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-rw-r--r--virt/kvm/arm/vgic/vgic-mmio.c911
1 files changed, 911 insertions, 0 deletions
diff --git a/virt/kvm/arm/vgic/vgic-mmio.c b/virt/kvm/arm/vgic/vgic-mmio.c
new file mode 100644
index 000000000..9d06a1f8e
--- /dev/null
+++ b/virt/kvm/arm/vgic/vgic-mmio.c
@@ -0,0 +1,911 @@
+/*
+ * 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 <linux/bitops.h>
+#include <linux/bsearch.h>
+#include <linux/kvm.h>
+#include <linux/kvm_host.h>
+#include <kvm/iodev.h>
+#include <kvm/arm_arch_timer.h>
+#include <kvm/arm_vgic.h>
+
+#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 */
+}
+
+int vgic_mmio_uaccess_write_wi(struct kvm_vcpu *vcpu, gpa_t addr,
+ unsigned int len, unsigned long val)
+{
+ /* Ignore */
+ return 0;
+}
+
+unsigned long vgic_mmio_read_group(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->group)
+ value |= BIT(i);
+
+ vgic_put_irq(vcpu->kvm, irq);
+ }
+
+ return value;
+}
+
+void vgic_mmio_write_group(struct kvm_vcpu *vcpu, gpa_t addr,
+ unsigned int len, unsigned long val)
+{
+ u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
+ int i;
+ unsigned long flags;
+
+ for (i = 0; i < len * 8; i++) {
+ struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+
+ spin_lock_irqsave(&irq->irq_lock, flags);
+ irq->group = !!(val & BIT(i));
+ vgic_queue_irq_unlock(vcpu->kvm, irq, flags);
+
+ vgic_put_irq(vcpu->kvm, irq);
+ }
+}
+
+/*
+ * 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;
+ unsigned long flags;
+
+ for_each_set_bit(i, &val, len * 8) {
+ struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+
+ spin_lock_irqsave(&irq->irq_lock, flags);
+ irq->enabled = true;
+ vgic_queue_irq_unlock(vcpu->kvm, irq, flags);
+
+ 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;
+ unsigned long flags;
+
+ for_each_set_bit(i, &val, len * 8) {
+ struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+
+ spin_lock_irqsave(&irq->irq_lock, flags);
+
+ irq->enabled = false;
+
+ spin_unlock_irqrestore(&irq->irq_lock, flags);
+ 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;
+}
+
+/*
+ * This function will return the VCPU that performed the MMIO access and
+ * trapped from within the VM, and will return NULL if this is a userspace
+ * access.
+ *
+ * We can disable preemption locally around accessing the per-CPU variable,
+ * and use the resolved vcpu pointer after enabling preemption again, because
+ * even if the current thread is migrated to another CPU, reading the per-CPU
+ * value later will give us the same value as we update the per-CPU variable
+ * in the preempt notifier handlers.
+ */
+static struct kvm_vcpu *vgic_get_mmio_requester_vcpu(void)
+{
+ struct kvm_vcpu *vcpu;
+
+ preempt_disable();
+ vcpu = kvm_arm_get_running_vcpu();
+ preempt_enable();
+ return vcpu;
+}
+
+/* Must be called with irq->irq_lock held */
+static void vgic_hw_irq_spending(struct kvm_vcpu *vcpu, struct vgic_irq *irq,
+ bool is_uaccess)
+{
+ if (is_uaccess)
+ return;
+
+ irq->pending_latch = true;
+ vgic_irq_set_phys_active(irq, true);
+}
+
+static bool is_vgic_v2_sgi(struct kvm_vcpu *vcpu, struct vgic_irq *irq)
+{
+ return (vgic_irq_is_sgi(irq->intid) &&
+ vcpu->kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V2);
+}
+
+void vgic_mmio_write_spending(struct kvm_vcpu *vcpu,
+ gpa_t addr, unsigned int len,
+ unsigned long val)
+{
+ bool is_uaccess = !vgic_get_mmio_requester_vcpu();
+ u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
+ int i;
+ unsigned long flags;
+
+ for_each_set_bit(i, &val, len * 8) {
+ struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+
+ /* GICD_ISPENDR0 SGI bits are WI */
+ if (is_vgic_v2_sgi(vcpu, irq)) {
+ vgic_put_irq(vcpu->kvm, irq);
+ continue;
+ }
+
+ spin_lock_irqsave(&irq->irq_lock, flags);
+ if (irq->hw)
+ vgic_hw_irq_spending(vcpu, irq, is_uaccess);
+ else
+ irq->pending_latch = true;
+ vgic_queue_irq_unlock(vcpu->kvm, irq, flags);
+ vgic_put_irq(vcpu->kvm, irq);
+ }
+}
+
+/* Must be called with irq->irq_lock held */
+static void vgic_hw_irq_cpending(struct kvm_vcpu *vcpu, struct vgic_irq *irq,
+ bool is_uaccess)
+{
+ if (is_uaccess)
+ return;
+
+ irq->pending_latch = false;
+
+ /*
+ * We don't want the guest to effectively mask the physical
+ * interrupt by doing a write to SPENDR followed by a write to
+ * CPENDR for HW interrupts, so we clear the active state on
+ * the physical side if the virtual interrupt is not active.
