[PATCH] iommu/arm-smmu-v3: Add default domain quirk for Arm Fast Models
Robin Murphy
robin.murphy at arm.com
Tue Jun 29 11:10:53 PDT 2021
On 2021-06-29 18:34, Will Deacon wrote:
> On Fri, Jun 18, 2021 at 05:24:49PM +0100, Robin Murphy wrote:
>> Arm Fast Models are still implementing legacy virtio-pci devices behind
>> the SMMU, which continue to be problematic as "real hardware" devices
>> (from the point of view of the simulated system) without the mitigating
>> VIRTIO_F_ACCESS_PLATFORM feature.
>>
>> Since we now have the ability to force passthrough on a device-specific
>> basis, let's use it to work around this particular oddity so that people
>> who just want to boot Linux on a model don't have to fiddle around with
>> things to avoid the SMMU getting in the way by default (and I don't have
>> to keep telling them which things...)
>>
>> Signed-off-by: Robin Murphy <robin.murphy at arm.com>
>> ---
>> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 15 +++++++++++++++
>> 1 file changed, 15 insertions(+)
>
> Any chance of getting the fastmodels updated instead? It feels like it
> has to happen *eventually*, and then there would be no need for this bodge.
If it's any consolation the JIRA ticket you raised in 2017 is still open...
Robin.
>
> Will
>
>> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
>> index 54b2f27b81d4..13cf16e8f45b 100644
>> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
>> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
>> @@ -2649,6 +2649,20 @@ static int arm_smmu_dev_disable_feature(struct device *dev,
>> }
>> }
>>
>> +static int arm_smmu_def_domain_type(struct device *dev)
>> +{
>> + if (dev_is_pci(dev)) {
>> + struct pci_dev *pdev = to_pci_dev(dev);
>> +
>> + /* Legacy virtio-block devices on Arm Fast Models */
>> + if (pdev->vendor == 0x1af4 && pdev->device == 0x1001 &&
>> + pdev->subsystem_vendor == 0x00ff && pdev->subsystem_device == 0x0002)
>> + return IOMMU_DOMAIN_IDENTITY;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> static struct iommu_ops arm_smmu_ops = {
>> .capable = arm_smmu_capable,
>> .domain_alloc = arm_smmu_domain_alloc,
>> @@ -2673,6 +2687,7 @@ static struct iommu_ops arm_smmu_ops = {
>> .sva_bind = arm_smmu_sva_bind,
>> .sva_unbind = arm_smmu_sva_unbind,
>> .sva_get_pasid = arm_smmu_sva_get_pasid,
>> + .def_domain_type = arm_smmu_def_domain_type,
>> .pgsize_bitmap = -1UL, /* Restricted during device attach */
>> .owner = THIS_MODULE,
>> };
>> --
>> 2.25.1
>>
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