From patchwork Sat Oct 9 09:08:50 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wanpeng Li X-Patchwork-Id: 12547365 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 87B52C433EF for ; Sat, 9 Oct 2021 09:09:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 61FA260E90 for ; Sat, 9 Oct 2021 09:09:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232912AbhJIJLm (ORCPT ); Sat, 9 Oct 2021 05:11:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44632 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229995AbhJIJLk (ORCPT ); Sat, 9 Oct 2021 05:11:40 -0400 Received: from mail-pl1-x631.google.com (mail-pl1-x631.google.com [IPv6:2607:f8b0:4864:20::631]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 18D6DC061570; Sat, 9 Oct 2021 02:09:44 -0700 (PDT) Received: by mail-pl1-x631.google.com with SMTP id 21so1515973plo.13; Sat, 09 Oct 2021 02:09:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id; bh=M1+1Yip8GFzyYIhL8WE/3+73lyzOVhHwNfK4uPgNVUA=; b=TxSfJMqva34WyinV6SrFZjI5WJv0mm07cxZh6lItXh62PrHp4Bkd98w8qgxkp+rjbG HYRbyRgaJhwbNknvStXuWi1LiAzfeCL79jsYMS8idExfOSZuGhCWBgzxK2fEqJi3WLmS uwr9/WTrtCwB6tszb4RsLpi9Wq+4pwkGY9pASkRbGJiKbwMBkmT2VWa7UYSouOXDvBo4 5wLAy4i7jN0q315/BmUWl07SWi6OO7VmVAOmuk8Mr/CmTZExrQFAulRzxCZiLvAa2xyr W57aXDUYj/9q3b1QXDaRGNGj1iLHftBuwujKOLkzzJP66QLIKc18VBGqlUT35xtQut3y 0LoQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=M1+1Yip8GFzyYIhL8WE/3+73lyzOVhHwNfK4uPgNVUA=; b=cdxnXG2dFEVZ3y0hlNh/tqOzB/DEGZ/HlBGUefEPkDMQnV8H35FKw07Nxs1N+OH+xR xj70oe8RzzOn4jrskWM/fJ8HuTRdsVGHS3XzdqWer6qa6RAiqrOI7PhE0UTnTqoY0lFC OFp3y1NtYBwIZB8e4fJFQIw+RzJHTYC7zXMtKnRRH2K1kJVgpnK8LiiYcQCfKAE436N+ 0WGZfYQH2TruvJJFhnCzLtrpqLkZr5RZhnYKRDcR6AUbnmBhXVtW1Cd1d3ZmFjzPlq+R hjFI8w+B0mnbGQHYbyyflgTZ68P/S8dsBfnNfXGmfAZjdRtLn0GHxwGSADowZWaTHlY5 aFkg== X-Gm-Message-State: AOAM530g0/smLwdSuO5PNrpUyZWVzJa4v41L/kvQwwFyEnPFY2QjLGsv 3bNazWc4h4vhMRDQ8gnxD+sqtOG5xKe7hg== X-Google-Smtp-Source: ABdhPJyXHBkNsEKax9+c6M7O7P32Le6wJOSQyZb+99ByoVuaqqf2Uj+vgntwbdGdKhQMza9tc2lVaA== X-Received: by 2002:a17:90a:1a06:: with SMTP id 6mr17862330pjk.150.1633770583346; Sat, 09 Oct 2021 02:09:43 -0700 (PDT) Received: from localhost.localdomain ([203.205.141.112]) by smtp.googlemail.com with ESMTPSA id u2sm13607217pji.30.2021.10.09.02.09.40 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Sat, 09 Oct 2021 02:09:43 -0700 (PDT) From: Wanpeng Li X-Google-Original-From: Wanpeng Li To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel Subject: [PATCH v2 1/3] KVM: emulate: Don't inject #GP when emulating RDMPC if CR0.PE=0 Date: Sat, 9 Oct 2021 02:08:50 -0700 Message-Id: <1633770532-23664-1-git-send-email-wanpengli@tencent.com> X-Mailer: git-send-email 2.7.4 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Wanpeng Li DM mentioned that, RDPMC: IF (((CR4.PCE = 1) or (CPL = 0) or (CR0.PE = 0)) and (ECX indicates a supported counter)) THEN EAX := counter[31:0]; EDX := ZeroExtend(counter[MSCB:32]); ELSE (* ECX is not valid or CR4.PCE is 0 and CPL is 1, 2, or 3 and CR0.PE is 1 *) #GP(0); FI; Let's add the CR0.PE is 1 checking to rdpmc emulate, though this isn't strictly necessary since it's impossible for CPL to be >0 if CR0.PE=0. Signed-off-by: Wanpeng Li Reviewed-by: Sean Christopherson --- v1 -> v2: * update patch description arch/x86/kvm/emulate.