runqemu: Add workaround for APIC hang on pre 4.15 kernels on qemux86

On pre 4.15 host kernels, an APIC window emulation bug can cause qemu
to hang. On 64 bit we can use the x2apic, for 32 bit, we just have to
disable the other timer sources and rely on kvm-clock.

[YOCTO #12301]

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit 82e67b82ea8e12aa0b7b9db1d84fec0436dec71b)
Signed-off-by: Armin Kuster <akuster808@gmail.com>

diff --git a/scripts/runqemu b/scripts/runqemu
index f0ddeea1bf239fc71dec71b7ae2a6e363f63c125..9b6d330f1f0d8e380712bd6a932ba50a980fde55 100755 (executable)
--- a/scripts/runqemu
+++ b/scripts/runqemu
@@ -482,6 +482,11 @@ class BaseConfig(object):
 
         if os.access(dev_kvm, os.W_OK|os.R_OK):
             self.qemu_opt_script += ' -enable-kvm'
+            if self.get('MACHINE') == "qemux86":
+                # Workaround for broken APIC window on pre 4.15 host kernels which causes boot hangs
+                # See YOCTO #12301
+                # On 64 bit we use x2apic
+                self.kernel_cmdline_script += " clocksource=kvm-clock hpet=disable noapic nolapic"
         else:
             logger.error("You have no read or write permission on /dev/kvm.")
             logger.error("Please change the ownership of this file as described at:")