From 37c51741892a89cf5710f5ac231091fb0a6352c7 Mon Sep 17 00:00:00 2001
From: Fam Zheng <famz@redhat.com>
Date: Wed, 28 Mar 2018 00:41:41 +0800
Subject: [PATCH] scsi-disk: Don't enlarge min_io_size to max_io_size
Some backends report big max_io_sectors. Making min_io_size the same
value in this case will make it impossible for guest to align memory,
therefore the disk may not be usable at all.
Do not enlarge them when they are zero.
Reported-by: David Gibson <dgibson@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <20180327164141.19075-1-famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
hw/scsi/scsi-disk.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c
index f5ab767ab5d..f8ed8cf2b4a 100644
--- a/hw/scsi/scsi-disk.c
+++ b/hw/scsi/scsi-disk.c
@@ -714,10 +714,12 @@ static int scsi_disk_emulate_inquiry(SCSIRequest *req, uint8_t *outbuf)
/* min_io_size and opt_io_size can't be greater than
* max_io_sectors */
- min_io_size =
- MIN_NON_ZERO(min_io_size, max_io_sectors);
- opt_io_size =
- MIN_NON_ZERO(opt_io_size, max_io_sectors);
+ if (min_io_size) {
+ min_io_size = MIN(min_io_size, max_io_sectors);
+ }
+ if (opt_io_size) {
+ opt_io_size = MIN(opt_io_size, max_io_sectors);
+ }
}
/* required VPD size with unmap support */
buflen = 0x40;
--
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