From 76967a108bed85915541183ec97c6f61b19d2181 Mon Sep 17 00:00:00 2001 From: Amit Shah Date: Tue, 27 Apr 2010 09:07:39 -0300 Subject: [PATCH 12/20] iov: Add iov_to_buf and iov_size helpers RH-Author: Amit Shah Message-id: <1272359264-8464-13-git-send-email-amit.shah@redhat.com> Patchwork-id: 8858 O-Subject: [RHEL6 PATCH v4 12/17] iov: Add iov_to_buf and iov_size helpers Bugzilla: 574296 RH-Acked-by: Gerd Hoffmann RH-Acked-by: Juan Quintela RH-Acked-by: Alon Levy iov_to_buf() puts the buffer contents in the iov in a linearized buffer. iov_size() gets the length of the contents in the iov. The iov_to_buf() function is the memcpy_to_iovec() function that was used in virtio-ballon.c. Bugzilla: 574296 Upstream: Signed-off-by: Amit Shah --- hw/iov.c | 37 +++++++++++++++++++++++++++++++++++++ hw/iov.h | 3 +++ hw/virtio-balloon.c | 35 ++++------------------------------- 3 files changed, 44 insertions(+), 31 deletions(-) Signed-off-by: Eduardo Habkost --- hw/iov.c | 37 +++++++++++++++++++++++++++++++++++++ hw/iov.h | 3 +++ hw/virtio-balloon.c | 35 ++++------------------------------- 3 files changed, 44 insertions(+), 31 deletions(-) diff --git a/hw/iov.c b/hw/iov.c index 07bd499..588cd04 100644 --- a/hw/iov.c +++ b/hw/iov.c @@ -31,3 +31,40 @@ size_t iov_from_buf(struct iovec *iov, unsigned int iovcnt, } return offset; } + +size_t iov_to_buf(const struct iovec *iov, const unsigned int iovcnt, + void *buf, size_t offset, size_t size) +{ + uint8_t *ptr; + size_t iov_off, buf_off; + unsigned int i; + + ptr = buf; + iov_off = 0; + buf_off = 0; + for (i = 0; i < iovcnt && size; i++) { + if (offset < (iov_off + iov[i].iov_len)) { + size_t len = MIN((iov_off + iov[i].iov_len) - offset , size); + + memcpy(ptr + buf_off, iov[i].iov_base + (offset - iov_off), len); + + buf_off += len; + offset += len; + size -= len; + } + iov_off += iov[i].iov_len; + } + return buf_off; +} + +size_t iov_size(const struct iovec *iov, const unsigned int iovcnt) +{ + size_t len; + unsigned int i; + + len = 0; + for (i = 0; i < iovcnt; i++) { + len += iov[i].iov_len; + } + return len; +} diff --git a/hw/iov.h b/hw/iov.h index 5e3e541..60a8547 100644 --- a/hw/iov.h +++ b/hw/iov.h @@ -14,3 +14,6 @@ size_t iov_from_buf(struct iovec *iov, unsigned int iovcnt, const void *buf, size_t size); +size_t iov_to_buf(const struct iovec *iov, const unsigned int iovcnt, + void *buf, size_t offset, size_t size); +size_t iov_size(const struct iovec *iov, const unsigned int iovcnt); diff --git a/hw/virtio-balloon.c b/hw/virtio-balloon.c index 1abad1c..a4e72ed 100644 --- a/hw/virtio-balloon.c +++ b/hw/virtio-balloon.c @@ -11,6 +11,7 @@ * */ +#include "iov.h" #include "qemu-common.h" #include "virtio.h" #include "pc.h" @@ -93,33 +94,6 @@ static QObject *get_stats_qobject(VirtIOBalloon *dev) return QOBJECT(dict); } -/* FIXME: once we do a virtio refactoring, this will get subsumed into common - * code */ -static size_t memcpy_from_iovector(void *data, size_t offset, size_t size, - struct iovec *iov, int iovlen) -{ - int i; - uint8_t *ptr = data; - size_t iov_off = 0; - size_t data_off = 0; - - for (i = 0; i < iovlen && size; i++) { - if (offset < (iov_off + iov[i].iov_len)) { - size_t len = MIN((iov_off + iov[i].iov_len) - offset , size); - - memcpy(ptr + data_off, iov[i].iov_base + (offset - iov_off), len); - - data_off += len; - offset += len; - size -= len; - } - - iov_off += iov[i].iov_len; - } - - return data_off; -} - static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq) { VirtIOBalloon *s = to_virtio_balloon(vdev); @@ -129,8 +103,7 @@ static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq) size_t offset = 0; uint32_t pfn; - while (memcpy_from_iovector(&pfn, offset, 4, - elem.out_sg, elem.out_num) == 4) { + while (iov_to_buf(elem.out_sg, elem.out_num, &pfn, offset, 4) == 4) { ram_addr_t pa; ram_addr_t addr; @@ -182,8 +155,8 @@ static void virtio_balloon_receive_stats(VirtIODevice *vdev, VirtQueue *vq) */ reset_stats(s); - while (memcpy_from_iovector(&stat, offset, sizeof(stat), elem->out_sg, - elem->out_num) == sizeof(stat)) { + while (iov_to_buf(elem->out_sg, elem->out_num, &stat, offset, sizeof(stat)) + == sizeof(stat)) { uint16_t tag = tswap16(stat.tag); uint64_t val = tswap64(stat.val); -- 1.7.0.3