On Thu, 16 Mar 2017 13:01:56 -0700 Stefano Stabellini <sstabell...@kernel.org> wrote:
> Implement xen_9pfs_init_in/out_iov_from_pdu and > xen_9pfs_pdu_vmarshal/vunmarshall by creating new sg pointing to the > data on the ring. > > This is safe as we only handle one request per ring at any given time. > > Signed-off-by: Stefano Stabellini <stef...@aporeto.com> > CC: anthony.per...@citrix.com > CC: jgr...@suse.com > CC: Aneesh Kumar K.V <aneesh.ku...@linux.vnet.ibm.com> > CC: Greg Kurz <gr...@kaod.org> > --- > hw/9pfs/xen-9p-backend.c | 92 > ++++++++++++++++++++++++++++++++++++++++++++++-- > 1 file changed, 90 insertions(+), 2 deletions(-) > > diff --git a/hw/9pfs/xen-9p-backend.c b/hw/9pfs/xen-9p-backend.c > index f757591..0a1eb34 100644 > --- a/hw/9pfs/xen-9p-backend.c > +++ b/hw/9pfs/xen-9p-backend.c > @@ -58,12 +58,78 @@ typedef struct Xen9pfsDev { > Xen9pfsRing *rings; > } Xen9pfsDev; > > +static void xen_9pfs_in_sg(Xen9pfsRing *ring, > + struct iovec *in_sg, > + int *num, > + uint32_t idx, > + uint32_t size) > +{ > + RING_IDX cons, prod, masked_prod, masked_cons; > + > + cons = ring->intf->in_cons; > + prod = ring->intf->in_prod; > + xen_rmb(); > + masked_prod = xen_9pfs_mask(prod, XEN_9PFS_RING_SIZE); > + masked_cons = xen_9pfs_mask(cons, XEN_9PFS_RING_SIZE); > + > + if (masked_prod < masked_cons) { > + in_sg[0].iov_base = ring->ring.in + masked_prod; > + in_sg[0].iov_len = masked_cons - masked_prod; > + *num = 1; > + } else { > + in_sg[0].iov_base = ring->ring.in + masked_prod; > + in_sg[0].iov_len = XEN_9PFS_RING_SIZE - masked_prod; > + in_sg[1].iov_base = ring->ring.in; > + in_sg[1].iov_len = masked_cons; > + *num = 2; > + } > +} > + > +static void xen_9pfs_out_sg(Xen9pfsRing *ring, > + struct iovec *out_sg, > + int *num, > + uint32_t idx) > +{ > + RING_IDX cons, prod, masked_prod, masked_cons; > + > + cons = ring->intf->out_cons; > + prod = ring->intf->out_prod; > + xen_rmb(); > + masked_prod = xen_9pfs_mask(prod, XEN_9PFS_RING_SIZE); > + masked_cons = xen_9pfs_mask(cons, XEN_9PFS_RING_SIZE); > + > + if (masked_cons < masked_prod) { > + out_sg[0].iov_base = ring->ring.out + masked_cons; > + out_sg[0].iov_len = ring->out_size; > + *num = 1; > + } else { > + if (ring->out_size > (XEN_9PFS_RING_SIZE - masked_cons)) { > + out_sg[0].iov_base = ring->ring.out + masked_cons; > + out_sg[0].iov_len = XEN_9PFS_RING_SIZE - masked_cons; > + out_sg[1].iov_base = ring->ring.out; > + out_sg[1].iov_len = ring->out_size - > + (XEN_9PFS_RING_SIZE - masked_cons); > + *num = 2; > + } else { > + out_sg[0].iov_base = ring->ring.out + masked_cons; > + out_sg[0].iov_len = ring->out_size; > + *num = 1; > + } > + } > +} > + > static ssize_t xen_9pfs_pdu_vmarshal(V9fsPDU *pdu, > size_t offset, > const char *fmt, > va_list ap) > { > - return 0; > + Xen9pfsDev *xen_9pfs = container_of(pdu->s, Xen9pfsDev, state); > + struct iovec in_sg[2]; > + int num; > + > + xen_9pfs_in_sg(&xen_9pfs->rings[pdu->tag % xen_9pfs->num_rings], > + in_sg, &num, pdu->idx, ROUND_UP(offset + 128, 512)); > + return v9fs_iov_vmarshal(in_sg, num, offset, 0, fmt, ap); > } > > static ssize_t xen_9pfs_pdu_vunmarshal(V9fsPDU *pdu, > @@ -71,13 +137,27 @@ static ssize_t xen_9pfs_pdu_vunmarshal(V9fsPDU *pdu, > const char *fmt, > va_list ap) > { > - return 0; > + Xen9pfsDev *xen_9pfs = container_of(pdu->s, Xen9pfsDev, state); > + struct iovec out_sg[2]; > + int num; > + > + xen_9pfs_out_sg(&xen_9pfs->rings[pdu->tag % xen_9pfs->num_rings], > + out_sg, &num, pdu->idx); > + return v9fs_iov_vunmarshal(out_sg, num, offset, 0, fmt, ap); > } > > static void xen_9pfs_init_out_iov_from_pdu(V9fsPDU *pdu, > struct iovec **piov, > unsigned int *pniov) > { > + Xen9pfsDev *xen_9pfs = container_of(pdu->s, Xen9pfsDev, state); > + Xen9pfsRing *ring = &xen_9pfs->rings[pdu->tag % xen_9pfs->num_rings]; > + struct iovec *sg = g_malloc0(sizeof(*sg) * 2); I had overlooked in v2, sorry for that. Where does *sg gets freed ? > + int num; > + > + xen_9pfs_out_sg(ring, sg, &num, pdu->idx); > + *piov = sg; > + *pniov = num; > } > > static void xen_9pfs_init_in_iov_from_pdu(V9fsPDU *pdu, > @@ -85,6 +165,14 @@ static void xen_9pfs_init_in_iov_from_pdu(V9fsPDU *pdu, > unsigned int *pniov, > size_t size) > { > + Xen9pfsDev *xen_9pfs = container_of(pdu->s, Xen9pfsDev, state); > + Xen9pfsRing *ring = &xen_9pfs->rings[pdu->tag % xen_9pfs->num_rings]; > + struct iovec *sg = g_malloc0(sizeof(*sg) * 2); Same here. > + int num; > + > + xen_9pfs_in_sg(ring, sg, &num, pdu->idx, size); > + *piov = sg; > + *pniov = num; > } > > static void xen_9pfs_push_and_notify(V9fsPDU *pdu)
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