Re: [PATCH v2 3/5] hvmloader: Remove minimum size for BARs to relocate to 64-bit space

[George Dunlap <george.dunlap@eu.citrix.com>]

On 19/06/13 22:14, Wei Liu wrote:
> On Tue, Jun 18, 2013 at 05:46:22PM +0100, George Dunlap wrote:
>> Allow devices with BARs less than 512MiB to be relocated to high memory.
>>
>> This will only be invoked if there is not enough low MMIO space to map
>> the device, and will be done preferentially to large devices first; so
>> in all likelihood only large devices will be remapped anyway.
>>
>> This is needed to work-around the issue of qemu-xen not being able to
>> handle moving guest memory around to resize the MMIO hole.  The default
>> MMIO hole size is less than 256MiB.
>>
>> Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
>> CC: Ian Jackson <ian.jackson@citrix.com>
>> CC: Ian Campbell <ian.campbell@citrix.com>
>> CC: Stefano Stabellini <stefano.stabellini@citrix.com>
>> CC: Hanweidong <hanweidong@huawei.com>
>> ---
>>   tools/firmware/hvmloader/config.h |    1 -
>>   tools/firmware/hvmloader/pci.c    |    5 ++---
>>   2 files changed, 2 insertions(+), 4 deletions(-)
>>
>> diff --git a/tools/firmware/hvmloader/config.h b/tools/firmware/hvmloader/config.h
>> index 8143d6f..6641197 100644
>> --- a/tools/firmware/hvmloader/config.h
>> +++ b/tools/firmware/hvmloader/config.h
>> @@ -55,7 +55,6 @@ extern struct bios_config ovmf_config;
>>   /* MMIO hole: Hardcoded defaults, which can be dynamically expanded. */
>>   #define PCI_MEM_START       0xf0000000
>>   #define PCI_MEM_END         0xfc000000
>> -#define PCI_MIN_BIG_BAR_SIZE          0x20000000
>>   
>>   extern unsigned long pci_mem_start, pci_mem_end;
>>   
>> diff --git a/tools/firmware/hvmloader/pci.c b/tools/firmware/hvmloader/pci.c
>> index 7f306a1..a483b02 100644
>> --- a/tools/firmware/hvmloader/pci.c
>> +++ b/tools/firmware/hvmloader/pci.c
>> @@ -265,9 +265,8 @@ void pci_setup(void)
>>           if ( (bar_data & PCI_BASE_ADDRESS_SPACE) ==
>>                PCI_BASE_ADDRESS_SPACE_MEMORY )
>>           {
>> -            /* Mapping high memory if PCI deivce is 64 bits bar and the bar size
>> -               is larger than 512M */
>> -            if (using_64bar && (bar_sz > PCI_MIN_BIG_BAR_SIZE)) {
>> +            /* Mapping high memory if PCI device is 64 bits bar */
>> +            if (using_64bar) {
> I think the original had style problem, if you look at other occurrences
> for 'if', it should be
>
>    if ( condition )
>        statement;

Ack.

  -George