE_REG, "dma");
 	if (ctrl && data) {
 		fw_cfg_reg_ctrl = fw_cfg_dev_base + ctrl->start;
 		fw_cfg_reg_data = fw_cfg_dev_base + data->start;
@@ -179,9 +277,17 @@ static int fw_cfg_do_platform_probe(struct platform_device *pdev)
 		fw_cfg_reg_data = fw_cfg_dev_base + FW_CFG_DATA_OFF;
 	}
 
+	if (dma)
+		fw_cfg_reg_dma = fw_cfg_dev_base + dma->start;
+#ifdef FW_CFG_DMA_OFF
+	else
+		fw_cfg_reg_dma = fw_cfg_dev_base + FW_CFG_DMA_OFF;
+#endif
+
 	/* verify fw_cfg device signature */
-	fw_cfg_read_blob(FW_CFG_SIGNATURE, sig, 0, FW_CFG_SIG_SIZE);
-	if (memcmp(sig, "QEMU", FW_CFG_SIG_SIZE) != 0) {
+	if (fw_cfg_read_blob(FW_CFG_SIGNATURE, sig,
+				0, FW_CFG_SIG_SIZE) < 0 ||
+		memcmp(sig, "QEMU", FW_CFG_SIG_SIZE) != 0) {
 		fw_cfg_io_cleanup();
 		return -ENODEV;
 	}
@@ -189,9 +295,6 @@ static int fw_cfg_do_platform_probe(struct platform_device *pdev)
 	return 0;
 }
 
-/* fw_cfg revision attribute, in /sys/firmware/qemu_fw_cfg top-level dir. */
-static u32 fw_cfg_rev;
-
 static ssize_t fw_cfg_showrev(struct kobject *k, struct attribute *a, char *buf)
 {
 	return sprintf(buf, "%u\n", fw_cfg_rev);
@@ -208,10 +311,38 @@ static const struct {
 /* fw_cfg_sysfs_entry type */
 struct fw_cfg_sysfs_entry {
 	struct kobject kobj;
-	struct fw_cfg_file f;
+	u32 size;
+	u16 select;
+	char name[FW_CFG_MAX_FILE_PATH];
 	struct list_head list;
 };
 
+#ifdef CONFIG_CRASH_CORE
+static ssize_t fw_cfg_write_vmcoreinfo(const struct fw_cfg_file *f)
+{
+	static struct fw_cfg_vmcoreinfo *data;
+	ssize_t ret;
+
+	data = kmalloc(sizeof(struct fw_cfg_vmcoreinfo), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	*data = (struct fw_cfg_vmcoreinfo) {
+		.guest_format = cpu_to_le16(FW_CFG_VMCOREINFO_FORMAT_ELF),
+		.size = cpu_to_le32(VMCOREINFO_NOTE_SIZE),
+		.paddr = cpu_to_le64(paddr_vmcoreinfo_note())
+	};
+	/* spare ourself reading host format support for now since we
+	 * don't know what else to format - host may ignore ours
+	 */
+	ret = fw_cfg_write_blob(be16_to_cpu(f->select), data,
+				0, sizeof(struct fw_cfg_vmcoreinfo));
+
+	kfree(data);
+	return ret;
+}
+#endif /* CONFIG_CRASH_CORE */
+
 /* get fw_cfg_sysfs_entry from kobject member */
 static inline struct fw_cfg_sysfs_entry *to_entry(struct kobject *kobj)
 {
@@ -272,17 +403,17 @@ struct fw_cfg_sysfs_attribute fw_cfg_sysfs_attr_##_attr = { \
 
 static ssize_t fw_cfg_sysfs_show_size(struct fw_cfg_sysfs_entry *e, char *buf)
 {
-	return sprintf(buf, "%u\n", e->f.size);
+	return sprintf(buf, "%u\n", e->size);
 }
 
 static ssize_t fw_cfg_sysfs_show_key(struct fw_cfg_sysfs_entry *e, char *buf)
 {
-	return sprintf(buf, "%u\n", e->f.select);
+	return sprintf(buf, "%u\n", e->select);
 }
 
 static ssize_t fw_cfg_sysfs_show_name(struct fw_cfg_sysfs_entry *e, char *buf)
 {
-	return sprintf(buf, "%s\n", e->f.name);
+	return sprintf(buf, "%s\n", e->name);
 }
 
 static FW_CFG_SYSFS_ATTR(size);
@@ -333,14 +464,13 @@ static ssize_t fw_cfg_sysfs_read_raw(struct file *filp, struct kobject *kobj,
 {
 	struct fw_cfg_sysfs_entry *entry = to_entry(kobj);
 
