/* * VGIC MMIO handling functions * * 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. */ #include #include #include #include #include #include #include "vgic.h" #include "vgic-mmio.h" unsigned long vgic_mmio_read_raz(struct kvm_vcpu *vcpu, gpa_t addr, unsigned int len) { return 0; } unsigned long vgic_mmio_read_rao(struct kvm_vcpu *vcpu, gpa_t addr, unsigned int len) { return -1UL; } void vgic_mmio_write_wi(struct kvm_vcpu *vcpu, gpa_t addr, unsigned int len, unsigned long val) { /* Ignore */ } /* * Read accesses to both GICD_ICENABLER and GICD_ISENABLER return the value * of the enabled bit, so there is only one function for both here. */ unsigned long vgic_mmio_read_enable(struct kvm_vcpu *vcpu, gpa_t addr, unsigned int len) { u32 intid = VGIC_ADDR_TO_INTID(addr, 1); u32 value = 0; int i; /* Loop over all IRQs affected by this read */ for (i = 0; i < len * 8; i++) { struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i); if (irq->enabled) value |= (1U << i); vgic_put_irq(vcpu->kvm, irq); } return value; } void vgic_mmio_write_senable(struct kvm_vcpu *vcpu, gpa_t addr, unsigned int len, unsigned long val) { u32 intid = VGIC_ADDR_TO_INTID(addr, 1); int i; for_each_set_bit(i, &val, len * 8) { struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i); spin_lock(&irq->irq_lock); irq->enabled = true; vgic_queue_irq_unlock(vcpu->kvm, irq); vgic_put_irq(vcpu->kvm, irq); } } void vgic_mmio_write_cenable(struct kvm_vcpu *vcpu, gpa_t addr, unsigned int len, unsigned long val) { u32 intid = VGIC_ADDR_TO_INTID(addr, 1); int i; for_each_set_bit(i, &val, len * 8) { struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i); spin_lock(&irq->irq_lock); irq->enabled = false; spin_unlock(&irq->irq_lock); vgic_put_irq(vcpu->kvm, irq); } } unsigned long vgic_mmio_read_pending(struct kvm_vcpu *vcpu, gpa_t addr, unsigned int len) { u32 intid = VGIC_ADDR_TO_INTID(addr, 1); u32 value = 0; int i; /* Loop over all IRQs affected by this read */ for (i = 0; i < len * 8; i++) { struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i); unsigned long flags; spin_lock_irqsave(&irq->irq_lock, flags); if (irq_is_pending(irq)) value |= (1U << i); spin_unlock_irqrestore(&irq->irq_lock, flags); vgic_put_irq(vcpu->kvm, irq); } return value; } void vgic_mmio_write_spending(struct kvm_vcpu *vcpu, gpa_t addr, unsigned int len, unsigned long val) { u32 intid = VGIC_ADDR_TO_INTID(addr, 1); int i; for_each_set_bit(i, &val, len * 8) { struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i); spin_lock(&irq->irq_lock); irq->pending_latch = true; vgic_queue_irq_unlock(vcpu->kvm, irq); vgic_put_irq(vcpu->kvm, irq); } } void vgic_mmio_write_cpending(struct kvm_vcpu *vcpu, gpa_t addr, unsigned int len, unsigned long val) { u32 intid = VGIC_ADDR_TO_INTID(addr, 1); int i; for_each_set_bit(i, &val, len * 8) { struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i); spin_lock(&irq->irq_lock); irq->pending_latch = false; spin_unlock(&irq->irq_lock); vgic_put_irq(vcpu->kvm, irq); } } unsigned long vgic_mmio_read_active(struct kvm_vcpu *vcpu, gpa_t addr, unsigned int len) { u32 intid = VGIC_ADDR_TO_INTID(addr, 1); u32 value = 0; int i; /* Loop over all IRQs affected by this read */ for (i = 0; i < len * 8; i++) { struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i); if (irq->active) value |= (1U << i); vgic_put_irq(vcpu->kvm, irq); } return value; } static void vgic_mmio_change_active(struct kvm_vcpu *vcpu, struct vgic_irq *irq, bool new_active_state) { struct kvm_vcpu *requester_vcpu; spin_lock(&irq->irq_lock); /* * The vcpu parameter here