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authorMarc Zyngier <marc.zyngier@arm.com>2019-01-11 14:57:58 +0000
committerMarc Zyngier <marc.zyngier@arm.com>2019-02-19 21:05:34 +0000
commitd18232ea8a9480606c53e91d7e2d062c3c151815 (patch)
tree4f5076fe69453e1cc96c2ab8aad6183ba8fb9e5b /arch
parent7cba8a8d0d39c8846d0095fc2d2225c7983f4009 (diff)
ARM: KVM: Teach some form of type-safety to kvm_call_hyp
Just like on arm64, and for the same reasons, kvm_call_hyp removes any form of type safety when calling into HYP. But we can still try to tell the compiler what we're trying to achieve. Here, we can add code that would do the function call if it wasn't guarded by an always-false predicate. Hopefully, the compiler is dumb enough to do the type checking and clever enough to not emit the corresponding code... Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/include/asm/kvm_host.h31
-rw-r--r--arch/arm/kvm/hyp/hyp-entry.S2
-rw-r--r--arch/arm/kvm/interrupts.S4
3 files changed, 31 insertions, 6 deletions
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 023c9f2b1eea..4b6193f2f0f6 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -215,8 +215,33 @@ int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *indices);
int kvm_arm_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg);
int kvm_arm_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg);
-unsigned long kvm_call_hyp(void *hypfn, ...);
-#define kvm_call_hyp_ret(f, ...) kvm_call_hyp(f, ##__VA_ARGS__)
+unsigned long __kvm_call_hyp(void *hypfn, ...);
+
+/*
+ * The has_vhe() part doesn't get emitted, but is used for type-checking.
+ */
+#define kvm_call_hyp(f, ...) \
+ do { \
+ if (has_vhe()) { \
+ f(__VA_ARGS__); \
+ } else { \
+ __kvm_call_hyp(kvm_ksym_ref(f), ##__VA_ARGS__); \
+ } \
+ } while(0)
+
+#define kvm_call_hyp_ret(f, ...) \
+ ({ \
+ typeof(f(__VA_ARGS__)) ret; \
+ \
+ if (has_vhe()) { \
+ ret = f(__VA_ARGS__); \
+ } else { \
+ ret = __kvm_call_hyp(kvm_ksym_ref(f), \
+ ##__VA_ARGS__); \
+ } \
+ \
+ ret; \
+ })
void force_vm_exit(const cpumask_t *mask);
int __kvm_arm_vcpu_get_events(struct kvm_vcpu *vcpu,
@@ -268,7 +293,7 @@ static inline void __cpu_init_hyp_mode(phys_addr_t pgd_ptr,
* compliant with the PCS!).
*/
- kvm_call_hyp((void*)hyp_stack_ptr, vector_ptr, pgd_ptr);
+ __kvm_call_hyp((void*)hyp_stack_ptr, vector_ptr, pgd_ptr);
}
static inline void __cpu_init_stage2(void)
diff --git a/arch/arm/kvm/hyp/hyp-entry.S b/arch/arm/kvm/hyp/hyp-entry.S
index aa3f9a9837ac..6ed3cf23fe89 100644
--- a/arch/arm/kvm/hyp/hyp-entry.S
+++ b/arch/arm/kvm/hyp/hyp-entry.S
@@ -176,7 +176,7 @@ THUMB( orr lr, lr, #PSR_T_BIT )
msr spsr_cxsf, lr
ldr lr, =panic
msr ELR_hyp, lr
- ldr lr, =kvm_call_hyp
+ ldr lr, =__kvm_call_hyp
clrex
eret
ENDPROC(__hyp_do_panic)
diff --git a/arch/arm/kvm/interrupts.S b/arch/arm/kvm/interrupts.S
index 80a1d6cd261c..a08e6419ebe9 100644
--- a/arch/arm/kvm/interrupts.S
+++ b/arch/arm/kvm/interrupts.S
@@ -42,7 +42,7 @@
* r12: caller save
* rest: callee save
*/
-ENTRY(kvm_call_hyp)
+ENTRY(__kvm_call_hyp)
hvc #0
bx lr
-ENDPROC(kvm_call_hyp)
+ENDPROC(__kvm_call_hyp)