This is a note to let you know that I've just added the patch titled
scsi: storvsc: Limit max_sectors for virtual Fibre Channel devices
to the 6.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
scsi-storvsc-limit-max_sectors-for-virtual-fibre-channel-devices.patch
and it can be found in the queue-6.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 010c1e1c5741365dbbf44a5a5bb9f30192875c4c Mon Sep 17 00:00:00 2001
From: Michael Kelley <mikelley@xxxxxxxxxxxxx>
Date: Thu, 20 Jul 2023 14:05:02 -0700
Subject: scsi: storvsc: Limit max_sectors for virtual Fibre Channel devices
From: Michael Kelley <mikelley@xxxxxxxxxxxxx>
commit 010c1e1c5741365dbbf44a5a5bb9f30192875c4c upstream.
The Hyper-V host is queried to get the max transfer size that it supports,
and this value is used to set max_sectors for the synthetic SCSI
controller. However, this max transfer size may be too large for virtual
Fibre Channel devices, which are limited to 512 Kbytes. If a larger
transfer size is used with a vFC device, Hyper-V always returns an error,
and storvsc logs a message like this where the SRB status and SCSI status
are both zero:
hv_storvsc <GUID>: tag#197 cmd 0x8a status: scsi 0x0 srb 0x0 hv 0xc0000001
Add logic to limit the max transfer size to 512 Kbytes for vFC devices.
Fixes: 1d3e0980782f ("scsi: storvsc: Correct reporting of Hyper-V I/O size limits")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/1689887102-32806-1-git-send-email-mikelley@xxxxxxxxxxxxx
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/scsi/storvsc_drv.c | 4 ++++
1 file changed, 4 insertions(+)
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -365,6 +365,7 @@ static void storvsc_on_channel_callback(
#define STORVSC_FC_MAX_LUNS_PER_TARGET 255
#define STORVSC_FC_MAX_TARGETS 128
#define STORVSC_FC_MAX_CHANNELS 8
+#define STORVSC_FC_MAX_XFER_SIZE ((u32)(512 * 1024))
#define STORVSC_IDE_MAX_LUNS_PER_TARGET 64
#define STORVSC_IDE_MAX_TARGETS 1
@@ -2004,6 +2005,9 @@ static int storvsc_probe(struct hv_devic
* protecting it from any weird value.
*/
max_xfer_bytes = round_down(stor_device->max_transfer_bytes, HV_HYP_PAGE_SIZE);
+ if (is_fc)
+ max_xfer_bytes = min(max_xfer_bytes, STORVSC_FC_MAX_XFER_SIZE);
+
/* max_hw_sectors_kb */
host->max_sectors = max_xfer_bytes >> 9;
/*
Patches currently in stable-queue which might be from mikelley@xxxxxxxxxxxxx are
queue-6.4/scsi-storvsc-limit-max_sectors-for-virtual-fibre-channel-devices.patch
queue-6.4/x86-hyperv-disable-ibt-when-hypercall-page-lacks-endbr-instruction.patch
