Re: [Qemu-devel] [PATCH -v2 02/22] vrtio-9p: Implement P9_TVERSION for 9P

["Aneesh Kumar K. V" <aneesh.kumar@linux.vnet.ibm.com>]

On Fri, 26 Mar 2010 11:15:47 -0500, Anthony Liguori <aliguori@linux.vnet.ibm.com> wrote:
> On 03/16/2010 04:15 AM, Aneesh Kumar K.V wrote:
> > From: Anthony Liguori<aliguori@us.ibm.com>
> >
> > [kiran@linux.vnet.ibm.com: malloc to qemu_malloc coversion]
> >
> > Signed-off-by: Anthony Liguori<aliguori@us.ibm.com>
> > Signed-off-by: Aneesh Kumar K.V<aneesh.kumar@linux.vnet.ibm.com>
> > ---
> >   hw/virtio-9p.c |  263 +++++++++++++++++++++++++++++++++++++++++++++++++++++++-
> >   1 files changed, 261 insertions(+), 2 deletions(-)
> >
> > diff --git a/hw/virtio-9p.c b/hw/virtio-9p.c
> > index 115c93b..53b3d78 100644
> > --- a/hw/virtio-9p.c
> > +++ b/hw/virtio-9p.c
> > @@ -111,10 +111,269 @@ static void free_pdu(V9fsState *s, V9fsPDU *pdu)
> >       }
> >   }
> >
> > +static void v9fs_string_free(V9fsString *str)
> > +{
> > +    free(str->data);
> >    
> 
> qemu_free.
> > +    str->data = NULL;
> > +    str->size = 0;
> > +}
> > +
> > +static size_t pdu_unpack(void *dst, V9fsPDU *pdu, size_t offset, size_t size)
> > +{
> > +    struct iovec *sg = pdu->elem.out_sg;
> > +    BUG_ON((offset + size)>  sg[0].iov_len);
> > +    memcpy(dst, sg[0].iov_base + offset, size);
> > +    return size;
> > +}
> > +
> > +/* FIXME i can do this with less variables */
> > +static size_t pdu_pack(V9fsPDU *pdu, size_t offset, const void *src, size_t size)
> > +{
> > +    struct iovec *sg = pdu->elem.in_sg;
> > +    size_t off = 0;
> > +    size_t copied = 0;
> > +    int i = 0;
> > +
> > +    for (i = 0; size&&  i<  pdu->elem.in_num; i++) {
> > +        size_t len;
> > +
> > +        if (offset>= off&&  offset<  (off + sg[i].iov_len)) {
> > +            len = MIN(sg[i].iov_len - (offset - off), size);
> > +            memcpy(sg[i].iov_base + (offset - off), src, len);
> > +            size -= len;
> > +            offset += len;
> > +            off = offset;
> > +            copied += len;
> > +            src += len;
> > +        } else {
> > +            off += sg[i].iov_len;
> > +        }
> > +    }
> > +
> > +    return copied;
> > +}
> > +
> > +static int pdu_copy_sg(V9fsPDU *pdu, size_t offset, int rx, struct iovec *sg)
> > +{
> > +    size_t pos = 0;
> > +    int i, j;
> > +    struct iovec *src_sg;
> > +    unsigned int num;
> > +
> > +    if (rx) {
> > +        src_sg = pdu->elem.in_sg;
> > +        num = pdu->elem.in_num;
> > +    } else {
> > +        src_sg = pdu->elem.out_sg;
> > +        num = pdu->elem.out_num;
> > +    }
> > +
> > +    j = 0;
> > +    for (i = 0; i<  num; i++) {
> > +        if (offset<= pos) {
> > +            sg[j].iov_base = src_sg[i].iov_base;
> > +            sg[j].iov_len = src_sg[i].iov_len;
> > +            j++;
> > +        } else if (offset<  (src_sg[i].iov_len + pos)) {
> > +            sg[j].iov_base = src_sg[i].iov_base;
> > +            sg[j].iov_len = src_sg[i].iov_len;
> > +            sg[j].iov_base += (offset - pos);
> > +            sg[j].iov_len -= (offset - pos);
> > +            j++;
> > +        }
> > +        pos += src_sg[i].iov_len;
> > +    }
> > +
> > +    return j;
> > +}
> > +
> > +static size_t pdu_unmarshal(V9fsPDU *pdu, size_t offset, const char *fmt, ...)
> > +{
> > +    size_t old_offset = offset;
> > +    va_list ap;
> > +    int i;
> > +
> > +    va_start(ap, fmt);
> > +    for (i = 0; fmt[i]; i++) {
> > +	switch (fmt[i]) {
> > +	case 'b': {
> > +	    int8_t *valp = va_arg(ap, int8_t *);
> > +	    offset += pdu_unpack(valp, pdu, offset, sizeof(*valp));
> > +	    break;
> > +	}
> > +	case 'w': {
> > +	    int16_t *valp = va_arg(ap, int16_t *);
> > +	    offset += pdu_unpack(valp, pdu, offset, sizeof(*valp));
> > +	    break;
> > +	}
> > +	case 'd': {
> > +	    int32_t *valp = va_arg(ap, int32_t *);
> > +	    offset += pdu_unpack(valp, pdu, offset, sizeof(*valp));
