diff options
Diffstat (limited to 'virt/kvm/arm/vgic/vgic-its.c')
| -rw-r--r-- | virt/kvm/arm/vgic/vgic-its.c | 1500 |
1 files changed, 1500 insertions, 0 deletions
diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c new file mode 100644 index 000000000000..07411cf967b9 --- /dev/null +++ b/virt/kvm/arm/vgic/vgic-its.c @@ -0,0 +1,1500 @@ +/* + * GICv3 ITS emulation + * + * Copyright (C) 2015,2016 ARM Ltd. + * Author: Andre Przywara <andre.przywara@arm.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/cpu.h> +#include <linux/kvm.h> +#include <linux/kvm_host.h> +#include <linux/interrupt.h> +#include <linux/list.h> +#include <linux/uaccess.h> + +#include <linux/irqchip/arm-gic-v3.h> + +#include <asm/kvm_emulate.h> +#include <asm/kvm_arm.h> +#include <asm/kvm_mmu.h> + +#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. + */ + vgic_get_irq_kref(irq); + + 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; + + /* the head for the list of ITTEs */ + struct list_head itt_head; + u32 device_id; +}; + +#define COLLECTION_NOT_MAPPED ((u32)~0) + +struct its_collection { + struct list_head coll_list; + + u32 collection_id; + u32 target_addr; +}; + +#define its_is_collection_mapped(coll) ((coll) && \ + ((coll)->target_addr != COLLECTION_NOT_MAPPED)) + +struct its_itte { + struct list_head itte_list; + + struct vgic_irq *irq; + struct its_collection *collection; + u32 lpi; + 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) + +/* + * Reads the configuration data for a given LPI from guest memory and + * updates the fields in struct vgic_irq. + * If filter_vcpu is not NULL, applies only if the IRQ is targeting this + * VCPU. Unconditionally applies if filter_vcpu is NULL. + */ +static int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq, + struct kvm_vcpu *filter_vcpu) +{ + u64 propbase = PROPBASER_ADDRESS(kvm->arch.vgic.propbaser); + u8 prop; + int ret; + + ret = kvm_read_guest(kvm, propbase + irq->intid - GIC_LPI_OFFSET, + &prop, 1); + + if (ret) + return ret; + + spin_lock(&irq->irq_lock); + + if (!filter_vcpu || filter_vcpu == irq->target_vcpu) { + irq->priority = LPI_PROP_PRIORITY(prop); + irq->enabled = LPI_PROP_ENABLE_BIT(prop); + + vgic_queue_irq_unlock(kvm, irq); + } else { + spin_unlock(&irq->irq_lock); + } + + return 0; +} + +/* + * Create a snapshot of the current LPI list, so that we can enumerate all + * LPIs without holding any lock. + * Returns the array length and puts the kmalloc'ed array into intid_ptr. + */ +static int vgic_copy_lpi_list(struct kvm *kvm, u32 **intid_ptr) +{ + struct vgic_dist *dist = &kvm->arch.vgic; + struct vgic_irq *irq; + u32 *intids; + int irq_count = dist->lpi_list_count, i = 0; + + /* + * We use the current value of the list length, which may change + * after the kmalloc. We don't care, because the guest shouldn't + * change anything while the command handling is still running, + * and in the worst case we would miss a new IRQ, which one wouldn't + * expect to be covered by this command anyway. + */ + intids = kmalloc_array(irq_count, sizeof(intids[0]), GFP_KERNEL); + if (!intids) + return -ENOMEM; + + spin_lock(&dist->lpi_list_lock); + list_for_each_entry(irq, &dist->lpi_list_head, lpi_list) { + /* We don't need to "get" the IRQ, as we hold the list lock. */ + intids[i] = irq->intid; + if (++i == irq_count) + break; + } + spin_unlock(&dist->lpi_list_lock); + + *intid_ptr = intids; + 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 + * mapped before. + */ +static int its_sync_lpi_pending_table(struct kvm_vcpu *vcpu) +{ + gpa_t pendbase = PENDBASER_ADDRESS(vcpu->arch.vgic_cpu.pendbaser); + struct vgic_irq *irq; + int last_byte_offset = -1; + int ret = 0; + u32 *intids; + int nr_irqs, i; + + nr_irqs = vgic_copy_lpi_list(vcpu->kvm, &intids); + if (nr_irqs < 0) + return nr_irqs; + + for (i = 0; i < nr_irqs; i++) { + int byte_offset, bit_nr; + u8 pendmask; + + byte_offset = intids[i] / BITS_PER_BYTE; + bit_nr = intids[i] % BITS_PER_BYTE; + + /* + * For contiguously allocated LPIs chances are we just read + * this very same byte in the last iteration. Reuse that. + */ + if (byte_offset != last_byte_offset) { + ret = kvm_read_guest(vcpu->kvm, pendbase + byte_offset, + &pendmask, 1); + if (ret) { + kfree(intids); + return ret; + } + last_byte_offset = byte_offset; + } + + irq = vgic_get_irq(vcpu->kvm, NULL, intids[i]); + spin_lock(&irq->irq_lock); + irq->pending = pendmask & (1U << bit_nr); + vgic_queue_irq_unlock(vcpu->kvm, irq); + vgic_put_irq(vcpu->kvm, irq); + } + + kfree(intids); + + return ret; +} + +static unsigned long vgic_mmio_read_its_ctlr(struct kvm *vcpu, + struct vgic_its *its, + gpa_t addr, unsigned int len) +{ + u32 reg = 0; + + mutex_lock(&its->cmd_lock); + if (its->creadr == its->cwriter) + reg |= GITS_CTLR_QUIESCENT; + if (its->enabled) + reg |= GITS_CTLR_ENABLE; + mutex_unlock(&its->cmd_lock); + + return reg; +} + +static void vgic_mmio_write_its_ctlr(struct kvm *kvm, struct vgic_its *its, + gpa_t addr, unsigned int len, + unsigned long val) +{ + its->enabled = !!(val & GITS_CTLR_ENABLE); +} + +static unsigned long vgic_mmio_read_its_typer(struct kvm *kvm, + struct vgic_its *its, + gpa_t addr, unsigned int len) +{ + u64 reg = GITS_TYPER_PLPIS; + + /* + * We use linear CPU numbers for redistributor addressing, + * so GITS_TYPER.PTA is 0. + * Also we force all PROPBASER registers to be the same, so + * CommonLPIAff is 0 as well. + * To avoid memory waste in the guest, we keep the number of IDBits and + * DevBits low - as least for the time being. + */ + reg |= 0x0f << GITS_TYPER_DEVBITS_SHIFT; + reg |= 0x0f << GITS_TYPER_IDBITS_SHIFT; + + return extract_bytes(reg, addr & 7, len); +} + +static unsigned long vgic_mmio_read_its_iidr(struct kvm *kvm, + struct vgic_its *its, + gpa_t addr, unsigned int len) +{ + return (PRODUCT_ID_KVM << 24) | (IMPLEMENTER_ARM << 0); +} + +static unsigned long vgic_mmio_read_its_idregs(struct kvm *kvm, + struct vgic_its *its, + gpa_t addr, unsigned int len) +{ + switch (addr & 0xffff) { + case GITS_PIDR0: + return 0x92; /* part number, bits[7:0] */ + case GITS_PIDR1: + return 0xb4; /* part number, bits[11:8] */ + case GITS_PIDR2: + return GIC_PIDR2_ARCH_GICv3 | 0x0b; + case