| Message ID | 1489694518-16978-7-git-send-email-sstabellini@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, 16 Mar 2017 13:01:56 -0700 Stefano Stabellini <sstabellini@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 <stefano@aporeto.com> > CC: anthony.perard@citrix.com > CC: jgross@suse.com > CC: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> > CC: Greg Kurz <groug@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)
On Fri, 17 Mar 2017, Greg Kurz wrote: > On Thu, 16 Mar 2017 13:01:56 -0700 > Stefano Stabellini <sstabellini@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 <stefano@aporeto.com> > > CC: anthony.perard@citrix.com > > CC: jgross@suse.com > > CC: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> > > CC: Greg Kurz <groug@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 ? Uhm, I mistakenly believed that qemu_iovec_destroy would do that, but actually it only frees the iovec allocated by qemu_iovec_init. I'll add a g_free here, xen_9pfs_init_in_iov_from_pdu, and in xen_9pfs_push_and_notify: the iovec is immediately concatenated into a different iovec, so there are no risks in freeing it at soon as possible. > > + 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)
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); + 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); + 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)
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 <stefano@aporeto.com> CC: anthony.perard@citrix.com CC: jgross@suse.com CC: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> CC: Greg Kurz <groug@kaod.org> --- hw/9pfs/xen-9p-backend.c | 92 ++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 90 insertions(+), 2 deletions(-)