Re: regression: nested: L1 3.15+ fails to load kvm-intel on L0 <3.15

2015-03-18 Thread Stefan Bader
On 18.03.2015 11:27, Paolo Bonzini wrote: > > > On 18/03/2015 10:59, Stefan Bader wrote: >>> @@ -2850,7 +2851,7 @@ static __init int setup_vmcs_config(struct >>> vmcs_config *vmcs_conf) vmx_capability.ept, >>> vmx_capability.vpid); } >>> >>> - min = 0; + min = VM_EXIT_SAVE_DEBUG_CONTROLS;

Re: regression: nested: L1 3.15+ fails to load kvm-intel on L0 <3.15

2015-03-18 Thread Paolo Bonzini
On 18/03/2015 10:59, Stefan Bader wrote: >> @@ -2850,7 +2851,7 @@ static __init int setup_vmcs_config(struct >> vmcs_config *vmcs_conf) vmx_capability.ept, >> vmx_capability.vpid); } >> >> -min = 0; + min = VM_EXIT_SAVE_DEBUG_CONTROLS; #ifdef >> CONFIG_X86_64 min |= VM_EXIT_HOST_ADDR_SP

Re: regression: nested: L1 3.15+ fails to load kvm-intel on L0 <3.15

2015-03-18 Thread Stefan Bader
On 18.03.2015 10:18, Paolo Bonzini wrote: > > > On 18/03/2015 09:46, Stefan Bader wrote: >> >> Regardless of that, I wonder whether the below (this version untested) sound >> acceptable for upstream? At least it would make debugging much simpler. :) >> >> --- a/arch/x86/kvm/vmx.c >> +++ b/arch/x8

Re: regression: nested: L1 3.15+ fails to load kvm-intel on L0 <3.15

2015-03-18 Thread Paolo Bonzini
On 18/03/2015 09:46, Stefan Bader wrote: > > Regardless of that, I wonder whether the below (this version untested) sound > acceptable for upstream? At least it would make debugging much simpler. :) > > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -2953,8 +2953,11 @@ static __init i

regression: nested: L1 3.15+ fails to load kvm-intel on L0 <3.15

2015-03-18 Thread Stefan Bader
Someone reported[1] that some of their L1 guests fail to load the kvm-intel module (without much details). Turns out that this was (at least) caused by KVM: vmx: Allow the guest to run with dirty debug registers as this adds VM_EXIT_SAVE_DEBUG_CONTROLS to the required MSR_IA32_VMX_EXIT_CTLS bits.