KVM: arm64: vgic-its: Implement ITS command queue command handlers (df9f58fb) · Commits · 戴 / test

virt/kvm/arm/vgic/vgic-its.c

+660 −1

Original line number	Diff line number	Diff line
		@@ -33,6 +33,67 @@
		#include "vgic.h"
		#include "vgic-mmio.h"

		/*
		* Creates a new (reference to a) struct vgic_irq for a given LPI.
		* If this LPI is already mapped on another ITS, we increase its refcount
		* and return a pointer to the existing structure.
		* If this is a "new" LPI, we allocate and initialize a new struct vgic_irq.
		* This function returns a pointer to the _unlocked_ structure.
		*/
		static struct vgic_irq vgic_add_lpi(struct kvm kvm, u32 intid)
		{
		struct vgic_dist *dist = &kvm->arch.vgic;
		struct vgic_irq irq = vgic_get_irq(kvm, NULL, intid), oldirq;

		/* In this case there is no put, since we keep the reference. */
		if (irq)
		return irq;

		irq = kzalloc(sizeof(struct vgic_irq), GFP_KERNEL);
		if (!irq)
		return NULL;

		INIT_LIST_HEAD(&irq->lpi_list);
		INIT_LIST_HEAD(&irq->ap_list);
		spin_lock_init(&irq->irq_lock);

		irq->config = VGIC_CONFIG_EDGE;
		kref_init(&irq->refcount);
		irq->intid = intid;

		spin_lock(&dist->lpi_list_lock);

		/*
		* There could be a race with another vgic_add_lpi(), so we need to
		* check that we don't add a second list entry with the same LPI.
		*/
		list_for_each_entry(oldirq, &dist->lpi_list_head, lpi_list) {
		if (oldirq->intid != intid)
		continue;

		/* Someone was faster with adding this LPI, lets use that. */
		kfree(irq);
		irq = oldirq;

		/*
		* This increases the refcount, the caller is expected to
		* call vgic_put_irq() on the returned pointer once it's
		* finished with the IRQ.
		*/
		kref_get(&irq->refcount);

		goto out_unlock;
		}

		list_add_tail(&irq->lpi_list, &dist->lpi_list_head);
		dist->lpi_list_count++;

		out_unlock:
		spin_unlock(&dist->lpi_list_lock);

		return irq;
		}

		struct its_device {
		struct list_head dev_list;

		@@ -62,16 +123,75 @@ struct its_itte {
		u32 event_id;
		};

		/*
		* Find and returns a device in the device table for an ITS.
		* Must be called with the its_lock mutex held.
		*/
		static struct its_device find_its_device(struct vgic_its its, u32 device_id)
		{
		struct its_device *device;

		list_for_each_entry(device, &its->device_list, dev_list)
		if (device_id == device->device_id)
		return device;

		return NULL;
		}

		/*
		* Find and returns an interrupt translation table entry (ITTE) for a given
		* Device ID/Event ID pair on an ITS.
		* Must be called with the its_lock mutex held.
		*/
		static struct its_itte find_itte(struct vgic_its its, u32 device_id,
		u32 event_id)
		{
		struct its_device *device;
		struct its_itte *itte;

		device = find_its_device(its, device_id);
		if (device == NULL)
		return NULL;

		list_for_each_entry(itte, &device->itt_head, itte_list)
		if (itte->event_id == event_id)
		return itte;

		return NULL;
		}

		/* To be used as an iterator this macro misses the enclosing parentheses */
		#define for_each_lpi_its(dev, itte, its) \
		list_for_each_entry(dev, &(its)->device_list, dev_list) \
		list_for_each_entry(itte, &(dev)->itt_head, itte_list)

		/*
		* We only implement 48 bits of PA at the moment, although the ITS
		* supports more. Let's be restrictive here.
		*/
		#define BASER_ADDRESS(x) ((x) & GENMASK_ULL(47, 16))
		#define CBASER_ADDRESS(x) ((x) & GENMASK_ULL(47, 12))
		#define PENDBASER_ADDRESS(x) ((x) & GENMASK_ULL(47, 16))
		#define PROPBASER_ADDRESS(x) ((x) & GENMASK_ULL(47, 12))