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 9a144ca8e146..ab7ec569e8c9 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -4213,6 +4213,7 @@ static int check_rdtsc(struct x86_emulate_ctxt *ctxt) static int check_rdpmc(struct x86_emulate_ctxt *ctxt) { u64 cr4 = ctxt->ops->get_cr(ctxt, 4); + u64 cr0 = ctxt->ops->get_cr(ctxt, 0); u64 rcx = reg_read(ctxt, VCPU_REGS_RCX); /* @@ -4222,7 +4223,7 @@ static int check_rdpmc(struct x86_emulate_ctxt *ctxt) if (enable_vmware_backdoor && is_vmware_backdoor_pmc(rcx)) return X86EMUL_CONTINUE; - if ((!(cr4 & X86_CR4_PCE) && ctxt->ops->cpl(ctxt)) || + if ((!(cr4 & X86_CR4_PCE) && ctxt->ops->cpl(ctxt) && (cr0 & X86_CR0_PE)) || ctxt->ops->check_pmc(ctxt, rcx)) return emulate_gp(ctxt, 0); From patchwork Sat Oct 9 09:08:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wanpeng Li X-Patchwork-Id: 12547367 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B00C2C433EF for ; Sat, 9 Oct 2021 09:09:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8BC9760E90 for ; Sat, 9 Oct 2021 09:09:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244317AbhJIJLo (ORCPT ); Sat, 9 Oct 2021 05:11:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44640 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244305AbhJIJLn (ORCPT ); Sat, 9 Oct 2021 05:11:43 -0400 Received: from mail-pj1-x102c.google.com (mail-pj1-x102c.google.com [IPv6:2607:f8b0:4864:20::102c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A64DAC061570; Sat, 9 Oct 2021 02:09:46 -0700 (PDT) Received: by mail-pj1-x102c.google.com with SMTP id ls18so9344660pjb.3; Sat, 09 Oct 2021 02:09:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=wuqphgKvr5OKJUpCclpJueDTJYxdQ5QHiNBmL1E9oj4=; b=e549eoABPAYOULGwuz5cXPZ8pUpri7ZPQiMo/32Ts16+KXghaviDkl/05Lq0j9onmm HtORzXLjbS7JQwJ7B+/KJbyU24I1NJox0LLNe/1U/mlFUTQylIf2lPyxLXK1umXk1eCP jomZeTVU/u4tZYJgAvfJcnVAFL+ttS+TkvvEqdkX/8Xvp7BiigByJNqVWG4rVsp+Cqn/ 8/VhjN99qEZNqwK9ez6lBXYR42OyM9n/u56QSwI0V+PKLrZ/cU7jUu6Ey+Bpvb1iZrA+ KO7upaTvdZe9rpDm9tn4bbJ/IK4Wd0eibOdz3GGTCdtlBI8Lu8CAV2LF62cGpEaNq3CB NErg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=wuqphgKvr5OKJUpCclpJueDTJYxdQ5QHiNBmL1E9oj4=; b=JNvjRz73zLGKfZF6pYQ4dsF8TpHuAof7cbZqdrRmKM0A9qnEJSdScb8XrbGhvAyMtA qDhh6gZxMDH11nXWrlPRCSqbFwsHiJuWVsD53GdL/0lxb3/KCV0W9TZvMrN6a0/Otvgo p1sGRL567SdEFRDcyrABHt0kbTW4ZwrSiVIw6ZKa0+yPGWl/XlRXqPG44tVrcj08iab+ Sjlex//z6RNGBWyEIwAi+CO9XWhPjDe6THzUnBKJkvarGL+t4TyUCNLnElOAFxHPJkpy ptpcujZNeAqs0m9mzgBwwIiiiiiUmvC1JghexU/wGIKr5Wtb5JM77nCedkMKzTnyacFB