From 2903ab6d961b2165f3cbfb786cd3be59a407a6b4 Mon Sep 17 00:00:00 2001

From: Hannes Reinecke <hare@suse.de>

Date: Mon, 16 Nov 2020 19:31:13 +0100

Subject: [PATCH] scsi: make io_timeout configurable

RH-Author: Paolo Bonzini <None>

RH-MergeRequest: 40: scsi: make io_timeout configurable

RH-Commit: [1/1] 147c4b7bac867c708c1905e98c4f9329ab4ef838

RH-Bugzilla: 1994041

RH-Acked-by: Jon Maloy <jmaloy@redhat.com>

RH-Acked-by: Thomas Huth <thuth@redhat.com>

RH-Acked-by: Laszlo Ersek <lersek@redhat.com>

The current code sets an infinite timeout on SG_IO requests,

causing the guest to stall if the host experiences a frame

loss.

This patch adds an 'io_timeout' parameter for SCSIDevice to

make the SG_IO timeout configurable, and also shortens the

default timeout to 30 seconds to avoid infinite stalls.

Signed-off-by: Hannes Reinecke <hare@suse.de>

Message-Id: <20201116183114.55703-3-hare@suse.de>

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

(cherry picked from commit c9b6609b69facad0cc5425d4fa7934c33d7f2e91)

---

 hw/scsi/scsi-disk.c    |  6 ++++--

 hw/scsi/scsi-generic.c | 17 +++++++++++------

 include/hw/scsi/scsi.h |  4 +++-

 3 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c

index e44c61eeb4..5cb5fd35bd 100644

--- a/hw/scsi/scsi-disk.c

+++ b/hw/scsi/scsi-disk.c

@@ -2610,7 +2610,7 @@ static int get_device_type(SCSIDiskState *s)

     cmd[4] = sizeof(buf);

     ret = scsi_SG_IO_FROM_DEV(s->qdev.conf.blk, cmd, sizeof(cmd),

-                              buf, sizeof(buf));

+                              buf, sizeof(buf), s->qdev.io_timeout);

     if (ret < 0) {

         return -1;

     }

@@ -2771,7 +2771,7 @@ static BlockAIOCB *scsi_block_do_sgio(SCSIBlockReq *req,

     /* The rest is as in scsi-generic.c.  */

     io_header->mx_sb_len = sizeof(r->req.sense);

     io_header->sbp = r->req.sense;

-    io_header->timeout = UINT_MAX;

+    io_header->timeout = s->qdev.io_timeout * 1000;

     io_header->usr_ptr = r;

     io_header->flags |= SG_FLAG_DIRECT_IO;

@@ -3089,6 +3089,8 @@ static Property scsi_block_properties[] = {

                        DEFAULT_MAX_IO_SIZE),

     DEFINE_PROP_INT32("scsi_version", SCSIDiskState, qdev.default_scsi_version,

                       -1),

+    DEFINE_PROP_UINT32("io_timeout", SCSIDiskState, qdev.io_timeout,

+                       DEFAULT_IO_TIMEOUT),

     DEFINE_PROP_END_OF_LIST(),

 };

diff --git a/hw/scsi/scsi-generic.c b/hw/scsi/scsi-generic.c

index e7798ebcd0..3a383fe4d6 100644

--- a/hw/scsi/scsi-generic.c

+++ b/hw/scsi/scsi-generic.c

@@ -114,6 +114,8 @@ static int execute_command(BlockBackend *blk,

                            SCSIGenericReq *r, int direction,

                            BlockCompletionFunc *complete)

 {

+    SCSIDevice *s = r->req.dev;

+

     r->io_header.interface_id = 'S';

     r->io_header.dxfer_direction = direction;

     r->io_header.dxferp = r->buf;

@@ -122,7 +124,7 @@ static int execute_command(BlockBackend *blk,

     r->io_header.cmd_len = r->req.cmd.len;

     r->io_header.mx_sb_len = sizeof(r->req.sense);

     r->io_header.sbp = r->req.sense;

-    r->io_header.timeout = MAX_UINT;

+    r->io_header.timeout = s->io_timeout * 1000;

     r->io_header.usr_ptr = r;

     r->io_header.flags |= SG_FLAG_DIRECT_IO;

@@ -503,7 +505,7 @@ static int read_naa_id(const uint8_t *p, uint64_t *p_wwn)

 }

 int scsi_SG_IO_FROM_DEV(BlockBackend *blk, uint8_t *cmd, uint8_t cmd_size,

-                        uint8_t *buf, uint8_t buf_size)