		#define GIC_LPI_OFFSET 8192

		/*
		* Finds and returns a collection in the ITS collection table.
		* Must be called with the its_lock mutex held.
		*/
		static struct its_collection find_collection(struct vgic_its its, int coll_id)
		{
		struct its_collection *collection;

		list_for_each_entry(collection, &its->collection_list, coll_list) {
		if (coll_id == collection->collection_id)
		return collection;
		}

		return NULL;
		}

		#define LPI_PROP_ENABLE_BIT(p) ((p) & LPI_PROP_ENABLED)
		#define LPI_PROP_PRIORITY(p) ((p) & 0xfc)

		@@ -144,6 +264,51 @@ static int vgic_copy_lpi_list(struct kvm kvm, u32 *intid_ptr)
		return irq_count;
		}

		/*
		* Promotes the ITS view of affinity of an ITTE (which redistributor this LPI
		* is targeting) to the VGIC's view, which deals with target VCPUs.
		* Needs to be called whenever either the collection for a LPIs has
		* changed or the collection itself got retargeted.
		*/
		static void update_affinity_itte(struct kvm kvm, struct its_itte itte)
		{
		struct kvm_vcpu *vcpu;

		if (!its_is_collection_mapped(itte->collection))
		return;

		vcpu = kvm_get_vcpu(kvm, itte->collection->target_addr);

		spin_lock(&itte->irq->irq_lock);
		itte->irq->target_vcpu = vcpu;
		spin_unlock(&itte->irq->irq_lock);
		}

		/*
		* Updates the target VCPU for every LPI targeting this collection.
		* Must be called with the its_lock mutex held.
		*/
		static void update_affinity_collection(struct kvm kvm, struct vgic_its its,
		struct its_collection *coll)
		{
		struct its_device *device;
		struct its_itte *itte;

		for_each_lpi_its(device, itte, its) {
		if (!itte->collection \|\| coll != itte->collection)
		continue;

		update_affinity_itte(kvm, itte);
		}
		}

		static u32 max_lpis_propbaser(u64 propbaser)
		{
		int nr_idbits = (propbaser & 0x1f) + 1;

		return 1U << min(nr_idbits, INTERRUPT_ID_BITS_ITS);
		}

		/*
		* Scan the whole LPI pending table and sync the pending bit in there
		* with our own data structures. This relies on the LPI being
		@@ -283,10 +448,504 @@ static void its_free_itte(struct kvm kvm, struct its_itte itte)
		kfree(itte);
		}

		static u64 its_cmd_mask_field(u64 *its_cmd, int word, int shift, int size)
		{
		return (le64_to_cpu(its_cmd[word]) >> shift) & (BIT_ULL(size) - 1);
		}

		#define its_cmd_get_command(cmd) its_cmd_mask_field(cmd, 0, 0, 8)
		#define its_cmd_get_deviceid(cmd) its_cmd_mask_field(cmd, 0, 32, 32)
		#define its_cmd_get_id(cmd) its_cmd_mask_field(cmd, 1, 0, 32)
		#define its_cmd_get_physical_id(cmd) its_cmd_mask_field(cmd, 1, 32, 32)
		#define its_cmd_get_collection(cmd) its_cmd_mask_field(cmd, 2, 0, 16)
		#define its_cmd_get_target_addr(cmd) its_cmd_mask_field(cmd, 2, 16, 32)
		#define its_cmd_get_validbit(cmd) its_cmd_mask_field(cmd, 2, 63, 1)

