[PATCH v2 02/10] kvm tools: Remove the non-iov interface from disk image ops

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Signed-off-by: Sasha Levin <levinsasha928@xxxxxxxxx>
---
 tools/kvm/disk/core.c              |   48 ++++++----------------------------
 tools/kvm/disk/qcow.c              |   47 +++++++++++++++++++++++++++++++--
 tools/kvm/disk/raw.c               |   50 +++++++++++++++++++++---------------
 tools/kvm/include/kvm/disk-image.h |   26 +++++++-----------
 4 files changed, 91 insertions(+), 80 deletions(-)

diff --git a/tools/kvm/disk/core.c b/tools/kvm/disk/core.c
index 20e1990..78495cc 100644
--- a/tools/kvm/disk/core.c
+++ b/tools/kvm/disk/core.c
@@ -134,36 +134,19 @@ void disk_image__close_all(struct disk_image **disks, int count)
 ssize_t disk_image__read(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount)
 {
 	ssize_t total = 0;
-	ssize_t nr;
 
 	if (debug_iodelay)
 		msleep(debug_iodelay);
 
-	if (disk->ops->read_sector_iov) {
-		/*
-		 * Try mulitple buffer based operation first
-		 */
-		total		= disk->ops->read_sector_iov(disk, sector, iov, iovcount);
+	if (disk->ops->read_sector) {
+		total = disk->ops->read_sector(disk, sector, iov, iovcount);
 		if (total < 0) {
 			pr_info("disk_image__read error: total=%ld\n", (long)total);
 			return -1;
 		}
-	} else if (disk->ops->read_sector) {
-		/*
-		 * Fallback to single buffer based operation
-		 */
-		while (iovcount--) {
-			nr 	= disk->ops->read_sector(disk, sector, iov->iov_base, iov->iov_len);
-			if (nr != (ssize_t)iov->iov_len) {
-				pr_info("disk_image__read error: nr = %ld iov_len=%ld\n", (long)nr, (long)iov->iov_len);
-				return -1;
-			}
-			sector	+= iov->iov_len >> SECTOR_SHIFT;
-			iov++;
-			total 	+= nr;
-		}
-	} else
+	} else {
 		die("No disk image operation for read\n");
+	}
 
 	return total;
 }
@@ -175,37 +158,22 @@ ssize_t disk_image__read(struct disk_image *disk, u64 sector, const struct iovec
 ssize_t disk_image__write(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount)
 {
 	ssize_t total = 0;
-	ssize_t nr;
 
 	if (debug_iodelay)
 		msleep(debug_iodelay);
 
-	if (disk->ops->write_sector_iov) {
+	if (disk->ops->write_sector) {
 		/*
 		 * Try writev based operation first
 		 */
-		total = disk->ops->write_sector_iov(disk, sector, iov, iovcount);
+		total = disk->ops->write_sector(disk, sector, iov, iovcount);
 		if (total < 0) {
 			pr_info("disk_image__write error: total=%ld\n", (long)total);
 			return -1;
 		}
-	} else if (disk->ops->write_sector) {
-		/*
-		 * Fallback to single buffer based operation
-		 */
-		while (iovcount--) {
-			nr	 = disk->ops->write_sector(disk, sector, iov->iov_base, iov->iov_len);
-			if (nr != (ssize_t)iov->iov_len) {
-				pr_info("disk_image__write error: nr=%ld iov_len=%ld\n", (long)nr, (long)iov->iov_len);
-				return -1;
-			}
-
-			sector	+= iov->iov_len >> SECTOR_SHIFT;
-			iov++;
-			total	+= nr;
-		}
-	} else
+	} else {
 		die("No disk image operation for read\n");
+	}
 
 	return total;
 }
diff --git a/tools/kvm/disk/qcow.c b/tools/kvm/disk/qcow.c
index bdf6bd8..288782e 100644
--- a/tools/kvm/disk/qcow.c
+++ b/tools/kvm/disk/qcow.c
@@ -452,7 +452,7 @@ out_error:
 	return -1;
 }
 
-static ssize_t qcow_read_sector(struct disk_image *disk, u64 sector,
+static ssize_t qcow_read_sector_single(struct disk_image *disk, u64 sector,
 	void *dst, u32 dst_len)
 {
 	struct qcow *q = disk->priv;
@@ -488,6 +488,26 @@ static ssize_t qcow_read_sector(struct disk_image *disk, u64 sector,
 	return dst_len;
 }
 
