Re: [PATCH v3 10/12] KVM: arm64: selftests: Add host support for vGIC

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

Signed-off-by: Raghavendra Rao Ananta <redacted>

---
 tools/testing/selftests/kvm/Makefile          |  2 +-
 .../selftests/kvm/include/aarch64/vgic.h      | 14 ++++
 .../testing/selftests/kvm/lib/aarch64/vgic.c  | 67 +++++++++++++++++++
 3 files changed, 82 insertions(+), 1 deletion(-)
 create mode 100644 tools/testing/selftests/kvm/include/aarch64/vgic.h
 create mode 100644 tools/testing/selftests/kvm/lib/aarch64/vgic.c

diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 5476a8ddef60..8342f65c1d96 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/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

diff --git a/tools/testing/selftests/kvm/include/aarch64/vgic.h b/tools/testing/selftests/kvm/include/aarch64/vgic.h
new file mode 100644
index 000000000000..45bbf238147a
--- /dev/null
+++ b/tools/testing/selftests/kvm/include/aarch64/vgic.h

@@ -0,0 +1,14 @@
+/* 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>
+
+int vgic_v3_setup(struct kvm_vm *vm, unsigned int nr_vcpus,
+		uint64_t gicd_base_gpa, uint64_t gicr_base_gpa, uint32_t slot);

+
+#endif /* SELFTEST_KVM_VGIC_H */

diff --git a/tools/testing/selftests/kvm/lib/aarch64/vgic.c b/tools/testing/selftests/kvm/lib/aarch64/vgic.c
new file mode 100644
index 000000000000..a0e4b986d335
--- /dev/null
+++ b/tools/testing/selftests/kvm/lib/aarch64/vgic.c

@@ -0,0 +1,67 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ARM Generic Interrupt Controller (GIC) v3 host support
+ */
+
+#include <linux/kvm.h>
+#include <linux/sizes.h>
+
+#include "kvm_util.h"
+
+#define VGIC_V3_GICD_SZ		(SZ_64K)
+#define VGIC_V3_GICR_SZ		(2 * SZ_64K)
+
+#define REDIST_REGION_ATTR_ADDR(count, base, flags, index) \
+	(((uint64_t)(count) << 52) | \
+	((uint64_t)((base) >> 16) << 16) | \
+	((uint64_t)(flags) << 12) | \
+	index)
+
+static void vgic_v3_map(struct kvm_vm *vm, uint64_t addr, unsigned int size)
+{
+	unsigned int n_pages = DIV_ROUND_UP(size, vm_get_page_size(vm));
+
+	virt_map(vm, addr, addr, n_pages);
+}
+
+/*
+ * vGIC-v3 default host setup
+ *
+ * Input args:
+ *	vm - KVM VM
+ *	nr_vcpus - Number of vCPUs for 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.
+ */
+int vgic_v3_setup(struct kvm_vm *vm, unsigned int nr_vcpus,
+		uint64_t gicd_base_gpa, uint64_t gicr_base_gpa)