diff --git a/Makefile b/Makefile
index 3f97904..e7c5c3a 100644
--- a/Makefile
+++ b/Makefile
@@ -74,7 +74,7 @@
 configure: ;
 
 .PHONY: all clean cscope distclean dvi html info install install-doc \
-	pdf recurse-all speed test dist
+	pdf recurse-all speed test dist msi
 
 $(call set-vpath, $(SRC_PATH))
 
@@ -287,10 +287,32 @@
 qemu-ga$(EXESUF): $(qga-obj-y) libqemuutil.a libqemustub.a
 	$(call LINK, $^)
 
+ifdef QEMU_GA_MSI_ENABLED
+QEMU_GA_MSI=qemu-ga-$(ARCH).msi
+
+msi: ${QEMU_GA_MSI}
+
+$(QEMU_GA_MSI): qemu-ga.exe
+
+ifdef QEMU_GA_MSI_WITH_VSS
+$(QEMU_GA_MSI): qga/vss-win32/qga-vss.dll
+endif
+
+$(QEMU_GA_MSI): config-host.mak
+
+$(QEMU_GA_MSI):  qga/installer/qemu-ga.wxs
+	$(call quiet-command,QEMU_GA_VERSION="$(QEMU_GA_VERSION)" QEMU_GA_MANUFACTURER="$(QEMU_GA_MANUFACTURER)" QEMU_GA_DISTRO="$(QEMU_GA_DISTRO)" \
+	wixl -o $@ $(QEMU_GA_MSI_ARCH) $(QEMU_GA_MSI_WITH_VSS) $(QEMU_GA_MSI_MINGW_DLL_PATH) $<, "  WIXL  $@")
+else
+msi:
+	@echo MSI build not configured or dependency resolution failed (reconfigure with --enable-guest-agent-msi option)
+endif
+
 clean:
 # avoid old build problems by removing potentially incorrect old files
 	rm -f config.mak op-i386.h opc-i386.h gen-op-i386.h op-arm.h opc-arm.h gen-op-arm.h
 	rm -f qemu-options.def
+	rm -f *.msi
 	find . \( -name '*.l[oa]' -o -name '*.so' -o -name '*.dll' -o -name '*.mo' -o -name '*.[oda]' \) -type f -exec rm {} +
 	rm -f $(filter-out %.tlb,$(TOOLS)) $(HELPERS-y) qemu-ga TAGS cscope.* *.pod *~ */*~
 	rm -f fsdev/*.pod
diff --git a/configure b/configure
index 222694f..6fed07b 100755
--- a/configure
+++ b/configure
@@ -315,6 +315,7 @@
 bzip2=""
 guest_agent=""
 guest_agent_with_vss="no"
+guest_agent_msi=""
 vss_win32_sdk=""
 win_sdk="no"
 want_tools="yes"
@@ -1078,6 +1079,10 @@
   ;;
   --disable-guest-agent) guest_agent="no"
   ;;
+  --enable-guest-agent-msi) guest_agent_msi="yes"
+  ;;
+  --disable-guest-agent-msi) guest_agent_msi="no"
+  ;;
   --with-vss-sdk) vss_win32_sdk=""
   ;;
   --with-vss-sdk=*) vss_win32_sdk="$optarg"
@@ -1394,6 +1399,8 @@
                            reading bzip2-compressed dmg images)
   --disable-guest-agent    disable building of the QEMU Guest Agent
   --enable-guest-agent     enable building of the QEMU Guest Agent
+  --enable-guest-agent-msi enable building guest agent Windows MSI installation package
+  --disable-guest-agent-msi disable building guest agent Windows MSI installation
   --with-vss-sdk=SDK-path  enable Windows VSS support in QEMU Guest Agent
   --with-win-sdk=SDK-path  path to Windows Platform SDK (to build VSS .tlb)
   --disable-seccomp        disable seccomp support
@@ -3862,6 +3869,56 @@
 fi
 
