From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38041) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d3ODg-0003Ox-6O for qemu-devel@nongnu.org; Wed, 26 Apr 2017 10:47:05 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d3ODa-0002Oo-Eq for qemu-devel@nongnu.org; Wed, 26 Apr 2017 10:47:04 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:47395) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1d3ODa-0002Nx-6b for qemu-devel@nongnu.org; Wed, 26 Apr 2017 10:46:58 -0400 Received: from pps.filterd (m0098394.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v3QEi2Ad086130 for ; Wed, 26 Apr 2017 10:46:57 -0400 Received: from e06smtp12.uk.ibm.com (e06smtp12.uk.ibm.com [195.75.94.108]) by mx0a-001b2d01.pphosted.com with ESMTP id 2a2wj306pj-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 26 Apr 2017 10:46:56 -0400 Received: from localhost by e06smtp12.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 26 Apr 2017 15:46:53 +0100 From: Eric Farman Date: Wed, 26 Apr 2017 16:46:44 +0200 In-Reply-To: <20170426144645.12476-1-farman@linux.vnet.ibm.com> References: <20170426144645.12476-1-farman@linux.vnet.ibm.com> Message-Id: <20170426144645.12476-5-farman@linux.vnet.ibm.com> Subject: [Qemu-devel] [RFC PATCH v1 4/5] 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: Paolo Bonzini , "Michael S . Tsirkin" , Cornelia Huck , Christian Borntraeger , Alexander Graf , 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 from the device and break up all virtio-scsi requests (both sd and sg) to avoid problem from the host drivers. Signed-off-by: Eric Farman --- pc-bios/s390-ccw/s390-ccw.h | 4 ++++ pc-bios/s390-ccw/virtio-scsi.c | 19 ++++++++++++++----- 2 files changed, 18 insertions(+), 5 deletions(-) diff --git a/pc-bios/s390-ccw/s390-ccw.h b/pc-bios/s390-ccw/s390-ccw.h index ded67bc..e1f3751 100644 --- a/pc-bios/s390-ccw/s390-ccw.h +++ b/pc-bios/s390-ccw/s390-ccw.h @@ -42,6 +42,10 @@ typedef unsigned long long __u64; #ifndef NULL #define NULL 0 #endif +#ifndef MIN +#define MIN(a, b) (((a) < (b)) ? (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..90a8cc8 100644 --- a/pc-bios/s390-ccw/virtio-scsi.c +++ b/pc-bios/s390-ccw/virtio-scsi.c @@ -254,12 +254,21 @@ 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(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