Commit 7c1e52ba authored by Dr. David Alan Gilbert's avatar Dr. David Alan Gilbert Committed by Juan Quintela
Browse files

Move copy out of qemu_peek_buffer 



qemu_peek_buffer currently copies the data it reads into a buffer,
however a future patch wants access to the buffer without the copy,
hence rework to remove the copy to the layer above.

Signed-off-by: default avatarDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: default avatarAmit Shah <amit.shah@redhat.com>
Reviewed-by: default avatarJuan Quintela <quintela@redhat.com>
Signed-off-by: default avatarJuan Quintela <quintela@redhat.com>
parent bca7856a

include/migration/qemu-file.h

+1 −1
Original line number Diff line number Diff line
@@ -157,7 +157,7 @@ static inline void qemu_put_ubyte(QEMUFile *f, unsigned int v) 
void qemu_put_be16(QEMUFile *f, unsigned int v);

void qemu_put_be32(QEMUFile *f, unsigned int v);

void qemu_put_be64(QEMUFile *f, uint64_t v);

int qemu_peek_buffer(QEMUFile *f, uint8_t *buf, int size, size_t offset);

int qemu_peek_buffer(QEMUFile *f, uint8_t **buf, int size, size_t offset);

int qemu_get_buffer(QEMUFile *f, uint8_t *buf, int size);

ssize_t qemu_put_compression_data(QEMUFile *f, const uint8_t *p, size_t size,

                                  int level);

migration/qemu-file.c

+7 −5
Original line number Diff line number Diff line
@@ -349,14 +349,14 @@ void qemu_file_skip(QEMUFile *f, int size) 
}



/*

 * Read 'size' bytes from file (at 'offset') into buf without moving the

 * pointer.

 * Read 'size' bytes from file (at 'offset') without moving the

 * pointer and set 'buf' to point to that data.

 *

 * It will return size bytes unless there was an error, in which case it will

 * return as many as it managed to read (assuming blocking fd's which

 * all current QEMUFile are)

 */

int qemu_peek_buffer(QEMUFile *f, uint8_t *buf, int size, size_t offset)

int qemu_peek_buffer(QEMUFile *f, uint8_t **buf, int size, size_t offset)

{

    int pending;

    int index;
@@ -392,7 +392,7 @@ int qemu_peek_buffer(QEMUFile *f, uint8_t *buf, int size, size_t offset) 
        size = pending;

    }



    memcpy(buf, f->buf + index, size);

    *buf = f->buf + index;

    return size;

}
@@ -411,11 +411,13 @@ int qemu_get_buffer(QEMUFile *f, uint8_t *buf, int size) 


    while (pending > 0) {

        int res;

        uint8_t *src;



        res = qemu_peek_buffer(f, buf, MIN(pending, IO_BUF_SIZE), 0);

        res = qemu_peek_buffer(f, &src, MIN(pending, IO_BUF_SIZE), 0);

        if (res == 0) {

            return done;

        }

        memcpy(buf, src, res);

        qemu_file_skip(f, res);

        buf += res;

        pending -= res;

migration/vmstate.c

+3 −2
Original line number Diff line number Diff line
@@ -358,7 +358,7 @@ static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd, 
    trace_vmstate_subsection_load(vmsd->name);



    while (qemu_peek_byte(f, 0) == QEMU_VM_SUBSECTION) {

        char idstr[256];

        char idstr[256], *idstr_ret;

        int ret;

        uint8_t version_id, len, size;

        const VMStateDescription *sub_vmsd;
@@ -369,11 +369,12 @@ static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd, 
            trace_vmstate_subsection_load_bad(vmsd->name, "(short)");

            return 0;

        }

        size = qemu_peek_buffer(f, (uint8_t *)idstr, len, 2);

        size = qemu_peek_buffer(f, (uint8_t **)&idstr_ret, len, 2);

        if (size != len) {

            trace_vmstate_subsection_load_bad(vmsd->name, "(peek fail)");

            return 0;

        }

        memcpy(idstr, idstr_ret, size);

        idstr[size] = 0;



        if (strncmp(vmsd->name, idstr, strlen(vmsd->name)) != 0) {