 ##########################################
+# Guest agent Window MSI  package
+
+if test "$guest_agent" != yes; then
+  if test "$guest_agent_msi" = yes; then
+    error_exit "MSI guest agent package requires guest agent enabled"
+  fi
+  guest_agent_msi=no
+elif test "$mingw32" != "yes"; then
+  if test "$guest_agent_msi" = "yes"; then
+    error_exit "MSI guest agent package is available only for MinGW Windows cross-compilation"
+  fi
+  guest_agent_msi=no
+elif ! has wixl; then
+  if test "$guest_agent_msi" = "yes"; then
+    error_exit "MSI guest agent package requires wixl tool installed ( usually from msitools package )"
+  fi
+  guest_agent_msi=no
+fi
+
+if test "$guest_agent_msi" != "no"; then
+  if test "$guest_agent_with_vss" = "yes"; then
+    QEMU_GA_MSI_WITH_VSS="-D InstallVss"
+  fi
+
+  if test "$QEMU_GA_MANUFACTURER" = ""; then
+    QEMU_GA_MANUFACTURER=QEMU
+  fi
+
+  if test "$QEMU_GA_DISTRO" = ""; then
+    QEMU_GA_DISTRO=Linux
+  fi
+
+  if test "$QEMU_GA_VERSION" = ""; then
+      QEMU_GA_VERSION=`cat $source_path/VERSION`
+  fi
+
+  QEMU_GA_MSI_MINGW_DLL_PATH="-D Mingw_dlls=`$pkg_config --variable=prefix glib-2.0`/bin"
+  
+  case "$cpu" in
+  x86_64)
+    QEMU_GA_MSI_ARCH="-a x64 -D Arch=64"
+    ;;
+  i386)
+    QEMU_GA_MSI_ARCH="-D Arch=32"
+    ;;
+  *)
+    error_exit "CPU $cpu not supported for building installation package"
+    ;;
+  esac
+fi
 
 ##########################################
 # check if we have fdatasync
@@ -4558,6 +4615,15 @@
     echo "CONFIG_QGA_VSS=y" >> $config_host_mak
     echo "WIN_SDK=\"$win_sdk\"" >> $config_host_mak
   fi
+  if test "$guest_agent_msi" != "no"; then
+    echo "QEMU_GA_MSI_ENABLED=yes" >> $config_host_mak  
+    echo "QEMU_GA_MSI_MINGW_DLL_PATH=${QEMU_GA_MSI_MINGW_DLL_PATH}" >> $config_host_mak
+    echo "QEMU_GA_MSI_WITH_VSS=${QEMU_GA_MSI_WITH_VSS}" >> $config_host_mak
+    echo "QEMU_GA_MSI_ARCH=${QEMU_GA_MSI_ARCH}" >> $config_host_mak
+    echo "QEMU_GA_MANUFACTURER=${QEMU_GA_MANUFACTURER}" >> $config_host_mak
+    echo "QEMU_GA_DISTRO=${QEMU_GA_DISTRO}" >> $config_host_mak
+    echo "QEMU_GA_VERSION=${QEMU_GA_VERSION}" >> $config_host_mak
+  fi
 else
   echo "CONFIG_POSIX=y" >> $config_host_mak
 fi
diff --git a/exec.c b/exec.c
index 76bfc4a..f7883d2 100644
--- a/exec.c
+++ b/exec.c
@@ -341,6 +341,7 @@
                                  hwaddr *plen, bool resolve_subpage)
 {
     MemoryRegionSection *section;
+    MemoryRegion *mr;
     Int128 diff;
 
     section = address_space_lookup_region(d, addr, resolve_subpage);
@@ -350,8 +351,11 @@
     /* Compute offset within MemoryRegion */
     *xlat = addr + section->offset_within_region;
 
-    diff = int128_sub(section->mr->size, int128_make64(addr));
-    *plen = int128_get64(int128_min(diff, int128_make64(*plen)));
+    mr = section->mr;
+    if (memory_region_is_ram(mr)) {
+        diff = int128_sub(section->size, int128_make64(addr));
+        *plen = int128_get64(int128_min(diff, int128_make64(*plen)));
+    }
     return section;
 }
 
diff --git a/hw/timer/i8254.c b/hw/timer/i8254.c
index 3450c98..9b65a33 100644
--- a/hw/timer/i8254.c
+++ b/hw/timer/i8254.c
@@ -196,6 +196,12 @@
     PITChannelState *s;
 
     addr &= 3;
+
+    if (addr == 3) {
+        /* Mode/Command register is write only, read is ignored */
+        return 0;
+    }
+
     s = &pit->channels[addr];
     if (s->status_latched) {
         s->status_latched = 0;
diff --git a/hw/timer/mc146818rtc.c b/hw/timer/mc146818rtc.c
index 3204825..2e3ffc8 100644
--- a/hw/timer/mc146818rtc.c
+++ b/hw/timer/mc146818rtc.c
@@ -723,6 +723,12 @@
         check_update_timer(s);
     }
 
