From patchwork Mon Mar 20 18:19:10 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefano Stabellini X-Patchwork-Id: 741120 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3vn44W5Gg1z9s0m for ; Tue, 21 Mar 2017 05:20:27 +1100 (AEDT) Received: from localhost ([::1]:34307 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cq1ur-0006dK-46 for incoming@patchwork.ozlabs.org; Mon, 20 Mar 2017 14:20:25 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34518) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cq1tv-0006Zy-St for qemu-devel@nongnu.org; Mon, 20 Mar 2017 14:19:29 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cq1tu-0007kf-Cw for qemu-devel@nongnu.org; Mon, 20 Mar 2017 14:19:27 -0400 Received: from mail.kernel.org ([198.145.29.136]:46198) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cq1tu-0007kM-3S for qemu-devel@nongnu.org; Mon, 20 Mar 2017 14:19:26 -0400 Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 2BA902038F; Mon, 20 Mar 2017 18:19:24 +0000 (UTC) Received: from sstabellini-ThinkPad-X260.hsd1.ca.comcast.net (96-82-76-110-static.hfc.comcastbusiness.net [96.82.76.110]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DC90320396; Mon, 20 Mar 2017 18:19:22 +0000 (UTC) From: Stefano Stabellini To: qemu-devel@nongnu.org Date: Mon, 20 Mar 2017 11:19:10 -0700 Message-Id: <1490033952-26735-6-git-send-email-sstabellini@kernel.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1490033952-26735-1-git-send-email-sstabellini@kernel.org> References: <1490033952-26735-1-git-send-email-sstabellini@kernel.org> X-Virus-Scanned: ClamAV using ClamSMTP X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [fuzzy] X-Received-From: 198.145.29.136 Subject: [Qemu-devel] [PATCH v4 6/8] xen/9pfs: implement in/out_iov_from_pdu and vmarshal/vunmarshal X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: jgross@suse.com, sstabellini@kernel.org, groug@kaod.org, Stefano Stabellini , "Aneesh Kumar K.V" , anthony.perard@citrix.com Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" 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 8222db6..3564452 100644 --- a/hw/9pfs/xen-9p-backend.c +++ b/hw/9pfs/xen-9p-backend.c @@ -58,12 +58,81 @@ 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, @@ -71,13 +140,29 @@ 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, @@ -85,6 +170,16 @@ 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)