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

["Michael S. Tsirkin" <mst@redhat.com>]

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