+    uint64_t now = qemu_clock_get_ns(rtc_clock);
+    if (now < s->next_periodic_time ||
+        now > (s->next_periodic_time + get_max_clock_jump())) {
+        periodic_timer_update(s, qemu_clock_get_ns(rtc_clock));
+    }
+
 #ifdef TARGET_I386
     if (version_id >= 2) {
         if (s->lost_tick_policy == LOST_TICK_POLICY_SLEW) {
diff --git a/include/qemu/timer.h b/include/qemu/timer.h
index e5bd494..9e4f90f 100644
--- a/include/qemu/timer.h
+++ b/include/qemu/timer.h
@@ -787,6 +787,15 @@
     return 1000000000LL;
 }
 
+static inline int64_t get_max_clock_jump(void)
+{
+    /* This should be small enough to prevent excessive interrupts from being
+     * generated by the RTC on clock jumps, but large enough to avoid frequent
+     * unnecessary resets in idle VMs.
+     */
+    return 60 * get_ticks_per_sec();
+}
+
 /*
  * Low level clock functions
  */
diff --git a/qemu-timer.c b/qemu-timer.c
index 5741f0d..aa6757e 100644
--- a/qemu-timer.c
+++ b/qemu-timer.c
@@ -573,7 +573,7 @@
         now = get_clock_realtime();
         last = clock->last;
         clock->last = now;
-        if (now < last) {
+        if (now < last || now > (last + get_max_clock_jump())) {
             notifier_list_notify(&clock->reset_notifiers, &now);
         }
         return now;
diff --git a/qga/channel-win32.c b/qga/channel-win32.c
index 0d5e5f5..04fa5e4 100644
--- a/qga/channel-win32.c
+++ b/qga/channel-win32.c
@@ -306,7 +306,7 @@
                            OPEN_EXISTING,
                            FILE_FLAG_NO_BUFFERING | FILE_FLAG_OVERLAPPED, NULL);
     if (c->handle == INVALID_HANDLE_VALUE) {
-        g_critical("error opening path");
+        g_critical("error opening path %s", newpath);
         return false;
     }
 
diff --git a/qga/commands-win32.c b/qga/commands-win32.c
index 3ef0549..d0aaec7 100644
--- a/qga/commands-win32.c
+++ b/qga/commands-win32.c
@@ -721,6 +721,7 @@
     }
 
