[PATCH] PCI: Mark broken INTx masking for Mellanox devices

[PATCH] PCI: Mark broken INTx masking for Mellanox devices

[Gavin Shan]

The VFIO driver is routing LSI interrupts by capturing, masking,
and then delivering. When passing though Mallanox adapters from
host to guest, interrupt storm was reported from host and guest.
That's because we can't mask the LSI interrupt with help of PCI
command register.

The patch marks broken INTx masking for Mellanox devices so that
the VFIO driver will always mask the interrupt from interrupt
controller side to avoid interrupt storm.

Suggested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
---
 drivers/pci/quirks.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index d0f6926..8c2b96f 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -2977,6 +2977,10 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_CHELSIO, 0x0030,
 			 quirk_broken_intx_masking);
 DECLARE_PCI_FIXUP_HEADER(0x1814, 0x0601, /* Ralink RT2800 802.11n PCI */
 			 quirk_broken_intx_masking);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_MELLANOX, 0x1003,
+			 quirk_broken_intx_masking);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_MELLANOX, 0x6750,
+			 quirk_broken_intx_masking);
 /*
  * Realtek RTL8169 PCI Gigabit Ethernet Controller (rev 10)
  * Subsystem: Realtek RTL8169/8110 Family PCI Gigabit Ethernet NIC
-- 
1.8.3.2

Re: [PATCH] PCI: Mark broken INTx masking for Mellanox devices

[Alex Williamson]

On Fri, 2014-08-01 at 13:51 +1000, Gavin Shan wrote:
> The VFIO driver is routing LSI interrupts by capturing, masking,
> and then delivering. When passing though Mallanox adapters from
> host to guest, interrupt storm was reported from host and guest.
> That's because we can't mask the LSI interrupt with help of PCI
> command register.
> 
> The patch marks broken INTx masking for Mellanox devices so that
> the VFIO driver will always mask the interrupt from interrupt
> controller side to avoid interrupt storm.
> 
> Suggested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
> ---
>  drivers/pci/quirks.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index d0f6926..8c2b96f 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -2977,6 +2977,10 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_CHELSIO, 0x0030,
>  			 quirk_broken_intx_masking);
>  DECLARE_PCI_FIXUP_HEADER(0x1814, 0x0601, /* Ralink RT2800 802.11n PCI */
>  			 quirk_broken_intx_masking);
> +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_MELLANOX, 0x1003,
> +			 quirk_broken_intx_masking);
> +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_MELLANOX, 0x6750,
> +			 quirk_broken_intx_masking);
>  /*
>   * Realtek RTL8169 PCI Gigabit Ethernet Controller (rev 10)
>   * Subsystem: Realtek RTL8169/8110 Family PCI Gigabit Ethernet NIC

Is there an lspci description for the devices that we can also include?
You might also want to cc the driver maintainers to see if they're aware
or have any comments.  Thanks,

Alex

Re: [PATCH] PCI: Mark broken INTx masking for Mellanox devices

[Gavin Shan]

On Thu, Jul 31, 2014 at 10:06:30PM -0600, Alex Williamson wrote:
>On Fri, 2014-08-01 at 13:51 +1000, Gavin Shan wrote:
>> The VFIO driver is routing LSI interrupts by capturing, masking,
>> and then delivering. When passing though Mallanox adapters from
>> host to guest, interrupt storm was reported from host and guest.
>> That's because we can't mask the LSI interrupt with help of PCI
>> command register.
>> 
>> The patch marks broken INTx masking for Mellanox devices so that
>> the VFIO driver will always mask the interrupt from interrupt
>> controller side to avoid interrupt storm.
>> 
>> Suggested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
>> Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
>> ---
>>  drivers/pci/quirks.c | 4 ++++
>>  1 file changed, 4 insertions(+)
>> 
>> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
>> index d0f6926..8c2b96f 100644
>> --- a/drivers/pci/quirks.c
>> +++ b/drivers/pci/quirks.c
>> @@ -2977,6 +2977,10 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_CHELSIO, 0x0030,
>>  			 quirk_broken_intx_masking);
>>  DECLARE_PCI_FIXUP_HEADER(0x1814, 0x0601, /* Ralink RT2800 802.11n PCI */
>>  			 quirk_broken_intx_masking);
>> +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_MELLANOX, 0x1003,
>> +			 quirk_broken_intx_masking);
>> +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_MELLANOX, 0x6750,
>> +			 quirk_broken_intx_masking);
>>  /*
>>   * Realtek RTL8169 PCI Gigabit Ethernet Controller (rev 10)
>>   * Subsystem: Realtek RTL8169/8110 Family PCI Gigabit Ethernet NIC
>
>Is there an lspci description for the devices that we can also include?
>You might also want to cc the driver maintainers to see if they're aware
>or have any comments.  Thanks,
>

Yes, I'll include that in next revision and cc driver's maintainer.

Thanks,
Gavin