Re: [Qemu-devel] [PATCH] vhost: Add vhost_commit callback for SeaBIOS ROM region re-mapping

[Paolo Bonzini <pbonzini@redhat.com>]

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