The LPI pending status for a GICv3 redistributor is held in a table in (guest) memory. To achieve reasonable performance, we cache this data in our struct vgic_irq. The initial pending state must be read from guest memory upon enabling LPIs for this redistributor. Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx> --- virt/kvm/arm/vgic/vgic-its.c | 81 ++++++++++++++++++++++++++++++++++++++++++++ virt/kvm/arm/vgic/vgic.h | 6 ++++ 2 files changed, 87 insertions(+) diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c index ca2eb968..2c88c72 100644 --- a/virt/kvm/arm/vgic/vgic-its.c +++ b/virt/kvm/arm/vgic/vgic-its.c @@ -93,6 +93,81 @@ struct its_itte { list_for_each_entry(itte, &(dev)->itt_head, itte_list) #define CBASER_ADDRESS(x) ((x) & GENMASK_ULL(51, 12)) +#define PENDBASER_ADDRESS(x) ((x) & GENMASK_ULL(51, 16)) + +static int vits_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_entry) { + if (kref_get_unless_zero(&irq->refcount)) { + intids[i] = irq->intid; + vgic_put_irq_locked(kvm, irq); + } + if (i++ == irq_count) + break; + } + spin_unlock(&dist->lpi_list_lock); + + *intid_ptr = intids; + return irq_count; +} + +/* + * 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; + u8 pendmask; + int ret = 0; + u32 *intids; + int nr_irqs, i; + + nr_irqs = vits_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; + + byte_offset = intids[i] / BITS_PER_BYTE; + bit_nr = intids[i] % BITS_PER_BYTE; + + ret = kvm_read_guest(vcpu->kvm, pendbase + byte_offset, + &pendmask, 1); + if (ret) { + kfree(intids); + return ret; + } + + 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); + } + + return ret; +} static unsigned long vgic_mmio_read_its_ctlr(struct kvm *vcpu, struct vgic_its *its, @@ -415,6 +490,12 @@ static struct vgic_register_region its_registers[] = { VGIC_ACCESS_32bit), }; +/* This is called on setting the LPI enable bit in the redistributor. */ +void vgic_enable_lpis(struct kvm_vcpu *vcpu) +{ + its_sync_lpi_pending_table(vcpu); +} + static int vits_register(struct kvm *kvm, struct vgic_its *its) { struct vgic_io_device *iodev = &its->iodev; diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h index eef9ec1..4a9165f 100644 --- a/virt/kvm/arm/vgic/vgic.h +++ b/virt/kvm/arm/vgic/vgic.h @@ -25,6 +25,7 @@ #define IS_VGIC_ADDR_UNDEF(_x) ((_x) == VGIC_ADDR_UNDEF) #define INTERRUPT_ID_BITS_SPIS 10 +#define INTERRUPT_ID_BITS_ITS 16 #define VGIC_PRI_BITS 5 #define vgic_irq_is_sgi(intid) ((intid) < VGIC_NR_SGIS) @@ -79,6 +80,7 @@ int vgic_register_redist_iodevs(struct kvm *kvm, gpa_t dist_base_address); bool vgic_has_its(struct kvm *kvm); int kvm_vgic_register_its_device(void); struct vgic_irq *vgic_its_get_lpi(struct kvm *kvm, u32 intid); +void vgic_enable_lpis(struct kvm_vcpu *vcpu); #else static inline void vgic_v3_process_maintenance(struct kvm_vcpu *vcpu) { @@ -145,6 +147,10 @@ static inline struct vgic_irq *vgic_its_get_lpi(struct kvm *kvm, u32 intid) { return NULL; } + +static inline void vgic_enable_lpis(struct kvm_vcpu *vcpu) +{ +} #endif int kvm_register_vgic_device(unsigned long type); -- 2.9.0 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html