-	if (pos > entry->f.size)
+	if (pos > entry->size)
 		return -EINVAL;
 
-	if (count > entry->f.size - pos)
-		count = entry->f.size - pos;
+	if (count > entry->size - pos)
+		count = entry->size - pos;
 
-	fw_cfg_read_blob(entry->f.select, buf, pos, count);
-	return count;
+	return fw_cfg_read_blob(entry->select, buf, pos, count);
 }
 
 static struct bin_attribute fw_cfg_sysfs_attr_raw = {
@@ -452,17 +582,28 @@ static int fw_cfg_register_file(const struct fw_cfg_file *f)
 	int err;
 	struct fw_cfg_sysfs_entry *entry;
 
+#ifdef CONFIG_CRASH_CORE
+	if (fw_cfg_dma_enabled() &&
+		strcmp(f->name, FW_CFG_VMCOREINFO_FILENAME) == 0 &&
+		!is_kdump_kernel()) {
+		if (fw_cfg_write_vmcoreinfo(f) < 0)
+			pr_warn("fw_cfg: failed to write vmcoreinfo");
+	}
+#endif
+
 	/* allocate new entry */
 	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 	if (!entry)
 		return -ENOMEM;
 
 	/* set file entry information */
-	memcpy(&entry->f, f, sizeof(struct fw_cfg_file));
+	entry->size = be32_to_cpu(f->size);
+	entry->select = be16_to_cpu(f->select);
+	memcpy(entry->name, f->name, FW_CFG_MAX_FILE_PATH);
 
 	/* register entry under "/sys/firmware/qemu_fw_cfg/by_key/" */
 	err = kobject_init_and_add(&entry->kobj, &fw_cfg_sysfs_entry_ktype,
-				   fw_cfg_sel_ko, "%d", entry->f.select);
+				   fw_cfg_sel_ko, "%d", entry->select);
 	if (err)
 		goto err_register;
 
@@ -472,7 +613,7 @@ static int fw_cfg_register_file(const struct fw_cfg_file *f)
 		goto err_add_raw;
 
 	/* try adding "/sys/firmware/qemu_fw_cfg/by_name/" symlink */
-	fw_cfg_build_symlink(fw_cfg_fname_kset, &entry->kobj, entry->f.name);
+	fw_cfg_build_symlink(fw_cfg_fname_kset, &entry->kobj, entry->name);
 
 	/* success, add entry to global cache */
 	fw_cfg_sysfs_cache_enlist(entry);
@@ -489,28 +630,35 @@ err_register:
 static int fw_cfg_register_dir_entries(void)
 {
 	int ret = 0;
+	__be32 files_count;
 	u32 count, i;
 	struct fw_cfg_file *dir;
 	size_t dir_size;
 
-	fw_cfg_read_blob(FW_CFG_FILE_DIR, &count, 0, sizeof(count));
-	count = be32_to_cpu(count);
+	ret = fw_cfg_read_blob(FW_CFG_FILE_DIR, &files_count,
+			0, sizeof(files_count));
+	if (ret < 0)
+		return ret;
+
+	count = be32_to_cpu(files_count);
 	dir_size = count * sizeof(struct fw_cfg_file);
 
 	dir = kmalloc(dir_size, GFP_KERNEL);
 	if (!dir)
 		return -ENOMEM;
 
-	fw_cfg_read_blob(FW_CFG_FILE_DIR, dir, sizeof(count), dir_size);
+	ret = fw_cfg_read_blob(FW_CFG_FILE_DIR, dir,
+			sizeof(files_count), dir_size);
+	if (ret < 0)
+		goto end;
 
 	for (i = 0; i < count; i++) {
-		dir[i].size = be32_to_cpu(dir[i].size);
-		dir[i].select = be16_to_cpu(dir[i].select);
 		ret = fw_cfg_register_file(&dir[i]);
 		if (ret)
 			break;
 	}
 
+end:
 	kfree(dir);
 	return ret;
 }
@@ -525,6 +673,7 @@ static inline void fw_cfg_kobj_cleanup(struct kobject *kobj)
 static int fw_cfg_sysfs_probe(struct platform_device *pdev)
 {
 	int err;
+	__le32 rev;
 