+static ssize_t qcow_read_sector(struct disk_image *disk, u64 sector,
+				const struct iovec *iov, int iovcount)
+{
+	ssize_t nr, total = 0;
+
+	while (iovcount--) {
+		nr = qcow_read_sector_single(disk, sector, iov->iov_base, iov->iov_len);
+		if (nr != (ssize_t)iov->iov_len) {
+			pr_info("qcow_read_sector error: nr=%ld iov_len=%ld\n", (long)nr, (long)iov->iov_len);
+			return -1;
+		}
+
+		sector	+= iov->iov_len >> SECTOR_SHIFT;
+		iov++;
+		total	+= nr;
+	}
+
+	return total;
+}
+
 static inline u64 file_size(int fd)
 {
 	struct stat st;
@@ -867,7 +887,7 @@ error:
 	return -1;
 }
 
-static ssize_t qcow_write_sector(struct disk_image *disk, u64 sector, void *src, u32 src_len)
+static ssize_t qcow_write_sector_single(struct disk_image *disk, u64 sector, void *src, u32 src_len)
 {
 	struct qcow *q = disk->priv;
 	struct qcow_header *header = q->header;
@@ -896,7 +916,28 @@ static ssize_t qcow_write_sector(struct disk_image *disk, u64 sector, void *src,
 	return nr_written;
 }
 
-static ssize_t qcow_nowrite_sector(struct disk_image *disk, u64 sector, void *src, u32 src_len)
+static ssize_t qcow_write_sector(struct disk_image *disk, u64 sector,
+				const struct iovec *iov, int iovcount)
+{
+	ssize_t nr, total = 0;
+
+	while (iovcount--) {
+		nr = qcow_write_sector_single(disk, sector, iov->iov_base, iov->iov_len);
+		if (nr != (ssize_t)iov->iov_len) {
+			pr_info("qcow_write_sector error: nr=%ld iov_len=%ld\n", (long)nr, (long)iov->iov_len);
+			return -1;
+		}
+
+		sector	+= iov->iov_len >> SECTOR_SHIFT;
+		iov++;
+		total	+= nr;
+	}
+
+	return total;
+}
+
+static ssize_t qcow_nowrite_sector(struct disk_image *disk, u64 sector,
+				const struct iovec *iov, int iovcount)
 {
 	/* I/O error */
 	pr_info("%s: no write support\n", __func__);
diff --git a/tools/kvm/disk/raw.c b/tools/kvm/disk/raw.c
index 66c52be..1c6a985 100644
--- a/tools/kvm/disk/raw.c
+++ b/tools/kvm/disk/raw.c
@@ -1,41 +1,49 @@
 #include "kvm/disk-image.h"
 
-ssize_t raw_image__read_sector_iov(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount)
+ssize_t raw_image__read_sector(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount)
 {
 	u64 offset = sector << SECTOR_SHIFT;
 
 	return preadv_in_full(disk->fd, iov, iovcount, offset);
 }
 
-ssize_t raw_image__write_sector_iov(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount)
+ssize_t raw_image__write_sector(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount)
 {
 	u64 offset = sector << SECTOR_SHIFT;
 
 	return pwritev_in_full(disk->fd, iov, iovcount, offset);
 }
 
-ssize_t raw_image__read_sector(struct disk_image *disk, u64 sector, void *dst, u32 dst_len)
+ssize_t raw_image__read_sector_mmap(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount)
 {
 	u64 offset = sector << SECTOR_SHIFT;
+	ssize_t nr, total = 0;
 
-	if (offset + dst_len > disk->size)
-		return -1;
+	while (iovcount--) {
+		memcpy(iov->iov_base, disk->priv + offset, iov->iov_len);
 
-	memcpy(dst, disk->priv + offset, dst_len);
+		sector	+= iov->iov_len >> SECTOR_SHIFT;
+		iov++;
+		total	+= nr;
+	}
 
-	return dst_len;
+	return total;
 }
 
-ssize_t raw_image__write_sector(struct disk_image *disk, u64 sector, void *src, u32 src_len)
+ssize_t raw_image__write_sector_mmap(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount)
 {
 	u64 offset = sector << SECTOR_SHIFT;
+	ssize_t nr, total = 0;
 
-	if (offset + src_len > disk->size)
-		return -1;
+	while (iovcount--) {
+		memcpy(disk->priv + offset, iov->iov_base, iov->iov_len);
 
-	memcpy(disk->priv + offset, src, src_len);
+		sector	+= iov->iov_len >> SECTOR_SHIFT;
+		iov++;
+		total	+= nr;
+	}
 