     if (!vss_init(true)) {
+        g_debug("vss_init failed, vss commands are going to be disabled");
         const char *list[] = {
             "guest-get-fsinfo", "guest-fsfreeze-status",
             "guest-fsfreeze-freeze", "guest-fsfreeze-thaw", NULL};
diff --git a/qga/installer/qemu-ga.wxs b/qga/installer/qemu-ga.wxs
new file mode 100644
index 0000000..2c43f1b
--- /dev/null
+++ b/qga/installer/qemu-ga.wxs
@@ -0,0 +1,145 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Wix xmlns="http://schemas.microsoft.com/wix/2006/wi">
+  <?ifndef env.QEMU_GA_VERSION ?>
+    <?error Environment variable QEMU_GA_VERSION undefined?>
+  <?endif?>
+
+  <?ifndef env.QEMU_GA_DISTRO ?>
+    <?error Environment variable QEMU_GA_DISTRO undefined?>
+  <?endif?>
+
+  <?ifndef env.QEMU_GA_MANUFACTURER ?>
+    <?error Environment variable QEMU_GA_MANUFACTURER undefined?>
+  <?endif?>
+
+  <?ifndef var.Arch?>
+    <?error Define Arch to 32 or 64?>
+  <?endif?>
+
+  <?ifndef var.Mingw_bin?>
+    <?if $(var.Arch) = "64"?>
+      <?define Mingw_bin=/usr/x86_64-w64-mingw32/sys-root/mingw/bin ?>
+    <?endif?>
+    <?if $(var.Arch) = "32"?>
+      <?define Mingw_bin=/usr/i686-w64-mingw32/sys-root/mingw/bin ?>
+    <?endif?>
+  <?endif?>
+
+  <?if $(var.Arch) = "64"?>
+    <?define ArchLib=libgcc_s_seh-1.dll?>
+    <?define GaProgramFilesFolder="ProgramFiles64Folder" ?>
+  <?endif?>
+
+  <?if $(var.Arch) = "32"?>
+    <?define ArchLib=libgcc_s_sjlj-1.dll?>
+    <?define GaProgramFilesFolder="ProgramFilesFolder" ?>
+  <?endif?>
+
+  <?ifndef var.ArchLib ?>
+    <?error Unexpected Arch value $(var.Arch)?>
+  <?endif?>
+
+  <Product
+    Name="QEMU guest agent"
+    Id="*"
+    UpgradeCode="{EB6B8302-C06E-4bec-ADAC-932C68A3A98D}"
+    Manufacturer="$(env.QEMU_GA_MANUFACTURER)"
+    Version="$(env.QEMU_GA_VERSION)"
+    Language="1033">
+    <?if $(var.Arch) = 32 ?>
+    <Condition Message="Error: 32-bit version of Qemu GA can not be installed on 64-bit Windows.">NOT VersionNT64</Condition>
+    <?endif?>
+    <Package
+      Manufacturer="$(env.QEMU_GA_MANUFACTURER)"
+      InstallerVersion="200"
+      Languages="1033"
+      Compressed="yes"
+      InstallScope="perMachine"
+      />
+    <Media Id="1" Cabinet="qemu_ga.$(env.QEMU_GA_VERSION).cab" EmbedCab="yes" />
+    <Property Id="WHSLogo">1</Property>
+    <Property Id="PREVIOUSVERSIONSINSTALLED" />
+    <Upgrade Id="{EB6B8302-C06E-4bec-ADAC-932C68A3A98D}">
+      <UpgradeVersion
+        Minimum="1.0.0.0" Maximum="$(env.QEMU_GA_VERSION)"
+        Property="PREVIOUSVERSIONSINSTALLED"
+        IncludeMinimum="yes" IncludeMaximum="no" />
+    </Upgrade>
+
+    <Directory Id="TARGETDIR" Name="SourceDir">
+      <Directory Id="$(var.GaProgramFilesFolder)" Name="QEMU Guest Agent">
+        <Directory Id="qemu_ga_directory" Name="Qemu-ga">
+          <Component Id="qemu_ga" Guid="{908B7199-DE2A-4dc6-A8D0-27A5AE444FEA}">
+            <File Id="qemu_ga.exe" Name="qemu-ga.exe" Source="../../qemu-ga.exe" KeyPath="yes" DiskId="1"/>
+            <?ifdef var.InstallVss ?>
+            <File Id="qga_vss.dll" Name="qga-vss.dll" Source="../vss-win32/qga-vss.dll" KeyPath="no" DiskId="1"/>
+            <File Id="qga_vss.tlb" Name="qga-vss.tlb" Source="../vss-win32/qga-vss.tlb" KeyPath="no" DiskId="1"/>
+            <?endif?>
+            <File Id="iconv.dll" Name="iconv.dll" Source="$(var.Mingw_bin)/iconv.dll" KeyPath="no" DiskId="1"/>
+            <File Id="libgcc_arch_lib" Name="$(var.ArchLib)" Source="$(var.Mingw_bin)/$(var.ArchLib)" KeyPath="no" DiskId="1"/>
+            <File Id="libglib_2.0_0.dll" Name="libglib-2.0-0.dll" Source="$(var.Mingw_bin)/libglib-2.0-0.dll" KeyPath="no" DiskId="1"/>
+            <File Id="libintl_8.dll" Name="libintl-8.dll" Source="$(var.Mingw_bin)/libintl-8.dll" KeyPath="no" DiskId="1"/>
+            <File Id="libssp_0.dll" Name="libssp-0.dll" Source="$(var.Mingw_bin)/libssp-0.dll" KeyPath="no" DiskId="1"/>
+            <File Id="libwinpthread_1.dll" Name="libwinpthread-1.dll" Source="$(var.Mingw_bin)/libwinpthread-1.dll" KeyPath="no" DiskId="1"/>
+            <ServiceInstall
+              Id="ServiceInstaller"
+              Type="ownProcess"
+              Vital="yes"
+              Name="QEMU-GA"
