[PATCH v2 01/13] powerpc/pseries: Introduce option to build secure virtual machines

[Thiago Jung Bauermann]

Introduce CONFIG_PPC_SVM to control support for secure guests and include
Ultravisor-related helpers when it is selected

Signed-off-by: Thiago Jung Bauermann <bauerman@xxxxxxxxxxxxx>
---
 arch/powerpc/include/asm/ultravisor.h  |  2 +-
 arch/powerpc/kernel/Makefile           |  4 +++-
 arch/powerpc/platforms/pseries/Kconfig | 11 +++++++++++
 3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/ultravisor.h b/arch/powerpc/include/asm/ultravisor.h
index a5e4516c8ddb..f5dc5af739b8 100644
--- a/arch/powerpc/include/asm/ultravisor.h
+++ b/arch/powerpc/include/asm/ultravisor.h
@@ -28,7 +28,7 @@ extern int early_init_dt_scan_ultravisor(unsigned long node, const char *uname,
  * This call supports up to 6 arguments and 4 return arguments. Use
  * UCALL_BUFSIZE to size the return argument buffer.
  */
-#if defined(CONFIG_PPC_POWERNV)
+#if defined(CONFIG_PPC_POWERNV) || defined(CONFIG_PPC_SVM)
 long ucall(unsigned long opcode, unsigned long *retbuf, ...);
 #else
 static long ucall(unsigned long opcode, unsigned long *retbuf, ...)
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 929f79d3e6a9..ea671f03eba2 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -155,7 +155,9 @@ endif
 
 obj-$(CONFIG_EPAPR_PARAVIRT)	+= epapr_paravirt.o epapr_hcalls.o
 obj-$(CONFIG_KVM_GUEST)		+= kvm.o kvm_emul.o
-obj-$(CONFIG_PPC_POWERNV)	+= ultravisor.o ucall.o
+ifneq ($(CONFIG_PPC_POWERNV)$(CONFIG_PPC_SVM),)
+obj-y				+= ultravisor.o ucall.o
+endif
 
 # Disable GCOV, KCOV & sanitizers in odd or sensitive code
 GCOV_PROFILE_prom_init.o := n
diff --git a/arch/powerpc/platforms/pseries/Kconfig b/arch/powerpc/platforms/pseries/Kconfig
index f7b484f55553..d09deb05bb66 100644
--- a/arch/powerpc/platforms/pseries/Kconfig
+++ b/arch/powerpc/platforms/pseries/Kconfig
@@ -145,3 +145,14 @@ config PAPR_SCM
 	tristate "Support for the PAPR Storage Class Memory interface"
 	help
 	  Enable access to hypervisor provided storage class memory.
+
+config PPC_SVM
+	bool "Secure virtual machine (SVM) support for POWER"
+	depends on PPC_PSERIES
+	help
+	 There are certain POWER platforms which support secure guests using
+	 the Protected Execution Facility, with the help of an Ultravisor
+	 executing below the hypervisor layer. This enables support for
+	 those guests.
+
+	 If unsure, say "N".