Commit 4989764d authored by Jason Gunthorpe's avatar Jason Gunthorpe
Browse files

iommu: Add IOMMU_CAP_ENFORCE_CACHE_COHERENCY 

This queries if a domain linked to a device should expect to support
enforce_cache_coherency() so iommufd can negotiate the rules for when a
domain should be shared or not.

For iommufd a device that declares IOMMU_CAP_ENFORCE_CACHE_COHERENCY will
not be attached to a domain that does not support it.

Link: https://lore.kernel.org/r/1-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com


Reviewed-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: default avatarKevin Tian <kevin.tian@intel.com>
Tested-by: default avatarNicolin Chen <nicolinc@nvidia.com>
Tested-by: default avatarYi Liu <yi.l.liu@intel.com>
Tested-by: default avatarLixiao Yang <lixiao.yang@intel.com>
Tested-by: default avatarMatthew Rosato <mjrosato@linux.ibm.com>
Tested-by: default avatarYu He <yu.he@intel.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
parent 69e61ede

drivers/iommu/amd/iommu.c

+2 −0
Original line number Original line Diff line number Diff line
@@ -2278,6 +2278,8 @@ static bool amd_iommu_capable(struct device *dev, enum iommu_cap cap) 
		return false;

		return false;

	case IOMMU_CAP_PRE_BOOT_PROTECTION:

	case IOMMU_CAP_PRE_BOOT_PROTECTION:

		return amdr_ivrs_remap_support;

		return amdr_ivrs_remap_support;

	case IOMMU_CAP_ENFORCE_CACHE_COHERENCY:

		return true;

	default:

	default:

		break;

		break;

	}

	}

drivers/iommu/intel/iommu.c

+11 −5
Original line number Original line Diff line number Diff line
@@ -4450,15 +4450,21 @@ static bool intel_iommu_enforce_cache_coherency(struct iommu_domain *domain) 




static bool intel_iommu_capable(struct device *dev, enum iommu_cap cap)

static bool intel_iommu_capable(struct device *dev, enum iommu_cap cap)

{

{

	if (cap == IOMMU_CAP_CACHE_COHERENCY)

	struct device_domain_info *info = dev_iommu_priv_get(dev);



	switch (cap) {

	case IOMMU_CAP_CACHE_COHERENCY:

		return true;

		return true;

	if (cap == IOMMU_CAP_INTR_REMAP)

	case IOMMU_CAP_INTR_REMAP:

		return irq_remapping_enabled == 1;

		return irq_remapping_enabled == 1;

	if (cap == IOMMU_CAP_PRE_BOOT_PROTECTION)

	case IOMMU_CAP_PRE_BOOT_PROTECTION:

		return dmar_platform_optin();

		return dmar_platform_optin();



	case IOMMU_CAP_ENFORCE_CACHE_COHERENCY:

		return ecap_sc_support(info->iommu->ecap);

	default:

		return false;

		return false;

	}

	}

}





static struct iommu_device *intel_iommu_probe_device(struct device *dev)

static struct iommu_device *intel_iommu_probe_device(struct device *dev)

{

{

include/linux/iommu.h

+5 −0
Original line number Original line Diff line number Diff line
@@ -124,6 +124,11 @@ enum iommu_cap { 
	IOMMU_CAP_NOEXEC,		/* IOMMU_NOEXEC flag */

	IOMMU_CAP_NOEXEC,		/* IOMMU_NOEXEC flag */

	IOMMU_CAP_PRE_BOOT_PROTECTION,	/* Firmware says it used the IOMMU for

	IOMMU_CAP_PRE_BOOT_PROTECTION,	/* Firmware says it used the IOMMU for

					   DMA protection and we should too */

					   DMA protection and we should too */

	/*

	 * Per-device flag indicating if enforce_cache_coherency() will work on

	 * this device.

	 */

	IOMMU_CAP_ENFORCE_CACHE_COHERENCY,

};

};





/* These are the possible reserved region types */

/* These are the possible reserved region types */