On Thu, May 04, 2017 at 12:16:38PM +0200, Kashyap Chamarthy wrote: > On Tue, May 02, 2017 at 05:31:15PM -0300, Eduardo Habkost wrote: > > Hi, > > Yet to try this series, a small question in-line. > > > Introduce a new CPUFeatureSetting QAPI data type, and use it to support > > feature=force on -cpu. > > > > Signed-off-by: Eduardo Habkost <ehabk...@redhat.com> [...] > > @@ -336,5 +340,13 @@ int main(int argc, char **argv) > > "-machine accel=kvm:tcg -cpu max,mmx=off", > > 1, 0, "EDX", 23, false); > > > > + { > > + FeatureTestArgs *a; > > + a = add_feature_test("x86/cpuid/features/monitor-force", > > + "-machine accel=kvm:tcg -cpu 486,monitor=force", > > Following your above test example, should the 'force' boolean also work > (understood: only for testing / debugging) as below, for a recognized > CPUID flag, taking the example of 'INVPCID'? > > $ qemu-system-x86_64 [...] -cpu Haswell-noTSX,invpcid=force [...]
This would be valid syntax and would enable invpcid on CPUID, yes. But on most cases this means you will get a broken VCPU because the host won't virtualize the feature properly (if it did, the feature would be reported as available in GET_SUPPORTED_CPUID and "feature=on" would already work). -- Eduardo