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 8cd37ea..65dc225 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 b875413..93bce17 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 e5de335..447188e 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 2257dfc..bd8cc03 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