Patchwork vhost: Add vhost_commit callback for SeaBIOS ROM region re-mapping

login
register
mail settings
Submitter Nicholas A. Bellinger
Date April 3, 2013, 9:15 a.m.
Message ID <1364980511-25122-1-git-send-email-nab@linux-iscsi.org>
Download mbox | patch
Permalink /patch/233323/
State New
Headers show

Comments

Nicholas A. Bellinger - April 3, 2013, 9:15 a.m.
From: Nicholas Bellinger <nab@linux-iscsi.org>

This patch follows MST's recommendation to move checks for
vhost_verify_ring_mappings() -> cpu_physical_memory_map() operations
from MemoryListener->region_[add,del]() -> vhost_set_memory() into
final MemoryListener->commit() -> vhost_commit() callback.

It addresses the case where virtio-scsi vq ioport RAM re-mapping
to read-only SeaBIOS ROM triggers a cpu_physical_memory_map()
NIL MemoryRegionSection pointer failure.

Also save vhost_dev->mem_changed_[start,end]_addr values in
vhost_set_memory() for final ranges_overlap checks.  (Thanks Paolo!)

Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Asias He <asias@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
---
 hw/vhost.c |   53 ++++++++++++++++++++++++++++++++++++++---------------
 hw/vhost.h |    3 +++
 2 files changed, 41 insertions(+), 15 deletions(-)
Michael S. Tsirkin - April 3, 2013, 9:49 a.m.
On Wed, Apr 03, 2013 at 09:15:11AM +0000, Nicholas A. Bellinger wrote:
> From: Nicholas Bellinger <nab@linux-iscsi.org>
> 
> This patch follows MST's recommendation to move checks for
> vhost_verify_ring_mappings() -> cpu_physical_memory_map() operations
> from MemoryListener->region_[add,del]() -> vhost_set_memory() into
> final MemoryListener->commit() -> vhost_commit() callback.
> 
> It addresses the case where virtio-scsi vq ioport RAM re-mapping
> to read-only SeaBIOS ROM triggers a cpu_physical_memory_map()
> NIL MemoryRegionSection pointer failure.
> 
> Also save vhost_dev->mem_changed_[start,end]_addr values in
> vhost_set_memory() for final ranges_overlap checks.  (Thanks Paolo!)
> 
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: Asias He <asias@redhat.com>
> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Looks good.
Acked-by: Michael S. Tsirkin <mst@redhat.com>

