From 91b87e6eea4d09a4d80f6a66515e8bc2821303ad Mon Sep 17 00:00:00 2001 From: Steffen Eiden Date: Thu, 2 Apr 2026 06:00:00 +0200 Subject: [PATCH] KVM: s390: arm64: Integrate arm on s390 Add all Kbuild/Makefile configurations to build a second KVM module on s390 implementing the arm64 KVM API. The new module is named kvm_arm64. Symbol conflicts with kvm_s390 are prevented by localising all internal symbols in kvm_arm64 when compiled as built-in (=y): kvm-unnamespaced.o holds all constituent objects. objcopy --localize-symbols then produces kvm-namespaced.o which is what kvm-arm64.o resolves to. For =m the normal module symbol scoping applies and no localisation step is needed. Because the %-arm64.o pattern targets do not match any kvm-arm64-y entry, kbuild would derive a wrong KBUILD_MODNAME (e.g. "kvm_main_arm64") and a wrong KBUILD_MODFILE for the virt/kvm and gmap copies. Co-developed-by: Andreas Grapentin Signed-off-by: Andreas Grapentin Co-developed-by: Nina Schoetterl-Glausch Signed-off-by: Nina Schoetterl-Glausch Co-developed-by: Gautam Gala Signed-off-by: Gautam Gala Signed-off-by: Steffen Eiden Signed-off-by: Christian Borntraeger --- arch/s390/kvm/Kconfig | 21 ++++--- arch/s390/kvm/Makefile | 1 + arch/s390/kvm/arm64/Makefile | 110 +++++++++++++++++++++++++++++++++++ 3 files changed, 125 insertions(+), 7 deletions(-) create mode 100644 arch/s390/kvm/arm64/Makefile diff --git a/arch/s390/kvm/Kconfig b/arch/s390/kvm/Kconfig index 9045ae20fd89..e7b525d04c6d 100644 --- a/arch/s390/kvm/Kconfig +++ b/arch/s390/kvm/Kconfig @@ -30,15 +30,22 @@ config KVM select KVM_MMU_LOCKLESS_AGING select KVM_GENERIC_PRE_FAULT_MEMORY help - Support hosting paravirtualized guest machines using the SIE - virtualization capability on the mainframe. This should work - on any 64bit machine. + Enable support for hosting virtualized, hardware-accelerated + virtual machines via two modules: kvm and kvm_arm64. - This module provides access to the hardware capabilities through - a character device node named /dev/kvm. + The kvm module provides access to host hardware-accelerated s390 + guests using the Start Interpretive Execution (SIE) instruction via a + character device node named /dev/kvm. This requires a 64-bit machine + (hardware model). - To compile this as a module, choose M here: the module - will be called kvm. + The kvm_arm64 module provides access to host hardware-accelerated + arm64 guests using the Start ARM Execution (SAE) instruction via a + character device node named /dev/kvm_arm64. This requires hardware + models that support the Arm execution facility (AEF). + + To compile this driver as a module, choose M here. The module will be + called kvm for the SIE acceleration and kvm_arm64 for the SAE + acceleration. If unsure, say N. diff --git a/arch/s390/kvm/Makefile b/arch/s390/kvm/Makefile index a4e3875b5bdd..380db443a0e9 100644 --- a/arch/s390/kvm/Makefile +++ b/arch/s390/kvm/Makefile @@ -4,3 +4,4 @@ # Copyright IBM Corp. 2008 obj-$(CONFIG_KVM) += s390/ +obj-$(CONFIG_KVM) += arm64/ diff --git a/arch/s390/kvm/arm64/Makefile b/arch/s390/kvm/arm64/Makefile new file mode 100644 index 000000000000..3f0fe5c9f0a1 --- /dev/null +++ b/arch/s390/kvm/arm64/Makefile @@ -0,0 +1,110 @@ +# SPDX-License-Identifier: GPL-2.0 + +KVM := ../../../../virt/kvm +KVM_DEV_NAME = kvm_arm64 +KVM_DEV_MINOR = MISC_DYNAMIC_MINOR +include $(srctree)/virt/kvm/Makefile.kvm +include $(srctree)/arch/$(SRCARCH)/kvm/gmap/Makefile +include $(src)/Makefile.gen + +ccflags-y += -I $(src) -I $(objtree)/$(obj) -I$(srctree)/arch/$(SRCARCH)/kvm/gmap -DKVM_S390_ARM64 + +kvm-arm64-local := \ + arm.o \ + guest.o \ + handle_exit.o \ + inject_fault.o \ + mmio.o \ + mmu.o \ + reset.o + +kvm-arm64-obj := $(kvm-arm64-local) +kvm-arm64-obj += $(patsubst %.o,%-arm64.o,$(kvm-y)) +kvm-arm64-obj += $(patsubst %.o,%-arm64.o,$(gmap-y)) + +targets += $(kvm-arm64-obj) + +$(obj)/%-arm64.o: $(src)/%.c FORCE + @mkdir -p $(dir $@) + $(call if_changed_rule,cc_o_c) + $(call cmd,force_checksrc) + +# %-arm64.o stems don't match any kvm-arm64-y entry so Kbuild derives wrong +# KBUILD_MODNAME/KBUILD_MODFILE. Force include a generated header to override. +KVM_ARM64_MODNAME_H := $(obj)/generated/kvm_arm64_modname.h +ccflags-y += -include $(KVM_ARM64_MODNAME_H) + +$(addprefix $(obj)/,$(kvm-arm64-obj)): $(KVM_ARM64_MODNAME_H) +$(foreach sfx, i s ll lst, \ + $(eval $(patsubst %.o,%.$(sfx),$(addprefix $(obj)/,$(kvm-arm64-local))): $(KVM_ARM64_MODNAME_H))) + +targets += generated/kvm_arm64_modname.h + +define filechk_kvm_arm64_modname + echo '#ifndef __KVM_ARM64_MODNAME_H'; \ + echo '#define __KVM_ARM64_MODNAME_H'; \ + echo '#undef KBUILD_MODNAME'; \ + echo '#define KBUILD_MODNAME "$(KVM_DEV_NAME)"'; \ + echo '#undef __KBUILD_MODNAME'; \ + echo '#define __KBUILD_MODNAME $(KVM_DEV_NAME)'; \ + echo '#undef KBUILD_MODFILE'; \ + echo '#define KBUILD_MODFILE "$(obj)/kvm-arm64"'; \ + echo '#endif /* __KVM_ARM64_MODNAME_H */' +endef + +$(KVM_ARM64_MODNAME_H): FORCE + $(call filechk,kvm_arm64_modname) + +# Members are not in real-obj-y. Set part-of-builtin to enable instrumentation. +$(addprefix $(obj)/,$(kvm-arm64-obj)): private part-of-builtin := y + +ifeq ($(CONFIG_KVM),m) + +kvm-arm64-y = $(kvm-arm64-obj) + +else ifeq ($(CONFIG_KVM),y) + +prereq-o-cmd = $(foreach o, $(filter %.o, $^), $(dir $(o)).$(notdir $(o)).cmd) +cmd_gen_symversions_o = \ + grep --no-filename "^\#SYMVER" $(prereq-o-cmd) >> $(dot-target).cmd || true + +cmd_ld_o_o = $(cmd_ld) +define rule_ld_o_o + $(call cmd_and_savecmd,ld) + $(call cmd,gen_symversions_o) +endef + +LDFLAGS_kvm-unnamespaced.o := -r +$(obj)/kvm-unnamespaced.o: $(addprefix $(obj)/,$(kvm-arm64-obj)) FORCE + $(call if_changed_rule,ld_o_o) + +quiet_cmd_nm_filter = NMFLTR $@ + cmd_nm_filter = $(NM) --defined-only --format=just-symbols $< | sort -u > $@ + +$(obj)/kvm_symbol_list: $(obj)/kvm-unnamespaced.o FORCE + $(call if_changed,nm_filter) + +# cmd_oc_o_o carries -DKBUILD_MODFILE so generate_builtin_ranges.awk +# can attribute kvm-namespaced.o to kvm_arm64 via its .cmd file. +cmd_oc_o_o = $(cmd_objcopy) -DKBUILD_MODFILE='"$(obj)/kvm-arm64"' +define rule_oc_o_o + $(call cmd,objcopy) + @printf '%s\n' 'savedcmd_$@ := $(call make-cmd,oc_o_o)' > $(dot-target).cmd + $(call cmd,gen_objtooldep) + $(call cmd,gen_symversions_o) +endef + +OBJCOPYFLAGS_kvm-namespaced.o := -O $(LD_BFD) --localize-symbols=$(obj)/kvm_symbol_list +$(obj)/kvm-namespaced.o: $(obj)/kvm-unnamespaced.o $(obj)/kvm_symbol_list FORCE + $(call if_changed_rule,oc_o_o) + +kvm-arm64-y = kvm-namespaced.o + +targets += kvm-unnamespaced.o kvm_symbol_list kvm-namespaced.o + +endif + +clean-files += kvm-unnamespaced.o kvm_symbol_list kvm-namespaced.o + +obj-$(CONFIG_KVM) += kvm-arm64.o +