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Commit 5abcdba4 authored by Joerg Roedel's avatar Joerg Roedel
Browse files

iommu/amd: Put IOMMUv2 capable devices in pt_domain 



If the device starts to use IOMMUv2 features the dma handles
need to stay valid. The only sane way to do this is to use a
identity mapping for the device and not translate it by the
iommu. This is implemented with this patch. Since this lifts
the device-isolation there is also a new kernel parameter
which allows to disable that feature.

Signed-off-by: default avatarJoerg Roedel <joerg.roedel@amd.com>
parent 400a28a0

Documentation/kernel-parameters.txt

+5 −0
Original line number Diff line number Diff line
@@ -329,6 +329,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted. 
				    is a lot of faster

			off	  - do not initialize any AMD IOMMU found in

				    the system

			force_isolation - Force device isolation for all

					  devices. The IOMMU driver is not

					  allowed anymore to lift isolation

					  requirements as needed. This option

					  does not override iommu=pt



	amijoy.map=	[HW,JOY] Amiga joystick support

			Map of devices attached to JOY0DAT and JOY1DAT

drivers/iommu/amd_iommu.c

+78 −16
Original line number Diff line number Diff line
@@ -67,6 +67,7 @@ struct iommu_cmd { 
};



static void update_domain(struct protection_domain *domain);

static int __init alloc_passthrough_domain(void);



/****************************************************************************

 *
@@ -147,6 +148,24 @@ static struct iommu_dev_data *get_dev_data(struct device *dev) 
	return dev->archdata.iommu;

}



static bool pci_iommuv2_capable(struct pci_dev *pdev)

{

	static const int caps[] = {

		PCI_EXT_CAP_ID_ATS,

		PCI_PRI_CAP,

		PCI_PASID_CAP,

	};

	int i, pos;



	for (i = 0; i < 3; ++i) {

		pos = pci_find_ext_capability(pdev, caps[i]);

		if (pos == 0)

			return false;

	}



	return true;

}



/*

 * In this function the list of preallocated protection domains is traversed to

 * find the domain for a specific device
@@ -204,6 +223,7 @@ static bool check_device(struct device *dev) 


static int iommu_init_device(struct device *dev)

{

	struct pci_dev *pdev = to_pci_dev(dev);

	struct iommu_dev_data *dev_data;

	u16 alias;
@@ -228,6 +248,13 @@ static int iommu_init_device(struct device *dev) 
		dev_data->alias_data = alias_data;

	}



	if (pci_iommuv2_capable(pdev)) {

		struct amd_iommu *iommu;



		iommu              = amd_iommu_rlookup_table[dev_data->devid];

		dev_data->iommu_v2 = iommu->is_iommu_v2;

	}



	dev->archdata.iommu = dev_data;



	return 0;
@@ -1762,7 +1789,7 @@ static void __detach_device(struct iommu_dev_data *dev_data) 
	 * passthrough domain if it is detached from any other domain.

	 * Make sure we can deassign from the pt_domain itself.

	 */

	if (iommu_pass_through &&

	if (dev_data->passthrough &&

	    (dev_data->domain == NULL && domain != pt_domain))

		__attach_device(dev_data, pt_domain);

}
@@ -1820,18 +1847,20 @@ static struct protection_domain *domain_for_device(struct device *dev) 
static int device_change_notifier(struct notifier_block *nb,

				  unsigned long action, void *data)

{

	struct device *dev = data;

	u16 devid;

	struct protection_domain *domain;

	struct dma_ops_domain *dma_domain;

	struct protection_domain *domain;

	struct iommu_dev_data *dev_data;

	struct device *dev = data;

	struct amd_iommu *iommu;

	unsigned long flags;

	u16 devid;



	if (!check_device(dev))

		return 0;



	devid    = get_device_id(dev);

	iommu    = amd_iommu_rlookup_table[devid];

	dev_data = get_dev_data(dev);



	switch (action) {

	case BUS_NOTIFY_UNBOUND_DRIVER:
@@ -1840,7 +1869,7 @@ static int device_change_notifier(struct notifier_block *nb, 


		if (!domain)

			goto out;

		if (iommu_pass_through)

		if (dev_data->passthrough)

			break;

		detach_device(dev);

		break;
@@ -2436,8 +2465,9 @@ static int amd_iommu_dma_supported(struct device *dev, u64 mask) 
 */

static void prealloc_protection_domains(void)

