hw/arm/boot: AArch32 kernels should be started in Hyp mode if available

The kernel booting specification for an AArch32 kernel requires that
it is booted in Hyp mode if available; otherwise the kernel can't
enable KVM. We were incorrectly leaving the kernel in SVC mode.
If we're booting an AArch32 kernel in the Nonsecure state and Hyp
mode is available, start in it.

Signed-off-by: Peter Maydell <[email protected]>
Reviewed-by: Richard Henderson <[email protected]>
Reviewed-by: Edgar E. Iglesias <[email protected]>
Reviewed-by: Luc Michel <[email protected]>
Message-id: 20180820153020[email protected]

diff --git a/hw/arm/boot.c b/hw/arm/boot.c
index ca9467e583fa9c8a72cbf79cc40d8c136fed206e..20c71d7d961fcc14cb201eb3fda0f2c4c475db92 100644 (file)
--- a/hw/arm/boot.c
+++ b/hw/arm/boot.c
@@ -736,6 +736,17 @@ static void do_cpu_reset(void *opaque)
                 }
             }
 
+            if (!env->aarch64 && !info->secure_boot &&
+                arm_feature(env, ARM_FEATURE_EL2)) {
+                /*
+                 * This is an AArch32 boot not to Secure state, and
+                 * we have Hyp mode available, so boot the kernel into
+                 * Hyp mode. This is not how the CPU comes out of reset,
+                 * so we need to manually put it there.
+                 */
+                cpsr_write(env, ARM_CPU_MODE_HYP, CPSR_M, CPSRWriteRaw);
+            }
+
             if (cs == first_cpu) {
                 AddressSpace *as = arm_boot_address_space(cpu, info);