From 140b086dd19771410915a924db2e635c2b51a0f4 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Thu, 26 Nov 2015 17:19:25 +0000 Subject: [PATCH] KVM: arm/arm64: vgic-new: Add GICv2 world switch backend Processing maintenance interrupts and accessing the list registers are dependent on the host's GIC version. Introduce vgic-v2.c to contain GICv2 specific functions. Implement the GICv2 specific code for syncing the emulation state into the VGIC registers. Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall Signed-off-by: Eric Auger Signed-off-by: Andre Przywara Reviewed-by: Eric Auger Reviewed-by: Christoffer Dall --- include/linux/irqchip/arm-gic.h | 1 + virt/kvm/arm/vgic/vgic-v2.c | 176 ++++++++++++++++++++++++++++++++ virt/kvm/arm/vgic/vgic.c | 6 ++ virt/kvm/arm/vgic/vgic.h | 6 ++ 4 files changed, 189 insertions(+) create mode 100644 virt/kvm/arm/vgic/vgic-v2.c diff --git a/include/linux/irqchip/arm-gic.h b/include/linux/irqchip/arm-gic.h index 9c940263ca23..be0d26f940af 100644 --- a/include/linux/irqchip/arm-gic.h +++ b/include/linux/irqchip/arm-gic.h @@ -76,6 +76,7 @@ #define GICH_LR_VIRTUALID (0x3ff << 0) #define GICH_LR_PHYSID_CPUID_SHIFT (10) #define GICH_LR_PHYSID_CPUID (0x3ff << GICH_LR_PHYSID_CPUID_SHIFT) +#define GICH_LR_PRIORITY_SHIFT 23 #define GICH_LR_STATE (3 << 28) #define GICH_LR_PENDING_BIT (1 << 28) #define GICH_LR_ACTIVE_BIT (1 << 29) diff --git a/virt/kvm/arm/vgic/vgic-v2.c b/virt/kvm/arm/vgic/vgic-v2.c new file mode 100644 index 000000000000..fb5e65ceffd0 --- /dev/null +++ b/virt/kvm/arm/vgic/vgic-v2.c @@ -0,0 +1,176 @@ +/* + * Copyright (C) 2015, 2016 ARM Ltd. + * + * 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 . + */ + +#include +#include +#include + +#include "vgic.h" + +/* + * Call this function to convert a u64 value to an unsigned long * bitmask + * in a way that works on both 32-bit and 64-bit LE and BE platforms. + * + * Warning: Calling this function may modify *val. + */ +static unsigned long *u64_to_bitmask(u64 *val) +{ +#if defined(CONFIG_CPU_BIG_ENDIAN) && BITS_PER_LONG == 32 + *val = (*val >> 32) | (*val << 32); +#endif + return (unsigned long *)val; +} + +void vgic_v2_process_maintenance(struct kvm_vcpu *vcpu) +{ + struct vgic_v2_cpu_if *cpuif = &vcpu->arch.vgic_cpu.vgic_v2; + + if (cpuif->vgic_misr & GICH_MISR_EOI) { + u64 eisr = cpuif->vgic_eisr; + unsigned long *eisr_bmap = u64_to_bitmask(&eisr); + int lr; + + for_each_set_bit(lr, eisr_bmap, kvm_vgic_global_state.nr_lr) { + u32 intid = cpuif->vgic_lr[lr] & GICH_LR_VIRTUALID; + + WARN_ON(cpuif->vgic_lr[lr] & GICH_LR_STATE); + + kvm_notify_acked_irq(vcpu->kvm, 0, + intid - VGIC_NR_PRIVATE_IRQS); + } + } + + /* check and disable underflow maintenance IRQ */ + cpuif->vgic_hcr &= ~GICH_HCR_UIE; + + /* + * In the next iterations of the vcpu loop, if we sync the + * vgic state after flushing it, but before entering the guest + * (this happens for pending signals and vmid rollovers), then + * make sure we don't pick up any old maintenance interrupts + * here. + */ + cpuif->vgic_eisr = 0; +} + +void vgic_v2_set_underflow(struct kvm_vcpu *vcpu) +{ + struct vgic_v2_cpu_if *cpuif = &vcpu->arch.vgic_cpu.vgic_v2; + + cpuif->vgic_hcr |= GICH_HCR_UIE; +} + +/* + * transfer the content of the LRs back into the corresponding ap_list: + * - active bit is transferred as is + * - pending bit is + * - transferred as is in case of edge sensitive IRQs + * - set to the line-level (resample time) for level sensitive IRQs + */ +void vgic_v2_fold_lr_state(struct kvm_vcpu *vcpu) +{ + struct vgic_v2_cpu_if *cpuif = &vcpu->arch.vgic_cpu.vgic_v2; + int lr; + + for (lr = 0; lr < vcpu->arch.vgic_cpu.used_lrs; lr++) { + u32 val = cpuif->vgic_lr[lr]; + u32 intid = val & GICH_LR_VIRTUALID; + struct vgic_irq *irq; + + irq = vgic_get_irq(vcpu->kvm, vcpu, intid); + + spin_lock(&irq->irq_lock); + + /* Always preserve the active bit */ + irq->active = !!