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

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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: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin 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: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Mark Rutland 2018-04-12 12:11:16 +01:00 committed by Greg Kroah-Hartman
parent 09ea80a05c
commit 9327f06963
4 changed files with 57 additions and 2 deletions
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10
arch/arm/include/asm/kvm_mmu.h
View File

@ -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__ */

9
arch/arm/kvm/arm.c
View File

@ -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
*/

38
arch/arm64/include/asm/kvm_mmu.h
View File

@ -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__ */

2
arch/arm64/kvm/hyp/switch.c
View File

@ -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)