From patchwork Fri May 17 17:39:25 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 13667269 Received: from mail-yb1-f201.google.com (mail-yb1-f201.google.com [209.85.219.201]) (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 A1B67158DA5 for ; Fri, 17 May 2024 17:41:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715967677; cv=none; b=NbG27b6wU4D+sZzyjgs1HRmnh7XLX1Da/yAxLWmQpuvFaf1F+FVGAVyzdTjs2nriyVeewNEnMTbnfgsR/IGna86pFB+FsWrXKHB9LdrgFWvcP43Bg3FjohfwqGLUvnTK8Y8kstP3OMBQexfT/Sw8d0EiX3vCMMq0i37xH0+b/Kw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715967677; c=relaxed/simple; bh=HOXpaaWb4URCLOevzhjfgICuW5P1mMzaORgDJr4eCpA=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=ukFHwEZLwpMtqJZUNywoszi8Px3+CFYPpnYlczO+YNbkbG3DYIKwHuTL6kSugbMBe4M4VSIrC3IGoNhLzVabBAYgR0/Ky4rIKnb51Xcqhhp2dHi92b+64s6yLaehSGsepXjmGA7rGgF1Jefst1xMk67Djj1f8Gv5WjiBVaeEL+w= 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=S446AXtj; arc=none smtp.client-ip=209.85.219.201 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="S446AXtj" Received: by mail-yb1-f201.google.com with SMTP id 3f1490d57ef6-de603db5d6aso16976236276.2 for ; Fri, 17 May 2024 10:41:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1715967675; x=1716572475; 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=umZiPbHCtUl8z62f2qPaeJm6haB1mlYCdYyI3+ZdsyU=; b=S446AXtjAgp9yV4YKEtnS2cjs4YAEtI49VxxQbizc2tTTO2w605C6RnwNciJNQDhFB 6Xctv6OMD7BOWAeo514/RgH/vO0NkpSxHQBRzoHpf/Wbz2wnRKsbxLUgSMr9/BM37/bo csQrGgxGqKGtyVcZ9BJ5FVW+9DHJNLBCjyJEgQ4pWS4ERfkfbqUF3iCXdM/jp91lCrKS zIETkGNHT7rCR4Rk+YuSLt/AHkVc0LQ+lyjorL5hNZfYNJZpCtLwXDzXL6YNN+BW1QzN pX5kAds46djjM+GRy0haxQmziiheeykgPg7X7Fe6P9SRZagtUft4bNjGZfTHuqQbZJwz 2Tvw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1715967675; x=1716572475; 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=umZiPbHCtUl8z62f2qPaeJm6haB1mlYCdYyI3+ZdsyU=; b=YhIfa/ot6xej5zRUxpqICiURDkOAFFnLc64nElGOFhRnka9NBj/+nr556za7Lk2RRT eX+rwwS/0cxQ0U3tSUrUpfv6Pt2WRkW5PuJqh0Jcey4iUSz/lXIfsR3C5YQKsRouDDQV xLKkzYPTrcnf3FqT66iIsv2V+sExYXgKiohz7b/x82/BmR4ccY9W2SCuYFYX6X3pZoSr rMmK8sMRw4VQtJtEX1u37+zC2OTXeiJz7RM+AbBOvQjL5RQ64gSqicHeHa0qlzMRjeHR RsornULI4gNdvywbY8nqVfimmHiekPOGebyOuXnsKfzjxpEzE/tV3eEn97Bo879UbDKO aM1w== X-Gm-Message-State: AOJu0Yz4NhFyrOkAKRbcAXgLAR+3nYB4Ks6CITJ58V9oZbX/+geUA9Cr QB5kAdZjUVyE1+CEL/akiynpNvzDTVYcvj3aXrL/iC+RaNUmQLruyhQ/JEGZ3aP+XgLH9Nwqykd QxQ== X-Google-Smtp-Source: AGHT+IEPEqbWQHead2/pqOJL8nUxVfuxKMTJB//+1VN8NOCh7DLAMpZPdi73AneodpvlwKjwt0xMHo7GzOw= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a25:d8d4:0:b0:de4:e042:eee9 with SMTP id 3f1490d57ef6-dee4f2e9594mr5191794276.6.1715967674621; Fri, 17 May 2024 10:41:14 -0700 (PDT) Reply-To: Sean Christopherson Date: Fri, 17 May 2024 10:39:25 -0700 In-Reply-To: <20240517173926.965351-1-seanjc@google.