[Qemu-devel] [RFC PATCH v2 07/17] fuzz: Add ramfile qemu-file type

["Oleinik, Alexander" <alxndr@bu.edu>]

Signed-off-by: Alexander Oleinik <alxndr@bu.edu>
---
 migration/qemu-file.c | 84 +++++++++++++++++++++++++++++++++++++++++++
 migration/qemu-file.h | 11 ++++++
 2 files changed, 95 insertions(+)

diff --git a/migration/qemu-file.c b/migration/qemu-file.c
index 0431585502..453e2897d5 100644
--- a/migration/qemu-file.c
+++ b/migration/qemu-file.c
@@ -786,3 +786,87 @@ void qemu_file_set_blocking(QEMUFile *f, bool block)
         f->ops->set_blocking(f->opaque, block);
     }
 }
+
+#ifdef CONFIG_FUZZ
+#define INCREMENT 10240
+static ssize_t ram_writev_buffer(void *opaque, struct iovec *iov, int iovcnt,
+        int64_t pos)
+{
+    ram_disk *rd = (ram_disk *)opaque;
+    gsize newsize;
+    ssize_t total_size = 0;
+    int i;
+    if (!rd->base) {
+        rd->base = g_malloc(INCREMENT);
+        rd->len = INCREMENT;
+    }
+    for (i = 0; i < iovcnt; i++) {
+        if (pos + iov[i].iov_len >= rd->len) {
+            newsize = ((pos + iov[i].iov_len) / INCREMENT + 1) * INCREMENT;
+            rd->base = g_realloc(rd->base, newsize);
+            rd->len = newsize;
+        }
+        memcpy(rd->base + pos, iov[i].iov_base, iov[i].iov_len);
+        pos += iov[i].iov_len;
+        total_size += iov[i].iov_len;
+    }
+    return total_size;
+}
+
+static ssize_t ram_get_buffer(void *opaque, uint8_t *buf, int64_t pos,
+        size_t size)
+{
+    ram_disk *rd = (ram_disk *)opaque;
+    if (pos + size > rd->len) {
+        if (rd->len - pos >= 0) {
+            memcpy(buf, rd->base + pos, rd->len - pos);
+            size = rd->len - pos;
+        }
+    } else {
+        memcpy(buf, rd->base + pos, size);
+    }
+    return size;
+}
+
+static int ram_fclose(void *opaque)
+{
+    return 0;
+}
+
+static const QEMUFileOps ram_read_ops = {
+    .get_buffer = ram_get_buffer,
+    .close =      ram_fclose
+};
+
+static const QEMUFileOps ram_write_ops = {
+    .writev_buffer = ram_writev_buffer,
+    .close =      ram_fclose
+};
+
+QEMUFile *qemu_fopen_ram(ram_disk **return_rd)
+{
+    ram_disk *rd = g_new0(ram_disk, 1);
+    *return_rd = rd;
+    return qemu_fopen_ops(rd, &ram_write_ops);
+}
+
+QEMUFile *qemu_fopen_ro_ram(ram_disk* rd)
+{
+    return qemu_fopen_ops(rd, &ram_read_ops);
+}
+
+void qemu_freopen_ro_ram(QEMUFile *f)
+{
+    void *rd = f->opaque;
+    f->bytes_xfer = 0;
+    f->xfer_limit = 0;
+    f->last_error = 0;
+    f->iovcnt = 0;
+    f->buf_index = 0;
+    f->buf_size = 0;
+    f->pos = 0;
+    f->ops = &ram_read_ops;
+    f->opaque = rd;
+    return;
+}
+#endif
diff --git a/migration/qemu-file.h b/migration/qemu-file.h
index 13baf896bd..7048674f1b 100644
--- a/migration/qemu-file.h
+++ b/migration/qemu-file.h
@@ -177,4 +177,15 @@ size_t ram_control_save_page(QEMUFile *f, ram_addr_t block_offset,
 
 void qemu_put_counted_string(QEMUFile *f, const char *name);
 
+#ifdef CONFIG_FUZZ
+typedef struct ram_disk {
+    void *base;
+    gsize len;
+} ram_disk;
+
+QEMUFile *qemu_fopen_ram(ram_disk **rd);
+QEMUFile *qemu_fopen_ro_ram(ram_disk* rd);
+void qemu_freopen_ro_ram(QEMUFile *f);
+#endif
+
 #endif
-- 
2.20.1