-	return src_len;
+	return total;
 }
 
 int raw_image__close(struct disk_image *disk)
@@ -51,17 +59,17 @@ int raw_image__close(struct disk_image *disk)
 /*
  * multiple buffer based disk image operations
  */
-static struct disk_image_operations raw_image_iov_ops = {
-	.read_sector_iov	= raw_image__read_sector_iov,
-	.write_sector_iov	= raw_image__write_sector_iov,
+static struct disk_image_operations raw_image_regular_ops = {
+	.read_sector		= raw_image__read_sector,
+	.write_sector		= raw_image__write_sector,
 };
 
 /*
- * single buffer based disk image operations
+ * mmap() based disk image operations
  */
-static struct disk_image_operations raw_image_ops = {
-	.read_sector		= raw_image__read_sector,
-	.write_sector		= raw_image__write_sector,
+static struct disk_image_operations raw_image_mmap_ops = {
+	.read_sector		= raw_image__read_sector_mmap,
+	.write_sector		= raw_image__write_sector_mmap,
 	.close			= raw_image__close,
 };
 
@@ -73,10 +81,10 @@ struct disk_image *raw_image__probe(int fd, struct stat *st, bool readonly)
 		 * Use mmap's MAP_PRIVATE to implement non-persistent write
 		 * FIXME: This does not work on 32-bit host.
 		 */
-		return disk_image__new(fd, st->st_size, &raw_image_ops, DISK_IMAGE_MMAP);
+		return disk_image__new(fd, st->st_size, &raw_image_mmap_ops, DISK_IMAGE_MMAP);
 	else
 		/*
 		 * Use read/write instead of mmap
 		 */
-		return disk_image__new(fd, st->st_size, &raw_image_iov_ops, DISK_IMAGE_REGULAR);
+		return disk_image__new(fd, st->st_size, &raw_image_regular_ops, DISK_IMAGE_REGULAR);
 }
diff --git a/tools/kvm/include/kvm/disk-image.h b/tools/kvm/include/kvm/disk-image.h
index 6acde53..6a6ae6f 100644
--- a/tools/kvm/include/kvm/disk-image.h
+++ b/tools/kvm/include/kvm/disk-image.h
@@ -31,18 +31,8 @@ enum {
 struct disk_image;
 
 struct disk_image_operations {
-	/*
-	 * The following two are used for reading or writing with a single buffer.
-	 * The implentation can use readv/writev or memcpy.
-	 */
-	ssize_t (*read_sector)(struct disk_image *disk, u64 sector, void *dst, u32 dst_len);
-	ssize_t (*write_sector)(struct disk_image *disk, u64 sector, void *src, u32 src_len);
-	/*
-	 * The following two are used for reading or writing with multiple buffers.
-	 * The implentation can use readv/writev or memcpy.
-	 */
-	ssize_t (*read_sector_iov)(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount);
-	ssize_t (*write_sector_iov)(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount);
+	ssize_t (*read_sector)(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount);
+	ssize_t (*write_sector)(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount);
 	int (*flush)(struct disk_image *disk);
 	int (*close)(struct disk_image *disk);
 };
@@ -67,10 +57,14 @@ ssize_t disk_image__get_serial(struct disk_image *disk, void *buffer, ssize_t *l
 struct disk_image *raw_image__probe(int fd, struct stat *st, bool readonly);
 struct disk_image *blkdev__probe(const char *filename, struct stat *st);
 
-ssize_t raw_image__read_sector_iov(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount);
-ssize_t raw_image__write_sector_iov(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount);
-ssize_t raw_image__read_sector(struct disk_image *disk, u64 sector, void *dst, u32 dst_len);
-ssize_t raw_image__write_sector(struct disk_image *disk, u64 sector, void *src, u32 src_len);
+ssize_t raw_image__read_sector(struct disk_image *disk, u64 sector,
+				const struct iovec *iov, int iovcount);
+ssize_t raw_image__write_sector(struct disk_image *disk, u64 sector,
+				const struct iovec *iov, int iovcount);
+ssize_t raw_image__read_sector_mmap(struct disk_image *disk, u64 sector,
+				const struct iovec *iov, int iovcount);
+ssize_t raw_image__write_sector_mmap(struct disk_image *disk, u64 sector,
+				const struct iovec *iov, int iovcount);
 int raw_image__close(struct disk_image *disk);
 
 #endif /* KVM__DISK_IMAGE_H */
-- 
1.7.7.1

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