> ---
>  hw/vhost.c |   53 ++++++++++++++++++++++++++++++++++++++---------------
>  hw/vhost.h |    3 +++
>  2 files changed, 41 insertions(+), 15 deletions(-)
> 
> diff --git a/hw/vhost.c b/hw/vhost.c
> index 832cc89..00345f2 100644
> --- a/hw/vhost.c
> +++ b/hw/vhost.c
> @@ -385,8 +385,6 @@ static void vhost_set_memory(MemoryListener *listener,
>      bool log_dirty = memory_region_is_logging(section->mr);
>      int s = offsetof(struct vhost_memory, regions) +
>          (dev->mem->nregions + 1) * sizeof dev->mem->regions[0];
> -    uint64_t log_size;
> -    int r;
>      void *ram;
>  
>      dev->mem = g_realloc(dev->mem, s);
> @@ -419,12 +417,47 @@ static void vhost_set_memory(MemoryListener *listener,
>          /* Remove old mapping for this memory, if any. */
>          vhost_dev_unassign_memory(dev, start_addr, size);
>      }
> +    dev->mem_changed_start_addr = MIN(dev->mem_changed_start_addr, start_addr);
> +    dev->mem_changed_end_addr = MAX(dev->mem_changed_end_addr, start_addr + size - 1);
> +    dev->memory_changed = true;
> +}
> +
> +static bool vhost_section(MemoryRegionSection *section)
> +{
> +    return memory_region_is_ram(section->mr);
> +}
> +
> +static void vhost_begin(MemoryListener *listener)
> +{
> +    struct vhost_dev *dev = container_of(listener, struct vhost_dev,
> +                                         memory_listener);
> +    dev->mem_changed_end_addr = 0;
> +    dev->mem_changed_start_addr = -1;
> +}
>  
> +static void vhost_commit(MemoryListener *listener)
> +{
> +    struct vhost_dev *dev = container_of(listener, struct vhost_dev,
> +                                         memory_listener);
> +    hwaddr start_addr = 0;
> +    ram_addr_t size = 0;
> +    uint64_t log_size;
> +    int r;
> +
> +    if (!dev->memory_changed) {
> +        return;
> +    }
>      if (!dev->started) {
>          return;
>      }
> +    if (dev->mem_changed_start_addr > dev->mem_changed_end_addr) {
> +        return;
> +    }
>  
>      if (dev->started) {
> +        start_addr = dev->mem_changed_start_addr;
> +        size = dev->mem_changed_end_addr - dev->mem_changed_start_addr + 1;
> +
>          r = vhost_verify_ring_mappings(dev, start_addr, size);
>          assert(r >= 0);
>      }
> @@ -432,6 +465,7 @@ static void vhost_set_memory(MemoryListener *listener,
>      if (!dev->log_enabled) {
>          r = ioctl(dev->control, VHOST_SET_MEM_TABLE, dev->mem);
>          assert(r >= 0);
> +        dev->memory_changed = false;
>          return;
>      }
>      log_size = vhost_get_log_size(dev);
> @@ -448,19 +482,7 @@ static void vhost_set_memory(MemoryListener *listener,
>      if (dev->log_size > log_size + VHOST_LOG_BUFFER) {
>          vhost_dev_log_resize(dev, log_size);
>      }
> -}
> -
> -static bool vhost_section(MemoryRegionSection *section)
> -{
> -    return memory_region_is_ram(section->mr);
> -}
> -
> -static void vhost_begin(MemoryListener *listener)
> -{
> -}
> -
> -static void vhost_commit(MemoryListener *listener)
> -{
> +    dev->memory_changed = false;
>  }
>  
>  static void vhost_region_add(MemoryListener *listener,
> @@ -854,6 +876,7 @@ int vhost_dev_init(struct vhost_dev *hdev, int devfd, const char *devpath,
>      hdev->log_size = 0;
>      hdev->log_enabled = false;
>      hdev->started = false;
> +    hdev->memory_changed = false;
>      memory_listener_register(&hdev->memory_listener, &address_space_memory);
>      hdev->force = force;
>      return 0;
> diff --git a/hw/vhost.h b/hw/vhost.h
> index f062d48..adb40c3 100644
> --- a/hw/vhost.h
> +++ b/hw/vhost.h
> @@ -45,6 +45,9 @@ struct vhost_dev {
>      vhost_log_chunk_t *log;
>      unsigned long long log_size;
>      bool force;
> +    bool memory_changed;
> +    hwaddr mem_changed_start_addr;
> +    hwaddr mem_changed_end_addr;
>  };
>  
>  int vhost_dev_init(struct vhost_dev *hdev, int devfd, const char *devpath,
> -- 
> 1.7.2.5
Paolo Bonzini - April 3, 2013, 10:06 a.m.
Il 03/04/2013 11:49, Michael S. Tsirkin ha scritto:
> On Wed, Apr 03, 2013 at 09:15:11AM +0000, Nicholas A. Bellinger wrote:
>> From: Nicholas Bellinger <nab@linux-iscsi.org>
>>
>> This patch follows MST's recommendation to move checks for
>> vhost_verify_ring_mappings() -> cpu_physical_memory_map() operations
>> from MemoryListener->region_[add,del]() -> vhost_set_memory() into
>> final MemoryListener->commit() -> vhost_commit() callback.
>>
>> It addresses the case where virtio-scsi vq ioport RAM re-mapping
>> to read-only SeaBIOS ROM triggers a cpu_physical_memory_map()
>> NIL MemoryRegionSection pointer failure.
>>
>> Also save vhost_dev->mem_changed_[start,end]_addr values in
>> vhost_set_memory() for final ranges_overlap checks.  (Thanks Paolo!)
>>
>> Cc: Michael S. Tsirkin <mst@redhat.com>
>> Cc: Paolo Bonzini <pbonzini@redhat.com>
>> Cc: Asias He <asias@redhat.com>
>> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
> 
> Looks good.
> Acked-by: Michael S. Tsirkin <mst@redhat.com>

Applied to the SCSI branch, thanks.