can mean multiple things depending on how * this function is called; when handling a trap from the kernel it * depends on the GIC version, and these functions are also called as * part of save/restore from userspace. * * Therefore, we have to figure out the requester in a reliable way. * * When accessing VGIC state from user space, the requester_vcpu is * NULL, which is fine, because we guarantee that no VCPUs are running * when accessing VGIC state from user space so irq->vcpu->cpu is * always -1. */ requester_vcpu = kvm_arm_get_running_vcpu(); /* * If this virtual IRQ was written into a list register, we * have to make sure the CPU that runs the VCPU thread has * synced back the LR state to the struct vgic_irq. * * As long as the conditions below are true, we know the VCPU thread * may be on its way back from the guest (we kicked the VCPU thread in * vgic_change_active_prepare) and still has to sync back this IRQ, * so we release and re-acquire the spin_lock to let the other thread * sync back the IRQ. */ while (irq->vcpu && /* IRQ may have state in an LR somewhere */ irq->vcpu != requester_vcpu && /* Current thread is not the VCPU thread */ irq->vcpu->cpu != -1) /* VCPU thread is running */ cond_resched_lock(&irq->irq_lock); irq->active = new_active_state; if (new_active_state) vgic_queue_irq_unlock(vcpu->kvm, irq); else spin_unlock(&irq->irq_lock); } /* * If we are fiddling with an IRQ's active state, we have to make sure the IRQ * is not queued on some running VCPU's LRs, because then the change to the * active state can be overwritten when the VCPU's state is synced coming back * from the guest. * * For shared interrupts, we have to stop all the VCPUs because interrupts can * be migrated while we don't hold the IRQ locks and we don't want to be * chasing moving targets. * * For private interrupts we don't have to do anything because userspace * accesses to the VGIC state already require all VCPUs to be stopped, and * only the VCPU itself can modify its private interrupts active state, which * guarantees that the VCPU is not running. */ static void vgic_change_active_prepare(struct kvm_vcpu *vcpu, u32 intid) { if (vcpu->kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3 || intid > VGIC_NR_PRIVATE_IRQS) kvm_arm_halt_guest(vcpu->kvm); } /* See vgic_change_active_prepare */ static void vgic_change_active_finish(struct kvm_vcpu *vcpu, u32 intid) { if (vcpu->kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3 || intid > VGIC_NR_PRIVATE_IRQS) kvm_arm_resume_guest(vcpu->kvm); } static void __vgic_mmio_write_cactive(struct kvm_vcpu *vcpu, gpa_t addr, unsigned int len, unsigned long val) { u32 intid = VGIC_ADDR_TO_INTID(addr, 1); int i; for_each_set_bit(i, &val, len * 8) { struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i); vgic_mmio_change_active(vcpu, irq, false); vgic_put_irq(vcpu->kvm, irq); } } void vgic_mmio_write_cactive(struct kvm_vcpu *vcpu, gpa_t addr, unsigned int len, unsigned long val) { u32 intid = VGIC_ADDR_TO_INTID(addr, 1); mutex_lock(&vcpu->kvm->lock); vgic_change_active_prepare(vcpu, intid); __vgic_mmio_write_cactive(vcpu, addr, len, val); vgic_change_active_finish(vcpu, intid); mutex_unlock(&vcpu->kvm->lock); } void vgic_mmio_uaccess_write_cactive(struct kvm_vcpu *vcpu, gpa_t addr, unsigned int len, unsigned long val) { __vgic_mmio_write_cactive(vcpu, addr, len, val); } static void __vgic_mmio_write_sactive(struct kvm_vcpu *vcpu, gpa_t addr, unsigned int len, unsigned long val) { u32 intid = VGIC_ADDR_TO_INTID(addr, 1); int i; for_each_set_bit(i, &val, len * 8) { struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i); vgic_mmio_change_active(vcpu, irq, true); vgic_put_irq(vcpu->kvm, irq); } } void vgic_mmio_write_sactive(struct kvm_vcpu *vcpu, gpa_t addr, unsigned int len, unsigned long val) { u32 intid = VGIC_ADDR_TO_INTID(addr, 1); mutex_lock(&vcpu->kvm->lock); vgic_change_active_prepare(vcpu, intid); __vgic_mmio_write_sactive(vcpu, addr, len, val); vgic_change_active_finish(vcpu, intid); mutex_unlock(&vcpu->kvm->lock); } void vgic_mmio_uaccess_write_sactive(struct kvm_vcpu *vcpu, gpa_t addr, unsigned int len, unsigned long val) { __vgic_mmio_write_sactive(vcpu, addr, len, val); } unsigned long vgic_mmio_read_priority(struct kvm_vcpu *vcpu, gpa_t addr, unsigned int len) { u32 intid = VGIC_ADDR_TO_INTID(addr, 8); int i; u64 val = 0; for (i = 0; i < len; i++) { struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i); val |= (u64)irq->priority << (i * 8); vgic_put_irq(vcpu->kvm, irq); } return val; } /* * We currently don't handle changing the priority of an interrupt that * is already pending on a VCPU. If there is a need for this, we would * need to make this VCPU exit and re-evaluate the priorities, potentially * leading to this interrupt getting presented now to the guest (if it has * been masked by the priority mask before). */ void vgic_mmio_write_priority(struct kvm_vcpu *vcpu, gpa_t addr, unsigned int len, unsigned long val) { u32 intid = VGIC_ADDR_TO_INTID(addr, 8); int i; for (i = 0; i < len; i++) { struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i); spin_lock(&irq->irq_lock); /* Narrow the priority range to what we actually support */ irq->priority = (val >> (i * 8)) & GENMASK(7, 8 - VGIC_PRI_BITS); spin_unlock(&irq->irq_lock); vgic_put_irq(vcpu->kvm, irq); } } unsigned long vgic_mmio_read_config(struct kvm_vcpu *vcpu, gpa_t addr, unsigned int len) { u32 intid = VGIC_ADDR_TO_INTID(addr, 2); u32 value = 0; int i; for (i = 0; i < len * 4; i++) { struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i); if (irq->config == VGIC_CONFIG_EDGE) value |= (2U << (i * 2)); vgic_put_irq(vcpu->kvm, irq); } return value; } void vgic_mmio_write_config(struct kvm_vcpu *vcpu, gpa_t addr, unsigned int len, unsigned long val) { u32 intid = VGIC_ADDR_TO_INTID(addr, 2); int i; for (i = 0; i < len * 4; i++) { struct vgic_irq *irq; /* * The configuration cannot be changed for SGIs in general, * for PPIs this is IMPLEMENTATION DEFINED. The arch timer * code relies on PPIs being level triggered, so we also * make them read-only here. */ if (intid + i < VGIC_NR_PRIVATE_IRQS) continue; irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i); spin_lock(&irq->irq_lock); if (test_bit(i * 2 + 1, &val)) irq->config = VGIC_CONFIG_EDGE; else irq->config = VGIC_CONFIG_LEVEL; spin_unlock(&irq->irq_lock); vgic_put_irq(vcpu->kvm, irq); } } u64 vgic_read_irq_line_level_info(struct kvm_vcpu *vcpu, u32 intid) { int i; u64 val = 0; int nr_irqs = vcpu->kvm->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS; for (i = 0; i < 32; i++) { struct vgic_irq *irq; if ((intid + i) < VGIC_NR_SGIS || (intid + i) >= nr_irqs) continue; irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i); if (irq->config == VGIC_CONFIG_LEVEL && irq->line_level) val |= (1U << i); vgic_put_irq(vcpu->kvm, irq); } return val; } void vgic_write_irq_line_level_info(struct kvm_vcpu *vcpu, u32 intid, const u64 val) { int i; int nr_irqs = vcpu->kvm->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS; for (i = 0; i < 32; i++) { struct vgic_irq *irq; bool new_level; if ((intid + i) < VGIC_NR_SGIS || (intid + i) >= nr_irqs) continue; irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i); /* * Line level is set irrespective of irq type * (level or edge) to avoid dependency that VM should * restore irq config before line level. */ new_level = !!