hw/arm/boot: If booting a kernel in EL2, set SCR_EL3.HCE

If we're directly booting a Linux kernel and the CPU supports both
EL3 and EL2, we start the kernel in EL2, as it expects. We must also
set the SCR_EL3.HCE bit in this situation, so that the HVC
instruction is enabled rather than UNDEFing. Otherwise at least some
kernels will panic when trying to initialize KVM in the guest.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20180313153458.26822-4-peter.maydell@linaro.org

diff --git a/hw/arm/boot.c b/hw/arm/boot.c
index e21a92f9721b2213ee4eeaeb2b487bdd55774ba2..9319b12fcd2a56b7b3e4fa387f99ac666dc01cdc 100644 (file)
--- a/hw/arm/boot.c
+++ b/hw/arm/boot.c
@@ -729,6 +729,11 @@ static void do_cpu_reset(void *opaque)
                     assert(!info->secure_board_setup);
                 }
 
+                if (arm_feature(env, ARM_FEATURE_EL2)) {
+                    /* If we have EL2 then Linux expects the HVC insn to work */
+                    env->cp15.scr_el3 |= SCR_HCE;
+                }
+
                 /* Set to non-secure if not a secure boot */
                 if (!info->secure_boot &&
                     (cs != first_cpu || !info->secure_board_setup)) {