From patchwork Sat Apr 16 11:45:44 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sasha Levin X-Patchwork-Id: 712381 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter1.kernel.org (8.14.4/8.14.3) with ESMTP id p3GBkKE4019741 for ; Sat, 16 Apr 2011 11:46:40 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759340Ab1DPLqR (ORCPT ); Sat, 16 Apr 2011 07:46:17 -0400 Received: from mail-wy0-f174.google.com ([74.125.82.174]:59971 "EHLO mail-wy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759329Ab1DPLqF (ORCPT ); Sat, 16 Apr 2011 07:46:05 -0400 Received: by wya21 with SMTP id 21so2842008wya.19 for ; Sat, 16 Apr 2011 04:46:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:from:to:cc:subject:date:message-id:x-mailer :in-reply-to:references; bh=jiRr3y2T1wZhk+DkCSJ0EkHIAw/Qt8E4fqIMWvzqilA=; b=E9G3sXPl08t4zeIWawfAFGhB+ScTH2T6Iz39qzn+U+jl0VzV5XFA87L7zSt4KM+rwi nZR1BRc/iHpNYxmLOPwy/Yk2iRiyqFXAp8sU0lSe+NLGanYo8arBzGfJrIC6mhZWH0y3 t9WISOXm1OVpt4PU8MZRKiTf7K2euiClrtQ9k= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; b=G/jSYfxbLIIrsqxs0Cl7iaM4Oyu8nIDcGWATbbjzZfPkvlN0aRh/yg+qQ2RVKqJ1ex igjkqWRInHMRbQGIrqErxeFWbrJSvd8iyZuymQTMkLRwIaQs4pjE6aTIkvHL9opd+4ti mppBYd6fN043yIvpBTBJ08N3zerDzr6GhYLuA= Received: by 10.216.143.134 with SMTP id l6mr476668wej.2.1302954364094; Sat, 16 Apr 2011 04:46:04 -0700 (PDT) Received: from localhost.localdomain (93-172-38-69.bb.netvision.net.il [93.172.38.69]) by mx.google.com with ESMTPS id n52sm1705158wer.24.2011.04.16.04.46.02 (version=TLSv1/SSLv3 cipher=OTHER); Sat, 16 Apr 2011 04:46:03 -0700 (PDT) From: Sasha Levin To: penberg@kernel.org Cc: mingo@elte.hu, asias.hejun@gmail.com, gorcunov@gmail.com, kvm@vger.kernel.org, Sasha Levin Subject: [PATCH 2/2] kvm tools: Add scatter-gather support for disk images Date: Sat, 16 Apr 2011 14:45:44 +0300 Message-Id: <1302954344-11700-2-git-send-email-levinsasha928@gmail.com> X-Mailer: git-send-email 1.7.5.rc1 In-Reply-To: <1302954344-11700-1-git-send-email-levinsasha928@gmail.com> References: <1302954344-11700-1-git-send-email-levinsasha928@gmail.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter1.kernel.org [140.211.167.41]); Sat, 16 Apr 2011 11:46:40 +0000 (UTC) Add optional support for scatter-gather to disk_image. Formats that can't take advantage of scatter-gather fallback to simple IO. Signed-off-by: Sasha Levin --- tools/kvm/disk-image.c | 22 ++++++++++++++++++++ tools/kvm/include/kvm/disk-image.h | 31 ++++++++++++++++++++++++++++ tools/kvm/virtio-blk.c | 39 +++++------------------------------ 3 files changed, 59 insertions(+), 33 deletions(-) diff --git a/tools/kvm/disk-image.c b/tools/kvm/disk-image.c index 4198ebb..dd54b99 100644 --- a/tools/kvm/disk-image.c +++ b/tools/kvm/disk-image.c @@ -72,6 +72,26 @@ static int raw_image__write_sector(struct disk_image *self, uint64_t sector, voi return 0; } +static size_t raw_image__read_sector_sg(struct disk_image *self, uint64_t sector, const struct iovec *iov, int iovcount) +{ + uint64_t offset = sector << SECTOR_SHIFT; + size_t ret = -1; + + ret = preadv(self->fd, iov, iovcount, offset); + + return ret; +} + +static size_t raw_image__write_sector_sg(struct disk_image *self, uint64_t sector, const struct iovec *iov, int iovcount) +{ + uint64_t offset = sector << SECTOR_SHIFT; + size_t ret = -1; + + ret = pwritev(self->fd, iov, iovcount, offset); + + return ret; +} + static int raw_image__read_sector_ro_mmap(struct disk_image *self, uint64_t sector, void *dst, uint32_t dst_len) { uint64_t offset = sector << SECTOR_SHIFT; @@ -105,6 +125,8 @@ static void raw_image__close_ro_mmap(struct disk_image *self) static struct disk_image_operations raw_image_ops = { .read_sector = raw_image__read_sector, .write_sector = raw_image__write_sector, + .read_sector_sg = raw_image__read_sector_sg, + .write_sector_sg = raw_image__write_sector_sg }; static struct disk_image_operations raw_image_ro_mmap_ops = { diff --git a/tools/kvm/include/kvm/disk-image.h b/tools/kvm/include/kvm/disk-image.h index 33962c6..a4a96a2 100644 --- a/tools/kvm/include/kvm/disk-image.h +++ b/tools/kvm/include/kvm/disk-image.h @@ -3,6 +3,7 @@ #include #include +#include #define SECTOR_SHIFT 9 #define SECTOR_SIZE (1UL << SECTOR_SHIFT) @@ -12,6 +13,8 @@ struct disk_image; struct disk_image_operations { int (*read_sector)(struct disk_image *self, uint64_t sector, void *dst, uint32_t dst_len); int (*write_sector)(struct disk_image *self, uint64_t sector, void *src, uint32_t src_len); + size_t (*read_sector_sg)(struct disk_image *self, uint64_t sector, const struct iovec *iov, int iovcount); + size_t (*write_sector_sg)(struct disk_image *self, uint64_t sector, const struct iovec *iov, int iovcount); void (*close)(struct disk_image *self); }; @@ -37,4 +40,32 @@ static inline int disk_image__write_sector(struct disk_image *self, uint64_t sec return self->ops->write_sector(self, sector, src, src_len); } +static inline size_t disk_image__read_sector_sg(struct disk_image *self, uint64_t sector, const struct iovec *iov, int iovcount) +{ + if (self->ops->read_sector_sg) + return self->ops->read_sector_sg(self, sector, iov, iovcount); + + while (iovcount--) { + self->ops->read_sector(self, sector, iov->iov_base, iov->iov_len); + sector += iov->iov_len >> SECTOR_SHIFT; + iov++; + } + + return sector << SECTOR_SHIFT; +} + +static inline size_t disk_image__write_sector_sg(struct disk_image *self, uint64_t sector, const struct iovec *iov, int iovcount) +{ + if (self->ops->write_sector_sg) + return self->ops->write_sector_sg(self, sector, iov, iovcount); + + while (iovcount--) { + self->ops->write_sector(self, sector, iov->iov_base, iov->iov_len); + sector += iov->iov_len >> SECTOR_SHIFT; + iov++; + } + + return sector << SECTOR_SHIFT; +} + #endif /* KVM__DISK_IMAGE_H */ diff --git a/tools/kvm/virtio-blk.c b/tools/kvm/virtio-blk.c index cb344d08..aee3b73 100644 --- a/tools/kvm/virtio-blk.c +++ b/tools/kvm/virtio-blk.c @@ -115,50 +115,23 @@ static bool virtio_blk_do_io_request(struct kvm *self, struct virt_queue *queue) { struct iovec iov[VIRTIO_BLK_QUEUE_SIZE]; struct virtio_blk_outhdr *req; - uint32_t block_len, block_cnt; + size_t block_cnt = -1; uint16_t out, in, head; uint8_t *status; - bool io_error; - void *block; - int err, i; - - io_error = false; head = virt_queue__get_iov(queue, iov, &out, &in, self); /* head */ req = iov[0].iov_base; - /* block */ - block_cnt = 0; - - for (i = 1; i < out + in - 1; i++) { - block = iov[i].iov_base; - block_len = iov[i].iov_len; - - switch (req->type) { - case VIRTIO_BLK_T_IN: - err = disk_image__read_sector(self->disk_image, req->sector, block, block_len); - if (err) - io_error = true; - break; - case VIRTIO_BLK_T_OUT: - err = disk_image__write_sector(self->disk_image, req->sector, block, block_len); - if (err) - io_error = true; - break; - default: - warning("request type %d", req->type); - io_error = true; - } - - req->sector += block_len >> SECTOR_SHIFT; - block_cnt += block_len; - } + if (req->type == VIRTIO_BLK_T_IN) + block_cnt = disk_image__read_sector_sg(self->disk_image, req->sector, iov + 1, in + out - 2); + else if (req->type == VIRTIO_BLK_T_OUT) + block_cnt = disk_image__write_sector_sg(self->disk_image, req->sector, iov + 1, in + out - 2); /* status */ status = iov[out + in - 1].iov_base; - *status = io_error ? VIRTIO_BLK_S_IOERR : VIRTIO_BLK_S_OK; + *status = (block_cnt == (size_t)-1) ? VIRTIO_BLK_S_IOERR : VIRTIO_BLK_S_OK; virt_queue__set_used_elem(queue, head, block_cnt);