Paolo

>> ---
>>  hw/vhost.c |   53 ++++++++++++++++++++++++++++++++++++++---------------
>>  hw/vhost.h |    3 +++
>>  2 files changed, 41 insertions(+), 15 deletions(-)
>>
>> diff --git a/hw/vhost.c b/hw/vhost.c
>> index 832cc89..00345f2 100644
>> --- a/hw/vhost.c
>> +++ b/hw/vhost.c
>> @@ -385,8 +385,6 @@ static void vhost_set_memory(MemoryListener *listener,
>>      bool log_dirty = memory_region_is_logging(section->mr);
>>      int s = offsetof(struct vhost_memory, regions) +
>>          (dev->mem->nregions + 1) * sizeof dev->mem->regions[0];
>> -    uint64_t log_size;
>> -    int r;
>>      void *ram;
>>  
>>      dev->mem = g_realloc(dev->mem, s);
>> @@ -419,12 +417,47 @@ static void vhost_set_memory(MemoryListener *listener,
>>          /* Remove old mapping for this memory, if any. */
>>          vhost_dev_unassign_memory(dev, start_addr, size);
>>      }
>> +    dev->mem_changed_start_addr = MIN(dev->mem_changed_start_addr, start_addr);
>> +    dev->mem_changed_end_addr = MAX(dev->mem_changed_end_addr, start_addr + size - 1);
>> +    dev->memory_changed = true;
>> +}
>> +
>> +static bool vhost_section(MemoryRegionSection *section)
>> +{
>> +    return memory_region_is_ram(section->mr);
>> +}
>> +
>> +static void vhost_begin(MemoryListener *listener)
>> +{
>> +    struct vhost_dev *dev = container_of(listener, struct vhost_dev,
>> +                                         memory_listener);
>> +    dev->mem_changed_end_addr = 0;
>> +    dev->mem_changed_start_addr = -1;
>> +}
>>  
>> +static void vhost_commit(MemoryListener *listener)
>> +{
>> +    struct vhost_dev *dev = container_of(listener, struct vhost_dev,
>> +                                         memory_listener);
>> +    hwaddr start_addr = 0;
>> +    ram_addr_t size = 0;
>> +    uint64_t log_size;
>> +    int r;
>> +
>> +    if (!dev->memory_changed) {
>> +        return;
>> +    }
>>      if (!dev->started) {
>>          return;
>>      }
>> +    if (dev->mem_changed_start_addr > dev->mem_changed_end_addr) {
>> +        return;
>> +    }
>>  
>>      if (dev->started) {
>> +        start_addr = dev->mem_changed_start_addr;
>> +        size = dev->mem_changed_end_addr - dev->mem_changed_start_addr + 1;
>> +
>>          r = vhost_verify_ring_mappings(dev, start_addr, size);
>>          assert(r >= 0);
>>      }
>> @@ -432,6 +465,7 @@ static void vhost_set_memory(MemoryListener *listener,
>>      if (!dev->log_enabled) {
>>          r = ioctl(dev->control, VHOST_SET_MEM_TABLE, dev->mem);
>>          assert(r >= 0);
>> +        dev->memory_changed = false;
>>          return;
>>      }
>>      log_size = vhost_get_log_size(dev);
>> @@ -448,19 +482,7 @@ static void vhost_set_memory(MemoryListener *listener,
>>      if (dev->log_size > log_size + VHOST_LOG_BUFFER) {
>>          vhost_dev_log_resize(dev, log_size);
>>      }
>> -}
>> -
>> -static bool vhost_section(MemoryRegionSection *section)
>> -{
>> -    return memory_region_is_ram(section->mr);
>> -}
>> -
>> -static void vhost_begin(MemoryListener *listener)
>> -{
>> -}
>> -
>> -static void vhost_commit(MemoryListener *listener)
>> -{
>> +    dev->memory_changed = false;
>>  }
>>  
>>  static void vhost_region_add(MemoryListener *listener,
>> @@ -854,6 +876,7 @@ int vhost_dev_init(struct vhost_dev *hdev, int devfd, const char *devpath,
>>      hdev->log_size = 0;
>>      hdev->log_enabled = false;
>>      hdev->started = false;
>> +    hdev->memory_changed = false;
>>      memory_listener_register(&hdev->memory_listener, &address_space_memory);
>>      hdev->force = force;
>>      return 0;
>> diff --git a/hw/vhost.h b/hw/vhost.h
>> index f062d48..adb40c3 100644
>> --- a/hw/vhost.h
>> +++ b/hw/vhost.h
>> @@ -45,6 +45,9 @@ struct vhost_dev {
>>      vhost_log_chunk_t *log;
>>      unsigned long long log_size;
>>      bool force;
>> +    bool memory_changed;
>> +    hwaddr mem_changed_start_addr;
>> +    hwaddr mem_changed_end_addr;
>>  };
>>  
>>  int vhost_dev_init(struct vhost_dev *hdev, int devfd, const char *devpath,
>> -- 
>> 1.7.2.5
Michael S. Tsirkin - April 3, 2013, 10:34 a.m.
On Wed, Apr 03, 2013 at 12:06:14PM +0200, Paolo Bonzini wrote:
> Il 03/04/2013 11:49, Michael S. Tsirkin ha scritto:
> > On Wed, Apr 03, 2013 at 09:15:11AM +0000, Nicholas A. Bellinger wrote:
> >> From: Nicholas Bellinger <nab@linux-iscsi.org>
> >>
> >> This patch follows MST's recommendation to move checks for
> >> vhost_verify_ring_mappings() -> cpu_physical_memory_map() operations
> >> from MemoryListener->region_[add,del]() -> vhost_set_memory() into
> >> final MemoryListener->commit() -> vhost_commit() callback.
> >>
> >> It addresses the case where virtio-scsi vq ioport RAM re-mapping
> >> to read-only SeaBIOS ROM triggers a cpu_physical_memory_map()
> >> NIL MemoryRegionSection pointer failure.
> >>
> >> Also save vhost_dev->mem_changed_[start,end]_addr values in
> >> vhost_set_memory() for final ranges_overlap checks.  (Thanks Paolo!)
> >>
> >> Cc: Michael S. Tsirkin <mst@redhat.com>
> >> Cc: Paolo Bonzini <pbonzini@redhat.com>
> >> Cc: Asias He <asias@redhat.com>
> >> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
> > 
> > Looks good.
> > Acked-by: Michael S. Tsirkin <mst@redhat.com>
> 
> Applied to the SCSI branch, thanks.
> 
> Paolo