		/*
		* The DISCARD command frees an Interrupt Translation Table Entry (ITTE).
		* Must be called with the its_lock mutex held.
		*/
		static int vgic_its_cmd_handle_discard(struct kvm kvm, struct vgic_its its,
		u64 *its_cmd)
		{
		u32 device_id = its_cmd_get_deviceid(its_cmd);
		u32 event_id = its_cmd_get_id(its_cmd);
		struct its_itte *itte;


		itte = find_itte(its, device_id, event_id);
		if (itte && itte->collection) {
		/*
		* Though the spec talks about removing the pending state, we
		* don't bother here since we clear the ITTE anyway and the
		* pending state is a property of the ITTE struct.
		*/
		its_free_itte(kvm, itte);
		return 0;
		}

		return E_ITS_DISCARD_UNMAPPED_INTERRUPT;
		}

		/*
		* The MOVI command moves an ITTE to a different collection.
		* Must be called with the its_lock mutex held.
		*/
		static int vgic_its_cmd_handle_movi(struct kvm kvm, struct vgic_its its,
		u64 *its_cmd)
		{
		u32 device_id = its_cmd_get_deviceid(its_cmd);
		u32 event_id = its_cmd_get_id(its_cmd);
		u32 coll_id = its_cmd_get_collection(its_cmd);
		struct kvm_vcpu *vcpu;
		struct its_itte *itte;
		struct its_collection *collection;

		itte = find_itte(its, device_id, event_id);
		if (!itte)
		return E_ITS_MOVI_UNMAPPED_INTERRUPT;

		if (!its_is_collection_mapped(itte->collection))
		return E_ITS_MOVI_UNMAPPED_COLLECTION;

		collection = find_collection(its, coll_id);
		if (!its_is_collection_mapped(collection))
		return E_ITS_MOVI_UNMAPPED_COLLECTION;

		itte->collection = collection;
		vcpu = kvm_get_vcpu(kvm, collection->target_addr);

		spin_lock(&itte->irq->irq_lock);
		itte->irq->target_vcpu = vcpu;
		spin_unlock(&itte->irq->irq_lock);

		return 0;
		}

		static void vgic_its_init_collection(struct vgic_its *its,
		struct its_collection *collection,
		u32 coll_id)
		{
		collection->collection_id = coll_id;
		collection->target_addr = COLLECTION_NOT_MAPPED;

		list_add_tail(&collection->coll_list, &its->collection_list);
		}

		/*
		* The MAPTI and MAPI commands map LPIs to ITTEs.
		* Must be called with its_lock mutex held.
		*/
		static int vgic_its_cmd_handle_mapi(struct kvm kvm, struct vgic_its its,
		u64 *its_cmd, u8 subcmd)
		{
		u32 device_id = its_cmd_get_deviceid(its_cmd);
		u32 event_id = its_cmd_get_id(its_cmd);
		u32 coll_id = its_cmd_get_collection(its_cmd);
		struct its_itte *itte;
		struct its_device *device;
		struct its_collection collection, new_coll = NULL;
		int lpi_nr;

		device = find_its_device(its, device_id);
		if (!device)
		return E_ITS_MAPTI_UNMAPPED_DEVICE;

		collection = find_collection(its, coll_id);
		if (!collection) {
		new_coll = kzalloc(sizeof(struct its_collection), GFP_KERNEL);
		if (!new_coll)
		return -ENOMEM;
		}

		if (subcmd == GITS_CMD_MAPTI)
		lpi_nr = its_cmd_get_physical_id(its_cmd);
		else
		lpi_nr = event_id;
		if (lpi_nr < GIC_LPI_OFFSET \|\|
		lpi_nr >= max_lpis_propbaser(kvm->arch.vgic.propbaser)) {
		kfree(new_coll);
		return E_ITS_MAPTI_PHYSICALID_OOR;
		}

		itte = find_itte(its, device_id, event_id);
		if (!itte) {
		itte = kzalloc(sizeof(struct its_itte), GFP_KERNEL);
		if (!itte) {
		kfree(new_coll);
		return -ENOMEM;
		}

		itte->event_id = event_id;
		list_add_tail(&itte->itte_list, &device->itt_head);
		}

		if (!collection) {
		collection = new_coll;
		vgic_its_init_collection(its, collection, coll_id);
		}

		itte->collection = collection;
		itte->lpi = lpi_nr;
		itte->irq = vgic_add_lpi(kvm, lpi_nr);
		update_affinity_itte(kvm, itte);

