Sean Christopherson <seanjc@xxxxxxxxxx> writes:
> Move Hyper-V's eVMCS initialization to a dedicated helper to clean up
> vmx_init(), and add a comment to call out that the Hyper-V init code
> doesn't need to be unwound if vmx_init() ultimately fails.
>
> No functional change intended.
>
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> ---
> arch/x86/kvm/vmx/vmx.c | 73 +++++++++++++++++++++++++-----------------
> 1 file changed, 43 insertions(+), 30 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index c0de7160700b..b8bf95b9710d 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -523,6 +523,8 @@ static inline void vmx_segment_cache_clear(struct vcpu_vmx *vmx)
> static unsigned long host_idt_base;
>
> #if IS_ENABLED(CONFIG_HYPERV)
> +static struct kvm_x86_ops vmx_x86_ops __initdata;
> +
> static bool __read_mostly enlightened_vmcs = true;
> module_param(enlightened_vmcs, bool, 0444);
>
> @@ -551,6 +553,43 @@ static int hv_enable_l2_tlb_flush(struct kvm_vcpu *vcpu)
> return 0;
> }
>
> +static __init void hv_init_evmcs(void)
> +{
> + int cpu;
> +
> + if (!enlightened_vmcs)
> + return;
> +
> + /*
> + * Enlightened VMCS usage should be recommended and the host needs
> + * to support eVMCS v1 or above.
> + */
> + if (ms_hyperv.hints & HV_X64_ENLIGHTENED_VMCS_RECOMMENDED &&
> + (ms_hyperv.nested_features & HV_X64_ENLIGHTENED_VMCS_VERSION) >=
> + KVM_EVMCS_VERSION) {
> +
> + /* Check that we have assist pages on all online CPUs */
> + for_each_online_cpu(cpu) {
> + if (!hv_get_vp_assist_page(cpu)) {
> + enlightened_vmcs = false;
> + break;
> + }
> + }
> +
> + if (enlightened_vmcs) {
> + pr_info("KVM: vmx: using Hyper-V Enlightened VMCS\n");
> + static_branch_enable(&enable_evmcs);
> + }
> +
> + if (ms_hyperv.nested_features & HV_X64_NESTED_DIRECT_FLUSH)
> + vmx_x86_ops.enable_l2_tlb_flush
> + = hv_enable_l2_tlb_flush;
> +
> + } else {
> + enlightened_vmcs = false;
> + }
> +}
> +
> static void hv_reset_evmcs(void)
> {
> struct hv_vp_assist_page *vp_ap;
> @@ -577,6 +616,7 @@ static void hv_reset_evmcs(void)
> }
>
> #else /* IS_ENABLED(CONFIG_HYPERV) */
> +static void hv_init_evmcs(void) {}
> static void hv_reset_evmcs(void) {}
> #endif /* IS_ENABLED(CONFIG_HYPERV) */
>
> @@ -8500,38 +8540,11 @@ static int __init vmx_init(void)
> {
> int r, cpu;
>
> -#if IS_ENABLED(CONFIG_HYPERV)
> /*
> - * Enlightened VMCS usage should be recommended and the host needs
> - * to support eVMCS v1 or above. We can also disable eVMCS support
> - * with module parameter.
> + * Note, hv_init_evmcs() touches only VMX knobs, i.e. there's nothing
> + * to unwind if a later step fails.
> */
> - if (enlightened_vmcs &&
> - ms_hyperv.hints & HV_X64_ENLIGHTENED_VMCS_RECOMMENDED &&
> - (ms_hyperv.nested_features & HV_X64_ENLIGHTENED_VMCS_VERSION) >=
> - KVM_EVMCS_VERSION) {
> -
> - /* Check that we have assist pages on all online CPUs */
> - for_each_online_cpu(cpu) {
> - if (!hv_get_vp_assist_page(cpu)) {
> - enlightened_vmcs = false;
> - break;
> - }
> - }
> -
> - if (enlightened_vmcs) {
> - pr_info("KVM: vmx: using Hyper-V Enlightened VMCS\n");
> - static_branch_enable(&enable_evmcs);
> - }
> -
> - if (ms_hyperv.nested_features & HV_X64_NESTED_DIRECT_FLUSH)
> - vmx_x86_ops.enable_l2_tlb_flush
> - = hv_enable_l2_tlb_flush;
> -
> - } else {
> - enlightened_vmcs = false;
> - }
> -#endif
> + hv_init_evmcs();
>
> r = kvm_init(&vmx_init_ops, sizeof(struct vcpu_vmx),
> __alignof__(struct vcpu_vmx), THIS_MODULE);
Reviewed-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
--
Vitaly
