[PATCH v10 15/17] KVM: arm64: implement ITS command queue command handlers

Marc Zyngier marc.zyngier at arm.com
Sat Jul 16 03:08:15 PDT 2016


On Fri, 15 Jul 2016 12:43:36 +0100
Andre Przywara <andre.przywara at arm.com> wrote:

> The connection between a device, an event ID, the LPI number and the
> associated CPU is stored in in-memory tables in a GICv3, but their
> format is not specified by the spec. Instead software uses a command
> queue in a ring buffer to let an ITS implementation use its own
> format.
> Implement handlers for the various ITS commands and let them store
> the requested relation into our own data structures. Those data
> structures are protected by the its_lock mutex.
> Our internal ring buffer read and write pointers are protected by the
> its_cmd mutex, so that only one VCPU per ITS can handle commands at
> any given time.
> Error handling is very basic at the moment, as we don't have a good
> way of communicating errors to the guest (usually an SError).
> The INT command handler is missing from this patch, as we gain the
> capability of actually injecting MSIs into the guest only later on.
> 
> Signed-off-by: Andre Przywara <andre.przywara at arm.com>
> ---
>  virt/kvm/arm/vgic/vgic-its.c | 661 ++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 660 insertions(+), 1 deletion(-)
> 
> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> index 6f43b3b..1408c88 100644
> --- a/virt/kvm/arm/vgic/vgic-its.c
> +++ b/virt/kvm/arm/vgic/vgic-its.c
> @@ -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);

Why not use the vgic_get_irq_kref() helper that you've introduced in
patch 6? You could make it a static inline in vgic.h if you wanted.

> +
> +		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;
>  
> @@ -63,15 +124,74 @@ struct its_itte {
>  };
>  
>  /*
> + * 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)
>  
> @@ -145,6 +265,51 @@ static int vgic_copy_lpi_list(struct kvm *kvm, u32 **intid_ptr)
>  }
>  
>  /*
> + * 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
>   * mapped before.
> @@ -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;

Careful. The ITS tables are written in LE format, so you need a

	indirect_ptr = le64_to_cpu(indirect_ptr);

to cater for the LE-on-BE case.

> +
> +	/* 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;

Another gotcha: Here, you're only checking for the CPU page that covers
the beginning of the ITS page. If the CPU page size is smaller, you may
end-up being out of bounds. You need something like:

	l2_index = device_id % (SZ_64K / GITS_BASER_ENTRY_SIZE(r));
	gfn = ((indirect_ptr & GENMASK_ULL(51, 16)) +
	       l2_index * GITS_BASER_ENTRY_SIZE(r)) >> PAGE_SHIFT;

so that you check the presence of the actual location you're virtually
touching.

> +
> +	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)


Thanks,

	M.
-- 
Jazz is not dead. It just smells funny.



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