GITS_PIDR4: + return 0x40; /* This is a 64K software visible page */ + /* The following are the ID registers for (any) GIC. */ + case GITS_CIDR0: + return 0x0d; + case GITS_CIDR1: + return 0xf0; + case GITS_CIDR2: + return 0x05; + case GITS_CIDR3: + return 0xb1; + } + + return 0; +} + +/* + * Find the target VCPU and the LPI number for a given devid/eventid pair + * and make this IRQ pending, possibly injecting it. + * Must be called with the its_lock mutex held. + */ +static void vgic_its_trigger_msi(struct kvm *kvm, struct vgic_its *its, + u32 devid, u32 eventid) +{ + struct its_itte *itte; + + if (!its->enabled) + return; + + itte = find_itte(its, devid, eventid); + /* Triggering an unmapped IRQ gets silently dropped. */ + if (itte && its_is_collection_mapped(itte->collection)) { + struct kvm_vcpu *vcpu; + + vcpu = kvm_get_vcpu(kvm, itte->collection->target_addr); + if (vcpu && vcpu->arch.vgic_cpu.lpis_enabled) { + spin_lock(&itte->irq->irq_lock); + itte->irq->pending = true; + vgic_queue_irq_unlock(kvm, itte->irq); + } + } +} + +/* + * Queries the KVM IO bus framework to get the ITS pointer from the given + * doorbell address. + * We then call vgic_its_trigger_msi() with the decoded data. + */ +int vgic_its_inject_msi(struct kvm *kvm, struct kvm_msi *msi) +{ + u64 address; + struct kvm_io_device *kvm_io_dev; + struct vgic_io_device *iodev; + + if (!vgic_has_its(kvm)) + return -ENODEV; + + if (!(msi->flags & KVM_MSI_VALID_DEVID)) + return -EINVAL; + + address = (u64)msi->address_hi << 32 | msi->address_lo; + + kvm_io_dev = kvm_io_bus_get_dev(kvm, KVM_MMIO_BUS, address); + if (!kvm_io_dev) + return -ENODEV; + + iodev = container_of(kvm_io_dev, struct vgic_io_device, dev); + + mutex_lock(&iodev->its->its_lock); + vgic_its_trigger_msi(kvm, iodev->its, msi->devid, msi->data); + mutex_unlock(&iodev->its->its_lock); + + return 0; +} + +/* Requires the its_lock to be held. */ +static void its_free_itte(struct kvm *kvm, struct its_itte *itte) +{ + list_del(&itte->itte_list); + + /* This put matches the get in vgic_add_lpi. */ + vgic_put_irq(kvm, itte->irq); + + 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; +} + +/* + * Check whether an ID can be stored into the corresponding guest table. + * 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_id(struct vgic_its *its, u64 baser, int id) +{ + int l1_tbl_size = GITS_BASER_NR_PAGES(baser) * SZ_64K; + int index; + u64 indirect_ptr; + gfn_t gfn; + + if (!(baser & GITS_BASER_INDIRECT)) { + phys_addr_t addr; + + if (id >= (l1_tbl_size / GITS_BASER_ENTRY_SIZE(baser))) + return false; + + addr = BASER_ADDRESS(baser) + id * GITS_BASER_ENTRY_SIZE(baser); + gfn = addr >> PAGE_SHIFT; + + return kvm_is_visible_gfn(its->dev->kvm, gfn); + } + + /* calculate and check the index into the 1st level */ + index = id / (SZ_64K / GITS_BASER_ENTRY_SIZE(baser)); + if (index >= (l1_tbl_size / sizeof(u64))) + return false; + + /* Each 1st level entry is represented by a 64-bit value. */ + if (kvm_read_guest(its->dev->kvm, + BASER_ADDRESS(baser) + index * sizeof(indirect_ptr), + &indirect_ptr, sizeof(indirect_ptr))) + return