kvm tools: Add optional callback on disk op completion

This patch adds an optional callback to be called when a disk op completes.

Currently theres not much use for it, but it is the infrastructure for adding
aio support.

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

diff --git a/tools/kvm/disk/core.c b/tools/kvm/disk/core.c
index 4f51cbef06fba72a399c4de61f9f62cd924cb94b..c1cb52f0b690777ece2bf25f195a1136a053261a 100644 (file)
--- a/tools/kvm/disk/core.c
+++ b/tools/kvm/disk/core.c
@@ -133,7 +133,8 @@ void disk_image__close_all(struct disk_image **disks, int count)
  * Fill iov with disk data, starting from sector 'sector'.
  * Return amount of bytes read.
  */
-ssize_t disk_image__read(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount)
+ssize_t disk_image__read(struct disk_image *disk, u64 sector, const struct iovec *iov,
+                               int iovcount, void *param)
 {
        ssize_t total = 0;
 
@@ -141,7 +142,7 @@ ssize_t disk_image__read(struct disk_image *disk, u64 sector, const struct iovec
                msleep(debug_iodelay);
 
        if (disk->ops->read_sector) {
-               total = disk->ops->read_sector(disk, sector, iov, iovcount);
+               total = disk->ops->read_sector(disk, sector, iov, iovcount, param);
                if (total < 0) {
                        pr_info("disk_image__read error: total=%ld\n", (long)total);
                        return -1;
@@ -150,6 +151,9 @@ ssize_t disk_image__read(struct disk_image *disk, u64 sector, const struct iovec
                /* Do nothing */
        }
 
+       if (disk->disk_req_cb)
+               disk->disk_req_cb(param);
+
        return total;
 }
 
@@ -157,7 +161,8 @@ ssize_t disk_image__read(struct disk_image *disk, u64 sector, const struct iovec
  * Write iov to disk, starting from sector 'sector'.
  * Return amount of bytes written.
  */
-ssize_t disk_image__write(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount)
+ssize_t disk_image__write(struct disk_image *disk, u64 sector, const struct iovec *iov,
+                               int iovcount, void *param)
 {
        ssize_t total = 0;
 
@@ -168,7 +173,8 @@ ssize_t disk_image__write(struct disk_image *disk, u64 sector, const struct iove
                /*
                 * Try writev based operation first
                 */
-               total = disk->ops->write_sector(disk, sector, iov, iovcount);
+
+               total = disk->ops->write_sector(disk, sector, iov, iovcount, param);
                if (total < 0) {
                        pr_info("disk_image__write error: total=%ld\n", (long)total);
                        return -1;
@@ -177,6 +183,9 @@ ssize_t disk_image__write(struct disk_image *disk, u64 sector, const struct iove
                /* Do nothing */
        }
 
+       if (disk->disk_req_cb)
+               disk->disk_req_cb(param);
+
        return total;
 }
 
@@ -190,3 +199,8 @@ ssize_t disk_image__get_serial(struct disk_image *disk, void *buffer, ssize_t *l
        *len = snprintf(buffer, *len, "%llu%llu%llu", (u64)st.st_dev, (u64)st.st_rdev, (u64)st.st_ino);
        return *len;
 }
+
+void disk_image__set_callback(struct disk_image *disk, void (*disk_req_cb)(void *param))
+{
+       disk->disk_req_cb = disk_req_cb;
+}

diff --git a/tools/kvm/disk/qcow.c b/tools/kvm/disk/qcow.c
index 288782e3e66d41ad939e743357e573cf863e94b1..ba65ab61a1b86735d03160965cdb0624d4cc8f8a 100644 (file)
--- a/tools/kvm/disk/qcow.c
+++ b/tools/kvm/disk/qcow.c
@@ -489,7 +489,7 @@ static ssize_t qcow_read_sector_single(struct disk_image *disk, u64 sector,
 }
 
 static ssize_t qcow_read_sector(struct disk_image *disk, u64 sector,
-                               const struct iovec *iov, int iovcount)
+                               const struct iovec *iov, int iovcount, void *param)
 {
        ssize_t nr, total = 0;
 
@@ -917,7 +917,7 @@ static ssize_t qcow_write_sector_single(struct disk_image *disk, u64 sector, voi
 }
 
 static ssize_t qcow_write_sector(struct disk_image *disk, u64 sector,
-                               const struct iovec *iov, int iovcount)
+                               const struct iovec *iov, int iovcount, void *param)
 {
        ssize_t nr, total = 0;
 
@@ -937,7 +937,7 @@ static ssize_t qcow_write_sector(struct disk_image *disk, u64 sector,
 }
 
 static ssize_t qcow_nowrite_sector(struct disk_image *disk, u64 sector,
-                               const struct iovec *iov, int iovcount)
+                               const struct iovec *iov, int iovcount, void *param)
 {
        /* 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 7255eb4477eb73fc7f3455fb4e0e7379a63f883a..51e83186267d8f3f87b8536bec69268e99f574e1 100644 (file)
--- a/tools/kvm/disk/raw.c
+++ b/tools/kvm/disk/raw.c
@@ -1,20 +1,23 @@
 #include "kvm/disk-image.h"
 