 	/* NOTE: If we supported multiple fw_cfg devices, we'd first create
 	 * a subdirectory named after e.g. pdev->id, then hang per-device
@@ -550,8 +699,11 @@ static int fw_cfg_sysfs_probe(struct platform_device *pdev)
 		goto err_probe;
 
 	/* get revision number, add matching top-level attribute */
-	fw_cfg_read_blob(FW_CFG_ID, &fw_cfg_rev, 0, sizeof(fw_cfg_rev));
-	fw_cfg_rev = le32_to_cpu(fw_cfg_rev);
+	err = fw_cfg_read_blob(FW_CFG_ID, &rev, 0, sizeof(rev));
+	if (err < 0)
+		goto err_probe;
+
+	fw_cfg_rev = le32_to_cpu(rev);
 	err = sysfs_create_file(fw_cfg_top_ko, &fw_cfg_rev_attr.attr);
 	if (err)
 		goto err_rev;
@@ -597,7 +749,7 @@ MODULE_DEVICE_TABLE(of, fw_cfg_sysfs_mmio_match);
 
 #ifdef CONFIG_ACPI
 static const struct acpi_device_id fw_cfg_sysfs_acpi_match[] = {
-	{ "QEMU0002", },
+	{ FW_CFG_ACPI_DEVICE_ID, },
 	{},
 };
 MODULE_DEVICE_TABLE(acpi, fw_cfg_sysfs_acpi_match);
@@ -629,6 +781,7 @@ static struct platform_device *fw_cfg_cmdline_dev;
 /* use special scanf/printf modifier for phys_addr_t, resource_size_t */
 #define PH_ADDR_SCAN_FMT "@%" __PHYS_ADDR_PREFIX "i%n" \
 			 ":%" __PHYS_ADDR_PREFIX "i" \
+			 ":%" __PHYS_ADDR_PREFIX "i%n" \
 			 ":%" __PHYS_ADDR_PREFIX "i%n"
 
 #define PH_ADDR_PR_1_FMT "0x%" __PHYS_ADDR_PREFIX "x@" \
@@ -638,12 +791,15 @@ static struct platform_device *fw_cfg_cmdline_dev;
 			 ":%" __PHYS_ADDR_PREFIX "u" \
 			 ":%" __PHYS_ADDR_PREFIX "u"
 
+#define PH_ADDR_PR_4_FMT PH_ADDR_PR_3_FMT \
+			 ":%" __PHYS_ADDR_PREFIX "u"
+
 static int fw_cfg_cmdline_set(const char *arg, const struct kernel_param *kp)
 {
-	struct resource res[3] = {};
+	struct resource res[4] = {};
 	char *str;
 	phys_addr_t base;
-	resource_size_t size, ctrl_off, data_off;
+	resource_size_t size, ctrl_off, data_off, dma_off;
 	int processed, consumed = 0;
 
 	/* only one fw_cfg device can exist system-wide, so if one
@@ -659,19 +815,20 @@ static int fw_cfg_cmdline_set(const char *arg, const struct kernel_param *kp)
 	/* consume "<size>" portion of command line argument */
 	size = memparse(arg, &str);
 
-	/* get "@<base>[:<ctrl_off>:<data_off>]" chunks */
+	/* get "@<base>[:<ctrl_off>:<data_off>[:<dma_off>]]" chunks */
 	processed = sscanf(str, PH_ADDR_SCAN_FMT,
 			   &base, &consumed,
-			   &ctrl_off, &data_off, &consumed);
+			   &ctrl_off, &data_off, &consumed,
+			   &dma_off, &consumed);
 
-	/* sscanf() must process precisely 1 or 3 chunks:
+	/* sscanf() must process precisely 1, 3 or 4 chunks:
 	 * <base> is mandatory, optionally followed by <ctrl_off>
-	 * and <data_off>;
+	 * and <data_off>, and <dma_off>;
 	 * there must be no extra characters after the last chunk,
 	 * so str[consumed] must be '\0'.
 	 */
 	if (str[consumed] ||
-	    (processed != 1 && processed != 3))
+	    (processed != 1 && processed != 3 && processed != 4))
 		return -EINVAL;
 
 	res[0].start = base;
@@ -688,6 +845,11 @@ static int fw_cfg_cmdline_set(const char *arg, const struct kernel_param *kp)
 		res[2].start = data_off;
 		res[2].flags = IORESOURCE_REG;
 	}
+	if (processed > 3) {
+		res[3].name = "dma";
+		res[3].start = dma_off;
+		res[3].flags = IORESOURCE_REG;
+	}
 