		/*
		* We "cache" the configuration table entries in out struct vgic_irq's.
		* However we only have those structs for mapped IRQs, so we read in
		* the respective config data from memory here upon mapping the LPI.
		*/
		update_lpi_config(kvm, itte->irq, NULL);

		return 0;
		}

		/* Requires the its_lock to be held. */
		static void vgic_its_unmap_device(struct kvm kvm, struct its_device device)
		{
		struct its_itte itte, temp;

		/*
		* The spec says that unmapping a device with still valid
		* ITTEs associated is UNPREDICTABLE. We remove all ITTEs,
		* since we cannot leave the memory unreferenced.
		*/
		list_for_each_entry_safe(itte, temp, &device->itt_head, itte_list)
		its_free_itte(kvm, itte);

		list_del(&device->dev_list);
		kfree(device);
		}

		/*
		* Check whether a device ID can be stored into the guest device tables.
		* For a direct table this is pretty easy, but gets a bit nasty for
		* indirect tables. We check whether the resulting guest physical address
		* is actually valid (covered by a memslot and guest accessbible).
		* For this we have to read the respective first level entry.
		*/
		static bool vgic_its_check_device_id(struct kvm kvm, struct vgic_its its,
		int device_id)
		{
		u64 r = its->baser_device_table;
		int nr_entries = GITS_BASER_NR_PAGES(r) * SZ_64K;
		int index;
		u64 indirect_ptr;
		gfn_t gfn;


		if (!(r & GITS_BASER_INDIRECT))
		return device_id < (nr_entries / GITS_BASER_ENTRY_SIZE(r));

		/* calculate and check the index into the 1st level */
		index = device_id / (SZ_64K / GITS_BASER_ENTRY_SIZE(r));
		if (index >= (nr_entries / sizeof(u64)))
		return false;

		/* Each 1st level entry is represented by a 64-bit value. */
		if (!kvm_read_guest(kvm,
		BASER_ADDRESS(r) + index * sizeof(indirect_ptr),
		&indirect_ptr, sizeof(indirect_ptr)))
		return false;

		/* check the valid bit of the first level entry */
		if (!(indirect_ptr & BIT_ULL(63)))
		return false;

		/*
		* Mask the guest physical address and calculate the frame number.
		* Any address beyond our supported 48 bits of PA will be caught
		* by the actual check in the final step.
		*/
		gfn = (indirect_ptr & GENMASK_ULL(51, 16)) >> PAGE_SHIFT;

		return kvm_is_visible_gfn(kvm, gfn);
		}

		/*
		* MAPD maps or unmaps a device ID to Interrupt Translation Tables (ITTs).
		* Must be called with the its_lock mutex held.
		*/
		static int vgic_its_cmd_handle_mapd(struct kvm kvm, struct vgic_its its,
		u64 *its_cmd)
		{
		u32 device_id = its_cmd_get_deviceid(its_cmd);
		bool valid = its_cmd_get_validbit(its_cmd);
		struct its_device *device;

		if (!vgic_its_check_device_id(kvm, its, device_id))
		return E_ITS_MAPD_DEVICE_OOR;

		device = find_its_device(its, device_id);

		/*
		* The spec says that calling MAPD on an already mapped device
		* invalidates all cached data for this device. We implement this
		* by removing the mapping and re-establishing it.
		*/
		if (device)
		vgic_its_unmap_device(kvm, device);

		/*
		* The spec does not say whether unmapping a not-mapped device
		* is an error, so we are done in any case.
		*/
		if (!valid)
		return 0;

		device = kzalloc(sizeof(struct its_device), GFP_KERNEL);
		if (!device)
		return -ENOMEM;

		device->device_id = device_id;
		INIT_LIST_HEAD(&device->itt_head);

		list_add_tail(&device->dev_list, &its->device_list);

		return 0;
		}

		static int vgic_its_nr_collection_ids(struct vgic_its *its)
		{
		u64 r = its->baser_coll_table;

