[PATCH v3 5/5] x86/Kconfig: Add HYPERV_VTL_MODE

Saurabh Sengar
2023-03-20T10:06:02Z

Add HYPERV_VTL_MODE Kconfig flag for VTL mode.

Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
---
arch/x86/Kconfig | 24 ++++++++++++++++++++++++
arch/x86/hyperv/Makefile | 1 +
2 files changed, 25 insertions(+)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 453f462f6c9c..c3faaaea1e31 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -782,6 +782,30 @@ menuconfig HYPERVISOR_GUEST

if HYPERVISOR_GUEST

+config HYPERV_VTL_MODE
+ bool "Enable Linux to boot in VTL context"
+ depends on X86_64 && HYPERV
+ default n
+ help
+ Virtual Secure Mode (VSM) is a set of hypervisor capabilities and
+ enlightenments offered to host and guest partitions which enables
+ the creation and management of new security boundaries within
+ operating system software.
+
+ VSM achieves and maintains isolation through Virtual Trust Levels
+ (VTLs). Virtual Trust Levels are hierarchical, with higher levels
+ being more privileged than lower levels. VTL0 is the least privileged
+ level, and currently only other level supported is VTL2.
+
+ Select this option to build a Linux kernel to run at a VTL other than
+ the normal VTL0, which currently is only VTL2. This option
+ initializes the x86 platform for VTL2, and adds the ability to boot
+ secondary CPUs directly into 64-bit context as required for VTLs other
+ than 0. A kernel built with this option must run at VTL2, and will
+ not run as a normal guest.
+
+ If unsure, say N
+
config PARAVIRT
bool "Enable paravirtualization code"
depends on HAVE_STATIC_CALL
diff --git a/arch/x86/hyperv/Makefile b/arch/x86/hyperv/Makefile
index 5d2de10809ae..3a1548054b48 100644
--- a/arch/x86/hyperv/Makefile
+++ b/arch/x86/hyperv/Makefile
@@ -1,6 +1,7 @@
# SPDX-License-Identifier: GPL-2.0-only
obj-y := hv_init.o mmu.o nested.o irqdomain.o ivm.o
obj-$(CONFIG_X86_64) += hv_apic.o hv_proc.o
+obj-$(CONFIG_HYPERV_VTL_MODE) += hv_vtl.o

ifdef CONFIG_X86_64
obj-$(CONFIG_PARAVIRT_SPINLOCKS) += hv_spinlock.o
--
2.34.1