(val & GICH_LR_ACTIVE_BIT); + + /* Edge is the only case where we preserve the pending bit */ + if (irq->config == VGIC_CONFIG_EDGE && + (val & GICH_LR_PENDING_BIT)) { + irq->pending = true; + + if (vgic_irq_is_sgi(intid)) { + u32 cpuid = val & GICH_LR_PHYSID_CPUID; + + cpuid >>= GICH_LR_PHYSID_CPUID_SHIFT; + irq->source |= (1 << cpuid); + } + } + + /* Clear soft pending state when level IRQs have been acked */ + if (irq->config == VGIC_CONFIG_LEVEL && + !(val & GICH_LR_PENDING_BIT)) { + irq->soft_pending = false; + irq->pending = irq->line_level; + } + + spin_unlock(&irq->irq_lock); + } +} + +/* + * Populates the particular LR with the state of a given IRQ: + * - for an edge sensitive IRQ the pending state is cleared in struct vgic_irq + * - for a level sensitive IRQ the pending state value is unchanged; + * it is dictated directly by the input level + * + * If @irq describes an SGI with multiple sources, we choose the + * lowest-numbered source VCPU and clear that bit in the source bitmap. + * + * The irq_lock must be held by the caller. + */ +void vgic_v2_populate_lr(struct kvm_vcpu *vcpu, struct vgic_irq *irq, int lr) +{ + u32 val = irq->intid; + + if (irq->pending) { + val |= GICH_LR_PENDING_BIT; + + if (irq->config == VGIC_CONFIG_EDGE) + irq->pending = false; + + if (vgic_irq_is_sgi(irq->intid)) { + u32 src = ffs(irq->source); + + BUG_ON(!src); + val |= (src - 1) << GICH_LR_PHYSID_CPUID_SHIFT; + irq->source &= ~(1 << (src - 1)); + if (irq->source) + irq->pending = true; + } + } + + if (irq->active) + val |= GICH_LR_ACTIVE_BIT; + + if (irq->hw) { + val |= GICH_LR_HW; + val |= irq->hwintid << GICH_LR_PHYSID_CPUID_SHIFT; + } else { + if (irq->config == VGIC_CONFIG_LEVEL) + val |= GICH_LR_EOI; + } + + /* The GICv2 LR only holds five bits of priority. */ + val |= (irq->priority >> 3) << GICH_LR_PRIORITY_SHIFT; + + vcpu->arch.vgic_cpu.vgic_v2.vgic_lr[lr] = val; +} + +void vgic_v2_clear_lr(struct kvm_vcpu *vcpu, int lr) +{ + vcpu->arch.vgic_cpu.vgic_v2.vgic_lr[lr] = 0; +} diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c index 08a862a98442..44d2533ac84e 100644 --- a/virt/kvm/arm/vgic/vgic.c +++ b/virt/kvm/arm/vgic/vgic.c @@ -400,10 +400,12 @@ retry: static inline void vgic_process_maintenance_interrupt(struct kvm_vcpu *vcpu) { + vgic_v2_process_maintenance(vcpu); } static inline void vgic_fold_lr_state(struct kvm_vcpu *vcpu) { + vgic_v2_fold_lr_state(vcpu); } /* Requires the irq_lock to be held. */ @@ -411,14 +413,18 @@ static inline void vgic_populate_lr(struct kvm_vcpu *vcpu, struct vgic_irq *irq, int lr) { DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&irq->irq_lock)); + + vgic_v2_populate_lr(vcpu, irq, lr); } static inline void vgic_clear_lr(struct kvm_vcpu *vcpu, int lr) { + vgic_v2_clear_lr(vcpu, lr); } static inline void vgic_set_underflow(struct kvm_vcpu *vcpu) { + vgic_v2_set_underflow(vcpu); } /* Requires the ap_list_lock to be held. */ diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h index 29b96b96a30b..0db490e491ef 100644 --- a/virt/kvm/arm/vgic/vgic.h +++ b/virt/kvm/arm/vgic/vgic.h @@ -22,4 +22,10 @@ struct vgic_irq *vgic_get_irq(struct kvm *kvm, struct kvm_vcpu *vcpu, u32 intid); bool vgic_queue_irq_unlock(struct kvm *kvm, struct vgic_irq *irq); +void vgic_v2_process_maintenance(struct kvm_vcpu *vcpu); +void vgic_v2_fold_lr_state(struct kvm_vcpu *vcpu); +void vgic_v2_populate_lr(struct kvm_vcpu *vcpu, struct vgic_irq *irq, int lr); +void vgic_v2_clear_lr(struct kvm_vcpu *vcpu, int lr); +void vgic_v2_set_underflow(struct kvm_vcpu *vcpu); + #endif