KVM: arm64: selftests: Add host support for vGIC

Implement a simple library to perform vGIC-v3 setup
from a host point of view. This includes creating a
vGIC device, setting up distributor and redistributor
attributes, and mapping the guest physical addresses.

The definition of REDIST_REGION_ATTR_ADDR is taken from
aarch64/vgic_init test. Hence, replace the definition
by including vgic.h in the test file.

Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
Reviewed-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211007233439.1826892-14-rananta@google.com

tools/testing/selftests/kvm/Makefile

@@ -35,7 +35,7 @@ endif
 
 LIBKVM = lib/assert.c lib/elf.c lib/io.c lib/kvm_util.c lib/rbtree.c lib/sparsebit.c lib/test_util.c lib/guest_modes.c lib/perf_test_util.c
 LIBKVM_x86_64 = lib/x86_64/apic.c lib/x86_64/processor.c lib/x86_64/vmx.c lib/x86_64/svm.c lib/x86_64/ucall.c lib/x86_64/handlers.S
-LIBKVM_aarch64 = lib/aarch64/processor.c lib/aarch64/ucall.c lib/aarch64/handlers.S lib/aarch64/spinlock.c lib/aarch64/gic.c lib/aarch64/gic_v3.c
+LIBKVM_aarch64 = lib/aarch64/processor.c lib/aarch64/ucall.c lib/aarch64/handlers.S lib/aarch64/spinlock.c lib/aarch64/gic.c lib/aarch64/gic_v3.c lib/aarch64/vgic.c
 LIBKVM_s390x = lib/s390x/processor.c lib/s390x/ucall.c lib/s390x/diag318_test_handler.c
 
 TEST_GEN_PROGS_x86_64 = x86_64/cr4_cpuid_sync_test

tools/testing/selftests/kvm/aarch64/vgic_init.c

@@ -13,11 +13,10 @@
 #include "test_util.h"
 #include "kvm_util.h"
 #include "processor.h"
+#include "vgic.h"
 
 #define NR_VCPUS		4
 
-#define REDIST_REGION_ATTR_ADDR(count, base, flags, index) (((uint64_t)(count) << 52) | \
-	((uint64_t)((base) >> 16) << 16) | ((uint64_t)(flags) << 12) | index)
 #define REG_OFFSET(vcpu, offset) (((uint64_t)vcpu << 32) | offset)
 
 #define GICR_TYPER 0x8

tools/testing/selftests/kvm/include/aarch64/vgic.h

@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * ARM Generic Interrupt Controller (GIC) host specific defines
+ */
+
+#ifndef SELFTEST_KVM_VGIC_H
+#define SELFTEST_KVM_VGIC_H
+
+#include <linux/kvm.h>
+
+#define REDIST_REGION_ATTR_ADDR(count, base, flags, index) \
+	(((uint64_t)(count) << 52) | \
+	((uint64_t)((base) >> 16) << 16) | \
+	((uint64_t)(flags) << 12) | \
+	index)
+
+int vgic_v3_setup(struct kvm_vm *vm, unsigned int nr_vcpus,
+		uint64_t gicd_base_gpa, uint64_t gicr_base_gpa);
+
+#endif /* SELFTEST_KVM_VGIC_H */

tools/testing/selftests/kvm/lib/aarch64/vgic.c

@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ARM Generic Interrupt Controller (GIC) v3 host support
+ */
+
+#include <linux/kvm.h>
+#include <linux/sizes.h>
+#include <asm/kvm.h>
+
+#include "kvm_util.h"
+#include "../kvm_util_internal.h"
+#include "vgic.h"
+
+/*
+ * vGIC-v3 default host setup
+ *
+ * Input args:
+ *	vm - KVM VM
+ *	nr_vcpus - Number of vCPUs supported by this VM
+ *	gicd_base_gpa - Guest Physical Address of the Distributor region
+ *	gicr_base_gpa - Guest Physical Address of the Redistributor region
+ *
+ * Output args: None
+ *
+ * Return: GIC file-descriptor or negative error code upon failure
+ *
+ * The function creates a vGIC-v3 device and maps the distributor and
+ * redistributor regions of the guest. Since it depends on the number of
+ * vCPUs for the VM, it must be called after all the vCPUs have been created.
+ */
+int vgic_v3_setup(struct kvm_vm *vm, unsigned int nr_vcpus,
+		uint64_t gicd_base_gpa, uint64_t gicr_base_gpa)
+{
+	int gic_fd;
+	uint64_t redist_attr;
+	struct list_head *iter;
+	unsigned int nr_gic_pages, nr_vcpus_created = 0;
+
+	TEST_ASSERT(nr_vcpus, "Number of vCPUs cannot be empty\n");
+
+	/*
+	 * Make sure that the caller is infact calling this
+	 * function after all the vCPUs are added.
+	 */
+	list_for_each(iter, &vm->vcpus)
+		nr_vcpus_created++;
+	TEST_ASSERT(nr_vcpus == nr_vcpus_created,
+			"Number of vCPUs requested (%u) doesn't match with the ones created for the VM (%u)\n",
+			nr_vcpus, nr_vcpus_created);
+
+	/* Distributor setup */
+	gic_fd = kvm_create_device(vm, KVM_DEV_TYPE_ARM_VGIC_V3, false);
+	kvm_device_access(gic_fd, KVM_DEV_ARM_VGIC_GRP_ADDR,
+			KVM_VGIC_V3_ADDR_TYPE_DIST, &gicd_base_gpa, true);
+	nr_gic_pages = vm_calc_num_guest_pages(vm->mode, KVM_VGIC_V3_DIST_SIZE);
+	virt_map(vm, gicd_base_gpa, gicd_base_gpa,  nr_gic_pages);
+
+	/* Redistributor setup */
+	redist_attr = REDIST_REGION_ATTR_ADDR(nr_vcpus, gicr_base_gpa, 0, 0);
+	kvm_device_access(gic_fd, KVM_DEV_ARM_VGIC_GRP_ADDR,
+			KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION, &redist_attr, true);
+	nr_gic_pages = vm_calc_num_guest_pages(vm->mode,
+						KVM_VGIC_V3_REDIST_SIZE * nr_vcpus);
+	virt_map(vm, gicr_base_gpa, gicr_base_gpa,  nr_gic_pages);
+
+	kvm_device_access(gic_fd, KVM_DEV_ARM_VGIC_GRP_CTRL,
+				KVM_DEV_ARM_VGIC_CTRL_INIT, NULL, true);
+
+	return gic_fd;
+}