Il 04/12/2013 08:58, Jan Kiszka ha scritto:
> We can easily emulate the HLT activity state for L1: If it decides that
> L2 shall be halted on entry, just invoke the normal emulation of halt
> after switching to L2. We do not depend on specific host features to
> provide this, so we can expose the capability unconditionally.
>
> Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
> ---
>
> Jailhouse would like to use this. Experimental code works fine so far,
> both on patched KVM and real HW.
Nice. :)
Do you have a testcase for kvm-unit-tests?
Paolo
> arch/x86/include/asm/vmx.h | 1 +
> arch/x86/kvm/vmx.c | 7 ++++++-
> 2 files changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
> index 966502d..2067264 100644
> --- a/arch/x86/include/asm/vmx.h
> +++ b/arch/x86/include/asm/vmx.h
> @@ -100,6 +100,7 @@
>
> #define VMX_MISC_PREEMPTION_TIMER_RATE_MASK 0x0000001f
> #define VMX_MISC_SAVE_EFER_LMA 0x00000020
> +#define VMX_MISC_ACTIVITY_HLT 0x00000040
>
> /* VMCS Encodings */
> enum vmcs_field {
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index b2fe1c2..00faf1f 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -2279,6 +2279,7 @@ static __init void nested_vmx_setup_ctls_msrs(void)
> rdmsr(MSR_IA32_VMX_MISC, nested_vmx_misc_low, nested_vmx_misc_high);
> nested_vmx_misc_low &= VMX_MISC_PREEMPTION_TIMER_RATE_MASK |
> VMX_MISC_SAVE_EFER_LMA;
> + nested_vmx_misc_low |= VMX_MISC_ACTIVITY_HLT;
> nested_vmx_misc_high = 0;
> }
>
> @@ -7882,7 +7883,8 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
> return 1;
> }
>
> - if (vmcs12->guest_activity_state != GUEST_ACTIVITY_ACTIVE) {
> + if (vmcs12->guest_activity_state != GUEST_ACTIVITY_ACTIVE &&
> + vmcs12->guest_activity_state != GUEST_ACTIVITY_HLT) {
> nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD);
> return 1;
> }
> @@ -8011,6 +8013,9 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
>
> prepare_vmcs02(vcpu, vmcs12);
>
> + if (vmcs12->guest_activity_state == GUEST_ACTIVITY_HLT)
> + return kvm_emulate_halt(vcpu);
> +
> /*
> * Note no nested_vmx_succeed or nested_vmx_fail here. At this point
> * we are no longer running L1, and VMLAUNCH/VMRESUME has not yet
>
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