From patchwork Tue Nov 12 03:34:27 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tianyu Lan X-Patchwork-Id: 11238507 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 52D3B159A for ; Tue, 12 Nov 2019 03:35:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1BA29206C3 for ; Tue, 12 Nov 2019 03:35:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Ar5AXk2p" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726932AbfKLDez (ORCPT ); Mon, 11 Nov 2019 22:34:55 -0500 Received: from mail-pf1-f193.google.com ([209.85.210.193]:36192 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726910AbfKLDez (ORCPT ); Mon, 11 Nov 2019 22:34:55 -0500 Received: by mail-pf1-f193.google.com with SMTP id b19so32067pfd.3 for ; Mon, 11 Nov 2019 19:34:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=RjB3o0NjWZXINNESvPz4COiSojg7wROs/y6CgxKZ/Pw=; b=Ar5AXk2psvjukJXi6gdH+xtvXmPp9uIXKwTYX28+pv4edMenYVt2Q9cSx6Sir1B8To U/Mp7UNwz4u9P6dJcQtjMhdBxKtaekycaC+pbD1ure7q3xluNVB4AY694Wdw5hhbXVnj LCOw7QFIpSTm4GC9WPrTKXscJfsQ5h8EPGAgNsqrxdBSfO9qYez338FgkBWHcDsFytET 4/fJcb2Qp8DPFg75MLd5Ed36cVo8VjZ3GhwtHY9VWQHzYNHgzp95trzk4oApjEOf1+Sv GdWYuiYl0LWZalpZUzwibW2heGA4Ks6Bn4tUENTyBrSlyKKZ4H+7oZX0er/id3Ug2alL KMqw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=RjB3o0NjWZXINNESvPz4COiSojg7wROs/y6CgxKZ/Pw=; b=h4EHiGUUYiOyOK+E+krC5IS4F/Tb3fWcRiBvlz09zFAWeCGjov5PggVDoBYla0FtRv cWzGgRReXQDNt69Ahhr1HBIn7CsXGQkJeiu1Y6wXN3biFfYQqBEGgo/BjPsDyvhCAGXn quYLbseMm3x0ebxr35GHZCL2+VEUArvBg9IUJt+lLcDkx0+gNWAgrF9pqPUMcu/MfbaC 8RX6ymjOcwvoNtv17JeLxzZa7pHYnCcbmqtT3MJP8yx1bPeCMGGB0Ku03I8/0Q1BGlx9 EY2EkJ4/GEDCZGfw7c4csHib9KRIjiXBROqqLXydoLy4bBBcMGedDkK39ZBquZXRaEma tEqg== X-Gm-Message-State: APjAAAXaJtXL7EyYE5ju/mdPqUd1khwcGW2M6jLR0w6k88N0H6KobVoF lsUgN4b9FSWaLRl81b/bdqk= X-Google-Smtp-Source: APXvYqxm3G75qyaUjRQQIkPwyZGO7sh/u2z8W5LqAbtVsVJkIsjXh8sN7kIATp92EqxAESEhDElMYQ== X-Received: by 2002:a65:46c1:: with SMTP id n1mr11037437pgr.257.1573529693925; Mon, 11 Nov 2019 19:34:53 -0800 (PST) Received: from localhost.corp.microsoft.com ([167.220.255.5]) by smtp.googlemail.com with ESMTPSA id f5sm114018pjp.1.2019.11.11.19.34.50 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 11 Nov 2019 19:34:53 -0800 (PST) From: lantianyu1986@gmail.com X-Google-Original-From: Tianyu.Lan@microsoft.com To: pbonzini@redhat.com, rth@twiddle.net, ehabkost@redhat.com, mtosatti@redhat.com, rkagan@virtuozzo.com, vkuznets@redhat.com Cc: Tianyu Lan , qemu-devel@nongnu.org, kvm@vger.kernel.org Subject: [PATCH V4] target/i386/kvm: Add Hyper-V direct tlb flush support Date: Tue, 12 Nov 2019 11:34:27 +0800 Message-Id: <20191112033427.7204-1-Tianyu.Lan@microsoft.com> X-Mailer: git-send-email 2.14.5 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Tianyu Lan Hyper-V direct tlb flush targets KVM on Hyper-V guest. Enable direct TLB flush for its guests meaning that TLB flush hypercalls are handled by Level 0 hypervisor (Hyper-V) bypassing KVM in Level 1. Due to the different ABI for hypercall parameters between Hyper-V and KVM, KVM capabilities should be hidden when enable Hyper-V direct tlb flush otherwise KVM hypercalls may be intercepted by Hyper-V. Add new parameter "hv-direct-tlbflush". Check expose_kvm and Hyper-V tlb flush capability status before enabling the feature. Signed-off-by: Tianyu Lan Reviewed-by: Roman Kagan --- Change since v3: - Fix logic of Hyper-V passthrough mode with direct tlb flush. Change sicne v2: - Update new feature description and name. - Change failure print log. Change since v1: - Add direct tlb flush's Hyper-V property and use hv_cpuid_check_and_set() to check the dependency of