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240517173926.965351-1-seanjc@google.com> X-Mailer: git-send-email 2.45.0.215.g3402c0e53f-goog Message-ID: <20240517173926.965351-49-seanjc@google.com> Subject: [PATCH v2 48/49] KVM: x86: Add a macro for features that are synthesized into boot_cpu_data From: Sean Christopherson To: Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Hou Wenlong , Kechen Lu , Oliver Upton , Maxim Levitsky , Binbin Wu , Yang Weijiang , Robert Hoo Add yet another CPUID macro, this time for features that the host kernel synthesizes into boot_cpu_data, i.e. that the kernel force sets even in situations where the feature isn't reported by CPUID. Thanks to the macro shenanigans of kvm_cpu_cap_init(), such features can now be handled in the core CPUID framework, i.e. don't need to be handled out-of-band and thus without as many guardrails. Adding a dedicated macro also helps document what's going on, e.g. the calls to kvm_cpu_cap_check_and_set() are very confusing unless the reader knows exactly how kvm_cpu_cap_init() generates kvm_cpu_caps (and even then, it's far from obvious). Signed-off-by: Sean Christopherson --- arch/x86/kvm/cpuid.c | 22 ++++++++++++++++------ 1 file changed, 16 insertions(+), 6 deletions(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 0130e0677387..0e64a6332052 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -106,6 +106,17 @@ u32 xstate_required_size(u64 xstate_bv, bool compacted) F(name); \ }) +/* + * Synthesized Feature - For features that are synthesized into boot_cpu_data, + * i.e. may not be present in the raw CPUID, but can still be advertised to + * userspace. Primarily used for mitigation related feature flags. + */ +#define SYN_F(name) \ +({ \ + kvm_cpu_cap_synthesized |= F(name); \ + F(name); \ +}) + /* * Aliased Features - For features in 0x8000_0001.EDX that are duplicates of * identical 0x1.EDX features, and thus are aliased from 0x1 to 0x8000_0001. @@ -727,13 +738,15 @@ do { \ const struct cpuid_reg cpuid = x86_feature_cpuid(leaf * 32); \ const u32 __maybe_unused kvm_cpu_cap_init_in_progress = leaf; \ u32 kvm_cpu_cap_emulated = 0; \ + u32 kvm_cpu_cap_synthesized = 0; \ \ if (leaf < NCAPINTS) \ kvm_cpu_caps[leaf] &= (mask); \ else \ kvm_cpu_caps[leaf] = (mask); \ \ - kvm_cpu_caps[leaf] &= raw_cpuid_get(cpuid); \ + kvm_cpu_caps[leaf] &= (raw_cpuid_get(cpuid) | \ + kvm_cpu_cap_synthesized); \ kvm_cpu_caps[leaf] |= kvm_cpu_cap_emulated; \ } while (0) @@ -913,13 +926,10 @@ void kvm_set_cpu_caps(void) kvm_cpu_cap_init(CPUID_8000_0021_EAX, F(NO_NESTED_DATA_BP) | F(LFENCE_RDTSC) | 0 /* SmmPgCfgLock */ | F(NULL_SEL_CLR_BASE) | F(AUTOIBRS) | 0 /* PrefetchCtlMsr */ | - F(WRMSR_XX_BASE_NS) + F(WRMSR_XX_BASE_NS) | SYN_F(SBPB) | SYN_F(IBPB_BRTYPE) | + SYN_F(SRSO_NO) ); - kvm_cpu_cap_check_and_set(X86_FEATURE_SBPB); - kvm_cpu_cap_check_and_set(X86_FEATURE_IBPB_BRTYPE); - kvm_cpu_cap_check_and_set(X86_FEATURE_SRSO_NO); - kvm_cpu_cap_init(CPUID_8000_0022_EAX, F(PERFMON_V2) );