ooRA== X-Gm-Message-State: AOAM5300kojXVdc93l8ydU7rLjwJMzNbCVGOolblEWz/YWO9P9OCNWry 5S0jx6dyhTGbu42gFKYot8xkTJJ4H28GDw== X-Google-Smtp-Source: ABdhPJzGRfiHAAak1Nm3nyjyGOuhSPnoY4eVJXfgeoMzXVoNt3eLBi192f3jpWB/begGfykx14NyJg== X-Received: by 2002:a17:90b:248:: with SMTP id fz8mr8349986pjb.157.1633770585982; Sat, 09 Oct 2021 02:09:45 -0700 (PDT) Received: from localhost.localdomain ([203.205.141.112]) by smtp.googlemail.com with ESMTPSA id u2sm13607217pji.30.2021.10.09.02.09.43 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Sat, 09 Oct 2021 02:09:45 -0700 (PDT) From: Wanpeng Li X-Google-Original-From: Wanpeng Li To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel Subject: [PATCH v2 2/3] KVM: vPMU: Fill get_msr MSR_CORE_PERF_GLOBAL_OVF_CTRL w/ 0 Date: Sat, 9 Oct 2021 02:08:51 -0700 Message-Id: <1633770532-23664-2-git-send-email-wanpengli@tencent.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1633770532-23664-1-git-send-email-wanpengli@tencent.com> References: <1633770532-23664-1-git-send-email-wanpengli@tencent.com> Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Wanpeng Li SDM section 18.2.3 mentioned that: "IA32_PERF_GLOBAL_OVF_CTL MSR allows software to clear overflow indicator(s) of any general-purpose or fixed-function counters via a single WRMSR." It is R/W mentioned by SDM, we read this msr on bare-metal during perf testing, the value is always 0 for ICX/SKX boxes on hands. Let's fill get_msr MSR_CORE_PERF_GLOBAL_OVF_CTRL w/ 0 as hardware behavior and drop global_ovf_ctrl variable. Tested-by: Like Xu Signed-off-by: Wanpeng Li --- v1 -> v2: * drop 'u64 global_ovf_ctrl' directly arch/x86/include/asm/kvm_host.h | 1 - arch/x86/kvm/vmx/pmu_intel.c | 6 ++---- 2 files changed, 2 insertions(+), 5 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index f8f48a7ec577..7aaac918e992 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -499,7 +499,6 @@ struct kvm_pmu { u64 fixed_ctr_ctrl; u64 global_ctrl; u64 global_status; - u64 global_ovf_ctrl; u64 counter_bitmask[2]; u64 global_ctrl_mask; u64 global_ovf_ctrl_mask; diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c index 10cc4f65c4ef..b8e0d21b7c8a 100644 --- a/arch/x86/kvm/vmx/pmu_intel.c +++ b/arch/x86/kvm/vmx/pmu_intel.c @@ -365,7 +365,7 @@ static int intel_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) msr_info->data = pmu->global_ctrl; return 0; case MSR_CORE_PERF_GLOBAL_OVF_CTRL: - msr_info->data = pmu->global_ovf_ctrl; + msr_info->data = 0; return 0; default: if ((pmc = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0)) || @@ -423,7 +423,6 @@ static int intel_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) if (!