Re: [Qemu-devel] [PATCH 5/5] vga optimization.

[Stefano Stabellini]

Anthony Liguori wrote:
>Glauber Costa wrote:
>> +static void map_linear_vram(CirrusVGAState *s)
>> +{
>> +    int phys_offset = s->vga_io_memory;
>> +
>> +    if (!s->map_addr && s->lfb_addr && s->lfb_end) {
>> +        s->map_addr = s->lfb_addr;
>> +        s->map_end = s->lfb_end;
>> +        cpu_register_physical_memory(s->map_addr, s->map_end - s->map_addr, 
>> s->vram_offset);
>> +        vga_dirty_log_start((VGAState *)s);
>>   
>
>So you register this region and enable dirty tracking.

I don't think it should be enabled here.

>> +    }
>> +
>> +    if(!(s->cirrus_srcptr != s->cirrus_srcptr_end)
>> +        && !((s->sr[0x07] & 0x01) == 0)
>> +        && !((s->gr[0x0B] & 0x14) == 0x14)
>> +        && !(s->gr[0x0B] & 0x02)) {
>> +        phys_offset = s->vram_offset | IO_MEM_RAM;
>> +    }
>> +    cpu_register_physical_memory(isa_mem_base + 0xa0000, 0x20000, 
>> phys_offset);
>>   
>
>But also potentially change 0xa0000..0xc0000 to RAM, but you don't 
>enable dirty tracking on this region.  I think you either have to leave 
>this region as MMIO or enable dirty tracking on it too.
>

To be honest I don't understand why this is part is needed.

@@ -2102,6 +2122,11 @@ static void vga_map(PCIDevice *pci_dev, int region_num,
     } else {
         cpu_register_physical_memory(addr, s->vram_size, s->vram_offset);
     }
+
+    s->map_addr = addr;
+    s->map_end = addr + VGA_RAM_SIZE;
+
+    vga_dirty_log_start(s);
 }

I think you should set lfb_addr and lfb_end here instead of map_addr and
map_end.