+              DisplayName="QEMU Guest Agent"
+              Description="QEMU Guest Agent"
+              Start="auto"
+              Account="LocalSystem"
+              ErrorControl="ignore"
+              Interactive="no"
+              Arguments="-d"
+              >
+            </ServiceInstall>
+            <ServiceControl Id="StartService" Start="install" Stop="both" Remove="uninstall" Name="QEMU-GA" Wait="no" />
+          </Component>
+
+          <Component Id="registry_entries" Guid="d075d109-51ca-11e3-9f8b-000c29858960">
+            <RegistryKey Root="HKLM"
+                         Key="Software\$(env.QEMU_GA_MANUFACTURER)\$(env.QEMU_GA_DISTRO)\Tools\QemuGA">
+              <RegistryValue Type="string" Name="ProductID" Value="fb0a0d66-c7fb-4e2e-a16b-c4a3bfe8d13b" />
+              <RegistryValue Type="string" Name="Version" Value="$(env.QEMU_GA_VERSION)" />
+            </RegistryKey>
+          </Component>
+        </Directory>
+      </Directory>
+    </Directory>
+
+    <Property Id="cmd" Value="cmd.exe"/>
+
+    <?ifdef var.InstallVss ?>
+    <CustomAction Id="RegisterCom"
+             ExeCommand='/c "[qemu_ga_directory]qemu-ga.exe" -s vss-install'
+              Execute="deferred"
+              Property="cmd"
+              Impersonate="no"
+              Return="check"
+              >
+    </CustomAction>
+    <CustomAction Id="UnRegisterCom"
+              ExeCommand='/c "[qemu_ga_directory]qemu-ga.exe" -s vss-uninstall'
+              Execute="deferred"
+              Property="cmd"
+              Impersonate="no"
+              Return="check"
+              ></CustomAction>
+    <?endif?>
+
+    <Feature Id="QEMUFeature" Title="QEMU Guest Agent" Level="1">
+      <ComponentRef Id="qemu_ga" />
+      <ComponentRef Id="registry_entries" />
+    </Feature>
+
+    <InstallExecuteSequence>
+      <RemoveExistingProducts Before="InstallInitialize" />
+      <?ifdef var.InstallVss ?>
+      <Custom Action="RegisterCom" After="InstallServices">NOT Installed</Custom>
+      <Custom Action="UnRegisterCom" After="StopServices">Installed</Custom>
+      <?endif?>
+    </InstallExecuteSequence>
+  </Product>
+</Wix>
diff --git a/qga/main.c b/qga/main.c
index 9939a2b..7e1e438 100644
--- a/qga/main.c
+++ b/qga/main.c
@@ -211,7 +211,7 @@
 "  -V, --version     print version information and exit\n"
 "  -d, --daemonize   become a daemon\n"
 #ifdef _WIN32
-"  -s, --service     service commands: install, uninstall\n"
+"  -s, --service     service commands: install, uninstall, vss-install, vss-uninstall\n"
 #endif
 "  -b, --blacklist   comma-separated list of RPCs to disable (no spaces, \"?\"\n"
 "                    to list available RPCs)\n"
@@ -1036,6 +1036,14 @@
             } else if (strcmp(service, "uninstall") == 0) {
                 ga_uninstall_vss_provider();
                 return ga_uninstall_service();
+            } else if (strcmp(service, "vss-install") == 0) {
+                if (ga_install_vss_provider()) {
+                    return EXIT_FAILURE;
+                }
+                return EXIT_SUCCESS;
+            } else if (strcmp(service, "vss-uninstall") == 0) {
+                ga_uninstall_vss_provider();
+                return EXIT_SUCCESS;
             } else {
                 printf("Unknown service command.\n");
                 return EXIT_FAILURE;
diff --git a/tests/Makefile b/tests/Makefile
index 4de40de..5dd0c56 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -371,7 +371,7 @@
 tests/virtio-blk-test$(EXESUF): tests/virtio-blk-test.o $(libqos-virtio-obj-y)
 tests/virtio-net-test$(EXESUF): tests/virtio-net-test.o $(libqos-pc-obj-y)
 tests/virtio-rng-test$(EXESUF): tests/virtio-rng-test.o $(libqos-pc-obj-y)
-tests/virtio-scsi-test$(EXESUF): tests/virtio-scsi-test.o
+tests/virtio-scsi-test$(EXESUF): tests/virtio-scsi-test.o $(libqos-virtio-obj-y)
 tests/virtio-9p-test$(EXESUF): tests/virtio-9p-test.o
 tests/virtio-serial-test$(EXESUF): tests/virtio-serial-test.o
 tests/virtio-console-test$(EXESUF): tests/virtio-console-test.o
diff --git a/tests/libqos/malloc.c b/tests/libqos/malloc.c
index 8276130..82b9df5 100644
--- a/tests/libqos/malloc.c
+++ b/tests/libqos/malloc.c
@@ -285,6 +285,9 @@
 