Is the rest of vhost-scsi there now?

> >> ---
> >>  hw/vhost.c |   53 ++++++++++++++++++++++++++++++++++++++---------------
> >>  hw/vhost.h |    3 +++
> >>  2 files changed, 41 insertions(+), 15 deletions(-)
> >>
> >> diff --git a/hw/vhost.c b/hw/vhost.c
> >> index 832cc89..00345f2 100644
> >> --- a/hw/vhost.c
> >> +++ b/hw/vhost.c
> >> @@ -385,8 +385,6 @@ static void vhost_set_memory(MemoryListener *listener,
> >>      bool log_dirty = memory_region_is_logging(section->mr);
> >>      int s = offsetof(struct vhost_memory, regions) +
> >>          (dev->mem->nregions + 1) * sizeof dev->mem->regions[0];
> >> -    uint64_t log_size;
> >> -    int r;
> >>      void *ram;
> >>  
> >>      dev->mem = g_realloc(dev->mem, s);
> >> @@ -419,12 +417,47 @@ static void vhost_set_memory(MemoryListener *listener,
> >>          /* Remove old mapping for this memory, if any. */
> >>          vhost_dev_unassign_memory(dev, start_addr, size);
> >>      }
> >> +    dev->mem_changed_start_addr = MIN(dev->mem_changed_start_addr, start_addr);
> >> +    dev->mem_changed_end_addr = MAX(dev->mem_changed_end_addr, start_addr + size - 1);
> >> +    dev->memory_changed = true;
> >> +}
> >> +
> >> +static bool vhost_section(MemoryRegionSection *section)
> >> +{
> >> +    return memory_region_is_ram(section->mr);
> >> +}
> >> +
> >> +static void vhost_begin(MemoryListener *listener)
> >> +{
> >> +    struct vhost_dev *dev = container_of(listener, struct vhost_dev,
> >> +                                         memory_listener);
> >> +    dev->mem_changed_end_addr = 0;
> >> +    dev->mem_changed_start_addr = -1;
> >> +}
> >>  
> >> +static void vhost_commit(MemoryListener *listener)
> >> +{
> >> +    struct vhost_dev *dev = container_of(listener, struct vhost_dev,
> >> +                                         memory_listener);
> >> +    hwaddr start_addr = 0;
> >> +    ram_addr_t size = 0;
> >> +    uint64_t log_size;
> >> +    int r;
> >> +
> >> +    if (!dev->memory_changed) {
> >> +        return;
> >> +    }
> >>      if (!dev->started) {
> >>          return;
> >>      }
> >> +    if (dev->mem_changed_start_addr > dev->mem_changed_end_addr) {
> >> +        return;
> >> +    }
> >>  
> >>      if (dev->started) {
> >> +        start_addr = dev->mem_changed_start_addr;
> >> +        size = dev->mem_changed_end_addr - dev->mem_changed_start_addr + 1;
> >> +
> >>          r = vhost_verify_ring_mappings(dev, start_addr, size);
> >>          assert(r >= 0);
> >>      }
> >> @@ -432,6 +465,7 @@ static void vhost_set_memory(MemoryListener *listener,
> >>      if (!dev->log_enabled) {
> >>          r = ioctl(dev->control, VHOST_SET_MEM_TABLE, dev->mem);
> >>          assert(r >= 0);
> >> +        dev->memory_changed = false;
> >>          return;
> >>      }
> >>      log_size = vhost_get_log_size(dev);
