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Commit 9327f069 authored by Mark Rutland's avatar Mark Rutland Committed by Greg Kroah-Hartman
Browse files

arm64: KVM: Use per-CPU vector when BP hardening is enabled 




From: Marc Zyngier <marc.zyngier@arm.com>

commit 6840bdd73d07216ab4bc46f5a8768c37ea519038 upstream.

Now that we have per-CPU vectors, let's plug then in the KVM/arm64 code.

Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
[v4.9: account for files moved to virt/ upstream, use cpus_have_cap()]
Signed-off-by: Mark Rutland <mark.rutland@arm.com> [v4.9 backport]
Tested-by: default avatarGreg Hackmann <ghackmann@google.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 09ea80a0

arch/arm/include/asm/kvm_mmu.h

+10 −0
Original line number Diff line number Diff line
@@ -223,6 +223,16 @@ static inline unsigned int kvm_get_vmid_bits(void) 
	return 8;

}



static inline void *kvm_get_hyp_vector(void)

{

	return kvm_ksym_ref(__kvm_hyp_vector);

}



static inline int kvm_map_vectors(void)

{

	return 0;

}



#endif	/* !__ASSEMBLY__ */



#endif /* __ARM_KVM_MMU_H__ */

arch/arm/kvm/arm.c

+8 −1
Original line number Diff line number Diff line
@@ -1088,7 +1088,7 @@ static void cpu_init_hyp_mode(void *dummy) 
	pgd_ptr = kvm_mmu_get_httbr();

	stack_page = __this_cpu_read(kvm_arm_hyp_stack_page);

	hyp_stack_ptr = stack_page + PAGE_SIZE;

	vector_ptr = (unsigned long)kvm_ksym_ref(__kvm_hyp_vector);

	vector_ptr = (unsigned long)kvm_get_hyp_vector();



	__cpu_init_hyp_mode(pgd_ptr, hyp_stack_ptr, vector_ptr);

	__cpu_init_stage2();
@@ -1345,6 +1345,13 @@ static int init_hyp_mode(void) 
		goto out_err;

	}





	err = kvm_map_vectors();

	if (err) {

		kvm_err("Cannot map vectors\n");

		goto out_err;

	}



	/*

	 * Map the Hyp stack pages

	 */

arch/arm64/include/asm/kvm_mmu.h

+38 −0
Original line number Diff line number Diff line
@@ -313,5 +313,43 @@ static inline unsigned int kvm_get_vmid_bits(void) 
	return (cpuid_feature_extract_unsigned_field(reg, ID_AA64MMFR1_VMIDBITS_SHIFT) == 2) ? 16 : 8;

}



#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR

#include <asm/mmu.h>



static inline void *kvm_get_hyp_vector(void)

{

	struct bp_hardening_data *data = arm64_get_bp_hardening_data();

	void *vect = kvm_ksym_ref(__kvm_hyp_vector);



	if (data->fn) {

		vect = __bp_harden_hyp_vecs_start +

		       data->hyp_vectors_slot * SZ_2K;



		if (!cpus_have_cap(ARM64_HAS_VIRT_HOST_EXTN))

			vect = lm_alias(vect);

	}



	return vect;

}



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);

}



#else

static inline void *kvm_get_hyp_vector(void)

{

	return kvm_ksym_ref(__kvm_hyp_vector);

}



static inline int kvm_map_vectors(void)

{

	return 0;

}

#endif



#endif /* __ASSEMBLY__ */

#endif /* __ARM64_KVM_MMU_H__ */

arch/arm64/kvm/hyp/switch.c

+1 −1
Original line number Diff line number Diff line
@@ -50,7 +50,7 @@ static void __hyp_text __activate_traps_vhe(void) 
	val &= ~CPACR_EL1_FPEN;

	write_sysreg(val, cpacr_el1);



	write_sysreg(__kvm_hyp_vector, vbar_el1);

	write_sysreg(kvm_get_hyp_vector(), vbar_el1);

}



static void __hyp_text __activate_traps_nvhe(void)