KVM: arm/arm64: GICv4: Add init/teardown of the per-VM vPE irq domain

In order to control the GICv4 view of virtual CPUs, we rely
on an irqdomain allocated for that purpose. Let's add a couple
of helpers to that effect.

At the same time, the vgic data structures gain new fields to
track all this... erm... wonderful stuff.

The way we hook into the vgic init is slightly convoluted. We
need the vgic to be initialized (in order to guarantee that
the number of vcpus is now fixed), and we must have a vITS
(otherwise this is all very pointless). So we end-up calling
the init from both vgic_init and vgic_its_create.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

diff --git a/arch/arm/kvm/Makefile b/arch/arm/kvm/Makefile
index d9beee652d36cbba48d0900e896f46b82df5c39e..0a1dd2cdb9289b3410c5874b482ed60dcace28ea 100644 (file)
--- a/arch/arm/kvm/Makefile
+++ b/arch/arm/kvm/Makefile
@@ -31,6 +31,7 @@ obj-y += $(KVM)/arm/vgic/vgic-init.o
 obj-y += $(KVM)/arm/vgic/vgic-irqfd.o
 obj-y += $(KVM)/arm/vgic/vgic-v2.o
 obj-y += $(KVM)/arm/vgic/vgic-v3.o
+obj-y += $(KVM)/arm/vgic/vgic-v4.o
 obj-y += $(KVM)/arm/vgic/vgic-mmio.o
 obj-y += $(KVM)/arm/vgic/vgic-mmio-v2.o
 obj-y += $(KVM)/arm/vgic/vgic-mmio-v3.o

diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
index 5d9810086c254defd58046c6a34da6aabfa42fa3..c30fd388ef80f1f9ecfe782189e6ef55639d4dc7 100644 (file)
--- a/arch/arm64/kvm/Makefile
+++ b/arch/arm64/kvm/Makefile
@@ -26,6 +26,7 @@ kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-init.o
 kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-irqfd.o
 kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-v2.o
 kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-v3.o
+kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-v4.o
 kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-mmio.o
 kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-mmio-v2.o
 kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-mmio-v3.o

diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index ba9fb450aa1bdc11ba219de00ed8e0a71f829e8d..7eeb6c2a2f9c348e7de699a5323bcde666054df6 100644 (file)
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -26,6 +26,8 @@
 #include <linux/list.h>
 #include <linux/jump_label.h>
 
+#include <linux/irqchip/arm-gic-v4.h>
+
 #define VGIC_V3_MAX_CPUS       255
 #define VGIC_V2_MAX_CPUS       8
 #define VGIC_NR_IRQS_LEGACY     256
@@ -236,6 +238,15 @@ struct vgic_dist {
 
        /* used by vgic-debug */
        struct vgic_state_iter *iter;
+
+       /*
+        * GICv4 ITS per-VM data, containing the IRQ domain, the VPE
+        * array, the property table pointer as well as allocation
+        * data. This essentially ties the Linux IRQ core and ITS
+        * together, and avoids leaking KVM's data structures anywhere
+        * else.
+        */
+       struct its_vm           its_vm;
 };
 
 struct vgic_v2_cpu_if {
@@ -254,6 +265,14 @@ struct vgic_v3_cpu_if {
        u32             vgic_ap0r[4];
        u32             vgic_ap1r[4];
        u64             vgic_lr[VGIC_V3_MAX_LRS];
+
+       /*
+        * GICv4 ITS per-VPE data, containing the doorbell IRQ, the
+        * pending table pointer, the its_vm pointer and a few other
+        * HW specific things. As for the its_vm structure, this is
+        * linking the Linux IRQ subsystem and the ITS together.
+        */
+       struct its_vpe  its_vpe;
 };
 
 struct vgic_cpu {

diff --git a/virt/kvm/arm/vgic/vgic-init.c b/virt/kvm/arm/vgic/vgic-init.c
index 5801261f3adddeaab819f4ffd23ecd5839d03c8a..40be908da238aa34b240d3d8beec36331ba976eb 100644 (file)
--- a/virt/kvm/arm/vgic/vgic-init.c
+++ b/virt/kvm/arm/vgic/vgic-init.c
@@ -285,6 +285,12 @@ int vgic_init(struct kvm *kvm)
        if (ret)
                goto out;
 
