Commit 6279017e authored by Will Deacon's avatar Will Deacon Committed by Marc Zyngier
Browse files

KVM: arm64: Move BP hardening helpers into spectre.h 



The BP hardening helpers are an integral part of the Spectre-v2
mitigation, so move them into asm/spectre.h and inline the
arm64_get_bp_hardening_data() function at the same time.

Signed-off-by: default avatarWill Deacon <will@kernel.org>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20201113113847.21619-6-will@kernel.org
parent 07cf8aa9

arch/arm64/include/asm/mmu.h

+0 −29
Original line number Diff line number Diff line
@@ -12,9 +12,6 @@ 
#define USER_ASID_FLAG	(UL(1) << USER_ASID_BIT)

#define TTBR_ASID_MASK	(UL(0xffff) << 48)



#define BP_HARDEN_EL2_SLOTS 4

#define __BP_HARDEN_HYP_VECS_SZ (BP_HARDEN_EL2_SLOTS * SZ_2K)



#ifndef __ASSEMBLY__



#include <linux/refcount.h>
@@ -41,32 +38,6 @@ static inline bool arm64_kernel_unmapped_at_el0(void) 
	return cpus_have_const_cap(ARM64_UNMAP_KERNEL_AT_EL0);

}



typedef void (*bp_hardening_cb_t)(void);



struct bp_hardening_data {

	int			hyp_vectors_slot;

	bp_hardening_cb_t	fn;

};



DECLARE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data);



static inline struct bp_hardening_data *arm64_get_bp_hardening_data(void)

{

	return this_cpu_ptr(&bp_hardening_data);

}



static inline void arm64_apply_bp_hardening(void)

{

	struct bp_hardening_data *d;



	if (!cpus_have_const_cap(ARM64_SPECTRE_V2))

		return;



	d = arm64_get_bp_hardening_data();

	if (d->fn)

		d->fn();

}



extern void arm64_memblock_init(void);

extern void paging_init(void);

extern void bootmem_init(void);

arch/arm64/include/asm/spectre.h

+30 −0
Original line number Diff line number Diff line
@@ -9,7 +9,15 @@ 
#ifndef __ASM_SPECTRE_H

#define __ASM_SPECTRE_H



#define BP_HARDEN_EL2_SLOTS 4

#define __BP_HARDEN_HYP_VECS_SZ (BP_HARDEN_EL2_SLOTS * SZ_2K)



#ifndef __ASSEMBLY__



#include <linux/percpu.h>



#include <asm/cpufeature.h>

#include <asm/virt.h>



/* Watch out, ordering is important here. */

enum mitigation_state {
@@ -20,6 +28,27 @@ enum mitigation_state { 


struct task_struct;



typedef void (*bp_hardening_cb_t)(void);



struct bp_hardening_data {

	int			hyp_vectors_slot;

	bp_hardening_cb_t	fn;

};



DECLARE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data);



static inline void arm64_apply_bp_hardening(void)

{

	struct bp_hardening_data *d;



	if (!cpus_have_const_cap(ARM64_SPECTRE_V2))

		return;



	d = this_cpu_ptr(&bp_hardening_data);

	if (d->fn)

		d->fn();

}



enum mitigation_state arm64_get_spectre_v2_state(void);

bool has_spectre_v2(const struct arm64_cpu_capabilities *cap, int scope);

void spectre_v2_enable_mitigation(const struct arm64_cpu_capabilities *__unused);
@@ -29,4 +58,5 @@ bool has_spectre_v4(const struct arm64_cpu_capabilities *cap, int scope); 
void spectre_v4_enable_mitigation(const struct arm64_cpu_capabilities *__unused);

void spectre_v4_enable_task_mitigation(struct task_struct *tsk);



#endif	/* __ASSEMBLY__ */

#endif	/* __ASM_SPECTRE_H */

arch/arm64/kvm/arm.c

+1 −1
Original line number Diff line number Diff line
@@ -1405,7 +1405,7 @@ static void cpu_hyp_reset(void) 
 */

static void cpu_set_hyp_vector(void)

{

	struct bp_hardening_data *data = arm64_get_bp_hardening_data();

	struct bp_hardening_data *data = this_cpu_ptr(&bp_hardening_data);

	void *vect = kern_hyp_va(kvm_ksym_ref(__kvm_hyp_vector));

	int slot = -1;

arch/arm64/kvm/hyp/hyp-entry.S

+1 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#include <asm/kvm_arm.h>

#include <asm/kvm_asm.h>

#include <asm/mmu.h>

#include <asm/spectre.h>



.macro save_caller_saved_regs_vect

	/* x0 and x1 were saved in the vector entry */