-ssize_t raw_image__read_sector(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, void *param)
 {
        u64 offset = sector << SECTOR_SHIFT;
 
        return preadv_in_full(disk->fd, iov, iovcount, offset);
 }
 
-ssize_t raw_image__write_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, void *param)
 {
        u64 offset = sector << SECTOR_SHIFT;
 
        return pwritev_in_full(disk->fd, iov, iovcount, offset);
 }
 
-ssize_t raw_image__read_sector_mmap(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, void *param)
 {
        u64 offset = sector << SECTOR_SHIFT;
        ssize_t total = 0;
@@ -31,7 +34,8 @@ ssize_t raw_image__read_sector_mmap(struct disk_image *disk, u64 sector, const s
        return total;
 }
 
-ssize_t raw_image__write_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, void *param)
 {
        u64 offset = sector << SECTOR_SHIFT;
        ssize_t total = 0;

diff --git a/tools/kvm/include/kvm/disk-image.h b/tools/kvm/include/kvm/disk-image.h
index 6a6ae6f2560d671919fdc26e42680f03ef77bbd9..f22213fa21e8778a59715bf777f0d423ee5d0844 100644 (file)
--- a/tools/kvm/include/kvm/disk-image.h
+++ b/tools/kvm/include/kvm/disk-image.h
@@ -31,8 +31,10 @@ enum {
 struct disk_image;
 
 struct disk_image_operations {
-       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);
+       ssize_t (*read_sector)(struct disk_image *disk, u64 sector, const struct iovec *iov,
+                               int iovcount, void *param);
+       ssize_t (*write_sector)(struct disk_image *disk, u64 sector, const struct iovec *iov,
+                               int iovcount, void *param);
        int (*flush)(struct disk_image *disk);
        int (*close)(struct disk_image *disk);
 };
@@ -42,6 +44,8 @@ struct disk_image {
        u64                             size;
        struct disk_image_operations    *ops;
        void                            *priv;
+       void                            *disk_req_cb_param;
+       void                            (*disk_req_cb)(void *param);
 };
 
 struct disk_image *disk_image__open(const char *filename, bool readonly);
@@ -50,21 +54,23 @@ struct disk_image *disk_image__new(int fd, u64 size, struct disk_image_operation
 int disk_image__close(struct disk_image *disk);
 void disk_image__close_all(struct disk_image **disks, int count);
 int disk_image__flush(struct disk_image *disk);
-ssize_t disk_image__read(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount);
-ssize_t disk_image__write(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount);
+ssize_t disk_image__read(struct disk_image *disk, u64 sector, const struct iovec *iov,
+                               int iovcount, void *param);
+ssize_t disk_image__write(struct disk_image *disk, u64 sector, const struct iovec *iov,
+                               int iovcount, void *param);
 ssize_t disk_image__get_serial(struct disk_image *disk, void *buffer, ssize_t *len);
 
 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(struct disk_image *disk, u64 sector,
-                               const struct iovec *iov, int iovcount);
+                               const struct iovec *iov, int iovcount, void *param);
 ssize_t raw_image__write_sector(struct disk_image *disk, u64 sector,
-                               const struct iovec *iov, int iovcount);
+                               const struct iovec *iov, int iovcount, void *param);
 ssize_t raw_image__read_sector_mmap(struct disk_image *disk, u64 sector,
-                               const struct iovec *iov, int iovcount);
+                               const struct iovec *iov, int iovcount, void *param);
 ssize_t raw_image__write_sector_mmap(struct disk_image *disk, u64 sector,
-                               const struct iovec *iov, int iovcount);
+                               const struct iovec *iov, int iovcount, void *param);
 int raw_image__close(struct disk_image *disk);
-
+void disk_image__set_callback(struct disk_image *disk, void (*disk_req_cb)(void *param));
 #endif /* KVM__DISK_IMAGE_H */

diff --git a/tools/kvm/virtio/blk.c b/tools/kvm/virtio/blk.c
index 6ffa75384e7430247469f85da26a4b43c59f2aeb..9db293e4e57eb6109a782da443ddba3c407b3e50 100644 (file)
--- a/tools/kvm/virtio/blk.c
+++ b/tools/kvm/virtio/blk.c
@@ -77,10 +77,12 @@ static void virtio_blk_do_io_request(struct kvm *kvm, void *param)
 
        switch (req->type) {
        case VIRTIO_BLK_T_IN:
-               block_cnt       = disk_image__read(bdev->disk, req->sector, iov + 1, in + out - 2);
+               block_cnt       = disk_image__read(bdev->disk, req->sector, iov + 1,
+                                       in + out - 2, NULL);
                break;
        case VIRTIO_BLK_T_OUT:
-               block_cnt       = disk_image__write(bdev->disk, req->sector, iov + 1, in + out - 2);
+               block_cnt       = disk_image__write(bdev->disk, req->sector, iov + 1,
+                                       in + out - 2, NULL);
                break;
        case VIRTIO_BLK_T_FLUSH:
                block_cnt       = disk_image__flush(bdev->disk);