> >> @@ -448,19 +482,7 @@ static void vhost_set_memory(MemoryListener *listener,
> >>      if (dev->log_size > log_size + VHOST_LOG_BUFFER) {
> >>          vhost_dev_log_resize(dev, log_size);
> >>      }
> >> -}
> >> -
> >> -static bool vhost_section(MemoryRegionSection *section)
> >> -{
> >> -    return memory_region_is_ram(section->mr);
> >> -}
> >> -
> >> -static void vhost_begin(MemoryListener *listener)
> >> -{
> >> -}
> >> -
> >> -static void vhost_commit(MemoryListener *listener)
> >> -{
> >> +    dev->memory_changed = false;
> >>  }
> >>  
> >>  static void vhost_region_add(MemoryListener *listener,
> >> @@ -854,6 +876,7 @@ int vhost_dev_init(struct vhost_dev *hdev, int devfd, const char *devpath,
> >>      hdev->log_size = 0;
> >>      hdev->log_enabled = false;
> >>      hdev->started = false;
> >> +    hdev->memory_changed = false;
> >>      memory_listener_register(&hdev->memory_listener, &address_space_memory);
> >>      hdev->force = force;
> >>      return 0;
> >> diff --git a/hw/vhost.h b/hw/vhost.h
> >> index f062d48..adb40c3 100644
> >> --- a/hw/vhost.h
> >> +++ b/hw/vhost.h
> >> @@ -45,6 +45,9 @@ struct vhost_dev {
> >>      vhost_log_chunk_t *log;
> >>      unsigned long long log_size;
> >>      bool force;
> >> +    bool memory_changed;
> >> +    hwaddr mem_changed_start_addr;
> >> +    hwaddr mem_changed_end_addr;
> >>  };
> >>  
> >>  int vhost_dev_init(struct vhost_dev *hdev, int devfd, const char *devpath,
> >> -- 
> >> 1.7.2.5
Paolo Bonzini - April 3, 2013, 10:34 a.m.
Il 03/04/2013 12:34, Michael S. Tsirkin ha scritto:
> > Applied to the SCSI branch, thanks.
> 
> Is the rest of vhost-scsi there now?

No, but it will be shortly. :)

Paolo
Nicholas A. Bellinger - April 3, 2013, 8:23 p.m.
On Wed, 2013-04-03 at 12:34 +0200, Paolo Bonzini wrote:
> Il 03/04/2013 12:34, Michael S. Tsirkin ha scritto:
> > > Applied to the SCSI branch, thanks.
> > 
> > Is the rest of vhost-scsi there now?
> 
> No, but it will be shortly. :)
> 

Hi Paolo,

Just a heads up that PATCH-v2 for vhost-scsi-pci does not apply cleanly
against the latest qemu.git/master.  Let me know if your OK with fixing
the fuzz, or would prefer a -v3 re-spin before for applying to SCSI
branch.  

Also, please include the uninitialized VQs checks that MST recently
ACK'ed here:
virtio/vhost: Add checks for uninitialized VQs
http://www.spinics.net/lists/target-devel/msg04298.html

Btw, has the SCSI branch been pushed to a public repo..?

--nab
Paolo Bonzini - April 4, 2013, 5:26 a.m.
Il 03/04/2013 22:23, Nicholas A. Bellinger ha scritto:
> 
> Just a heads up that PATCH-v2 for vhost-scsi-pci does not apply cleanly
> against the latest qemu.git/master.  Let me know if your OK with fixing
> the fuzz, or would prefer a -v3 re-spin before for applying to SCSI
> branch.  

