Thanks for the quick reply! On 07/31/2015 06:13 PM, Andrew Cooper wrote: >> Looking in the code, the only two __vmwrite(GUEST_SYSENTER_EIP, ...) >> calls occur in xen/arch/x86/hvm/vmx/vmx.c. One is in >> vmx_msr_write_intercept(), but adding a printk() just after produces no >> output after starting and stopping a guest. > > Write interception for that MSR is disabled (if the hardware supports > disabling interception) because it is not interesting. > > You can re-enable interception by commenting out the appropriate > vmx_disable_intercept_for_msr() line in construct_vmcs()
It shouldn't be disabled, it's in the vmx_introspection_force_enabled_msrs[] list and I'm testing it with memory introspection. >> The other is in vmx_vmcs_restore(), which seems to dutifully restore the >> never-set value of zero after a save. >> >> So this doesn't seem to be actually initialized anywhere. Could somebody >> please recommend the best place to initialize it, and the best value to >> initialize it with? Or maybe you could point out what I'm missing, if >> that's the case? > > Are you certain that the guest is actually setting it? If the guest > never sets it in the first place, 0 will be the expected value. That might be it, I'll need to look closer. Thanks, Razvan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
