Re: [Qemu-devel] [QEMU][RFC PATCH 3/6] memory: Add xen memory hook

[Julien Grall <julien.grall@citrix.com>]

On 03/26/2012 12:02 PM, Avi Kivity wrote:
> On 03/26/2012 01:01 PM, Stefano Stabellini wrote:
>    
>> On Sun, 25 Mar 2012, Avi Kivity wrote:
>>      
>>> On 03/23/2012 06:37 PM, Jan Kiszka wrote:
>>>        
>>>> On 2012-03-23 16:08, Julien Grall wrote:
>>>>          
>>>>> On 03/22/2012 05:44 PM, Jan Kiszka wrote:
>>>>>            
>>>>>>>    static void core_region_nop(MemoryListener *listener,
>>>>>>> diff --git a/ioport.c b/ioport.c
>>>>>>> index 78a3b89..073ed75 100644
>>>>>>> --- a/ioport.c
>>>>>>> +++ b/ioport.c
>>>>>>> @@ -28,6 +28,7 @@
>>>>>>>    #include "ioport.h"
>>>>>>>    #include "trace.h"
>>>>>>>    #include "memory.h"
>>>>>>> +#include "hw/xen.h"
>>>>>>>
>>>>>>>    /***********************************************************/
>>>>>>>    /* IO Port */
>>>>>>> @@ -155,6 +156,11 @@ int register_ioport_read(pio_addr_t start, int
>>>>>>> length, int size,
>>>>>>>                         i);
>>>>>>>            ioport_opaque[i] = opaque;
>>>>>>>        }
>>>>>>> +
>>>>>>> +    if (xen_enabled()) {
>>>>>>> +        xen_map_iorange(start, length, 0);
>>>>>>> +    }
>>>>>>> +
>>>>>>>        return 0;
>>>>>>>    }
>>>>>>>
>>>>>>> @@ -175,7 +181,13 @@ int register_ioport_write(pio_addr_t start, int
>>>>>>> length, int size,
>>>>>>>                         i);
>>>>>>>            ioport_opaque[i] = opaque;
>>>>>>>        }
>>>>>>> +
>>>>>>> +    if (xen_enabled()) {
>>>>>>> +        xen_map_iorange(start, length, 0);
>>>>>>> +    }
>>>>>>> +
>>>>>>>        return 0;
>>>>>>> +
>>>>>>>    }
>>>>>>>
>>>>>>>    static uint32_t ioport_readb_thunk(void *opaque, uint32_t addr)
>>>>>>> @@ -260,6 +272,11 @@ void isa_unassign_ioport(pio_addr_t start, int
>>>>>>> length)
>>>>>>>            ioport_destructor_table[start](ioport_opaque[start]);
>>>>>>>            ioport_destructor_table[start] = NULL;
>>>>>>>        }
>>>>>>> +
>>>>>>> +    if (xen_enabled()) {
>>>>>>> +        xen_unmap_iorange(start, length, 0);
>>>>>>> +    }
>>>>>>> +
>>>>>>>        for(i = start; i<   start + length; i++) {
>>>>>>>            ioport_read_table[0][i] = NULL;
>>>>>>>            ioport_read_table[1][i] = NULL;
>>>>>>>
>>>>>>>                
>>>>>> memory_listener_register(xen_hooks, system_io)?
>>>>>>
>>>>>>              
>>>>> QEMU doesn't seem to call region_add/region_del for ioport.
>>>>> Moreover, some of ioport are directly register without
>>>>> using memory hook (for example cirrus vga).
>>>>>
>>>>> What is the best way to do it ?
>>>>>            
>>>> I haven't looked at details. Maybe it is just a combination of "use case
>>>> not yet considered, but can easily be added" and "need to switch legacy
>>>> code to new scheme". Then this still remains the better option than this
>>>> hook. Avi?
>>>>          
>>> Just the second - region_add/del will be called, but only for ioports
>>> registered via the MemoryRegion APIs.
>>>        
>> It looks like there are quite a few register_ioport_read/write left
>> around, especially in the following files:
>>
>> hw/acpi_piix4.c
>> hw/cirrus_vga.c
>> hw/serial.c
>> hw/pckbd.c
>> hw/pc.c
>>
>> I guess they should all be converted to memory_region_init_io, right?
>>      
> Right
I will modify theses files and send a different patch series.