{

	struct pci_dev *dev = NULL;

	struct iommu_dev_data *dev_data;

	struct dma_ops_domain *dma_dom;

	struct pci_dev *dev = NULL;

	u16 devid;



	for_each_pci_dev(dev) {
@@ -2446,6 +2476,16 @@ static void prealloc_protection_domains(void) 
		if (!check_device(&dev->dev))

			continue;



		dev_data = get_dev_data(&dev->dev);

		if (!amd_iommu_force_isolation && dev_data->iommu_v2) {

			/* Make sure passthrough domain is allocated */

			alloc_passthrough_domain();

			dev_data->passthrough = true;

			attach_device(&dev->dev, pt_domain);

			pr_info("AMD-Vi: Using passthough domain for device %s\n",

				dev_name(&dev->dev));

		}



		/* Is there already any domain for it? */

		if (domain_for_device(&dev->dev))

			continue;
@@ -2476,6 +2516,7 @@ static struct dma_map_ops amd_iommu_dma_ops = { 


static unsigned device_dma_ops_init(void)

{

	struct iommu_dev_data *dev_data;

	struct pci_dev *pdev = NULL;

	unsigned unhandled = 0;
@@ -2485,7 +2526,12 @@ static unsigned device_dma_ops_init(void) 
			continue;

		}



		dev_data = get_dev_data(&pdev->dev);



		if (!dev_data->passthrough)

			pdev->dev.archdata.dma_ops = &amd_iommu_dma_ops;

		else

			pdev->dev.archdata.dma_ops = &nommu_dma_ops;

	}



	return unhandled;
@@ -2612,6 +2658,20 @@ static struct protection_domain *protection_domain_alloc(void) 
	return NULL;

}



static int __init alloc_passthrough_domain(void)

{

	if (pt_domain != NULL)

		return 0;



	/* allocate passthrough domain */

	pt_domain = protection_domain_alloc();

	if (!pt_domain)

		return -ENOMEM;



	pt_domain->mode = PAGE_MODE_NONE;



	return 0;

}

static int amd_iommu_domain_init(struct iommu_domain *dom)

{

	struct protection_domain *domain;
@@ -2798,21 +2858,23 @@ static struct iommu_ops amd_iommu_ops = { 


int __init amd_iommu_init_passthrough(void)

{

	struct amd_iommu *iommu;

	struct iommu_dev_data *dev_data;

	struct pci_dev *dev = NULL;

	struct amd_iommu *iommu;

	u16 devid;

	int ret;



	/* allocate passthrough domain */

	pt_domain = protection_domain_alloc();

	if (!pt_domain)

		return -ENOMEM;



	pt_domain->mode |= PAGE_MODE_NONE;

	ret = alloc_passthrough_domain();

	if (ret)

		return ret;



	for_each_pci_dev(dev) {

		if (!check_device(&dev->dev))

			continue;



		dev_data = get_dev_data(&dev->dev);

		dev_data->passthrough = true;



		devid = get_device_id(&dev->dev);



		iommu = amd_iommu_rlookup_table[devid];

drivers/iommu/amd_iommu_init.c

+4 −0
Original line number Diff line number Diff line
@@ -146,6 +146,8 @@ u32 amd_iommu_max_pasids __read_mostly = ~0; 


bool amd_iommu_v2_present __read_mostly;



bool amd_iommu_force_isolation __read_mostly;



/*

 * The ACPI table parsing functions set this variable on an error

 */
@@ -1642,6 +1644,8 @@ static int __init parse_amd_iommu_options(char *str) 
			amd_iommu_unmap_flush = true;

		if (strncmp(str, "off", 3) == 0)

			amd_iommu_disabled = true;

		if (strncmp(str, "force_isolation", 15) == 0)

			amd_iommu_force_isolation = true;

	}



	return 1;

drivers/iommu/amd_iommu_types.h

+4 −0
Original line number Diff line number Diff line
@@ -330,6 +330,8 @@ struct iommu_dev_data { 
	struct protection_domain *domain; /* Domain the device is bound to */

	atomic_t bind;			  /* Domain attach reverent count */

	u16 devid;			  /* PCI Device ID */

	bool iommu_v2;			  /* Device can make use of IOMMUv2 */

	bool passthrough;		  /* Default for device is pt_domain */

	struct {

		bool enabled;

		int qdep;
@@ -575,6 +577,8 @@ extern u32 amd_iommu_max_pasids; 


extern bool amd_iommu_v2_present;



extern bool amd_iommu_force_isolation;



/* takes bus and device/function and returns the device id

 * FIXME: should that be in generic PCI code? */

static inline u16 calc_devid(u8 bus, u8 devfn)