aboutsummaryrefslogtreecommitdiffstats
path: root/arch/arm64/include/asm/kvm_asm.h
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm64/include/asm/kvm_asm.h')
-rw-r--r--arch/arm64/include/asm/kvm_asm.h43
1 files changed, 43 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index fb1a922b31ba..6f98fbd0ac81 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -169,6 +169,34 @@ extern char __smccc_workaround_1_smc[__SMCCC_WORKAROUND_1_SMC_SZ];
*__hyp_this_cpu_ptr(sym); \
})
+#define __KVM_EXTABLE(from, to) \
+ " .pushsection __kvm_ex_table, \"a\"\n" \
+ " .align 3\n" \
+ " .long (" #from " - .), (" #to " - .)\n" \
+ " .popsection\n"
+
+
+#define __kvm_at(at_op, addr) \
+( { \
+ int __kvm_at_err = 0; \
+ u64 spsr, elr; \
+ asm volatile( \
+ " mrs %1, spsr_el2\n" \
+ " mrs %2, elr_el2\n" \
+ "1: at "at_op", %3\n" \
+ " isb\n" \
+ " b 9f\n" \
+ "2: msr spsr_el2, %1\n" \
+ " msr elr_el2, %2\n" \
+ " mov %w0, %4\n" \
+ "9:\n" \
+ __KVM_EXTABLE(1b, 2b) \
+ : "+r" (__kvm_at_err), "=&r" (spsr), "=&r" (elr) \
+ : "r" (addr), "i" (-EFAULT)); \
+ __kvm_at_err; \
+} )
+
+
#else /* __ASSEMBLY__ */
.macro hyp_adr_this_cpu reg, sym, tmp
@@ -193,6 +221,21 @@ extern char __smccc_workaround_1_smc[__SMCCC_WORKAROUND_1_SMC_SZ];
ldr \vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
.endm
+/*
+ * KVM extable for unexpected exceptions.
+ * In the same format _asm_extable, but output to a different section so that
+ * it can be mapped to EL2. The KVM version is not sorted. The caller must
+ * ensure:
+ * x18 has the hypervisor value to allow any Shadow-Call-Stack instrumented
+ * code to write to it, and that SPSR_EL2 and ELR_EL2 are restored by the fixup.
+ */
+.macro _kvm_extable, from, to
+ .pushsection __kvm_ex_table, "a"
+ .align 3
+ .long (\from - .), (\to - .)
+ .popsection
+.endm
+
#endif
#endif /* __ARM_KVM_ASM_H__ */