From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx> In Intel IOMMU, if the Page Request Queue (PRQ) is full, it will automatically respond to the device with a success message as a keep alive. And when sending the success message, IOMMU will include PASID in the Response Message when the Page Request has a PASID in Request Message and it does not check against the PRG Response PASID requirement of the device before sending the response. Also, if the device receives the PRG response with PASID when its not expecting it the device behavior is undefined. So if PASID is enabled in the device, enable PRI only if device expects PASID in PRG Response Message. Cc: Ashok Raj <ashok.raj@xxxxxxxxx> Cc: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx> Cc: Keith Busch <keith.busch@xxxxxxxxx> Suggested-by: Ashok Raj <ashok.raj@xxxxxxxxx> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx> --- drivers/iommu/intel-iommu.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 78188bf7e90d..5b174c09b80d 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -1402,7 +1402,9 @@ static void iommu_enable_dev_iotlb(struct device_domain_info *info) if (info->pasid_supported && !pci_enable_pasid(pdev, info->pasid_supported & ~1)) info->pasid_enabled = 1; - if (info->pri_supported && !pci_reset_pri(pdev) && !pci_enable_pri(pdev, 32)) + if (info->pri_supported && + (info->pasid_enabled ? pci_prg_resp_pasid_required(pdev) : 1) && + !pci_reset_pri(pdev) && !pci_enable_pri(pdev, 32)) info->pri_enabled = 1; #endif if (!pdev->untrusted && info->ats_supported && -- 2.20.1