+ * This may lead to taking an additional interrupt on the
+ * host, but that should not be a problem as the worst that
+ * can happen is an additional vgic injection. We also clear
+ * the pending state to maintain proper semantics for edge HW
+ * interrupts.
+ */
+ vgic_irq_set_phys_pending(irq, false);
+ if (!irq->active)
+ vgic_irq_set_phys_active(irq, false);
+}
+
+void vgic_mmio_write_cpending(struct kvm_vcpu *vcpu,
+ gpa_t addr, unsigned int len,
+ unsigned long val)
+{
+ bool is_uaccess = !vgic_get_mmio_requester_vcpu();
+ u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
+ int i;
+ unsigned long flags;
+
+ for_each_set_bit(i, &val, len * 8) {
+ struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+
+ /* GICD_ICPENDR0 SGI bits are WI */
+ if (is_vgic_v2_sgi(vcpu, irq)) {
+ vgic_put_irq(vcpu->kvm, irq);
+ continue;
+ }
+
+ spin_lock_irqsave(&irq->irq_lock, flags);
+
+ if (irq->hw)
+ vgic_hw_irq_cpending(vcpu, irq, is_uaccess);
+ else
+ irq->pending_latch = false;
+
+ spin_unlock_irqrestore(&irq->irq_lock, flags);
+ 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;
+}
+
+/* Must be called with irq->irq_lock held */
+static void vgic_hw_irq_change_active(struct kvm_vcpu *vcpu, struct vgic_irq *irq,
+ bool active, bool is_uaccess)
+{
+ if (is_uaccess)
+ return;
+
+ irq->active = active;
+ vgic_irq_set_phys_active(irq, active);
+}
+
+static void vgic_mmio_change_active(struct kvm_vcpu *vcpu, struct vgic_irq *irq,
+ bool active)
+{
+ unsigned long flags;
+ struct kvm_vcpu *requester_vcpu = vgic_get_mmio_requester_vcpu();
+
+ spin_lock_irqsave(&irq->irq_lock, flags);
+
+ if (irq->hw) {
+ vgic_hw_irq_change_active(vcpu, irq, active, !requester_vcpu);
+ } else {
+ u32 model = vcpu->kvm->arch.vgic.vgic_model;
+ u8 active_source;
+
+ irq->active = active;
+
+ /*
+ * The GICv2 architecture indicates that the source CPUID for
+ * an SGI should be provided during an EOI which implies that
+ * the active state is stored somewhere, but at the same time
+ * this state is not architecturally exposed anywhere and we
+ * have no way of knowing the right source.
+ *
+ * This may lead to a VCPU not being able to receive
+ * additional instances of a particular SGI after migration
+ * for a GICv2 VM on some GIC implementations. Oh well.
+ */
+ active_source = (requester_vcpu) ? requester_vcpu->vcpu_id : 0;
+
+ if (model == KVM_DEV_TYPE_ARM_VGIC_V2 &&
+ active && vgic_irq_is_sgi(irq->intid))
+ irq->active_source = active_source;
+ }
+
+ if (irq->active)
+ vgic_queue_irq_unlock(vcpu->kvm, irq, flags);
+ else
+ spin_unlock_irqrestore(&irq->irq_lock, flags);
+}
+
+/*
+ * 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);
+}
+
+int 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);
+ return 0;
+}
+
+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);
+}
+
+int 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);
+ return 0;
+}
+
+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;
+ unsigned long flags;
+
+ for (i = 0; i < len; i++) {
+ struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+
+ spin_lock_irqsave(&irq->irq_lock, flags);
+ /* Narrow the priority range to what we actually support */
+ irq->priority = (val >> (i * 8)) & GENMASK(7, 8 - VGIC_PRI_BITS);
+ spin_unlock_irqrestore(&irq->irq_lock, flags);
+
+ 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;
+ unsigned long flags;
+
+ 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_irqsave(&irq->irq_lock, flags);
+
+ if (test_bit(i * 2 + 1, &val))
+ irq->config = VGIC_CONFIG_EDGE;
+ else
+ irq->config = VGIC_CONFIG_LEVEL;
+
+ spin_unlock_irqrestore(&irq->irq_lock, flags);
+ 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;
+ unsigned long flags;
+
+ 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_irqsave(&irq->irq_lock, flags);
+ irq->line_level = new_level;
+ if (new_level)
+ vgic_queue_irq_unlock(vcpu->kvm, irq, flags);
+ else
+ spin_unlock_irqrestore(&irq->irq_lock, flags);
+
+ 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)
+ return region->uaccess_write(r_vcpu, addr, sizeof(u32), *val);
+
+ 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;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-25 04:28:25 +0000