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Diffstat (limited to 'arch/arm64/kvm/hyp/hyp-entry.S')
-rw-r--r--arch/arm64/kvm/hyp/hyp-entry.S38
1 files changed, 37 insertions, 1 deletions
diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S
index bffece27b5c1..05d836979032 100644
--- a/arch/arm64/kvm/hyp/hyp-entry.S
+++ b/arch/arm64/kvm/hyp/hyp-entry.S
@@ -106,8 +106,44 @@ el1_hvc_guest:
*/
ldr x1, [sp] // Guest's x0
eor w1, w1, #ARM_SMCCC_ARCH_WORKAROUND_1
+ cbz w1, wa_epilogue
+
+ /* ARM_SMCCC_ARCH_WORKAROUND_2 handling */
+ eor w1, w1, #(ARM_SMCCC_ARCH_WORKAROUND_1 ^ \
+ ARM_SMCCC_ARCH_WORKAROUND_2)
cbnz w1, el1_trap
- mov x0, x1
+
+#ifdef CONFIG_ARM64_SSBD
+alternative_cb arm64_enable_wa2_handling
+ b wa2_end
+alternative_cb_end
+ get_vcpu_ptr x2, x0
+ ldr x0, [x2, #VCPU_WORKAROUND_FLAGS]
+
+ // Sanitize the argument and update the guest flags
+ ldr x1, [sp, #8] // Guest's x1
+ clz w1, w1 // Murphy's device:
+ lsr w1, w1, #5 // w1 = !!w1 without using
+ eor w1, w1, #1 // the flags...
+ bfi x0, x1, #VCPU_WORKAROUND_2_FLAG_SHIFT, #1
+ str x0, [x2, #VCPU_WORKAROUND_FLAGS]
+
+ /* Check that we actually need to perform the call */
+ hyp_ldr_this_cpu x0, arm64_ssbd_callback_required, x2
+ cbz x0, wa2_end
+
+ mov w0, #ARM_SMCCC_ARCH_WORKAROUND_2
+ smc #0
+
+ /* Don't leak data from the SMC call */
+ mov x3, xzr
+wa2_end:
+ mov x2, xzr
+ mov x1, xzr
+#endif
+
+wa_epilogue:
+ mov x0, xzr
add sp, sp, #16
eret