 	/* "processed" happens to nicely match the number of resources
 	 * we need to pass in to this platform device.
@@ -720,6 +882,13 @@ static int fw_cfg_cmdline_get(char *buf, const struct kernel_param *kp)
 				fw_cfg_cmdline_dev->resource[0].start,
 				fw_cfg_cmdline_dev->resource[1].start,
 				fw_cfg_cmdline_dev->resource[2].start);
+	case 4:
+		return snprintf(buf, PAGE_SIZE, PH_ADDR_PR_4_FMT,
+				resource_size(&fw_cfg_cmdline_dev->resource[0]),
+				fw_cfg_cmdline_dev->resource[0].start,
+				fw_cfg_cmdline_dev->resource[1].start,
+				fw_cfg_cmdline_dev->resource[2].start,
+				fw_cfg_cmdline_dev->resource[3].start);
 	}
 
 	/* Should never get here */
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 5320039671b7..bec722e41f58 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -1334,7 +1334,7 @@ err:
 	return -EFAULT;
 }
 
-long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp)
+long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp)
 {
 	struct file *eventfp, *filep = NULL;
 	bool pollstart = false, pollstop = false;
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index ac4b6056f19a..d8ee85ae8fdc 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -45,7 +45,7 @@ void vhost_poll_stop(struct vhost_poll *poll);
 void vhost_poll_flush(struct vhost_poll *poll);
 void vhost_poll_queue(struct vhost_poll *poll);
 void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work);
-long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp);
+long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp);
 
 struct vhost_log {
 	u64 addr;
@@ -177,7 +177,7 @@ void vhost_dev_reset_owner(struct vhost_dev *, struct vhost_umem *);
 void vhost_dev_cleanup(struct vhost_dev *);
 void vhost_dev_stop(struct vhost_dev *);
 long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp);
-long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp);
+long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp);
 int vhost_vq_access_ok(struct vhost_virtqueue *vq);
 int vhost_log_access_ok(struct vhost_dev *);
 
diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
index 0898dbdbf955..34bc3ab40c6d 100644
--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -699,12 +699,23 @@ static long vhost_vsock_dev_ioctl(struct file *f, unsigned int ioctl,
 	}
 }
 
+#ifdef CONFIG_COMPAT
+static long vhost_vsock_dev_compat_ioctl(struct file *f, unsigned int ioctl,
+					 unsigned long arg)
+{
+	return vhost_vsock_dev_ioctl(f, ioctl, (unsigned long)compat_ptr(arg));
+}
+#endif
+
 static const struct file_operations vhost_vsock_fops = {
 	.owner          = THIS_MODULE,
 	.open           = vhost_vsock_dev_open,
 	.release        = vhost_vsock_dev_release,
 	.llseek		= noop_llseek,
 	.unlocked_ioctl = vhost_vsock_dev_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl   = vhost_vsock_dev_compat_ioctl,
+#endif
 };
 