I know, I'll fix it.

Paolo

Patch

diff --git a/hw/vhost.c b/hw/vhost.c
index 832cc89..00345f2 100644
--- a/hw/vhost.c
+++ b/hw/vhost.c
@@ -385,8 +385,6 @@  static void vhost_set_memory(MemoryListener *listener,
     bool log_dirty = memory_region_is_logging(section->mr);
     int s = offsetof(struct vhost_memory, regions) +
         (dev->mem->nregions + 1) * sizeof dev->mem->regions[0];
-    uint64_t log_size;
-    int r;
     void *ram;
 
     dev->mem = g_realloc(dev->mem, s);
@@ -419,12 +417,47 @@  static void vhost_set_memory(MemoryListener *listener,
         /* Remove old mapping for this memory, if any. */
         vhost_dev_unassign_memory(dev, start_addr, size);
     }
+    dev->mem_changed_start_addr = MIN(dev->mem_changed_start_addr, start_addr);
+    dev->mem_changed_end_addr = MAX(dev->mem_changed_end_addr, start_addr + size - 1);
+    dev->memory_changed = true;
+}
+
+static bool vhost_section(MemoryRegionSection *section)
+{
+    return memory_region_is_ram(section->mr);
+}
+
+static void vhost_begin(MemoryListener *listener)
+{
+    struct vhost_dev *dev = container_of(listener, struct vhost_dev,
+                                         memory_listener);
+    dev->mem_changed_end_addr = 0;
+    dev->mem_changed_start_addr = -1;
+}
 
+static void vhost_commit(MemoryListener *listener)
+{
+    struct vhost_dev *dev = container_of(listener, struct vhost_dev,
+                                         memory_listener);
+    hwaddr start_addr = 0;
+    ram_addr_t size = 0;
+    uint64_t log_size;
+    int r;
+
+    if (!dev->memory_changed) {
+        return;
+    }
     if (!dev->started) {
         return;
     }
+    if (dev->mem_changed_start_addr > dev->mem_changed_end_addr) {
+        return;
+    }
 
     if (dev->started) {
+        start_addr = dev->mem_changed_start_addr;
+        size = dev->mem_changed_end_addr - dev->mem_changed_start_addr + 1;
+
         r = vhost_verify_ring_mappings(dev, start_addr, size);
         assert(r >= 0);
     }
@@ -432,6 +465,7 @@  static void vhost_set_memory(MemoryListener *listener,
     if (!dev->log_enabled) {
         r = ioctl(dev->control, VHOST_SET_MEM_TABLE, dev->mem);
         assert(r >= 0);
+        dev->memory_changed = false;
         return;
     }
     log_size = vhost_get_log_size(dev);
@@ -448,19 +482,7 @@  static void vhost_set_memory(MemoryListener *listener,
     if (dev->log_size > log_size + VHOST_LOG_BUFFER) {
         vhost_dev_log_resize(dev, log_size);
     }
-}
-
-static bool vhost_section(MemoryRegionSection *section)
-{
-    return memory_region_is_ram(section->mr);
-}
-
-static void vhost_begin(MemoryListener *listener)
-{
-}
-
-static void vhost_commit(MemoryListener *listener)
-{
+    dev->memory_changed = false;
 }
 
 static void vhost_region_add(MemoryListener *listener,
@@ -854,6 +876,7 @@  int vhost_dev_init(struct vhost_dev *hdev, int devfd, const char *devpath,
     hdev->log_size = 0;
     hdev->log_enabled = false;
     hdev->started = false;
+    hdev->memory_changed = false;
     memory_listener_register(&hdev->memory_listener, &address_space_memory);
     hdev->force = force;
     return 0;
diff --git a/hw/vhost.h b/hw/vhost.h
index f062d48..adb40c3 100644
--- a/hw/vhost.h
+++ b/hw/vhost.h
@@ -45,6 +45,9 @@  struct vhost_dev {
     vhost_log_chunk_t *log;
     unsigned long long log_size;
     bool force;
+    bool memory_changed;
+    hwaddr mem_changed_start_addr;
+    hwaddr mem_changed_end_addr;
 };
 
 int vhost_dev_init(struct vhost_dev *hdev, int devfd, const char *devpath,