From 5ffd4a3c2d75db3ed31752d0936f96719ee0257b Mon Sep 17 00:00:00 2001 From: Eric Farman Date: Wed, 10 May 2017 17:53:54 +0200 Subject: [PATCH] pc-bios/s390-ccw: Break up virtio-scsi read into multiples 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 Message-Id: <20170510155359.32727-4-farman@linux.vnet.ibm.com> Signed-off-by: Cornelia Huck --- 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 07d8cbcb20..2089274842 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 6d070e2f73..ff65e2ee30 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; } -- 2.11.4.GIT