commit 93c015d5098ff7205d3c3f2b23f134718aba65e4
author Ilja H. Friedel <ihf@chromium.org> Fri Jan 19 21:21:06 2018 -0800
committer chrome-bot <chrome-bot@chromium.org> Thu Feb 01 02:41:45 2018 -0800
tree d3fcc64fde9235cd6b46268746e1d7124eca0fab
parent 6c7947c9ec9ad8958234b11a2c8a2760deca2153

Relax and statically verify QEMU cpu features.

Remove pinetrail code which is obsolete. Also do not use qemu64
CPU by default, which has a very limited feature set. Instead
request by default to use the Haswell CPU feature set, which is
the lowest common denominator on Chrome OS infrastructure.

Adding "check" should warn the user when the requested features
are not available locally.

Furthermore add command line option "kvm_cpu" to allow arbitrary
CPU feature set selection.

BUG=chromium:800554
TEST=Started VM with different options.

Change-Id: I323131fcb56d092fc7608afc389d3e185fb45562
Reviewed-on: https://chromium-review.googlesource.com/877622
Commit-Ready: Ilja H. Friedel <ihf@chromium.org>
Tested-by: Ilja H. Friedel <ihf@chromium.org>
Reviewed-by: Dominik Behr <dbehr@chromium.org>

lib/cros_vm_lib.sh

diff --git a/lib/cros_vm_lib.sh b/lib/cros_vm_lib.sh
index bb8a7a6..1a7fdef 100644
--- a/lib/cros_vm_lib.sh
+++ b/lib/cros_vm_lib.sh
@@ -29,6 +29,11 @@
 DEFINE_string qemu_binary \
   "${DEFAULT_CHROOT_DIR}"/usr/bin/qemu-system-x86_64 \
   "The qemu binary to be used. Defaults to qemu shipped with the SDK."
+DEFINE_string kvm_cpu "Haswell-noTSX,-invpcid,-tsc-deadline" \
+    "Configures guest CPU model and features. The default should be the
+     least restrictive option supported by all of Chrome OS infrastructure.
+     Other locally valid choices are for instance 'qemu64' (least features)
+     or 'host' (maximum features)."
 DEFINE_string kvm_m 8G "Configure guest RAM"
 DEFINE_integer kvm_smp 0 \
   "Configure guest CPU counts (0 means auto-detect cpu count)"
@@ -174,14 +179,8 @@
   disable_ksmd
   set_kvm
 
-  # Determine appropriate qemu CPU for board.
-  # TODO(spang): Let the overlay provide appropriate options.
-  local cpu_option=""
-  case "${board}" in
-    x86-alex*|x86-mario*|x86-zgb*)
-      cpu_option="-cpu n270"
-      ;;
-  esac
+  # Append 'check' option to warn if requested CPU is not fully supported.
+  local kvm_cpu="${FLAGS_kvm_cpu},check"
 
   # Override default pid file.
   local start_vm=0
@@ -316,15 +315,16 @@
     # to ensure that it is quoted if set, but _not_ quoted if
     # unset. (QEMU chokes on empty arguments).
     local cmd=(
-      "${KVM_BINARY}" ${kvm_flag} -m ${FLAGS_kvm_m}
+      "${KVM_BINARY}" ${kvm_flag}
+      -m ${FLAGS_kvm_m}
       -smp ${kvm_smp}
+      -cpu ${kvm_cpu}
       -vga virtio
       -pidfile "${KVM_PID_FILE}"
       -chardev pipe,id=control_pipe,path="${KVM_PIPE_PREFIX}"
       -serial "file:${KVM_SERIAL_FILE}"
       -mon chardev=control_pipe
       -daemonize
-      ${cpu_option}
       ${net_option}
       ${nographics}
       ${snapshot}