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[Qemu-devel] [PULL 15/21] xen/9pfs: implement in/out_iov_from_pdu and vm
From: |
Stefano Stabellini |
Subject: |
[Qemu-devel] [PULL 15/21] xen/9pfs: implement in/out_iov_from_pdu and vmarshal/vunmarshal |
Date: |
Fri, 21 Apr 2017 13:14:56 -0700 |
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 <address@hidden>
CC: address@hidden
CC: address@hidden
CC: Aneesh Kumar K.V <address@hidden>
CC: Greg Kurz <address@hidden>
---
hw/9pfs/xen-9p-backend.c | 99 +++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 97 insertions(+), 2 deletions(-)
diff --git a/hw/9pfs/xen-9p-backend.c b/hw/9pfs/xen-9p-backend.c
index 60d49d1..0c1dd5e 100644
--- a/hw/9pfs/xen-9p-backend.c
+++ b/hw/9pfs/xen-9p-backend.c
@@ -57,12 +57,81 @@ 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_FLEX_RING_SIZE(ring->ring_order));
+ masked_cons = xen_9pfs_mask(cons, XEN_FLEX_RING_SIZE(ring->ring_order));
+
+ 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_FLEX_RING_SIZE(ring->ring_order) - 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_FLEX_RING_SIZE(ring->ring_order));
+ masked_cons = xen_9pfs_mask(cons, XEN_FLEX_RING_SIZE(ring->ring_order));
+
+ 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_FLEX_RING_SIZE(ring->ring_order) - masked_cons)) {
+ out_sg[0].iov_base = ring->ring.out + masked_cons;
+ out_sg[0].iov_len = XEN_FLEX_RING_SIZE(ring->ring_order) -
+ masked_cons;
+ out_sg[1].iov_base = ring->ring.out;
+ out_sg[1].iov_len = ring->out_size -
+ (XEN_FLEX_RING_SIZE(ring->ring_order) -
+ 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,
@@ -70,13 +139,29 @@ 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];
+ int num;
+
+ g_free(ring->sg);
+
+ ring->sg = g_malloc0(sizeof(*ring->sg) * 2);
+ xen_9pfs_out_sg(ring, ring->sg, &num, pdu->idx);
+ *piov = ring->sg;
+ *pniov = num;
}
static void xen_9pfs_init_in_iov_from_pdu(V9fsPDU *pdu,
@@ -84,6 +169,16 @@ 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];
+ int num;
+
+ g_free(ring->sg);
+
+ ring->sg = g_malloc0(sizeof(*ring->sg) * 2);
+ xen_9pfs_in_sg(ring, ring->sg, &num, pdu->idx, size);
+ *piov = ring->sg;
+ *pniov = num;
}
static void xen_9pfs_push_and_notify(V9fsPDU *pdu)
--
1.9.1
- [Qemu-devel] [PULL 06/21] xen: use 5 digit xen versions, (continued)
- [Qemu-devel] [PULL 06/21] xen: use 5 digit xen versions, Stefano Stabellini, 2017/04/21
- [Qemu-devel] [PULL 07/21] xen: use libxendevice model to restrict operations, Stefano Stabellini, 2017/04/21
- [Qemu-devel] [PULL 08/21] xen: additionally restrict xenforeignmemory operations, Stefano Stabellini, 2017/04/21
- [Qemu-devel] [PULL 09/21] configure: use pkg-config for obtaining xen version, Stefano Stabellini, 2017/04/21
- [Qemu-devel] [PULL 11/21] 9p: introduce a type for the 9p header, Stefano Stabellini, 2017/04/21
- [Qemu-devel] [PULL 10/21] xen: import ring.h from xen, Stefano Stabellini, 2017/04/21
- [Qemu-devel] [PULL 12/21] xen/9pfs: introduce Xen 9pfs backend, Stefano Stabellini, 2017/04/21
- [Qemu-devel] [PULL 13/21] xen/9pfs: connect to the frontend, Stefano Stabellini, 2017/04/21
- [Qemu-devel] [PULL 14/21] xen/9pfs: receive requests from the frontend, Stefano Stabellini, 2017/04/21
- [Qemu-devel] [PULL 16/21] xen/9pfs: send responses back to the frontend, Stefano Stabellini, 2017/04/21
- [Qemu-devel] [PULL 15/21] xen/9pfs: implement in/out_iov_from_pdu and vmarshal/vunmarshal,
Stefano Stabellini <=
- [Qemu-devel] [PULL 17/21] xen/9pfs: build and register Xen 9pfs backend, Stefano Stabellini, 2017/04/21
- [Qemu-devel] [PULL 18/21] add xen-9p-backend to MAINTAINERS under Xen, Stefano Stabellini, 2017/04/21
- [Qemu-devel] [PULL 19/21] move xen-common.c to hw/xen/, Stefano Stabellini, 2017/04/21
- [Qemu-devel] [PULL 21/21] move xen-mapcache.c to hw/i386/xen/, Stefano Stabellini, 2017/04/21
- [Qemu-devel] [PULL 20/21] move xen-hvm.c to hw/i386/xen/, Stefano Stabellini, 2017/04/21
- Re: [Qemu-devel] [PULL 0/21] Please pull xen-20170421-tag for 2.10, Peter Maydell, 2017/04/24