Re: [PATCH v2 2/3] KVM: VMX: Fold loaded_vmcs_init() into alloc_loaded_vmcs()

Vitaly Kuznetsov
2020-03-22T13:08:21Z

Sean Christopherson <sean.j.christopherson@intel.com> writes:

> Subsume loaded_vmcs_init() into alloc_loaded_vmcs(), its only remaining
> caller, and drop the VMCLEAR on the shadow VMCS, which is guaranteed to
> be NULL. loaded_vmcs_init() was previously used by loaded_vmcs_clear(),
> but loaded_vmcs_clear() also subsumed loaded_vmcs_init() to properly
> handle smp_wmb() with respect to VMCLEAR.
>
> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
> ---
> arch/x86/kvm/vmx/vmx.c | 14 ++++----------
> arch/x86/kvm/vmx/vmx.h | 1 -
> 2 files changed, 4 insertions(+), 11 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index efaca09455bf..07634caa560d 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -653,15 +653,6 @@ static int vmx_set_guest_msr(struct vcpu_vmx *vmx, struct shared_msr_entry *msr,
> return ret;
> }
>
> -void loaded_vmcs_init(struct loaded_vmcs *loaded_vmcs)
> -{
> - vmcs_clear(loaded_vmcs->vmcs);
> - if (loaded_vmcs->shadow_vmcs && loaded_vmcs->launched)
> - vmcs_clear(loaded_vmcs->shadow_vmcs);
> - loaded_vmcs->cpu = -1;
> - loaded_vmcs->launched = 0;
> -}
> -
> #ifdef CONFIG_KEXEC_CORE
> static void crash_vmclear_local_loaded_vmcss(void)
> {
> @@ -2555,9 +2546,12 @@ int alloc_loaded_vmcs(struct loaded_vmcs *loaded_vmcs)
> if (!loaded_vmcs->vmcs)
> return -ENOMEM;
>
> + vmcs_clear(loaded_vmcs->vmcs);
> +
> loaded_vmcs->shadow_vmcs = NULL;
> loaded_vmcs->hv_timer_soft_disabled = false;
> - loaded_vmcs_init(loaded_vmcs);
> + loaded_vmcs->cpu = -1;
> + loaded_vmcs->launched = 0;
>
> if (cpu_has_vmx_msr_bitmap()) {
> loaded_vmcs->msr_bitmap = (unsigned long *)
> diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
> index be93d597306c..79d38f41ef7a 100644
> --- a/arch/x86/kvm/vmx/vmx.h
> +++ b/arch/x86/kvm/vmx/vmx.h
> @@ -492,7 +492,6 @@ struct vmcs *alloc_vmcs_cpu(bool shadow, int cpu, gfp_t flags);
> void free_vmcs(struct vmcs *vmcs);
> int alloc_loaded_vmcs(struct loaded_vmcs *loaded_vmcs);
> void free_loaded_vmcs(struct loaded_vmcs *loaded_vmcs);
> -void loaded_vmcs_init(struct loaded_vmcs *loaded_vmcs);
> void loaded_vmcs_clear(struct loaded_vmcs *loaded_vmcs);
>
> static inline struct vmcs *alloc_vmcs(bool shadow)

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>

--
Vitaly