[RFC PATCH 39/45] KVM: arm/arm64: vgic-new: vgic_init: implement vgic_create

Andre Przywara
2016-03-25T02:05:24Z

From: Eric Auger <eric.auger@linaro.org>

This patch implements the vgic_creation function which is
called on CREATE_IRQCHIP VM IOCTL (v2 only) or KVM_CREATE_DEVICE

Signed-off-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
---
include/kvm/vgic/vgic.h | 1 +
virt/kvm/arm/vgic/vgic_init.c | 84 +++++++++++++++++++++++++++++++++++++++++++
2 files changed, 85 insertions(+)

diff --git a/include/kvm/vgic/vgic.h b/include/kvm/vgic/vgic.h
index 1bc7b66..536582b 100644
--- a/include/kvm/vgic/vgic.h
+++ b/include/kvm/vgic/vgic.h
@@ -195,6 +195,7 @@ struct vgic_cpu {
};

int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write);
+int kvm_vgic_create(struct kvm *kvm, u32 type);
int kvm_vgic_hyp_init(void);

int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int intid,
diff --git a/virt/kvm/arm/vgic/vgic_init.c b/virt/kvm/arm/vgic/vgic_init.c
index d7c50bb..80bf283 100644
--- a/virt/kvm/arm/vgic/vgic_init.c
+++ b/virt/kvm/arm/vgic/vgic_init.c
@@ -24,6 +24,90 @@
#include <asm/kvm_mmu.h>
#include "vgic.h"

+/* CREATION */
+
+/**
+ * kvm_vgic_create: triggered by the instantiation of the VGIC device by
+ * user space, either through the legacy ARM specific VM IOCTL (CREATE_IRQCHIP)
+ * or through the generic VM IOCTL, KVM_CREATE_DEVICE API.
+ * Completion can be tested by irqchip_in_kernel
+ */
+int kvm_vgic_create(struct kvm *kvm, u32 type)
+{
+ int i, vcpu_lock_idx = -1, ret;
+ struct kvm_vcpu *vcpu;
+
+ mutex_lock(&kvm->lock);
+
+ if (irqchip_in_kernel(kvm)) {
+ ret = -EEXIST;
+ goto out;
+ }
+
+ /*
+ * This function is also called by the KVM_CREATE_IRQCHIP handler,
+ * which had no chance yet to check the availability of the GICv2
+ * emulation. So check this here again. KVM_CREATE_DEVICE does
+ * the proper checks already.
+ */
+ if (type == KVM_DEV_TYPE_ARM_VGIC_V2 &&
+ !kvm_vgic_global_state.can_emulate_gicv2) {
+ ret = -ENODEV;
+ goto out;
+ }
+
+ /*
+ * Any time a vcpu is run, vcpu_load is called which tries to grab the
+ * vcpu->mutex. By grabbing the vcpu->mutex of all VCPUs we ensure
+ * that no other VCPUs are run while we create the vgic.
+ */
+ ret = -EBUSY;
+ kvm_for_each_vcpu(i, vcpu, kvm) {
+ if (!mutex_trylock(&vcpu->mutex))
+ goto out_unlock;
+ vcpu_lock_idx = i;
+ }
+
+ kvm_for_each_vcpu(i, vcpu, kvm) {
+ if (vcpu->arch.has_run_once)
+ goto out_unlock;
+ }
+ ret = 0;
+
+ if (type == KVM_DEV_TYPE_ARM_VGIC_V2)
+ kvm->arch.max_vcpus = VGIC_V2_MAX_CPUS;
+ else
+ kvm->arch.max_vcpus = VGIC_V3_MAX_CPUS;
+
+ if (atomic_read(&kvm->online_vcpus) > kvm->arch.max_vcpus) {
+ ret = -E2BIG;
+ goto out_unlock;
+ }
+
+ kvm->arch.vgic.in_kernel = true;
+ kvm->arch.vgic.vgic_model = type;
+
+ /*
+ * kvm_vgic_global_state.vctrl_base is set on vgic probe (kvm_arch_init)
+ * it is stored in distributor struct for asm save/restore purpose
+ */
+ kvm->arch.vgic.vctrl_base = kvm_vgic_global_state.vctrl_base;
+
+ kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF;
+ kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF;
+ kvm->arch.vgic.vgic_redist_base = VGIC_ADDR_UNDEF;
+
+out_unlock:
+ for (; vcpu_lock_idx >= 0; vcpu_lock_idx--) {
+ vcpu = kvm_get_vcpu(kvm, vcpu_lock_idx);
+ mutex_unlock(&vcpu->mutex);
+ }
+
+out:
+ mutex_unlock(&kvm->lock);
+ return ret;
+}
+
/* GENERIC PROBE */

static void vgic_init_maintenance_interrupt(void *info)
--
2.7.3