arm64: KVM: Move BP hardening vectors into .hyp.text section

There is no reason why the BP hardening vectors shouldn't be part
of the HYP text at compile time, rather than being mapped at runtime.

Also introduce a new config symbol that controls the compilation
of bpi.S.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index 8cd37eac6292dccb0c9f945f42cfa32b8a8745c2..65dc225d019c920bec696ca27619f98c64e18ce6 100644 (file)
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -380,9 +380,7 @@ static inline void *kvm_get_hyp_vector(void)
 
 static inline int kvm_map_vectors(void)
 {
-       return create_hyp_mappings(kvm_ksym_ref(__bp_harden_hyp_vecs_start),
-                                  kvm_ksym_ref(__bp_harden_hyp_vecs_end),
-                                  PAGE_HYP_EXEC);
+       return 0;
 }
 
 #else

diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index b87541360f43824e6df20961af87a3154f1f7c0f..93bce17109a68a4e076df883b8ffbc69722e5640 100644 (file)
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -54,9 +54,7 @@ arm64-reloc-test-y := reloc_test_core.o reloc_test_syms.o
 arm64-obj-$(CONFIG_CRASH_DUMP)         += crash_dump.o
 arm64-obj-$(CONFIG_ARM_SDE_INTERFACE)  += sdei.o
 
-ifeq ($(CONFIG_KVM),y)
-arm64-obj-$(CONFIG_HARDEN_BRANCH_PREDICTOR)    += bpi.o
-endif
+arm64-obj-$(CONFIG_KVM_INDIRECT_VECTORS)+= bpi.o
 
 obj-y                                  += $(arm64-obj-y) vdso/ probes/
 obj-m                                  += $(arm64-obj-m)

diff --git a/arch/arm64/kernel/bpi.S b/arch/arm64/kernel/bpi.S
index e5de33513b5d77a79015c8def568827a89173843..447188e2a66470735a59e7bec5d2d1097bb947e7 100644 (file)
--- a/arch/arm64/kernel/bpi.S
+++ b/arch/arm64/kernel/bpi.S
@@ -48,6 +48,10 @@
        ventry \target + 0x780
 .endm
 
+
+       .text
+       .pushsection    .hyp.text, "ax"
+
        .align  11
 ENTRY(__bp_harden_hyp_vecs_start)
        .rept 4
@@ -55,6 +59,8 @@ ENTRY(__bp_harden_hyp_vecs_start)
        .endr
 ENTRY(__bp_harden_hyp_vecs_end)
 
+       .popsection
+
 ENTRY(__qcom_hyp_sanitize_link_stack_start)
        stp     x29, x30, [sp, #-16]!
        .rept   16

diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index 2257dfcc44cce003b54d139e00aebe1743ed5e35..bd8cc03d75223eebbf0be3a6c8aaa1821bf81f2e 100644 (file)
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -57,6 +57,9 @@ config KVM_ARM_PMU
          Adds support for a virtual Performance Monitoring Unit (PMU) in
          virtual machines.
 
+config KVM_INDIRECT_VECTORS
+       def_bool KVM && HARDEN_BRANCH_PREDICTOR
+
 source drivers/vhost/Kconfig
 
 endif # VIRTUALIZATION