From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52287) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d35JR-00083b-4Z for qemu-devel@nongnu.org; Tue, 25 Apr 2017 14:35:46 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d35JQ-0005qo-3A for qemu-devel@nongnu.org; Tue, 25 Apr 2017 14:35:45 -0400 Received: from mail.kernel.org ([198.145.29.136]:50160) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1d35JP-0005qT-Qd for qemu-devel@nongnu.org; Tue, 25 Apr 2017 14:35:44 -0400 From: Stefano Stabellini Date: Tue, 25 Apr 2017 11:35:07 -0700 Message-Id: <1493145313-31311-15-git-send-email-sstabellini@kernel.org> In-Reply-To: <1493145313-31311-1-git-send-email-sstabellini@kernel.org> References: <1493145313-31311-1-git-send-email-sstabellini@kernel.org> Subject: [Qemu-devel] [PATCH 15/21] xen/9pfs: implement in/out_iov_from_pdu and vmarshal/vunmarshal List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: peter.maydell@linaro.org Cc: stefanha@gmail.com, sstabellini@kernel.org, stefanha@redhat.com, anthony.perard@citrix.com, xen-devel@lists.xenproject.org, qemu-devel@nongnu.org, Stefano Stabellini , jgross@suse.com, "Aneesh Kumar K.V" , Greg Kurz 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 CC: anthony.perard@citrix.com CC: jgross@suse.com CC: Aneesh Kumar K.V CC: Greg Kurz --- 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 8820e8f..9068703 100644 --- a/hw/9pfs/xen-9p-backend.c +++ b/hw/9pfs/xen-9p-backend.c @@ -54,12 +54,81 @@ 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, @@ -67,13 +136,29 @@ 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, @@ -81,6 +166,16 @@ 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