Re: [Qemu-devel] [PATCH v1 5/6] kvm: kvm_log_start/stop are only called with known sections

[David Hildenbrand <david@redhat.com>]

On 10.10.2017 15:29, Paolo Bonzini wrote:
> On 10/10/2017 11:06, Thomas Huth wrote:
>> On 11.09.2017 19:49, David Hildenbrand wrote:
>>> Let's properly align the sections first and bail out if we would ever
>>> get called with a memory section we don't know yet.
>>>
>>> Signed-off-by: David Hildenbrand <david@redhat.com>
>>> ---
>>>  accel/kvm/kvm-all.c | 18 ++++++++++++------
>>>  1 file changed, 12 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
>>> index b677d1b13e..2ae459453d 100644
>>> --- a/accel/kvm/kvm-all.c
>>> +++ b/accel/kvm/kvm-all.c
>>> @@ -411,15 +411,21 @@ static int kvm_slot_update_flags(KVMMemoryListener *kml, KVMSlot *mem,
>>>  static int kvm_section_update_flags(KVMMemoryListener *kml,
>>>                                      MemoryRegionSection *section)
>>>  {
>>> -    hwaddr phys_addr = section->offset_within_address_space;
>>> -    ram_addr_t size = int128_get64(section->size);
>>> -    KVMSlot *mem = kvm_lookup_matching_slot(kml, phys_addr, size);
>>> +    hwaddr start_addr, size;
>>> +    KVMSlot *mem;
>>>  
>>> -    if (mem == NULL)  {
>>> +    size = kvm_align_section(section, &start_addr);
>>> +    if (!size) {
>>>          return 0;
>>> -    } else {
>>> -        return kvm_slot_update_flags(kml, mem, section->mr);
>>>      }
>>> +
>>> +    mem = kvm_lookup_matching_slot(kml, start_addr, size);
>>> +    if (!mem) {
>>> +        fprintf(stderr, "%s: error finding slot\n", __func__);
>>> +        abort();
>>> +    }
>>
>> FYI, this abort now triggers with the "isa-vga" device:
>>
>> $ x86_64-softmmu/qemu-system-x86_64 -S -accel kvm -device isa-vga
>> kvm_section_update_flags: error finding slot
>> Aborted (core dumped)
>>
>> Any ideas how to fix this?
> 
> Reverting, unless David has some time to look into it.
> 
> Paolo
> 

Just returned from vacation, I'll have a look this week.

Thanks for that nice reproducer Thomas, that should help a lot!

-- 

Thanks,

David