false; + + indirect_ptr = le64_to_cpu(indirect_ptr); + + /* 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. + */ + indirect_ptr &= GENMASK_ULL(51, 16); + + /* Find the address of the actual entry */ + index = id % (SZ_64K / GITS_BASER_ENTRY_SIZE(baser)); + indirect_ptr += index * GITS_BASER_ENTRY_SIZE(baser); + gfn = indirect_ptr >> PAGE_SHIFT; + + return kvm_is_visible_gfn(its->dev->kvm, gfn); +} + +static int vgic_its_alloc_collection(struct vgic_its *its, + struct its_collection **colp, + u32 coll_id) +{ + struct its_collection *collection; + + if (!vgic_its_check_id(its, its->baser_coll_table, coll_id)) + return E_ITS_MAPC_COLLECTION_OOR; + + collection = kzalloc(sizeof(*collection), GFP_KERNEL); + + collection->collection_id = coll_id; + collection->target_addr = COLLECTION_NOT_MAPPED; + + list_add_tail(&collection->coll_list, &its->collection_list); + *colp = collection; + + return 0; +} + +static void vgic_its_free_collection(struct vgic_its *its, u32 coll_id) +{ + struct its_collection *collection; + 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. + */ + collection = find_collection(its, coll_id); + if (!collection) + return; + + 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); +} + +/* + * 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) +{ + 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; + + if (its_cmd_get_command(its_cmd) == 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)) + return E_ITS_MAPTI_PHYSICALID_OOR; + + collection = find_collection(its, coll_id); + if (!collection) { + int ret = vgic_its_alloc_collection(its, &collection, coll_id); + if (ret) + return ret; + new_coll = collection; + } + + itte = find_itte(its, device_id, event_id); + if (!itte) { + itte = kzalloc(sizeof(struct its_itte), GFP_KERNEL); + if (!itte) { + if (new_coll) + vgic_its_free_collection(its, coll_id); + return -ENOMEM; + } + + itte->event_id = event_id; + list_add_tail(&itte->itte_list, &device->itt_head); + } + + 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); +} + +/* + * 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_id(its, its->baser_device_table, 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; +} + +/* + * 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 (!valid) { + vgic_its_free_collection(its, coll_id); + } else { + collection = find_collection(its, coll_id); + + if (!collection) { + int ret; + + ret = vgic_its_alloc_collection(its, &collection, + coll_id); + if (ret) + return ret; + 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; +} + +/* + * The INT command injects the LPI associated with that DevID/EvID pair. + * Must be called with the its_lock mutex held. + */ +static int vgic_its_cmd_handle_int(struct kvm *kvm, struct vgic_its *its, + u64 *its_cmd) +{ + u32 msi_data = its_cmd_get_id(its_cmd); + u64 msi_devid = its_cmd_get_deviceid(its_cmd); + + vgic_its_trigger_msi(kvm, its, msi_devid, msi_data); + + 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) +{ + int ret = -ENODEV; + + mutex_lock(&its->its_lock); + switch (its_cmd_get_command(its_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); + break; + case GITS_CMD_MAPTI: + ret = vgic_its_cmd_handle_mapi(kvm, its, its_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_INT: + ret = vgic_its_cmd_handle_int(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) +{ + reg = vgic_sanitise_field(reg, GITS_BASER_SHAREABILITY_MASK, + GITS_BASER_SHAREABILITY_SHIFT, + vgic_sanitise_shareability); + reg = vgic_sanitise_field(reg, GITS_BASER_INNER_CACHEABILITY_MASK, + GITS_BASER_INNER_CACHEABILITY_SHIFT, + vgic_sanitise_inner_cacheability); + reg = vgic_sanitise_field(reg, GITS_BASER_OUTER_CACHEABILITY_MASK, + GITS_BASER_OUTER_CACHEABILITY_SHIFT, + vgic_sanitise_outer_cacheability); + + /* Bits 15:12 contain bits 51:48 of the PA, which we don't support. */ + reg &= ~GENMASK_ULL(15, 12); + + /* We support only one (ITS) page size: 64K */ + reg = (reg & ~GITS_BASER_PAGE_SIZE_MASK) | GITS_BASER_PAGE_SIZE_64K; + + return reg; +} + +static u64 vgic_sanitise_its_cbaser(u64 reg) +{ + reg = vgic_sanitise_field(reg, GITS_CBASER_SHAREABILITY_MASK, + GITS_CBASER_SHAREABILITY_SHIFT, + vgic_sanitise_shareability); + reg = vgic_sanitise_field(reg, GITS_CBASER_INNER_CACHEABILITY_MASK, + GITS_CBASER_INNER_CACHEABILITY_SHIFT, + vgic_sanitise_inner_cacheability); + reg = vgic_sanitise_field(reg, GITS_CBASER_OUTER_CACHEABILITY_MASK, + GITS_CBASER_OUTER_CACHEABILITY_SHIFT, + vgic_sanitise_outer_cacheability); + + /* + * Sanitise the physical address to be 64k aligned. + * Also limit the physical addresses to 48 bits. + */ + reg &= ~(GENMASK_ULL(51, 48) | GENMASK_ULL(15, 12)); + + return reg; +} + +static unsigned long vgic_mmio_read_its_cbaser(struct kvm *kvm, + struct vgic_its *its, + gpa_t addr, unsigned int len) +{ + return extract_bytes(its->cbaser, addr & 7, len); +} + +static void vgic_mmio_write_its_cbaser(struct kvm *kvm, struct vgic_its *its, + gpa_t addr, unsigned int len, + unsigned long val) +{ + /* When GITS_CTLR.Enable is 1, this register is RO. */ + if (its->enabled) + return; + + mutex_lock(&its->cmd_lock); + its->cbaser = update_64bit_reg(its->cbaser, addr & 7, len, val); + its->cbaser = vgic_sanitise_its_cbaser(its->cbaser); + its->creadr = 0; + /* + * CWRITER is architecturally UNKNOWN on reset, but we need to reset + * it to CREADR to make sure we start with an empty command buffer. + */ + its->cwriter = its->creadr; + mutex_unlock(&its->cmd_lock); +} + +#define ITS_CMD_BUFFER_SIZE(baser) ((((baser) & 0xff) + 1) << 12) +#define ITS_CMD_SIZE 32 +#define ITS_CMD_OFFSET(reg) ((reg) & GENMASK(19, 5)) + +/* + * By writing to CWRITER the guest announces new commands to be processed. + * To avoid any races in the first place, we take the its_cmd lock, which + * protects our ring buffer variables, so that there is only one user + * per ITS handling commands at a given time. + */ +static void vgic_mmio_write_its_cwriter(struct kvm *kvm, struct vgic_its *its, + gpa_t addr, unsigned int len, + unsigned long val) +{ + gpa_t cbaser; + u64 cmd_buf[4]; + u32 reg; + + if (!its) + return; + + mutex_lock(&its->cmd_lock); + + reg = update_64bit_reg(its->cwriter, addr & 7, len, val); + reg = ITS_CMD_OFFSET(reg); + if (reg >= ITS_CMD_BUFFER_SIZE(its->cbaser)) { + mutex_unlock(&its->cmd_lock); + return; + } + + its->cwriter = reg; + cbaser = CBASER_ADDRESS(its->cbaser); + + while (its->cwriter != its->creadr) { + int ret = kvm_read_guest(kvm, cbaser + its->creadr, + cmd_buf, ITS_CMD_SIZE); + /* + * If kvm_read_guest() fails, this could be due to the guest + * programming a bogus value in CBASER or something else going + * wrong from which we cannot easily recover. + * According to section 6.3.2 in the GICv3 spec we can just + * ignore that command then. + */ + if (!ret) + vgic_its_handle_command(kvm, its, cmd_buf); + + its->creadr += ITS_CMD_SIZE; + if (its->creadr == ITS_CMD_BUFFER_SIZE(its->cbaser)) + its->creadr = 0; + } + + mutex_unlock(&its->cmd_lock); +} + +static unsigned long vgic_mmio_read_its_cwriter(struct kvm *kvm, + struct vgic_its *its, + gpa_t addr, unsigned int len) +{ + return extract_bytes(its->cwriter, addr & 0x7, len); +} + +static unsigned long vgic_mmio_read_its_creadr(struct kvm *kvm, + struct vgic_its *its, + gpa_t addr, unsigned int len) +{ + return extract_bytes(its->creadr, addr & 0x7, len); +} + +#define BASER_INDEX(addr) (((addr) / sizeof(u64)) & 0x7) +static unsigned long vgic_mmio_read_its_baser(struct kvm *kvm, + struct vgic_its *its, + gpa_t addr, unsigned int len) +{ + u64 reg; + + switch (BASER_INDEX(addr)) { + case 0: + reg = its->baser_device_table; + break; + case 1: + reg = its->baser_coll_table; + break; + default: + reg = 0; + break; + } + + return extract_bytes(reg, addr & 7, len); +} + +#define GITS_BASER_RO_MASK (GENMASK_ULL(52, 48) | GENMASK_ULL(58, 56)) +static void vgic_mmio_write_its_baser(struct kvm *kvm, + struct vgic_its *its, + gpa_t addr, unsigned int len, + unsigned long val) +{ + u64 entry_size, device_type; + u64 reg, *regptr, clearbits = 0; + + /* When GITS_CTLR.Enable is 1, we ignore write accesses. */ + if (its->enabled) + return; + + switch (BASER_INDEX(addr)) { + case 0: + regptr = &its->baser_device_table; + entry_size = 8; + device_type = GITS_BASER_TYPE_DEVICE; + break; + case 1: + regptr = &its->baser_coll_table; + entry_size = 8; + device_type = GITS_BASER_TYPE_COLLECTION; + clearbits = GITS_BASER_INDIRECT; + break; + default: + return; + } + + reg = update_64bit_reg(*regptr, addr & 7, len, val); + reg &= ~GITS_BASER_RO_MASK; + reg &= ~clearbits; + + reg |= (entry_size - 1) << GITS_BASER_ENTRY_SIZE_SHIFT; + reg |= device_type << GITS_BASER_TYPE_SHIFT; + reg = vgic_sanitise_its_baser(reg); + + *regptr = reg; +} + +#define REGISTER_ITS_DESC(off, rd, wr, length, acc) \ +{ \ + .reg_offset = off, \ + .len = length, \ + .access_flags = acc, \ + .its_read = rd, \ + .its_write = wr, \ +} + +static void its_mmio_write_wi(struct kvm *kvm, struct vgic_its *its, + gpa_t addr, unsigned int len, unsigned long val) +{ + /* Ignore */ +} + +static struct vgic_register_region its_registers[] = { + REGISTER_ITS_DESC(GITS_CTLR, + vgic_mmio_read_its_ctlr, vgic_mmio_write_its_ctlr, 4, + VGIC_ACCESS_32bit), + REGISTER_ITS_DESC(GITS_IIDR, + vgic_mmio_read_its_iidr, its_mmio_write_wi, 