> > +	    break;
> > +	}
> > +	case 'q': {
> > +	    int64_t *valp = va_arg(ap, int64_t *);
> > +	    offset += pdu_unpack(valp, pdu, offset, sizeof(*valp));
> > +	    break;
> > +	}
> > +	case 'v': {
> > +	    struct iovec *iov = va_arg(ap, struct iovec *);
> > +	    int *iovcnt = va_arg(ap, int *);
> > +	    *iovcnt = pdu_copy_sg(pdu, offset, 0, iov);
> > +	    break;
> > +	}
> > +	case 's': {
> > +	    V9fsString *str = va_arg(ap, V9fsString *);
> > +	    offset += pdu_unmarshal(pdu, offset, "w",&str->size);
> > +	    /* FIXME: sanity check str->size */
> > +	    str->data = qemu_malloc(str->size + 1);
> > +	    offset += pdu_unpack(str->data, pdu, offset, str->size);
> > +	    str->data[str->size] = 0;
> > +	    break;
> > +	}
> > +	case 'Q': {
> > +	    V9fsQID *qidp = va_arg(ap, V9fsQID *);
> > +	    offset += pdu_unmarshal(pdu, offset, "bdq",
> > +				&qidp->type,&qidp->version,&qidp->path);
> > +	    break;
> > +	}
> > +	case 'S': {
> > +	    V9fsStat *statp = va_arg(ap, V9fsStat *);
> > +	    offset += pdu_unmarshal(pdu, offset, "wwdQdddqsssssddd",
> > +				&statp->size,&statp->type,&statp->dev,
> > +				&statp->qid,&statp->mode,&statp->atime,
> > +				&statp->mtime,&statp->length,
> > +				&statp->name,&statp->uid,&statp->gid,
> > +				&statp->muid,&statp->extension,
> > +				&statp->n_uid,&statp->n_gid,
> > +				&statp->n_muid);
> > +	    break;
> > +	}
> > +	default:
> > +	    break;
> > +	}
> > +    }
> > +
> > +    va_end(ap);
> > +
> > +    return offset - old_offset;
> > +}
> > +
> > +static size_t pdu_marshal(V9fsPDU *pdu, size_t offset, const char *fmt, ...)
> > +{
> > +    size_t old_offset = offset;
> > +    va_list ap;
> > +    int i;
> > +
> > +    va_start(ap, fmt);
> > +    for (i = 0; fmt[i]; i++) {
> > +	switch (fmt[i]) {
> > +	case 'b': {
> > +	    int8_t val = va_arg(ap, int);
> > +	    offset += pdu_pack(pdu, offset,&val, sizeof(val));
> > +	    break;
> > +	}
> > +	case 'w': {
> > +	    int16_t val = va_arg(ap, int);
> > +	    offset += pdu_pack(pdu, offset,&val, sizeof(val));
> > +	    break;
> > +	}
> > +	case 'd': {
> > +	    int32_t val = va_arg(ap, int);
> > +	    offset += pdu_pack(pdu, offset,&val, sizeof(val));
> > +	    break;
> > +	}
> > +	case 'q': {
> > +	    int64_t val = va_arg(ap, int64_t);
> > +	    offset += pdu_pack(pdu, offset,&val, sizeof(val));
> > +	    break;
> > +	}
> > +	case 'v': {
> > +	    struct iovec *iov = va_arg(ap, struct iovec *);
> > +	    int *iovcnt = va_arg(ap, int *);
> > +	    *iovcnt = pdu_copy_sg(pdu, offset, 1, iov);
> > +	    break;
> > +	}
> > +	case 's': {
> > +	    V9fsString *str = va_arg(ap, V9fsString *);
> > +	    offset += pdu_marshal(pdu, offset, "w", str->size);
> > +	    offset += pdu_pack(pdu, offset, str->data, str->size);
> > +	    break;
> > +	}
> > +	case 'Q': {
> > +	    V9fsQID *qidp = va_arg(ap, V9fsQID *);
> > +	    offset += pdu_marshal(pdu, offset, "bdq",
> > +				  qidp->type, qidp->version, qidp->path);
> > +	    break;
> > +	}
> > +	case 'S': {
> > +	    V9fsStat *statp = va_arg(ap, V9fsStat *);
> > +	    offset += pdu_marshal(pdu, offset, "wwdQdddqsssssddd",
> > +				  statp->size, statp->type, statp->dev,
> > +				&statp->qid, statp->mode, statp->atime,
> > +				  statp->mtime, statp->length,&statp->name,
> > +				&statp->uid,&statp->gid,&statp->muid,
> > +				&statp->extension, statp->n_uid,
> > +				  statp->n_gid, statp->n_muid);
> > +	    break;
> > +	}
> > +	default:
> > +	    break;
> > +	}
> > +    }
> > +    va_end(ap);
> > +
> > +    return offset - old_offset;
> > +}
> >    
> 
> Adding the marshalling in  patch to implement P9_TVERSION is probably 
> not ideal.
> 

Qemu Makefile rules won't allow to add functions that are not used. The
error checking is strict. So there is not an easy way i can add these
functional logically and let each of the changeset successfully build.
Any suggestions how to do the above ?

-aneesh