 void guest_free(QGuestAllocator *allocator, uint64_t addr)
 {
+    if (!addr) {
+        return;
+    }
     mlist_free(allocator, addr);
     if (allocator->opts & ALLOC_PARANOID) {
         mlist_check(allocator);
diff --git a/tests/libqos/virtio.h b/tests/libqos/virtio.h
index 2449fee..0101278 100644
--- a/tests/libqos/virtio.h
+++ b/tests/libqos/virtio.h
@@ -19,8 +19,14 @@
 #define QVIRTIO_DRIVER          0x2
 #define QVIRTIO_DRIVER_OK       0x4
 
-#define QVIRTIO_NET_DEVICE_ID   0x1
-#define QVIRTIO_BLK_DEVICE_ID   0x2
+#define QVIRTIO_NET_DEVICE_ID       0x1
+#define QVIRTIO_BLK_DEVICE_ID       0x2
+#define QVIRTIO_CONSOLE_DEVICE_ID   0x3
+#define QVIRTIO_RNG_DEVICE_ID       0x4
+#define QVIRTIO_BALLOON_DEVICE_ID   0x5
+#define QVIRTIO_RPMSG_DEVICE_ID     0x7
+#define QVIRTIO_SCSI_DEVICE_ID      0x8
+#define QVIRTIO_9P_DEVICE_ID        0x9
 
