From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:53512 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389765AbeHNUTp (ORCPT ); Tue, 14 Aug 2018 16:19:45 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Thomas Gleixner , Jiri Kosina , Josh Poimboeuf Subject: [PATCH 4.17 67/97] x86/kvm: Add static key for flush always Date: Tue, 14 Aug 2018 19:17:19 +0200 Message-Id: <20180814171435.698618346@linuxfoundation.org> In-Reply-To: <20180814171433.160434170@linuxfoundation.org> References: <20180814171433.160434170@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Thomas Gleixner commit 4c6523ec59fe895ea352a650218a6be0653910b1 upstream Avoid the conditional in the L1D flush control path. Signed-off-by: Thomas Gleixner Tested-by: Jiri Kosina Reviewed-by: Greg Kroah-Hartman Reviewed-by: Josh Poimboeuf Link: https://lkml.kernel.org/r/20180713142322.790914912@linutronix.de Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/vmx.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -192,6 +192,7 @@ module_param(ple_window_max, uint, 0444) extern const ulong vmx_return; static DEFINE_STATIC_KEY_FALSE(vmx_l1d_should_flush); +static DEFINE_STATIC_KEY_FALSE(vmx_l1d_flush_always); /* Storage for pre module init parameter parsing */ static enum vmx_l1d_flush_state __read_mostly vmentry_l1d_flush_param = VMENTER_L1D_FLUSH_AUTO; @@ -232,8 +233,12 @@ static int vmx_setup_l1d_flush(enum vmx_ l1tf_vmx_mitigation = l1tf; - if (l1tf != VMENTER_L1D_FLUSH_NEVER) - static_branch_enable(&vmx_l1d_should_flush); + if (l1tf == VMENTER_L1D_FLUSH_NEVER) + return 0; + + static_branch_enable(&vmx_l1d_should_flush); + if (l1tf == VMENTER_L1D_FLUSH_ALWAYS) + static_branch_enable(&vmx_l1d_flush_always); return 0; } @@ -9421,7 +9426,6 @@ static void *vmx_l1d_flush_pages; static void vmx_l1d_flush(struct kvm_vcpu *vcpu) { int size = PAGE_SIZE << L1D_CACHE_ORDER; - bool always; /* * This code is only executed when the the flush mode is 'cond' or @@ -9431,8 +9435,10 @@ static void vmx_l1d_flush(struct kvm_vcp * it. The flush bit gets set again either from vcpu_run() or from * one of the unsafe VMEXIT handlers. */ - always = l1tf_vmx_mitigation == VMENTER_L1D_FLUSH_ALWAYS; - vcpu->arch.l1tf_flush_l1d = always; + if (static_branch_unlikely(&vmx_l1d_flush_always)) + vcpu->arch.l1tf_flush_l1d = true; + else + vcpu->arch.l1tf_flush_l1d = false; vcpu->stat.l1d_flush++;