From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f201.google.com (mail-pg1-f201.google.com [209.85.215.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1B4A4296163 for ; Tue, 10 Jun 2025 23:20:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749597623; cv=none; b=NZH6VQI49Q9dnBouKGfQMZAD7T19gZqYJCl7i8QtpCthq9S/UNE32Q54lMupeOYJcPh+TmsX8H7ccgZxfyE4r7rIwrv688vXl8x0Qo7JsEqfNeJEsDeMSapetUxg5DGXrFluOqzh8CxC6I22nWnVEaPdVORsM/cCYyuBvdOEV5o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749597623; c=relaxed/simple; bh=d6ch4wFyzgD/snzZgnO2eV+6ES7j1OumzJhm7QshG3Q=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=Y8Fm2ITNZEHAWBDd2ElQmJtIMfShwLEddCmxm8F+lYV3alh6u1umo64iHuc1Mri3ff4YzNKW09yZcOy41ljO1KNcXgzSqhWCF4qEscWGEch5PTxr6EWkpAIEix8y+0Z8aGrA4jxBxteA9f2xoAsC2XLwe0RwM4EEXQgqCWb/KBg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=Sd6763k8; arc=none smtp.client-ip=209.85.215.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Sd6763k8" Received: by mail-pg1-f201.google.com with SMTP id 41be03b00d2f7-b2fa1a84565so2085891a12.1 for ; Tue, 10 Jun 2025 16:20:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1749597621; x=1750202421; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:from:to:cc:subject:date:message-id:reply-to; bh=HHsuZnF4V8CqTjAQoLQV6ObUx/gLCkMj4Na53qEjTK8=; b=Sd6763k879hkqyUR5tOqLpcJAAa1leLxkbn91nPI31pl2AviKwUift7cMnEppxNLT2 mNcxWOCLtZvkVZGCn5RDSVU03uLn3kviTepROplSNu8LbuG6qSUeoIwQcSko+F7B5+vP KC1D5DQKew0hAfoiXwGj55rBNirIjODeKgmABWvsBxjDMVlZUqznNoonCjSPrwI5buM8 dskmcnObbJPI0w2gFScSDk3tX9BAUKEkfSKKZx36+dpw5IBDFd0tZIZXv+SGwncRzrbx JUVAKPe916vUidiPcM8MvqDX2BKYdOWdP3R1yEikgHNUOFk2JW3B1Tzd/HJS4QQ6BUM5 9SCA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1749597621; x=1750202421; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=HHsuZnF4V8CqTjAQoLQV6ObUx/gLCkMj4Na53qEjTK8=; b=WBWux1E4ndg6xk/4/u5YoA2wurxilw2Yk/8PwBqlnAKmQsOdKOwMgCj8btdgBEv10r OYgE5B6PbT2rQH34+557pr3vqz4O2SopJSpZaXXfDqfwIr6kRdYdC8DRMYM3GtI/qCTm Iz1w61XTrt/+ZixoJ/Yk6qti6rpAF72MLEwAzc5Gcguu2PFZE5laJTcwoQIj/WqYAXqI 4rsaeR2uCiFi4Qig5fHkjaPpt7dF+YKA4IIqxKhQMJOjQps7WT/LF4qY8A7bbOKlJ1Ob 1J/3CmizM/onFOMNyNe6bd2eAoutcdjkeV176XKTN+SZeTXPX9HYMsZYZpavJgQZU8pU aHtQ== X-Gm-Message-State: AOJu0Yybk3fH86ROjEmVPM6siue0/uuV9pt5D82NHyHBHBM9w2dNZwa7 uKl3Lgv4zwbXypRg8fu9PE4aO2B3e15hI/XAGaOIF7W5SuQyPba9E396Yn7V0bX6HBEYoOZACAG 7CZwa4Q== X-Google-Smtp-Source: AGHT+IE421/JEGwRo8d9Ea0QC6Ps3NvN/Iwm9+D8SNEcgSRCuj3kTU86U0uXrHJRxcs4U5fyl1urJM88xFg= X-Received: from plbmt8.prod.google.com ([2002:a17:903:b08:b0:235:c96e:dd92]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:902:d4cc:b0:234:f4da:7eed with SMTP id d9443c01a7336-236426b5630mr8666335ad.44.1749597621540; Tue, 10 Jun 2025 16:20:21 -0700 (PDT) Reply-To: Sean Christopherson Date: Tue, 10 Jun 2025 16:20:07 -0700 In-Reply-To: <20250610232010.162191-1-seanjc@google.