+                        uint8_t *buf, uint8_t buf_size, uint32_t timeout)

 {

     sg_io_hdr_t io_header;

     uint8_t sensebuf[8];

@@ -518,7 +520,7 @@ int scsi_SG_IO_FROM_DEV(BlockBackend *blk, uint8_t *cmd, uint8_t cmd_size,

     io_header.cmd_len = cmd_size;

     io_header.mx_sb_len = sizeof(sensebuf);

     io_header.sbp = sensebuf;

-    io_header.timeout = 6000; /* XXX */

+    io_header.timeout = timeout * 1000;

     ret = blk_ioctl(blk, SG_IO, &io_header);

     if (ret < 0 || io_header.driver_status || io_header.host_status) {

@@ -548,7 +550,7 @@ static void scsi_generic_set_vpd_bl_emulation(SCSIDevice *s)

     cmd[4] = sizeof(buf);

     ret = scsi_SG_IO_FROM_DEV(s->conf.blk, cmd, sizeof(cmd),

-                              buf, sizeof(buf));

+                              buf, sizeof(buf), s->io_timeout);

     if (ret < 0) {

         /*

          * Do not assume anything if we can't retrieve the

@@ -584,7 +586,7 @@ static void scsi_generic_read_device_identification(SCSIDevice *s)

     cmd[4] = sizeof(buf);

     ret = scsi_SG_IO_FROM_DEV(s->conf.blk, cmd, sizeof(cmd),

-                              buf, sizeof(buf));

+                              buf, sizeof(buf), s->io_timeout);

     if (ret < 0) {

         return;

     }

@@ -635,7 +637,7 @@ static int get_stream_blocksize(BlockBackend *blk)

     cmd[0] = MODE_SENSE;

     cmd[4] = sizeof(buf);

-    ret = scsi_SG_IO_FROM_DEV(blk, cmd, sizeof(cmd), buf, sizeof(buf));

+    ret = scsi_SG_IO_FROM_DEV(blk, cmd, sizeof(cmd), buf, sizeof(buf), 6);

     if (ret < 0) {

         return -1;

     }

@@ -725,6 +727,7 @@ static void scsi_generic_realize(SCSIDevice *s, Error **errp)

     /* Only used by scsi-block, but initialize it nevertheless to be clean.  */

     s->default_scsi_version = -1;

+    s->io_timeout = DEFAULT_IO_TIMEOUT;

     scsi_generic_read_device_inquiry(s);

 }

@@ -748,6 +751,8 @@ static SCSIRequest *scsi_new_request(SCSIDevice *d, uint32_t tag, uint32_t lun,

 static Property scsi_generic_properties[] = {

     DEFINE_PROP_DRIVE("drive", SCSIDevice, conf.blk),

     DEFINE_PROP_BOOL("share-rw", SCSIDevice, conf.share_rw, false),

+    DEFINE_PROP_UINT32("io_timeout", SCSIDevice, io_timeout,

+                       DEFAULT_IO_TIMEOUT),

     DEFINE_PROP_END_OF_LIST(),

 };

diff --git a/include/hw/scsi/scsi.h b/include/hw/scsi/scsi.h

index 332ef602f4..ae0724a32d 100644

--- a/include/hw/scsi/scsi.h

+++ b/include/hw/scsi/scsi.h

@@ -17,6 +17,7 @@ typedef struct SCSIReqOps SCSIReqOps;

 #define SCSI_SENSE_BUF_SIZE_OLD 96

 #define SCSI_SENSE_BUF_SIZE 252

+#define DEFAULT_IO_TIMEOUT 30

 struct SCSIRequest {

     SCSIBus           *bus;

@@ -88,6 +89,7 @@ struct SCSIDevice

     uint64_t port_wwn;

     int scsi_version;

     int default_scsi_version;

+    uint32_t io_timeout;

     bool needs_vpd_bl_emulation;

     bool hba_supports_iothread;

 };

@@ -192,7 +194,7 @@ void scsi_device_unit_attention_reported(SCSIDevice *dev);

 void scsi_generic_read_device_inquiry(SCSIDevice *dev);

 int scsi_device_get_sense(SCSIDevice *dev, uint8_t *buf, int len, bool fixed);

 int scsi_SG_IO_FROM_DEV(BlockBackend *blk, uint8_t *cmd, uint8_t cmd_size,

-                        uint8_t *buf, uint8_t buf_size);

+                        uint8_t *buf, uint8_t buf_size, uint32_t timeout);

 SCSIDevice *scsi_device_find(SCSIBus *bus, int channel, int target, int lun);

 /* scsi-generic.c. */

-- 

2.18.2