+       if (vgic_supports_direct_msis(kvm)) {
+               ret = vgic_v4_init(kvm);
+               if (ret)
+                       goto out;
+       }
+
        kvm_for_each_vcpu(i, vcpu, kvm)
                kvm_vgic_vcpu_enable(vcpu);
 
@@ -320,6 +326,9 @@ static void kvm_vgic_dist_destroy(struct kvm *kvm)
 
        kfree(dist->spis);
        dist->nr_spis = 0;
+
+       if (vgic_supports_direct_msis(kvm))
+               vgic_v4_teardown(kvm);
 }
 
 void kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu)

diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index 09accdfed189edcdf4467943b2abefca8ca016e2..54f81eb24a0756080ecdb47017d6c91d451712b2 100644 (file)
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -1638,6 +1638,14 @@ static int vgic_its_create(struct kvm_device *dev, u32 type)
        if (!its)
                return -ENOMEM;
 
+       if (vgic_initialized(dev->kvm)) {
+               int ret = vgic_v4_init(dev->kvm);
+               if (ret) {
+                       kfree(its);
+                       return ret;
+               }
+       }
+
        mutex_init(&its->its_lock);
        mutex_init(&its->cmd_lock);
 

diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
new file mode 100644 (file)
index 0000000..c794f0c
--- /dev/null
+++ b/virt/kvm/arm/vgic/vgic-v4.c
@@ -0,0 +1,83 @@
+/*
+ * Copyright (C) 2017 ARM Ltd.
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ *
+ * 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 <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/irqdomain.h>
+#include <linux/kvm_host.h>
+
+#include "vgic.h"
+
+/**
+ * vgic_v4_init - Initialize the GICv4 data structures
+ * @kvm:       Pointer to the VM being initialized
+ *
+ * We may be called each time a vITS is created, or when the
+ * vgic is initialized. This relies on kvm->lock to be
+ * held. In both cases, the number of vcpus should now be
+ * fixed.
+ */
+int vgic_v4_init(struct kvm *kvm)
+{
+       struct vgic_dist *dist = &kvm->arch.vgic;
+       struct kvm_vcpu *vcpu;
+       int i, nr_vcpus, ret;
+
+       if (dist->its_vm.vpes)
+               return 0;
+
+       nr_vcpus = atomic_read(&kvm->online_vcpus);
+
+       dist->its_vm.vpes = kzalloc(sizeof(*dist->its_vm.vpes) * nr_vcpus,
+                                   GFP_KERNEL);
+       if (!dist->its_vm.vpes)
+               return -ENOMEM;
+
+       dist->its_vm.nr_vpes = nr_vcpus;
+
+       kvm_for_each_vcpu(i, vcpu, kvm)
+               dist->its_vm.vpes[i] = &vcpu->arch.vgic_cpu.vgic_v3.its_vpe;
+
+       ret = its_alloc_vcpu_irqs(&dist->its_vm);
+       if (ret < 0) {
+               kvm_err("VPE IRQ allocation failure\n");
+               kfree(dist->its_vm.vpes);
+               dist->its_vm.nr_vpes = 0;
+               dist->its_vm.vpes = NULL;
+               return ret;
+       }
+
+       return ret;
+}
+
+/**
+ * vgic_v4_teardown - Free the GICv4 data structures
+ * @kvm:       Pointer to the VM being destroyed
+ *
+ * Relies on kvm->lock to be held.
+ */
+void vgic_v4_teardown(struct kvm *kvm)
+{
+       struct its_vm *its_vm = &kvm->arch.vgic.its_vm;
+
+       if (!its_vm->vpes)
+               return;
+
+       its_free_vcpu_irqs(its_vm);
+       kfree(its_vm->vpes);
+       its_vm->nr_vpes = 0;
+       its_vm->vpes = NULL;
+}

diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
index 67509b203cf52313fedf1229eaa3289858f77235..bf03a9648fbb019cb0549e7d32e5c44dbb049e85 100644 (file)
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -242,5 +242,7 @@ int vgic_its_resolve_lpi(struct kvm *kvm, struct vgic_its *its,
 struct vgic_its *vgic_msi_to_its(struct kvm *kvm, struct kvm_msi *msi);
 
 bool vgic_supports_direct_msis(struct kvm *kvm);
+int vgic_v4_init(struct kvm *kvm);
+void vgic_v4_teardown(struct kvm *kvm);
 
 #endif