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250610232010.162191-1-seanjc@google.com> X-Mailer: git-send-email 2.50.0.rc0.642.g800a2b2222-goog Message-ID: <20250610232010.162191-6-seanjc@google.com> Subject: [PATCH v6 5/8] KVM: VMX: Extract checking of guest's DEBUGCTL into helper From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Adrian Hunter , Maxim Levitsky Content-Type: text/plain; charset="UTF-8" Move VMX's logic to check DEBUGCTL values into a standalone helper so that the code can be used by nested VM-Enter to apply the same logic to the value being loaded from vmcs12. KVM needs to explicitly check vmcs12->guest_ia32_debugctl on nested VM-Enter, as hardware may support features that KVM does not, i.e. relying on hardware to detect invalid guest state will result in false negatives. Unfortunately, that means applying KVM's funky suppression of BTF and LBR to vmcs12 so as not to break existing guests. No functional change intended. Signed-off-by: Sean Christopherson --- arch/x86/kvm/vmx/vmx.c | 29 +++++++++++++++++------------ 1 file changed, 17 insertions(+), 12 deletions(-) diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index ab5c742db140..358c7036272a 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -2191,6 +2191,19 @@ static u64 vmx_get_supported_debugctl(struct kvm_vcpu *vcpu, bool host_initiated return debugctl; } +static bool vmx_is_valid_debugctl(struct kvm_vcpu *vcpu, u64 data, + bool host_initiated) +{ + u64 invalid; + + invalid = data & ~vmx_get_supported_debugctl(vcpu, host_initiated); + if (invalid & (DEBUGCTLMSR_BTF|DEBUGCTLMSR_LBR)) { + kvm_pr_unimpl_wrmsr(vcpu, MSR_IA32_DEBUGCTLMSR, data); + invalid &= ~(DEBUGCTLMSR_BTF|DEBUGCTLMSR_LBR); + } + return !invalid; +} + /* * Writes msr value into the appropriate "register". * Returns 0 on success, non-0 otherwise. @@ -2259,19 +2272,12 @@ int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) } vmcs_writel(GUEST_SYSENTER_ESP, data); break; - case MSR_IA32_DEBUGCTLMSR: { - u64 invalid; - - invalid = data & ~vmx_get_supported_debugctl(vcpu, msr_info->host_initiated); - if (invalid & (DEBUGCTLMSR_BTF|DEBUGCTLMSR_LBR)) { - kvm_pr_unimpl_wrmsr(vcpu, msr_index, data); - data &= ~(DEBUGCTLMSR_BTF|DEBUGCTLMSR_LBR); - invalid &= ~(DEBUGCTLMSR_BTF|DEBUGCTLMSR_LBR); - } - - if (invalid) + case MSR_IA32_DEBUGCTLMSR: + if (!vmx_is_valid_debugctl(vcpu, data, msr_info->host_initiated)) return 1; + data &= vmx_get_supported_debugctl(vcpu, msr_info->host_initiated); + if (is_guest_mode(vcpu) && get_vmcs12(vcpu)->vm_exit_controls & VM_EXIT_SAVE_DEBUG_CONTROLS) get_vmcs12(vcpu)->guest_ia32_debugctl = data; @@ -2281,7 +2287,6 @@ int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) (data & DEBUGCTLMSR_LBR)) intel_pmu_create_guest_lbr_event(vcpu); return 0; - } case MSR_IA32_BNDCFGS: if (!kvm_mpx_supported() || (!msr_info->host_initiated && -- 2.50.0.rc0.642.g800a2b2222-goog