 #define QVIRTIO_F_NOTIFY_ON_EMPTY       0x01000000
 #define QVIRTIO_F_ANY_LAYOUT            0x08000000
diff --git a/tests/virtio-scsi-test.c b/tests/virtio-scsi-test.c
index 989f825..11ccdd6 100644
--- a/tests/virtio-scsi-test.c
+++ b/tests/virtio-scsi-test.c
@@ -2,6 +2,7 @@
  * QTest testcase for VirtIO SCSI
  *
  * Copyright (c) 2014 SUSE LINUX Products GmbH
+ * Copyright (c) 2015 Red Hat Inc.
  *
  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  * See the COPYING file in the top-level directory.
@@ -11,16 +12,187 @@
 #include <string.h>
 #include "libqtest.h"
 #include "qemu/osdep.h"
+#include <stdio.h>
+#include "libqos/virtio.h"
+#include "libqos/virtio-pci.h"
+#include "libqos/pci-pc.h"
+#include "libqos/malloc.h"
+#include "libqos/malloc-pc.h"
+#include "libqos/malloc-generic.h"
+
+#define PCI_SLOT                0x02
+#define PCI_FN                  0x00
+#define QVIRTIO_SCSI_TIMEOUT_US (1 * 1000 * 1000)
+#define CDB_SIZE 32
+
+#define MAX_NUM_QUEUES 64
+
+typedef struct {
+    QVirtioDevice *dev;
+    QGuestAllocator *alloc;
+    QPCIBus *bus;
+    int num_queues;
+    QVirtQueue *vq[MAX_NUM_QUEUES + 2];
+} QVirtIOSCSI;
+
+typedef struct {
+    uint8_t lun[8];
+    int64_t tag;
+    uint8_t task_attr;
+    uint8_t prio;
+    uint8_t crn;
+    uint8_t cdb[CDB_SIZE];
+} QEMU_PACKED QVirtIOSCSICmdReq;
+
+typedef struct {
+    uint32_t sense_len;
+    uint32_t resid;
+    uint16_t status_qualifier;
+    uint8_t status;
+    uint8_t response;
+    uint8_t sense[96];
+} QEMU_PACKED QVirtIOSCSICmdResp;
+
+static void qvirtio_scsi_start(const char *extra_opts)
+{
+    char *cmdline;
+
+    cmdline = g_strdup_printf(
+                "-drive id=drv0,if=none,file=/dev/null,format=raw "
+                "-device virtio-scsi-pci,id=vs0 "
+                "-device scsi-hd,bus=vs0.0,drive=drv0 %s",
+                extra_opts ? : "");
+    qtest_start(cmdline);
+    g_free(cmdline);
+}
+
+static void qvirtio_scsi_stop(void)
+{
+    qtest_end();
+}
+
+static QVirtIOSCSI *qvirtio_scsi_pci_init(int slot)
+{
+    QVirtIOSCSI *vs;
+    QVirtioPCIDevice *dev;
+    void *addr;
+    int i;
+
+    vs = g_new0(QVirtIOSCSI, 1);
+    vs->alloc = pc_alloc_init();
+    vs->bus = qpci_init_pc();
+
+    dev = qvirtio_pci_device_find(vs->bus, QVIRTIO_SCSI_DEVICE_ID);
+    vs->dev = (QVirtioDevice *)dev;
+    g_assert(dev != NULL);
+    g_assert_cmphex(vs->dev->device_type, ==, QVIRTIO_SCSI_DEVICE_ID);
+
+    qvirtio_pci_device_enable(dev);
+    qvirtio_reset(&qvirtio_pci, vs->dev);
+    qvirtio_set_acknowledge(&qvirtio_pci, vs->dev);
+    qvirtio_set_driver(&qvirtio_pci, vs->dev);
+
+    addr = dev->addr + QVIRTIO_PCI_DEVICE_SPECIFIC_NO_MSIX;
+    vs->num_queues = qvirtio_config_readl(&qvirtio_pci, vs->dev,
+                                          (uint64_t)(uintptr_t)addr);
+
+    g_assert_cmpint(vs->num_queues, <, MAX_NUM_QUEUES);
+
+    for (i = 0; i < vs->num_queues + 2; i++) {
+        vs->vq[i] = qvirtqueue_setup(&qvirtio_pci, vs->dev, vs->alloc, i);
+    }
+
+    return vs;
+}
+
+static void qvirtio_scsi_pci_free(QVirtIOSCSI *vs)
+{
+    int i;
+
+    for (i = 0; i < vs->num_queues + 2; i++) {
+        guest_free(vs->alloc, vs->vq[i]->desc);
+    }
+    pc_alloc_uninit(vs->alloc);
+    qvirtio_pci_device_disable(container_of(vs->dev, QVirtioPCIDevice, vdev));
+    g_free(vs->dev);
+    qpci_free_pc(vs->bus);
+}
+
+static uint64_t qvirtio_scsi_alloc(QVirtIOSCSI *vs, size_t alloc_size,
+                                   const void *data)
+{
+    uint64_t addr;
+
+    addr = guest_alloc(vs->alloc, alloc_size);
+    if (data) {
+        memwrite(addr, data, alloc_size);
+    }
+
+    return addr;
+}
+
+static uint8_t virtio_scsi_do_command(QVirtIOSCSI *vs, const uint8_t *cdb,
+                                      const uint8_t *data_in,
+                                      size_t data_in_len,
+                                      uint8_t *data_out, size_t data_out_len)
+{
+    QVirtQueue *vq;
+    QVirtIOSCSICmdReq req = { { 0 } };
+    QVirtIOSCSICmdResp resp = { .response = 0xff, .status = 0xff };
+    uint64_t req_addr, resp_addr, data_in_addr = 0, data_out_addr = 0;
+    uint8_t response;
+    uint32_t free_head;
+
+    vq = vs->vq[2];
+
+    req.lun[0] = 1; /* Select LUN */
+    req.lun[1] = 1; /* Select target 1 */
+    memcpy(req.cdb, cdb, CDB_SIZE);
+
+    /* XXX: Fix endian if any multi-byte field in req/resp is used */
+
+    /* Add request header */
+    req_addr = qvirtio_scsi_alloc(vs, sizeof(req), &req);
+    free_head = qvirtqueue_add(vq, req_addr, sizeof(req), false, true);
+
+    if (data_out_len) {
+        data_out_addr = qvirtio_scsi_alloc(vs, data_out_len, data_out);
+        qvirtqueue_add(vq, data_out_addr, data_out_len, false, true);
+    }
+
+    /* Add response header */
+    resp_addr = qvirtio_scsi_alloc(vs, sizeof(resp), &resp);
+    qvirtqueue_add(vq, resp_addr, sizeof(resp), true, !!data_in_len);
+
+    if (data_in_len) {
+        data_in_addr = qvirtio_scsi_alloc(vs, data_in_len, data_in);
+        qvirtqueue_add(vq, data_in_addr, data_in_len, true, false);
+    }
+
+    qvirtqueue_kick(&qvirtio_pci, vs->dev, vq, free_head);
+    qvirtio_wait_queue_isr(&qvirtio_pci, vs->dev, vq, QVIRTIO_SCSI_TIMEOUT_US);
+
+    response = readb(resp_addr + offsetof(QVirtIOSCSICmdResp, response));
+
+    guest_free(vs->alloc, req_addr);
+    guest_free(vs->alloc, resp_addr);
+    guest_free(vs->alloc, data_in_addr);
+    guest_free(vs->alloc, data_out_addr);
+    return response;
+}
 
