Re: [Qemu-devel] [PATCH v6 2/2] enable multi-function hot-add

[Cao jin <caoj.fnst@cn.fujitsu.com>]

Hi Alex

On 10/27/2015 10:21 PM, Alex Williamson wrote:
> On Tue, 2015-10-27 at 20:51 +0800, Cao jin wrote:
>> Enable PCIe device multi-function hot-add, just ensure function 0 is added
>> last, then driver will got the notification to scan the slot.
>>
>> Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com>
>> ---
>>   hw/pci/pci.c         | 40 +++++++++++++++++++++++++++++++++++++++-
>>   hw/pci/pci_host.c    | 13 +++++++++++--
>>   hw/pci/pcie.c        | 18 +++++++++---------
>>   include/hw/pci/pci.h |  1 +
>>   4 files changed, 60 insertions(+), 12 deletions(-)
>
>> diff --git a/hw/pci/pci_host.c b/hw/pci/pci_host.c
>> index 3e26f92..63d7d2f 100644
>> --- a/hw/pci/pci_host.c
>> +++ b/hw/pci/pci_host.c
>> @@ -20,6 +20,7 @@
>>
>>   #include "hw/pci/pci.h"
>>   #include "hw/pci/pci_host.h"
>> +#include "hw/pci/pci_bus.h"
>>   #include "trace.h"
>>
>>   /* debug PCI */
>> @@ -75,7 +76,11 @@ void pci_data_write(PCIBus *s, uint32_t addr, uint32_t val, int len)
>>       PCIDevice *pci_dev = pci_dev_find_by_addr(s, addr);
>>       uint32_t config_addr = addr & (PCI_CONFIG_SPACE_SIZE - 1);
>>
>> -    if (!pci_dev) {
>> +    /* non-zero functions are only exposed when function 0 is present,
>> +     * allowing direct removal of unexposed functions.
>> +     */
>> +    if (!pci_dev ||
>> +        (pci_dev->qdev.hotplugged && !pci_get_function_0(pci_dev))) {
>>           return;
>>       }
>>
>> @@ -91,7 +96,11 @@ uint32_t pci_data_read(PCIBus *s, uint32_t addr, int len)
>>       uint32_t config_addr = addr & (PCI_CONFIG_SPACE_SIZE - 1);
>>       uint32_t val;
>>
>> -    if (!pci_dev) {
>> +    /* non-zero functions are only exposed when function 0 is present,
>> +     * allowing direct removal of unexposed functions.
>> +     */
>> +    if (!pci_dev ||
>> +        (pci_dev->qdev.hotplugged && !pci_get_function_0(pci_dev))) {
>>           return ~0x0;
>>       }
>
>
> Don't we need to do this in pci_host_config_read_common() and
> pci_host_config_write_common() instead?  Otherwise I don't think we
> catch config access via mmcfg.  Thanks,
>

Yup...my carelessness, will fix it. Thanks for reminding:)

> Alex
>
> .
>

-- 
Yours Sincerely,

Cao Jin