Re: [PATCH RFC v1 02/10] KVM: VMX: Add missing CPU based VM execution controls to vmcs_config

From: Vitaly Kuznetsov
Date: Mon Jun 27 2022 - 11:13:30 EST


Sean Christopherson <seanjc@xxxxxxxxxx> writes:

> Maybe say "dynamically enabled" or so instead of "missing"?
>

...

> On Wed, Jun 22, 2022, Vitaly Kuznetsov wrote:
>> Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
>> ---
>> arch/x86/kvm/vmx/vmx.c | 15 ++++++++++++++-
>> 1 file changed, 14 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
>> index 24da9e93bdab..01294a2fc1c1 100644
>> --- a/arch/x86/kvm/vmx/vmx.c
>> +++ b/arch/x86/kvm/vmx/vmx.c
>> @@ -2483,8 +2483,14 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf,
>> CPU_BASED_INVLPG_EXITING |
>> CPU_BASED_RDPMC_EXITING;
>>
>> - opt = CPU_BASED_TPR_SHADOW |
>> + opt = CPU_BASED_INTR_WINDOW_EXITING |
>> + CPU_BASED_RDTSC_EXITING |
>> + CPU_BASED_TPR_SHADOW |
>> + CPU_BASED_NMI_WINDOW_EXITING |
>> + CPU_BASED_USE_IO_BITMAPS |
>> + CPU_BASED_MONITOR_TRAP_FLAG |
>> CPU_BASED_USE_MSR_BITMAPS |
>> + CPU_BASED_PAUSE_EXITING |
>> CPU_BASED_ACTIVATE_SECONDARY_CONTROLS |
>> CPU_BASED_ACTIVATE_TERTIARY_CONTROLS;

CPU_BASED_INTR_WINDOW_EXITING and CPU_BASED_NMI_WINDOW_EXITING are
actually "dynamically enabled" but CPU_BASED_RDTSC_EXITING/
CPU_BASED_USE_IO_BITMAPS/ CPU_BASED_MONITOR_TRAP_FLAG /
CPU_BASED_PAUSE_EXITING are not (and I found the first two immediately
after implementing 'macro shananigans' you suggested, of course :-), KVM
just doesn't use them for L1. So this is going to get splitted in two
patches.

--
Vitaly