		return (GITS_BASER_NR_PAGES(r) * SZ_64K) / GITS_BASER_ENTRY_SIZE(r);
		}

		/*
		* The MAPC command maps collection IDs to redistributors.
		* Must be called with the its_lock mutex held.
		*/
		static int vgic_its_cmd_handle_mapc(struct kvm kvm, struct vgic_its its,
		u64 *its_cmd)
		{
		u16 coll_id;
		u32 target_addr;
		struct its_collection *collection;
		bool valid;

		valid = its_cmd_get_validbit(its_cmd);
		coll_id = its_cmd_get_collection(its_cmd);
		target_addr = its_cmd_get_target_addr(its_cmd);

		if (target_addr >= atomic_read(&kvm->online_vcpus))
		return E_ITS_MAPC_PROCNUM_OOR;

		if (coll_id >= vgic_its_nr_collection_ids(its))
		return E_ITS_MAPC_COLLECTION_OOR;

		collection = find_collection(its, coll_id);

		if (!valid) {
		struct its_device *device;
		struct its_itte *itte;
		/*
		* Clearing the mapping for that collection ID removes the
		* entry from the list. If there wasn't any before, we can
		* go home early.
		*/
		if (!collection)
		return 0;

		for_each_lpi_its(device, itte, its)
		if (itte->collection &&
		itte->collection->collection_id == coll_id)
		itte->collection = NULL;

		list_del(&collection->coll_list);
		kfree(collection);
		} else {
		if (!collection) {
		collection = kzalloc(sizeof(struct its_collection),
		GFP_KERNEL);
		if (!collection)
		return -ENOMEM;

		vgic_its_init_collection(its, collection, coll_id);
		collection->target_addr = target_addr;
		} else {
		collection->target_addr = target_addr;
		update_affinity_collection(kvm, its, collection);
		}
		}

		return 0;
		}

		/*
		* The CLEAR command removes the pending state for a particular LPI.
		* Must be called with the its_lock mutex held.
		*/
		static int vgic_its_cmd_handle_clear(struct kvm kvm, struct vgic_its its,
		u64 *its_cmd)
		{
		u32 device_id = its_cmd_get_deviceid(its_cmd);
		u32 event_id = its_cmd_get_id(its_cmd);
		struct its_itte *itte;


		itte = find_itte(its, device_id, event_id);
		if (!itte)
		return E_ITS_CLEAR_UNMAPPED_INTERRUPT;

		itte->irq->pending = false;

		return 0;
		}

		/*
		* The INV command syncs the configuration bits from the memory table.
		* Must be called with the its_lock mutex held.
		*/
		static int vgic_its_cmd_handle_inv(struct kvm kvm, struct vgic_its its,
		u64 *its_cmd)
		{
		u32 device_id = its_cmd_get_deviceid(its_cmd);
		u32 event_id = its_cmd_get_id(its_cmd);
		struct its_itte *itte;


		itte = find_itte(its, device_id, event_id);
		if (!itte)
		return E_ITS_INV_UNMAPPED_INTERRUPT;

		return update_lpi_config(kvm, itte->irq, NULL);
		}

		/*
		* The INVALL command requests flushing of all IRQ data in this collection.
		* Find the VCPU mapped to that collection, then iterate over the VM's list
		* of mapped LPIs and update the configuration for each IRQ which targets
		* the specified vcpu. The configuration will be read from the in-memory
		* configuration table.
		* Must be called with the its_lock mutex held.
		*/
		static int vgic_its_cmd_handle_invall(struct kvm kvm, struct vgic_its its,
		u64 *its_cmd)
		{
		u32 coll_id = its_cmd_get_collection(its_cmd);
		struct its_collection *collection;
		struct kvm_vcpu *vcpu;
		struct vgic_irq *irq;
		u32 *intids;
		int irq_count, i;

		collection = find_collection(its, coll_id);
		if (!its_is_collection_mapped(collection))
		return E_ITS_INVALL_UNMAPPED_COLLECTION;

		vcpu = kvm_get_vcpu(kvm, collection->target_addr);

		irq_count = vgic_copy_lpi_list(kvm, &intids);
		if (irq_count < 0)
		return irq_count;