tlbflush feature. - Make new feature work with Hyper-V passthrough mode. --- docs/hyperv.txt | 10 ++++++++++ target/i386/cpu.c | 2 ++ target/i386/cpu.h | 1 + target/i386/kvm.c | 24 ++++++++++++++++++++++++ 4 files changed, 37 insertions(+) diff --git a/docs/hyperv.txt b/docs/hyperv.txt index 8fdf25c829..140a5c7e44 100644 --- a/docs/hyperv.txt +++ b/docs/hyperv.txt @@ -184,6 +184,16 @@ enabled. Requires: hv-vpindex, hv-synic, hv-time, hv-stimer +3.18. hv-direct-tlbflush +======================= +Enable direct TLB flush for KVM when it is running as a nested +hypervisor on top Hyper-V. When enabled, TLB flush hypercalls from L2 +guests are being passed through to L0 (Hyper-V) for handling. Due to ABI +differences between Hyper-V and KVM hypercalls, L2 guests will not be +able to issue KVM hypercalls (as those could be mishanled by L0 +Hyper-V), this requires KVM hypervisor signature to be hidden. + +Requires: hv-tlbflush, -kvm 4. Development features ======================== diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 44f1bbdcac..7bc7fee512 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -6156,6 +6156,8 @@ static Property x86_cpu_properties[] = { HYPERV_FEAT_IPI, 0), DEFINE_PROP_BIT64("hv-stimer-direct", X86CPU, hyperv_features, HYPERV_FEAT_STIMER_DIRECT, 0), + DEFINE_PROP_BIT64("hv-direct-tlbflush", X86CPU, hyperv_features, + HYPERV_FEAT_DIRECT_TLBFLUSH, 0), DEFINE_PROP_BOOL("hv-passthrough", X86CPU, hyperv_passthrough, false), DEFINE_PROP_BOOL("check", X86CPU, check_cpuid, true), diff --git a/target/i386/cpu.h b/target/i386/cpu.h index eaa5395aa5..3cb105f7d6 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -907,6 +907,7 @@ typedef uint64_t FeatureWordArray[FEATURE_WORDS]; #define HYPERV_FEAT_EVMCS 12 #define HYPERV_FEAT_IPI 13 #define HYPERV_FEAT_STIMER_DIRECT 14 +#define HYPERV_FEAT_DIRECT_TLBFLUSH 15 #ifndef HYPERV_SPINLOCK_NEVER_RETRY #define HYPERV_SPINLOCK_NEVER_RETRY 0xFFFFFFFF diff --git a/target/i386/kvm.c b/target/i386/kvm.c index 11b9c854b5..43f5cbc3f6 100644 --- a/target/i386/kvm.c +++ b/target/i386/kvm.c @@ -900,6 +900,10 @@ static struct { }, .dependencies = BIT(HYPERV_FEAT_STIMER) }, + [HYPERV_FEAT_DIRECT_TLBFLUSH] = { + .desc = "direct paravirtualized TLB flush (hv-direct-tlbflush)", + .dependencies = BIT(HYPERV_FEAT_TLBFLUSH) + }, }; static struct kvm_cpuid2 *try_get_hv_cpuid(CPUState *cs, int max) @@ -1224,6 +1228,7 @@ static int hyperv_handle_properties(CPUState *cs, r |= hv_cpuid_check_and_set(cs, cpuid, HYPERV_FEAT_EVMCS); r |= hv_cpuid_check_and_set(cs, cpuid, HYPERV_FEAT_IPI); r |= hv_cpuid_check_and_set(cs, cpuid, HYPERV_FEAT_STIMER_DIRECT); + r |= hv_cpuid_check_and_set(cs, cpuid, HYPERV_FEAT_DIRECT_TLBFLUSH); /* Additional dependencies not covered by kvm_hyperv_properties[] */ if (hyperv_feat_enabled(cpu, HYPERV_FEAT_SYNIC) && @@ -1243,6 +1248,25 @@ static int hyperv_handle_properties(CPUState *cs, goto free; } + if (hyperv_feat_enabled(cpu, HYPERV_FEAT_DIRECT_TLBFLUSH)) { + if (kvm_vcpu_enable_cap(cs, KVM_CAP_HYPERV_DIRECT_TLBFLUSH, 0, 0)) { + if (!cpu->hyperv_passthrough) { + fprintf(stderr, + "Hyper-V %s is not supported by kernel\n", + kvm_hyperv_properties[HYPERV_FEAT_DIRECT_TLBFLUSH].desc); + return -ENOSYS; + } + + cpu->hyperv_features &= ~BIT(HYPERV_FEAT_DIRECT_TLBFLUSH); + } else if (cpu->expose_kvm) { + fprintf(stderr, + "Hyper-V %s requires KVM hypervisor signature " + "to be hidden (-kvm).\n", + kvm_hyperv_properties[HYPERV_FEAT_DIRECT_TLBFLUSH].desc); + return -ENOSYS; + } + } + if (cpu->hyperv_passthrough) { /* We already copied all feature words from KVM as is */ r = cpuid->nent;