(val & (1U << i)); spin_lock(&irq->irq_lock); irq->line_level = new_level; if (new_level) vgic_queue_irq_unlock(vcpu->kvm, irq); else spin_unlock(&irq->irq_lock); vgic_put_irq(vcpu->kvm, irq); } } static int match_region(const void *key, const void *elt) { const unsigned int offset = (unsigned long)key; const struct vgic_register_region *region = elt; if (offset < region->reg_offset) return -1; if (offset >= region->reg_offset + region->len) return 1; return 0; } const struct vgic_register_region * vgic_find_mmio_region(const struct vgic_register_region *regions, int nr_regions, unsigned int offset) { return bsearch((void *)(uintptr_t)offset, regions, nr_regions, sizeof(regions[0]), match_region); } void vgic_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr) { if (kvm_vgic_global_state.type == VGIC_V2) vgic_v2_set_vmcr(vcpu, vmcr); else vgic_v3_set_vmcr(vcpu, vmcr); } void vgic_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr) { if (kvm_vgic_global_state.type == VGIC_V2) vgic_v2_get_vmcr(vcpu, vmcr); else vgic_v3_get_vmcr(vcpu, vmcr); } /* * kvm_mmio_read_buf() returns a value in a format where it can be converted * to a byte array and be directly observed as the guest wanted it to appear * in memory if it had done the store itself, which is LE for the GIC, as the * guest knows the GIC is always LE. * * We convert this value to the CPUs native format to deal with it as a data * value. */ unsigned long vgic_data_mmio_bus_to_host(const void *val, unsigned int len) { unsigned long data = kvm_mmio_read_buf(val, len); switch (len) { case 1: return data; case 2: return le16_to_cpu(data); case 4: return le32_to_cpu(data); default: return le64_to_cpu(data); } } /* * kvm_mmio_write_buf() expects a value in a format such that if converted to * a byte array it is observed as the guest would see it if it could perform * the load directly. Since the GIC is LE, and the guest knows this, the * guest expects a value in little endian format. * * We convert the data value from the CPUs native format to LE so that the * value is returned in the proper format. */ void vgic_data_host_to_mmio_bus(void *buf, unsigned int len, unsigned long data) { switch (len) { case 1: break; case 2: data = cpu_to_le16(data); break; case 4: data = cpu_to_le32(data); break; default: data = cpu_to_le64(data); } kvm_mmio_write_buf(buf, len, data); } static struct vgic_io_device *kvm_to_vgic_iodev(const struct kvm_io_device *dev) { return container_of(dev, struct vgic_io_device, dev); } static bool check_region(const struct kvm *kvm, const struct vgic_register_region *region, gpa_t addr, int len) { int flags, nr_irqs = kvm->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS; switch (len) { case sizeof(u8): flags = VGIC_ACCESS_8bit; break; case sizeof(u32): flags = VGIC_ACCESS_32bit; break; case sizeof(u64): flags = VGIC_ACCESS_64bit; break; default: return false; } if ((region->access_flags & flags) && IS_ALIGNED(addr, len)) { if (!region->bits_per_irq) return true; /* Do we access a non-allocated IRQ? */ return VGIC_ADDR_TO_INTID(addr, region->bits_per_irq) < nr_irqs; } return false; } const struct vgic_register_region * vgic_get_mmio_region(struct kvm_vcpu *vcpu, struct vgic_io_device *iodev, gpa_t addr, int len) { const struct vgic_register_region *region; region = vgic_find_mmio_region(iodev->regions, iodev->nr_regions, addr - iodev->base_addr); if (!region || !check_region(vcpu->kvm, region, addr, len)) return NULL; return region; } static int vgic_uaccess_read(struct kvm_vcpu *vcpu, struct kvm_io_device *dev, gpa_t addr, u32 *val) { struct vgic_io_device *iodev = kvm_to_vgic_iodev(dev); const struct vgic_register_region *region; struct kvm_vcpu *r_vcpu; region = vgic_get_mmio_region(vcpu, iodev, addr, sizeof(u32)); if (!region) { *val = 0; return 0; } r_vcpu = iodev->redist_vcpu ? iodev->redist_vcpu : vcpu; if (region->uaccess_read) *val = region->uaccess_read(r_vcpu, addr, sizeof(u32)); else *val = region->read(r_vcpu, addr, sizeof(u32)); return 0; } static int vgic_uaccess_write(struct kvm_vcpu *vcpu, struct kvm_io_device *dev, gpa_t addr, const u32 *val) { struct vgic_io_device *iodev = kvm_to_vgic_iodev(dev); const struct vgic_register_region *region; struct kvm_vcpu *r_vcpu; region = vgic_get_mmio_region(vcpu, iodev, addr, sizeof(u32)); if (!region) return 0; r_vcpu = iodev->redist_vcpu ? iodev->redist_vcpu : vcpu; if (region->uaccess_write) region->uaccess_write(r_vcpu, addr, sizeof(u32), *val); else region->write(r_vcpu, addr, sizeof(u32), *val); return 0; } /* * Userland access to VGIC registers. */ int vgic_uaccess(struct kvm_vcpu *vcpu, struct vgic_io_device *dev, bool is_write, int offset, u32 *val) { if (is_write) return vgic_uaccess_write(vcpu, &dev->dev, offset, val); else return vgic_uaccess_read(vcpu, &dev->dev, offset, val); } static int dispatch_mmio_read(struct kvm_vcpu *vcpu, struct kvm_io_device *dev, gpa_t addr, int len, void *val) { struct vgic_io_device *iodev = kvm_to_vgic_iodev(dev); const struct vgic_register_region *region; unsigned long data = 0; region = vgic_get_mmio_region(vcpu, iodev, addr, len); if (!region) { memset(val, 0, len); return 0; } switch (iodev->iodev_type) { case IODEV_CPUIF: data = region->read(vcpu, addr, len); break; case IODEV_DIST: data = region->read(vcpu, addr, len); break; case IODEV_REDIST: data = region->read(iodev->redist_vcpu, addr, len); break; case IODEV_ITS: data = region->its_read(vcpu->kvm, iodev->its, addr, len); break; } vgic_data_host_to_mmio_bus(val, len, data); return 0; } static int dispatch_mmio_write(struct kvm_vcpu *vcpu, struct kvm_io_device *dev, gpa_t addr, int len, const void *val) { struct vgic_io_device *iodev = kvm_to_vgic_iodev(dev); const struct vgic_register_region *region; unsigned long data = vgic_data_mmio_bus_to_host(val, len); region = vgic_get_mmio_region(vcpu, iodev, addr, len); if (!region) return 0; switch (iodev->iodev_type) { case IODEV_CPUIF: region->write(vcpu, addr, len, data); break; case IODEV_DIST: region->write(vcpu, addr, len, data); break; case IODEV_REDIST: region->write(iodev->redist_vcpu, addr, len, data); break; case IODEV_ITS: region->its_write(vcpu->kvm, iodev->its, addr, len, data); break; } return 0; } struct kvm_io_device_ops kvm_io_gic_ops = { .read = dispatch_mmio_read, .write = dispatch_mmio_write, }; int vgic_register_dist_iodev(struct kvm *kvm, gpa_t dist_base_address, enum vgic_type type) { struct vgic_io_device *io_device = &kvm->arch.vgic.dist_iodev; int ret = 0; unsigned int len; switch (type) { case VGIC_V2: len = vgic_v2_init_dist_iodev(io_device); break; case VGIC_V3: len = vgic_v3_init_dist_iodev(io_device); break; default: BUG_ON(1); } io_device->base_addr = dist_base_address; io_device->iodev_type = IODEV_DIST; io_device->redist_vcpu = NULL; mutex_lock(&kvm->slots_lock); ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, dist_base_address, len, &io_device->dev); mutex_unlock(&kvm->slots_lock); return ret; }