 /* Tests only initialization so far. TODO: Replace with functional tests */
 static void pci_nop(void)
 {
+    qvirtio_scsi_start(NULL);
+    qvirtio_scsi_stop();
 }
 
 static void hotplug(void)
 {
     QDict *response;
 
+    qvirtio_scsi_start("-drive id=drv1,if=none,file=/dev/null,format=raw");
     response = qmp("{\"execute\": \"device_add\","
                    " \"arguments\": {"
                    "   \"driver\": \"scsi-hd\","
@@ -42,6 +214,27 @@
     g_assert(qdict_haskey(response, "event"));
     g_assert(!strcmp(qdict_get_str(response, "event"), "DEVICE_DELETED"));
     QDECREF(response);
+    qvirtio_scsi_stop();
+}
+
+/* Test WRITE SAME with the lba not aligned */
+static void test_unaligned_write_same(void)
+{
+    QVirtIOSCSI *vs;
+    uint8_t buf[512] = { 0 };
+    const uint8_t write_same_cdb[CDB_SIZE] = { 0x41, 0x00, 0x00, 0x00, 0x00,
+                                               0x01, 0x00, 0x00, 0x02, 0x00 };
+
+    qvirtio_scsi_start("-drive file=blkdebug::null-co://,if=none,id=dr1"
+                       ",format=raw,file.align=4k "
+                       "-device scsi-disk,drive=dr1,lun=0,scsi-id=1");
+    vs = qvirtio_scsi_pci_init(PCI_SLOT);
+
+    g_assert_cmphex(0, ==,
+        virtio_scsi_do_command(vs, write_same_cdb, NULL, 0, buf, 512));
+
+    qvirtio_scsi_pci_free(vs);
+    qvirtio_scsi_stop();
 }
 
 int main(int argc, char **argv)
@@ -51,14 +244,10 @@
     g_test_init(&argc, &argv, NULL);
     qtest_add_func("/virtio/scsi/pci/nop", pci_nop);
     qtest_add_func("/virtio/scsi/pci/hotplug", hotplug);
+    qtest_add_func("/virtio/scsi/pci/scsi-disk/unaligned-write-same",
+                   test_unaligned_write_same);
 
-    qtest_start("-drive id=drv0,if=none,file=/dev/null,format=raw "
-                "-drive id=drv1,if=none,file=/dev/null,format=raw "
-                "-device virtio-scsi-pci,id=vscsi0 "
-                "-device scsi-hd,bus=vscsi0.0,drive=drv0");
     ret = g_test_run();
 
-    qtest_end();
-
     return ret;
 }
diff --git a/vl.c b/vl.c
index 278cd6a..1a920e6 100644
--- a/vl.c
+++ b/vl.c
@@ -3997,17 +3997,14 @@
         exit(0);
     }
 
-    /* Open the logfile at this point, if necessary. We can't open the logfile
-     * when encountering either of the logging options (-d or -D) because the
-     * other one may be encountered later on the command line, changing the
-     * location or level of logging.
+    /* Open the logfile at this point and set the log mask if necessary.
      */
+    if (log_file) {
+        qemu_set_log_filename(log_file);
+    }
+
     if (log_mask) {
         int mask;
-        if (log_file) {
-            qemu_set_log_filename(log_file);
-        }
-
         mask = qemu_str_to_log_mask(log_mask);
         if (!mask) {
             qemu_print_log_usage(stdout);