		for (i = 0; i < irq_count; i++) {
		irq = vgic_get_irq(kvm, NULL, intids[i]);
		if (!irq)
		continue;
		update_lpi_config(kvm, irq, vcpu);
		vgic_put_irq(kvm, irq);
		}

		kfree(intids);

		return 0;
		}

		/*
		* The MOVALL command moves the pending state of all IRQs targeting one
		* redistributor to another. We don't hold the pending state in the VCPUs,
		* but in the IRQs instead, so there is really not much to do for us here.
		* However the spec says that no IRQ must target the old redistributor
		* afterwards, so we make sure that no LPI is using the associated target_vcpu.
		* This command affects all LPIs in the system that target that redistributor.
		*/
		static int vgic_its_cmd_handle_movall(struct kvm kvm, struct vgic_its its,
		u64 *its_cmd)
		{
		struct vgic_dist *dist = &kvm->arch.vgic;
		u32 target1_addr = its_cmd_get_target_addr(its_cmd);
		u32 target2_addr = its_cmd_mask_field(its_cmd, 3, 16, 32);
		struct kvm_vcpu vcpu1, vcpu2;
		struct vgic_irq *irq;

		if (target1_addr >= atomic_read(&kvm->online_vcpus) \|\|
		target2_addr >= atomic_read(&kvm->online_vcpus))
		return E_ITS_MOVALL_PROCNUM_OOR;

		if (target1_addr == target2_addr)
		return 0;

		vcpu1 = kvm_get_vcpu(kvm, target1_addr);
		vcpu2 = kvm_get_vcpu(kvm, target2_addr);

		spin_lock(&dist->lpi_list_lock);

		list_for_each_entry(irq, &dist->lpi_list_head, lpi_list) {
		spin_lock(&irq->irq_lock);

		if (irq->target_vcpu == vcpu1)
		irq->target_vcpu = vcpu2;

		spin_unlock(&irq->irq_lock);
		}

		spin_unlock(&dist->lpi_list_lock);

		return 0;
		}

		/*
		* This function is called with the its_cmd lock held, but the ITS data
		* structure lock dropped.
		*/
		static int vgic_its_handle_command(struct kvm kvm, struct vgic_its its,
		u64 *its_cmd)
		{
		return -ENODEV;
		u8 cmd = its_cmd_get_command(its_cmd);
		int ret = -ENODEV;

		mutex_lock(&its->its_lock);
		switch (cmd) {
		case GITS_CMD_MAPD:
		ret = vgic_its_cmd_handle_mapd(kvm, its, its_cmd);
		break;
		case GITS_CMD_MAPC:
		ret = vgic_its_cmd_handle_mapc(kvm, its, its_cmd);
		break;
		case GITS_CMD_MAPI:
		ret = vgic_its_cmd_handle_mapi(kvm, its, its_cmd, cmd);
		break;
		case GITS_CMD_MAPTI:
		ret = vgic_its_cmd_handle_mapi(kvm, its, its_cmd, cmd);
		break;
		case GITS_CMD_MOVI:
		ret = vgic_its_cmd_handle_movi(kvm, its, its_cmd);
		break;
		case GITS_CMD_DISCARD:
		ret = vgic_its_cmd_handle_discard(kvm, its, its_cmd);
		break;
		case GITS_CMD_CLEAR:
		ret = vgic_its_cmd_handle_clear(kvm, its, its_cmd);
		break;
		case GITS_CMD_MOVALL:
		ret = vgic_its_cmd_handle_movall(kvm, its, its_cmd);
		break;
		case GITS_CMD_INV:
		ret = vgic_its_cmd_handle_inv(kvm, its, its_cmd);
		break;
		case GITS_CMD_INVALL:
		ret = vgic_its_cmd_handle_invall(kvm, its, its_cmd);
		break;
		case GITS_CMD_SYNC:
		/* we ignore this command: we are in sync all of the time */
		ret = 0;
		break;
		}
		mutex_unlock(&its->its_lock);

		return ret;
		}

		static u64 vgic_sanitise_its_baser(u64 reg)

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