From d5f3c043ac71af3e7339c452c2a1ca2dd916ff35 Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Wed, 22 Feb 2012 14:11:59 +0100
Subject: [PATCH 043/109] scsi: notify the device when unit attention is
 reported

RH-Author: Paolo Bonzini <pbonzini@redhat.com>
Message-id: <1329919979-20948-43-git-send-email-pbonzini@redhat.com>
Patchwork-id: 37526
O-Subject: [RHEL 6.3 qemu-kvm PATCH v2 042/102] scsi: notify the device when unit attention is reported
Bugzilla: 782029
RH-Acked-by: Laszlo Ersek <lersek@redhat.com>
RH-Acked-by: Orit Wasserman <owasserm@redhat.com>
RH-Acked-by: Gerd Hoffmann <kraxel@redhat.com>

Reporting media change events via unit attention sense codes requires
a small state machine: first report "NO MEDIUM", then report "MEDIUM MAY
HAVE CHANGED".  Unfortunately there is no good hooking point for the
device to notice that its pending unit attention condition has been
reported.  This patch reworks the generic machinery to add one.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
(cherry picked from 3653d8c40e04d78eb6b5b069522daf7cc72d4f06)
---
 hw/scsi-bus.c |   32 +++++++++++++++++++++++++++-----
 hw/scsi.h     |    2 ++
 2 files changed, 29 insertions(+), 5 deletions(-)

Signed-off-by: Michal Novotny <minovotn@redhat.com>
---
 hw/scsi-bus.c |   32 +++++++++++++++++++++++++++-----
 hw/scsi.h     |    2 ++
 2 files changed, 29 insertions(+), 5 deletions(-)

diff --git a/hw/scsi-bus.c b/hw/scsi-bus.c
index a177542..b385213 100644
--- a/hw/scsi-bus.c
+++ b/hw/scsi-bus.c
@@ -344,6 +344,13 @@ static int32_t scsi_target_send_command(SCSIRequest *req, uint8_t *buf)
         r->len = scsi_device_get_sense(r->req.dev, r->buf,
                                        MIN(req->cmd.xfer, sizeof r->buf),
                                        (req->cmd.buf[1] & 1) == 0);
+        if (r->req.dev->sense_is_ua) {
+            if (r->req.dev->info->unit_attention_reported) {
+                r->req.dev->info->unit_attention_reported(req->dev);
+            }
+            r->req.dev->sense_len = 0;
+            r->req.dev->sense_is_ua = false;
+        }
         break;
     default:
         scsi_req_build_sense(req, SENSE_CODE(LUN_NOT_SUPPORTED));
@@ -432,7 +439,13 @@ SCSIRequest *scsi_req_new(SCSIDevice *d, uint32_t tag, uint32_t lun,
             (buf[0] != INQUIRY &&
              buf[0] != REPORT_LUNS &&
              buf[0] != GET_CONFIGURATION &&
-             buf[0] != GET_EVENT_STATUS_NOTIFICATION)) {
+             buf[0] != GET_EVENT_STATUS_NOTIFICATION &&
+
+             /*
+              * If we already have a pending unit attention condition,
+              * report this one before triggering another one.
+              */
+             !(buf[0] == REQUEST_SENSE && d->sense_is_ua))) {
             req = scsi_req_alloc(&reqops_unit_attention, d, tag, lun,
                                  hba_private);
         } else if (lun != d->lun ||
@@ -528,10 +541,15 @@ int scsi_req_get_sense(SCSIRequest *req, uint8_t *buf, int len)
      *
      * We assume UA_INTLCK_CTRL to be 00b for HBAs that support autosense, and
      * 10b for HBAs that do not support it (do not call scsi_req_get_sense).
-     * In the latter case, scsi_req_complete clears unit attention conditions
-     * after moving them to the device's sense buffer.
+     * Here we handle unit attention clearing for UA_INTLCK_CTRL == 00b.
      */
-    scsi_clear_unit_attention(req);
+    if (req->dev->sense_is_ua) {
+        if (req->dev->info->unit_attention_reported) {
+            req->dev->info->unit_attention_reported(req->dev);
+        }
+        req->dev->sense_len = 0;
+        req->dev->sense_is_ua = false;
+    }
     return ret;
 }
 
@@ -1147,8 +1165,12 @@ void scsi_req_complete(SCSIRequest *req, int status)
 
     if (req->sense_len) {
         memcpy(req->dev->sense, req->sense, req->sense_len);
+        req->dev->sense_len = req->sense_len;
+        req->dev->sense_is_ua = (req->ops == &reqops_unit_attention);
+    } else {
+        req->dev->sense_len = 0;
+        req->dev->sense_is_ua = false;
     }
-    req->dev->sense_len = req->sense_len;
 
     /*
      * Unit attention state is now stored in the device's sense buffer
diff --git a/hw/scsi.h b/hw/scsi.h
index 6c922c5..afa5994 100644
--- a/hw/scsi.h
+++ b/hw/scsi.h
@@ -64,6 +64,7 @@ struct SCSIDevice
     BlockConf conf;
     SCSIDeviceInfo *info;
     SCSISense unit_attention;
+    bool sense_is_ua;
     uint8_t sense[SCSI_SENSE_BUF_SIZE];
     uint32_t sense_len;
     QTAILQ_HEAD(, SCSIRequest) requests;
@@ -95,6 +96,7 @@ struct SCSIDeviceInfo {
     void (*destroy)(SCSIDevice *s);
     SCSIRequest *(*alloc_req)(SCSIDevice *s, uint32_t tag, uint32_t lun,
                               void *hba_private);
+    void (*unit_attention_reported)(SCSIDevice *s);
     SCSIReqOps reqops;
 };
 
-- 
1.7.7.6