(data & pmu->global_ovf_ctrl_mask)) { if (!msr_info->host_initiated) pmu->global_status &= ~data; - pmu->global_ovf_ctrl = data; return 0; } break; @@ -588,8 +587,7 @@ static void intel_pmu_reset(struct kvm_vcpu *vcpu) pmc->counter = 0; } - pmu->fixed_ctr_ctrl = pmu->global_ctrl = pmu->global_status = - pmu->global_ovf_ctrl = 0; + pmu->fixed_ctr_ctrl = pmu->global_ctrl = pmu->global_status = 0; intel_pmu_release_guest_lbr_event(vcpu); } From patchwork Sat Oct 9 09:08:52 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wanpeng Li X-Patchwork-Id: 12547369 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E0599C433F5 for ; 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Sat, 09 Oct 2021 02:09:48 -0700 (PDT) Received: from localhost.localdomain ([203.205.141.112]) by smtp.googlemail.com with ESMTPSA id u2sm13607217pji.30.2021.10.09.02.09.46 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Sat, 09 Oct 2021 02:09:48 -0700 (PDT) From: Wanpeng Li X-Google-Original-From: Wanpeng Li To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel Subject: [PATCH v2 3/3] KVM: vCPU kick tax cut for running vCPU Date: Sat, 9 Oct 2021 02:08:52 -0700 Message-Id: <1633770532-23664-3-git-send-email-wanpengli@tencent.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1633770532-23664-1-git-send-email-wanpengli@tencent.com> References: <1633770532-23664-1-git-send-email-wanpengli@tencent.com> Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Wanpeng Li Sometimes a vCPU kick is following a pending request, even if @vcpu is the running vCPU. It suffers from both rcuwait_wake_up() which has rcu/memory barrier operations and cmpxchg(). Let's check vcpu->wait before rcu_wait_wake_up() and whether @vcpu is the running vCPU before cmpxchg() to tax cut this overhead. We evaluate the kvm-unit-test/vmexit.flat on an Intel ICX box, most of the scores can improve ~600 cpu cycles especially when APICv is disabled. tscdeadline_immed tscdeadline self_ipi_sti_nop .............. x2apic_self_ipi_tpr_sti_hlt Suggested-by: Sean Christopherson Signed-off-by: Wanpeng Li --- v1 -> v2: * move checking running vCPU logic to kvm_vcpu_kick * check rcuwait_active(&vcpu->wait) etc virt/kvm/kvm_main.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 7851f3a1b5f7..18209d7b3711 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -3314,8 +3314,15 @@ void kvm_vcpu_kick(struct kvm_vcpu *vcpu) { int me, cpu; - if (kvm_vcpu_wake_up(vcpu)) - return; + me = get_cpu(); + + if (rcuwait_active(&vcpu->wait) && kvm_vcpu_wake_up(vcpu)) + goto out; + + if (vcpu == __this_cpu_read(kvm_running_vcpu)) { + WARN_ON_ONCE(vcpu->mode == IN_GUEST_MODE); + goto out; + } /* * Note, the vCPU could get migrated to a different pCPU at any point @@ -3324,12 +3331,12 @@ void kvm_vcpu_kick(struct kvm_vcpu *vcpu) * IPI is to force the vCPU to leave IN_GUEST_MODE, and migrating the * vCPU also requires it to leave IN_GUEST_MODE. */ - me = get_cpu(); if (kvm_arch_vcpu_should_kick(vcpu)) { cpu = READ_ONCE(vcpu->cpu); if (cpu != me && (unsigned)cpu < nr_cpu_ids && cpu_online(cpu)) smp_send_reschedule(cpu); } +out: put_cpu(); } EXPORT_SYMBOL_GPL(kvm_vcpu_kick);