From 6d3cfbe21bef5b66530b50ad16c88fdc71a04c35 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Thu, 4 Dec 2014 15:02:24 +0000 Subject: arm/arm64: KVM: vgic: move reset initialization into vgic_init_maps() VGIC initialization currently happens in three phases: (1) kvm_vgic_create() (triggered by userspace GIC creation) (2) vgic_init_maps() (triggered by userspace GIC register read/write requests, or from kvm_vgic_init() if not already run) (3) kvm_vgic_init() (triggered by first VM run) We were doing initialization of some state to correspond with the state of a freshly-reset GIC in kvm_vgic_init(); this is too late, since it will overwrite changes made by userspace using the register access APIs before the VM is run. Move this initialization earlier, into the vgic_init_maps() phase. This fixes a bug where QEMU could successfully restore a saved VM state snapshot into a VM that had already been run, but could not restore it "from cold" using the -loadvm command line option (the symptoms being that the restored VM would run but interrupts were ignored). Finally rename vgic_init_maps to vgic_init and renamed kvm_vgic_init to kvm_vgic_map_resources. [ This patch is originally written by Peter Maydell, but I have modified it somewhat heavily, renaming various bits and moving code around. If something is broken, I am to be blamed. - Christoffer ] Acked-by: Marc Zyngier Reviewed-by: Eric Auger Signed-off-by: Peter Maydell Signed-off-by: Christoffer Dall --- virt/kvm/arm/vgic.c | 77 ++++++++++++++++++++++------------------------------- 1 file changed, 32 insertions(+), 45 deletions(-) (limited to 'virt') diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c index 21e035cc5460..1ce4e364c1e0 100644 --- a/virt/kvm/arm/vgic.c +++ b/virt/kvm/arm/vgic.c @@ -91,6 +91,7 @@ #define ACCESS_WRITE_VALUE (3 << 1) #define ACCESS_WRITE_MASK(x) ((x) & (3 << 1)) +static int vgic_init(struct kvm *kvm); static void vgic_retire_disabled_irqs(struct kvm_vcpu *vcpu); static void vgic_retire_lr(int lr_nr, int irq, struct kvm_vcpu *vcpu); static void vgic_update_state(struct kvm *kvm); @@ -1732,39 +1733,14 @@ static int vgic_vcpu_init_maps(struct kvm_vcpu *vcpu, int nr_irqs) int sz = (nr_irqs - VGIC_NR_PRIVATE_IRQS) / 8; vgic_cpu->pending_shared = kzalloc(sz, GFP_KERNEL); - vgic_cpu->vgic_irq_lr_map = kzalloc(nr_irqs, GFP_KERNEL); + vgic_cpu->vgic_irq_lr_map = kmalloc(nr_irqs, GFP_KERNEL); if (!vgic_cpu->pending_shared || !vgic_cpu->vgic_irq_lr_map) { kvm_vgic_vcpu_destroy(vcpu); return -ENOMEM; } - return 0; -} - -/** - * kvm_vgic_vcpu_init - Initialize per-vcpu VGIC state - * @vcpu: pointer to the vcpu struct - * - * Initialize the vgic_cpu struct and vgic_dist struct fields pertaining to - * this vcpu and enable the VGIC for this VCPU - */ -static void kvm_vgic_vcpu_init(struct kvm_vcpu *vcpu) -{ - struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu; - struct vgic_dist *dist = &vcpu->kvm->arch.vgic; - int i; - - for (i = 0; i < dist->nr_irqs; i++) { - if (i < VGIC_NR_PPIS) - vgic_bitmap_set_irq_val(&dist->irq_enabled, - vcpu->vcpu_id, i, 1); - if (i < VGIC_NR_PRIVATE_IRQS) - vgic_bitmap_set_irq_val(&dist->irq_cfg, - vcpu->vcpu_id, i, VGIC_CFG_EDGE); - - vgic_cpu->vgic_irq_lr_map[i] = LR_EMPTY; - } + memset(vgic_cpu->vgic_irq_lr_map, LR_EMPTY, nr_irqs); /* * Store the number of LRs per vcpu, so we don't have to go @@ -1773,7 +1749,7 @@ static void kvm_vgic_vcpu_init(struct kvm_vcpu *vcpu) */ vgic_cpu->nr_lr = vgic->nr_lr; - vgic_enable(vcpu); + return 0; } void kvm_vgic_destroy(struct kvm *kvm) @@ -1810,12 +1786,12 @@ void kvm_vgic_destroy(struct kvm *kvm) * Allocate and initialize the various data structures. Must be called * with kvm->lock held! */ -static int vgic_init_maps(struct kvm *kvm) +static int vgic_init(struct kvm *kvm) { struct vgic_dist *dist = &kvm->arch.vgic; struct kvm_vcpu *vcpu; int nr_cpus, nr_irqs; - int ret, i; + int ret, i, vcpu_id; if (dist->nr_cpus) /* Already allocated */ return 0; @@ -1865,16 +1841,28 @@ static int vgic_init_maps(struct kvm *kvm) if (ret) goto out; - kvm_for_each_vcpu(i, vcpu, kvm) { + for (i = VGIC_NR_PRIVATE_IRQS; i < dist->nr_irqs; i += 4) + vgic_set_target_reg(kvm, 0, i); + + kvm_for_each_vcpu(vcpu_id, vcpu, kvm) { ret = vgic_vcpu_init_maps(vcpu, nr_irqs); if (ret) { kvm_err("VGIC: Failed to allocate vcpu memory\n"); break; } - } - for (i = VGIC_NR_PRIVATE_IRQS; i < dist->nr_irqs; i += 4) - vgic_set_target_reg(kvm, 0, i); + for (i = 0; i < dist->nr_irqs; i++) { + if (i < VGIC_NR_PPIS) + vgic_bitmap_set_irq_val(&dist->irq_enabled, + vcpu->vcpu_id, i, 1); + if (i < VGIC_NR_PRIVATE_IRQS) + vgic_bitmap_set_irq_val(&dist->irq_cfg, + vcpu->vcpu_id, i, + VGIC_CFG_EDGE); + } + + vgic_enable(vcpu); + } out: if (ret) @@ -1884,18 +1872,16 @@ out: } /** - * kvm_vgic_init - Initialize global VGIC state before running any VCPUs + * kvm_vgic_map_resources - Configure global VGIC state before running any VCPUs * @kvm: pointer to the kvm struct * * Map the virtual CPU interface into the VM before running any VCPUs. We * can't do this at creation time, because user space must first set the - * virtual CPU interface address in the guest physical address space. Also - * initialize the ITARGETSRn regs to 0 on the emulated distributor. + * virtual CPU interface address in the guest physical address space. */ -int kvm_vgic_init(struct kvm *kvm) +int kvm_vgic_map_resources(struct kvm *kvm) { - struct kvm_vcpu *vcpu; - int ret = 0, i; + int ret = 0; if (!irqchip_in_kernel(kvm)) return 0; @@ -1912,7 +1898,11 @@ int kvm_vgic_init(struct kvm *kvm) goto out; } - ret = vgic_init_maps(kvm); + /* + * Initialize the vgic if this hasn't already been done on demand by + * accessing the vgic state from userspace. + */ + ret = vgic_init(kvm); if (ret) { kvm_err("Unable to allocate maps\n"); goto out; @@ -1926,9 +1916,6 @@ int kvm_vgic_init(struct kvm *kvm) goto out; } - kvm_for_each_vcpu(i, vcpu, kvm) - kvm_vgic_vcpu_init(vcpu); - kvm->arch.vgic.ready = true; out: if (ret) @@ -2173,7 +2160,7 @@ static int vgic_attr_regs_access(struct kvm_device *dev, mutex_lock(&dev->kvm->lock); - ret = vgic_init_maps(dev->kvm); + ret = vgic_init(dev->kvm); if (ret) goto out; -- cgit v1.2.3