From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:53615) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Qp1Vj-00051k-Fa for qemu-devel@nongnu.org; Thu, 04 Aug 2011 13:15:09 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Qp1Vh-0001OL-Fh for qemu-devel@nongnu.org; Thu, 04 Aug 2011 13:15:07 -0400 Received: from mail-wy0-f173.google.com ([74.125.82.173]:56803) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Qp1Vh-0001Kh-AC for qemu-devel@nongnu.org; Thu, 04 Aug 2011 13:15:05 -0400 Received: by mail-wy0-f173.google.com with SMTP id 20so1348207wye.4 for ; Thu, 04 Aug 2011 10:15:04 -0700 (PDT) Sender: Paolo Bonzini From: Paolo Bonzini Date: Thu, 4 Aug 2011 19:14:47 +0200 Message-Id: <1312478089-806-10-git-send-email-pbonzini@redhat.com> In-Reply-To: <1312478089-806-1-git-send-email-pbonzini@redhat.com> References: <1312478089-806-1-git-send-email-pbonzini@redhat.com> Subject: [Qemu-devel] [PATCH 09/10] scsi-disk: lazily allocate bounce buffer List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org It will not be needed for reads and writes if the HBA provides a sglist. Signed-off-by: Paolo Bonzini --- hw/scsi-disk.c | 33 ++++++++++++++++++++++----------- 1 files changed, 22 insertions(+), 11 deletions(-) diff --git a/hw/scsi-disk.c b/hw/scsi-disk.c index 37dd9d6..509407f 100644 --- a/hw/scsi-disk.c +++ b/hw/scsi-disk.c @@ -54,6 +54,7 @@ typedef struct SCSIDiskReq { /* Both sector and sector_count are in terms of qemu 512 byte blocks. */ uint64_t sector; uint32_t sector_count; + uint32_t buflen; struct iovec iov; QEMUIOVector qiov; uint32_t status; @@ -77,13 +78,15 @@ struct SCSIDiskState }; static int scsi_handle_rw_error(SCSIDiskReq *r, int error, int type); -static int scsi_disk_emulate_command(SCSIDiskReq *r, uint8_t *outbuf); +static int scsi_disk_emulate_command(SCSIDiskReq *r); static void scsi_free_request(SCSIRequest *req) { SCSIDiskReq *r = DO_UPCAST(SCSIDiskReq, req, req); - qemu_vfree(r->iov.iov_base); + if (r->iov.iov_base) { + qemu_vfree(r->iov.iov_base); + } } /* Helper function for command completion with sense. */ @@ -109,7 +112,13 @@ static void scsi_cancel_io(SCSIRequest *req) static uint32_t scsi_init_iovec(SCSIDiskReq *r) { - r->iov.iov_len = MIN(r->sector_count * 512, SCSI_DMA_BUF_SIZE); + SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev); + + if (!r->iov.iov_base) { + r->buflen = SCSI_DMA_BUF_SIZE; + r->iov.iov_base = qemu_blockalign(s->bs, r->buflen); + } + r->iov.iov_len = MIN(r->sector_count * 512, r->buflen); qemu_iovec_init_external(&r->qiov, &r->iov, 1); return r->qiov.size / 512; } @@ -288,7 +297,7 @@ static void scsi_dma_restart_bh(void *opaque) scsi_write_data(&r->req); break; case SCSI_REQ_STATUS_RETRY_FLUSH: - ret = scsi_disk_emulate_command(r, r->iov.iov_base); + ret = scsi_disk_emulate_command(r); if (ret == 0) { scsi_req_complete(&r->req, GOOD); } @@ -780,14 +789,21 @@ static int scsi_disk_emulate_read_toc(SCSIRequest *req, uint8_t *outbuf) return toclen; } -static int scsi_disk_emulate_command(SCSIDiskReq *r, uint8_t *outbuf) +static int scsi_disk_emulate_command(SCSIDiskReq *r) { SCSIRequest *req = &r->req; SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, req->dev); uint64_t nb_sectors; + uint8_t *outbuf; int buflen = 0; int ret; + if (!r->iov.iov_base) { + r->buflen = 4096; + r->iov.iov_base = qemu_blockalign(s->bs, 4096); + } + + outbuf = r->iov.iov_base; switch (req->cmd.buf[0]) { case TEST_UNIT_READY: if (!bdrv_is_inserted(s->bs)) @@ -950,11 +966,9 @@ static int32_t scsi_send_command(SCSIRequest *req, uint8_t *buf) SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, req->dev); int32_t len; uint8_t command; - uint8_t *outbuf; int rc; command = buf[0]; - outbuf = (uint8_t *)r->iov.iov_base; DPRINTF("Command: lun=%d tag=0x%x data=0x%02x", req->lun, req->tag, buf[0]); #ifdef DEBUG_SCSI @@ -985,7 +999,7 @@ static int32_t scsi_send_command(SCSIRequest *req, uint8_t *buf) case SERVICE_ACTION_IN: case VERIFY: case REZERO_UNIT: - rc = scsi_disk_emulate_command(r, outbuf); + rc = scsi_disk_emulate_command(r); if (rc < 0) { return 0; } @@ -1206,11 +1220,8 @@ static SCSIRequest *scsi_new_request(SCSIDevice *d, uint32_t tag, { SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, d); SCSIRequest *req; - SCSIDiskReq *r; req = scsi_req_alloc(&scsi_disk_reqops, &s->qdev, tag, lun, hba_private); - r = DO_UPCAST(SCSIDiskReq, req, req); - r->iov.iov_base = qemu_blockalign(s->bs, SCSI_DMA_BUF_SIZE); return req; } -- 1.7.6