 static struct miscdevice vhost_vsock_misc = {
diff --git a/include/uapi/linux/qemu_fw_cfg.h b/include/uapi/linux/qemu_fw_cfg.h
new file mode 100644
index 000000000000..e089c0159ec2
--- /dev/null
+++ b/include/uapi/linux/qemu_fw_cfg.h
@@ -0,0 +1,97 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+#ifndef _LINUX_FW_CFG_H
+#define _LINUX_FW_CFG_H
+
+#include <linux/types.h>
+
+#define FW_CFG_ACPI_DEVICE_ID	"QEMU0002"
+
+/* selector key values for "well-known" fw_cfg entries */
+#define FW_CFG_SIGNATURE	0x00
+#define FW_CFG_ID		0x01
+#define FW_CFG_UUID		0x02
+#define FW_CFG_RAM_SIZE		0x03
+#define FW_CFG_NOGRAPHIC	0x04
+#define FW_CFG_NB_CPUS		0x05
+#define FW_CFG_MACHINE_ID	0x06
+#define FW_CFG_KERNEL_ADDR	0x07
+#define FW_CFG_KERNEL_SIZE	0x08
+#define FW_CFG_KERNEL_CMDLINE	0x09
+#define FW_CFG_INITRD_ADDR	0x0a
+#define FW_CFG_INITRD_SIZE	0x0b
+#define FW_CFG_BOOT_DEVICE	0x0c
+#define FW_CFG_NUMA		0x0d
+#define FW_CFG_BOOT_MENU	0x0e
+#define FW_CFG_MAX_CPUS		0x0f
+#define FW_CFG_KERNEL_ENTRY	0x10
+#define FW_CFG_KERNEL_DATA	0x11
+#define FW_CFG_INITRD_DATA	0x12
+#define FW_CFG_CMDLINE_ADDR	0x13
+#define FW_CFG_CMDLINE_SIZE	0x14
+#define FW_CFG_CMDLINE_DATA	0x15
+#define FW_CFG_SETUP_ADDR	0x16
+#define FW_CFG_SETUP_SIZE	0x17
+#define FW_CFG_SETUP_DATA	0x18
+#define FW_CFG_FILE_DIR		0x19
+
+#define FW_CFG_FILE_FIRST	0x20
+#define FW_CFG_FILE_SLOTS_MIN	0x10
+
+#define FW_CFG_WRITE_CHANNEL	0x4000
+#define FW_CFG_ARCH_LOCAL	0x8000
+#define FW_CFG_ENTRY_MASK	(~(FW_CFG_WRITE_CHANNEL | FW_CFG_ARCH_LOCAL))
+
+#define FW_CFG_INVALID		0xffff
+
+/* width in bytes of fw_cfg control register */
+#define FW_CFG_CTL_SIZE		0x02
+
+/* fw_cfg "file name" is up to 56 characters (including terminating nul) */
+#define FW_CFG_MAX_FILE_PATH	56
+
+/* size in bytes of fw_cfg signature */
+#define FW_CFG_SIG_SIZE 4
+
+/* FW_CFG_ID bits */
+#define FW_CFG_VERSION		0x01
+#define FW_CFG_VERSION_DMA	0x02
+
+/* fw_cfg file directory entry type */
+struct fw_cfg_file {
+	__be32 size;
+	__be16 select;
+	__u16 reserved;
+	char name[FW_CFG_MAX_FILE_PATH];
+};
+
+/* FW_CFG_DMA_CONTROL bits */
+#define FW_CFG_DMA_CTL_ERROR	0x01
+#define FW_CFG_DMA_CTL_READ	0x02
+#define FW_CFG_DMA_CTL_SKIP	0x04
+#define FW_CFG_DMA_CTL_SELECT	0x08
+#define FW_CFG_DMA_CTL_WRITE	0x10
+
+#define FW_CFG_DMA_SIGNATURE    0x51454d5520434647ULL /* "QEMU CFG" */
+
+/* Control as first field allows for different structures selected by this
+ * field, which might be useful in the future
+ */
+struct fw_cfg_dma_access {
+	__be32 control;
+	__be32 length;
+	__be64 address;
+};
+
+#define FW_CFG_VMCOREINFO_FILENAME "etc/vmcoreinfo"
+
+#define FW_CFG_VMCOREINFO_FORMAT_NONE 0x0
+#define FW_CFG_VMCOREINFO_FORMAT_ELF 0x1
+
+struct fw_cfg_vmcoreinfo {
+	__le16 host_format;
+	__le16 guest_format;
+	__le32 size;
+	__le64 paddr;
+};
+
+#endif
diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index 4f63597c824d..a93590cdd9e1 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c
@@ -376,6 +376,7 @@ phys_addr_t __weak paddr_vmcoreinfo_note(void)
 {
 	return __pa(vmcoreinfo_note);
 }
+EXPORT_SYMBOL(paddr_vmcoreinfo_note);
 
 static int __init crash_save_vmcoreinfo_init(void)
 {
diff --git a/tools/virtio/ringtest/ptr_ring.c b/tools/virtio/ringtest/ptr_ring.c
index 477899c12c51..2d566fbd236b 100644
--- a/tools/virtio/ringtest/ptr_ring.c
+++ b/tools/virtio/ringtest/ptr_ring.c
@@ -17,6 +17,8 @@
 #define likely(x)    (__builtin_expect(!!(x), 1))
 #define ALIGN(x, a) (((x) + (a) - 1) / (a) * (a))
 #define SIZE_MAX        (~(size_t)0)
+#define KMALLOC_MAX_SIZE SIZE_MAX
+#define BUG_ON(x) assert(x)
 
 typedef pthread_spinlock_t  spinlock_t;
 
@@ -57,6 +59,9 @@ static void kfree(void *p)
 		free(p);
 }
 
+#define kvmalloc_array kmalloc_array
+#define kvfree kfree
+
 static void spin_lock_init(spinlock_t *lock)
 {
 	int r = pthread_spin_init(lock, 0);