[PATCH v8 07/29] KVM: Make device name configurable

[Steffen Eiden <seiden@linux.ibm.com>]

Allow KVM implementations to choose alternative device names. This is
especially useful for architectures providing multiple KVM
implementations simultaneously. Architectures providing multiple KVM
implementations must compile the KVM common code once per
implementation and mange symbols.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
 arch/s390/kvm/gmap/trace_gmap.h |  4 +++-
 arch/s390/kvm/s390/Makefile     |  2 +-
 include/linux/kvm_host.h        |  3 +++
 include/trace/events/kvm.h      |  8 +++++++-
 virt/kvm/Makefile.kvm           |  5 +++++
 virt/kvm/kvm_main.c             | 10 +++++-----
 6 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/arch/s390/kvm/gmap/trace_gmap.h b/arch/s390/kvm/gmap/trace_gmap.h
index 15ec88bdce55..78d26dae59f9 100644
--- a/arch/s390/kvm/gmap/trace_gmap.h
+++ b/arch/s390/kvm/gmap/trace_gmap.h
@@ -4,8 +4,10 @@
 
 #include <linux/tracepoint.h>
 
+#undef UNPACK_KVM
+#define UNPACK_KVM(name) name
 #undef TRACE_SYSTEM
-#define TRACE_SYSTEM kvm
+#define TRACE_SYSTEM UNPACK_KVM(KVM_DEV_NAME)
 #undef TRACE_INCLUDE_PATH
 #define TRACE_INCLUDE_PATH ../gmap
 #undef TRACE_INCLUDE_FILE
diff --git a/arch/s390/kvm/s390/Makefile b/arch/s390/kvm/s390/Makefile
index 762a63826423..b91334db90a2 100644
--- a/arch/s390/kvm/s390/Makefile
+++ b/arch/s390/kvm/s390/Makefile
@@ -4,7 +4,7 @@ KVM := ../../../../virt/kvm
 include $(srctree)/virt/kvm/Makefile.kvm
 include $(srctree)/arch/s390/kvm/gmap/Makefile
 
-ccflags-y := -I$(src) -I$(srctree)/arch/s390/kvm/gmap
+ccflags-y += -I$(src) -I$(srctree)/arch/s390/kvm/gmap
 
 kvm-y += s390.o intercept.o interrupt.o priv.o sigp.o
 kvm-y += diag.o gaccess.o guestdbg.o vsie.o pv.o
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 2b56fb4e8555..5926478563e8 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -45,6 +45,9 @@
 #include <asm/kvm_host.h>
 #include <linux/kvm_dirty_ring.h>
 
+#define __KVM_DEV_STRING(name, x) __stringify(name ## _ ## x)
+#define KVM_DEV_STRING(x) __KVM_DEV_STRING(KVM_DEV_NAME, x)
+
 #ifndef KVM_MAX_VCPU_IDS
 #define KVM_MAX_VCPU_IDS KVM_MAX_VCPUS
 #endif
diff --git a/include/trace/events/kvm.h b/include/trace/events/kvm.h
index b282e3a86769..f37582730ffc 100644
--- a/include/trace/events/kvm.h
+++ b/include/trace/events/kvm.h
@@ -4,8 +4,14 @@
 
 #include <linux/tracepoint.h>
 
+#undef UNPACK_KVM
+#define UNPACK_KVM(name) name
 #undef TRACE_SYSTEM
-#define TRACE_SYSTEM kvm
+#define TRACE_SYSTEM UNPACK_KVM(KVM_DEV_NAME)
+#undef TRACE_SYSTEM_VAR
+#define TRACE_SYSTEM_VAR kvm
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE kvm
 
 #define ERSN(x) { KVM_EXIT_##x, "KVM_EXIT_" #x }
 
diff --git a/virt/kvm/Makefile.kvm b/virt/kvm/Makefile.kvm
index dd40544b8ecb..ee66d460c494 100644
--- a/virt/kvm/Makefile.kvm
+++ b/virt/kvm/Makefile.kvm
@@ -5,6 +5,11 @@
 
 KVM ?= ../../../virt/kvm
 
+KVM_DEV_NAME ?= kvm
+KVM_DEV_MINOR ?= KVM_MINOR
+
+ccflags-y +=-DKVM_DEV_NAME=$(KVM_DEV_NAME) -DKVM_DEV_MINOR=$(KVM_DEV_MINOR)
+
 kvm-y := $(KVM)/kvm_main.o $(KVM)/eventfd.o $(KVM)/binary_stats.o
 kvm-$(CONFIG_KVM_VFIO) += $(KVM)/vfio.o
 kvm-$(CONFIG_KVM_MMIO) += $(KVM)/coalesced_mmio.o
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 891a67cb365a..4f25e170b542 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -5596,8 +5596,8 @@ static struct file_operations kvm_chardev_ops = {
 };
 
 static struct miscdevice kvm_dev = {
-	KVM_MINOR,
-	"kvm",
+	KVM_DEV_MINOR,
+	__stringify(KVM_DEV_NAME),
 	&kvm_chardev_ops,
 };
 
@@ -6376,7 +6376,7 @@ static void kvm_init_debug(void)
 	const struct kvm_stats_desc *pdesc;
 	int i;
 
-	kvm_debugfs_dir = debugfs_create_dir("kvm", NULL);
+	kvm_debugfs_dir = debugfs_create_dir(__stringify(KVM_DEV_NAME), NULL);
 
 	for (i = 0; i < kvm_vm_stats_header.num_desc; ++i) {
 		pdesc = &kvm_vm_stats_desc[i];
@@ -6521,7 +6521,7 @@ int kvm_init(unsigned vcpu_size, unsigned vcpu_align, struct module *module)
 	if (!vcpu_align)
 		vcpu_align = __alignof__(struct kvm_vcpu);
 	kvm_vcpu_cache =
-		kmem_cache_create_usercopy("kvm_vcpu", vcpu_size, vcpu_align,
+		kmem_cache_create_usercopy(KVM_DEV_STRING(vcpu), vcpu_size, vcpu_align,
 					   SLAB_ACCOUNT,
 					   offsetof(struct kvm_vcpu, arch),
 					   offsetofend(struct kvm_vcpu, stats_id)
@@ -6574,7 +6574,7 @@ int kvm_init(unsigned vcpu_size, unsigned vcpu_align, struct module *module)
 	 */
 	r = misc_register(&kvm_dev);
 	if (r) {
-		pr_err("kvm: misc device register failed\n");
+		pr_err(__stringify(KVM_DEV_NAME) ": misc device register failed\n");
 		goto err_register;
 	}
 
-- 
2.53.0