4, + VGIC_ACCESS_32bit), + REGISTER_ITS_DESC(GITS_TYPER, + vgic_mmio_read_its_typer, its_mmio_write_wi, 8, + VGIC_ACCESS_64bit | VGIC_ACCESS_32bit), + REGISTER_ITS_DESC(GITS_CBASER, + vgic_mmio_read_its_cbaser, vgic_mmio_write_its_cbaser, 8, + VGIC_ACCESS_64bit | VGIC_ACCESS_32bit), + REGISTER_ITS_DESC(GITS_CWRITER, + vgic_mmio_read_its_cwriter, vgic_mmio_write_its_cwriter, 8, + VGIC_ACCESS_64bit | VGIC_ACCESS_32bit), + REGISTER_ITS_DESC(GITS_CREADR, + vgic_mmio_read_its_creadr, its_mmio_write_wi, 8, + VGIC_ACCESS_64bit | VGIC_ACCESS_32bit), + REGISTER_ITS_DESC(GITS_BASER, + vgic_mmio_read_its_baser, vgic_mmio_write_its_baser, 0x40, + VGIC_ACCESS_64bit | VGIC_ACCESS_32bit), + REGISTER_ITS_DESC(GITS_IDREGS_BASE, + vgic_mmio_read_its_idregs, its_mmio_write_wi, 0x30, + VGIC_ACCESS_32bit), +}; + +/* This is called on setting the LPI enable bit in the redistributor. */ +void vgic_enable_lpis(struct kvm_vcpu *vcpu) +{ + if (!(vcpu->arch.vgic_cpu.pendbaser & GICR_PENDBASER_PTZ)) + its_sync_lpi_pending_table(vcpu); +} + +static int vgic_its_init_its(struct kvm *kvm, struct vgic_its *its) +{ + struct vgic_io_device *iodev = &its->iodev; + int ret; + + if (its->initialized) + return 0; + + if (IS_VGIC_ADDR_UNDEF(its->vgic_its_base)) + return -ENXIO; + + iodev->regions = its_registers; + iodev->nr_regions = ARRAY_SIZE(its_registers); + kvm_iodevice_init(&iodev->dev, &kvm_io_gic_ops); + + iodev->base_addr = its->vgic_its_base; + iodev->iodev_type = IODEV_ITS; + iodev->its = its; + mutex_lock(&kvm->slots_lock); + ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, iodev->base_addr, + KVM_VGIC_V3_ITS_SIZE, &iodev->dev); + mutex_unlock(&kvm->slots_lock); + + if (!ret) + its->initialized = true; + + return ret; +} + +#define INITIAL_BASER_VALUE \ + (GIC_BASER_CACHEABILITY(GITS_BASER, INNER, RaWb) | \ + GIC_BASER_CACHEABILITY(GITS_BASER, OUTER, SameAsInner) | \ + GIC_BASER_SHAREABILITY(GITS_BASER, InnerShareable) | \ + ((8ULL - 1) << GITS_BASER_ENTRY_SIZE_SHIFT) | \ + GITS_BASER_PAGE_SIZE_64K) + +#define INITIAL_PROPBASER_VALUE \ + (GIC_BASER_CACHEABILITY(GICR_PROPBASER, INNER, RaWb) | \ + GIC_BASER_CACHEABILITY(GICR_PROPBASER, OUTER, SameAsInner) | \ + GIC_BASER_SHAREABILITY(GICR_PROPBASER, InnerShareable)) + +static int vgic_its_create(struct kvm_device *dev, u32 type) +{ + struct vgic_its *its; + + if (type != KVM_DEV_TYPE_ARM_VGIC_ITS) + return -ENODEV; + + its = kzalloc(sizeof(struct vgic_its), GFP_KERNEL); + if (!its) + return -ENOMEM; + + mutex_init(&its->its_lock); + mutex_init(&its->cmd_lock); + + its->vgic_its_base = VGIC_ADDR_UNDEF; + + INIT_LIST_HEAD(&its->device_list); + INIT_LIST_HEAD(&its->collection_list); + + dev->kvm->arch.vgic.has_its = true; + its->initialized = false; + its->enabled = false; + its->dev = dev; + + its->baser_device_table = INITIAL_BASER_VALUE | + ((u64)GITS_BASER_TYPE_DEVICE << GITS_BASER_TYPE_SHIFT); + its->baser_coll_table = INITIAL_BASER_VALUE | + ((u64)GITS_BASER_TYPE_COLLECTION << GITS_BASER_TYPE_SHIFT); + dev->kvm->arch.vgic.propbaser = INITIAL_PROPBASER_VALUE; + + dev->private = its; + + return 0; +} + +static void vgic_its_destroy(struct kvm_device *kvm_dev) +{ + struct kvm *kvm = kvm_dev->kvm; + struct vgic_its *its = kvm_dev->private; + struct its_device *dev; + struct its_itte *itte; + struct list_head *dev_cur, *dev_temp; + struct list_head *cur, *temp; + + /* + * We may end up here without the lists ever having been initialized. + * Check this and bail out early to avoid dereferencing a NULL pointer. + */ + if (!its->device_list.next) + return; + + mutex_lock(&its->its_lock); + list_for_each_safe(dev_cur, dev_temp, &its->device_list) { + dev = container_of(dev_cur, struct its_device, dev_list); + list_for_each_safe(cur, temp, &dev->itt_head) { + itte = (container_of(cur, struct its_itte, itte_list)); + its_free_itte(kvm, itte); + } + list_del(dev_cur); + kfree(dev); + } + + list_for_each_safe(cur, temp, &its->collection_list) { + list_del(cur); + kfree(container_of(cur, struct its_collection, coll_list)); + } + mutex_unlock(&its->its_lock); + + kfree(its); +} + +static int vgic_its_has_attr(struct kvm_device *dev, + struct kvm_device_attr *attr) +{ + switch (attr->group) { + case KVM_DEV_ARM_VGIC_GRP_ADDR: + switch (attr->attr) { + case KVM_VGIC_ITS_ADDR_TYPE: + return 0; + } + break; + case KVM_DEV_ARM_VGIC_GRP_CTRL: + switch (attr->attr) { + case KVM_DEV_ARM_VGIC_CTRL_INIT: + return 0; + } + break; + } + return -ENXIO; +} + +static int vgic_its_set_attr(struct kvm_device *dev, + struct kvm_device_attr *attr) +{ + struct vgic_its *its = dev->private; + int ret; + + switch (attr->group) { + case KVM_DEV_ARM_VGIC_GRP_ADDR: { + u64 __user *uaddr = (u64 __user *)(long)attr->addr; + unsigned long type = (unsigned long)attr->attr; + u64 addr; + + if (type != KVM_VGIC_ITS_ADDR_TYPE) + return -ENODEV; + + if (its->initialized) + return -EBUSY; + + if (copy_from_user(&addr, uaddr, sizeof(addr))) + return -EFAULT; + + ret = vgic_check_ioaddr(dev->kvm, &its->vgic_its_base, + addr, SZ_64K); + if (ret) + return ret; + + its->vgic_its_base = addr; + + return 0; + } + case KVM_DEV_ARM_VGIC_GRP_CTRL: + switch (attr->attr) { + case KVM_DEV_ARM_VGIC_CTRL_INIT: + return vgic_its_init_its(dev->kvm, its); + } + break; + } + return -ENXIO; +} + +static int vgic_its_get_attr(struct kvm_device *dev, + struct kvm_device_attr *attr) +{ + switch (attr->group) { + case KVM_DEV_ARM_VGIC_GRP_ADDR: { + struct vgic_its *its = dev->private; + u64 addr = its->vgic_its_base; + u64 __user *uaddr = (u64 __user *)(long)attr->addr; + unsigned long type = (unsigned long)attr->attr; + + if (type != KVM_VGIC_ITS_ADDR_TYPE) + return -ENODEV; + + if (copy_to_user(uaddr, &addr, sizeof(addr))) + return -EFAULT; + break; + default: + return -ENXIO; + } + } + + return 0; +} + +static struct kvm_device_ops kvm_arm_vgic_its_ops = { + .name = "kvm-arm-vgic-its", + .create = vgic_its_create, + .destroy = vgic_its_destroy, + .set_attr = vgic_its_set_attr, + .get_attr = vgic_its_get_attr, + .has_attr = vgic_its_has_attr, +}; + +int kvm_vgic_register_its_device(void) +{ + return kvm_register_device_ops(&kvm_arm_vgic_its_ops, + KVM_DEV_TYPE_ARM_VGIC_ITS); +} |