From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49633) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d8TwV-00018B-Mg for qemu-devel@nongnu.org; Wed, 10 May 2017 11:54:28 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d8TwR-0002zn-L2 for qemu-devel@nongnu.org; Wed, 10 May 2017 11:54:23 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:48542 helo=mx0a-001b2d01.pphosted.com) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1d8TwR-0002zR-EP for qemu-devel@nongnu.org; Wed, 10 May 2017 11:54:19 -0400 Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v4AFrtaH050084 for ; Wed, 10 May 2017 11:54:18 -0400 Received: from e06smtp10.uk.ibm.com (e06smtp10.uk.ibm.com [195.75.94.106]) by mx0b-001b2d01.pphosted.com with ESMTP id 2abqg4mntw-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 10 May 2017 11:54:18 -0400 Received: from localhost by e06smtp10.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 10 May 2017 16:54:16 +0100 From: Eric Farman Date: Wed, 10 May 2017 17:53:54 +0200 In-Reply-To: <20170510155359.32727-1-farman@linux.vnet.ibm.com> References: <20170510155359.32727-1-farman@linux.vnet.ibm.com> Message-Id: <20170510155359.32727-4-farman@linux.vnet.ibm.com> Subject: [Qemu-devel] [RFC PATCH v2 3/8] pc-bios/s390-ccw: Break up virtio-scsi read into multiples List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Cornelia Huck , Christian Borntraeger , Alexander Graf , Paolo Bonzini , Fam Zheng , Eric Farman A virtio-scsi request that goes through the host sd driver and exceeds the maximum transfer size is automatically broken up for us. But the equivalent request going to the sg driver presumes that any length requirements have already been honored. Let's use the max_sectors field on the virtio-scsi controller device, and break up all requests (both sd and sg) to avoid this problem. Signed-off-by: Eric Farman --- pc-bios/s390-ccw/s390-ccw.h | 7 +++++++ pc-bios/s390-ccw/virtio-scsi.c | 20 +++++++++++++++----- 2 files changed, 22 insertions(+), 5 deletions(-) diff --git a/pc-bios/s390-ccw/s390-ccw.h b/pc-bios/s390-ccw/s390-ccw.h index 07d8cbc..2089274 100644 --- a/pc-bios/s390-ccw/s390-ccw.h +++ b/pc-bios/s390-ccw/s390-ccw.h @@ -42,6 +42,13 @@ typedef unsigned long long __u64; #ifndef NULL #define NULL 0 #endif +#ifndef MIN +#define MIN(a, b) (((a) < (b)) ? (a) : (b)) +#endif +#ifndef MIN_NON_ZERO +#define MIN_NON_ZERO(a, b) ((a) == 0 ? (b) : \ + ((b) == 0 ? (a) : (MIN(a, b)))) +#endif #include "cio.h" #include "iplb.h" diff --git a/pc-bios/s390-ccw/virtio-scsi.c b/pc-bios/s390-ccw/virtio-scsi.c index 6d070e2..ff65e2e 100644 --- a/pc-bios/s390-ccw/virtio-scsi.c +++ b/pc-bios/s390-ccw/virtio-scsi.c @@ -202,6 +202,7 @@ static void virtio_scsi_locate_device(VDev *vdev) debug_print_int("config.scsi.max_channel", vdev->config.scsi.max_channel); debug_print_int("config.scsi.max_target ", vdev->config.scsi.max_target); debug_print_int("config.scsi.max_lun ", vdev->config.scsi.max_lun); + debug_print_int("config.scsi.max_sectors", vdev->config.scsi.max_sectors); if (vdev->scsi_device_selected) { sdev->channel = vdev->selected_scsi_device.channel; @@ -254,12 +255,21 @@ static void virtio_scsi_locate_device(VDev *vdev) int virtio_scsi_read_many(VDev *vdev, ulong sector, void *load_addr, int sec_num) { + int sector_count; int f = vdev->blk_factor; - unsigned int data_size = sec_num * virtio_get_block_size() * f; - - if (!scsi_read_10(vdev, sector * f, sec_num * f, load_addr, data_size)) { - virtio_scsi_verify_response(&resp, "virtio-scsi:read_many"); - } + unsigned int data_size; + + do { + sector_count = MIN_NON_ZERO(sec_num, vdev->config.scsi.max_sectors); + data_size = sector_count * virtio_get_block_size() * f; + if (!scsi_read_10(vdev, sector * f, sector_count * f, load_addr, + data_size)) { + virtio_scsi_verify_response(&resp, "virtio-scsi:read_many"); + } + load_addr += data_size; + sector += sector_count; + sec_num -= sector_count; + } while (sec_num > 0); return 0; } -- 2.10.2