From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f202.google.com (mail-pg1-f202.google.com [209.85.215.202]) (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 E7FA426B955 for ; Mon, 20 Oct 2025 16:34:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760978084; cv=none; b=hej1Sz/nhABy7FwGbJrjJEP6o6p/sYu7yFhMd5hMvs7CBB5O2Z0BYd87ZKGZFdUgzRsN9XfRZiE3QgqnS1Jy7xok+2XHZKVJpt3PINUOACotTeIcnlUIh6vTeEydxlad86MMtYh20ATyuq0L+gu1T9qbevchAskunDp2wxEtKIk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760978084; c=relaxed/simple; bh=EKnvTmQWXIb3QulB8OxEwhVGwFls1eJdoaM7jZiZ60E=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=FCMbYwiZaz5HMBcRqs8nyL0yE3KwqYGramzRoEuetW8vB2kYXNYUMT0Feqp0mWHiUultXpPPYgS74m5HOqp35DHvJNEZHaT+NbYeJDCLveCgNl5/XYKnGCSfdVxA0C/FPVRmyCx+6Xph+drsKP7/dv8mTEBxKnc0iswWUOG/eP0= 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=n/dXFgmu; arc=none smtp.client-ip=209.85.215.202 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="n/dXFgmu" Received: by mail-pg1-f202.google.com with SMTP id 41be03b00d2f7-b55443b4110so3355832a12.1 for ; Mon, 20 Oct 2025 09:34:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1760978082; x=1761582882; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=fp2M7y/YIkoquLfcKGxuSyhApeoEnp7Mnl/v7xe2miU=; b=n/dXFgmuWRvUCLuK+lHCZg5+/VHIUUtOdcpfm3hyZK6D/T0AI4whW7uN/7Jh5+j4H4 c2Q3NBuNAaCs5fauwCaRVnh8z44w+rPA1PDHgiVKT7QHMLJbvssvG7fOPU4k5LkYh68z cVhtrXeQSNIPCwGI9uCm47xpOKrNi4be5dMOQtGrpNwclgk2g9Kk9SHUsvthFExr8li7 5zsLK+eJTm8WbFl234DRqicsfry+ExMCPnq+xBuAEEl3cY+eNkBNOlVeaUcyQqL66iM+ CaiagWinsdl17qr51+n5dbw3N++X+nsZjQ8FqCRtMzKsabF4/uYYeqN18kHc4oD3COq1 oH3A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1760978082; x=1761582882; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=fp2M7y/YIkoquLfcKGxuSyhApeoEnp7Mnl/v7xe2miU=; b=t+s4CDAdEAKS5PGwXQyBU8oJqGcrKlEr3eswy5N7tAthJuyvObt7VOr1UZ7jj40Dvw HYZNnhW5X4C43ARroCXTevC3ewoj2inb2t4KQ2cUXJsvTAh4czGO4X6OVnvFpsKGHSgb Z/04qwqnb0oqLHm4IYq0PigVUrZYfBt/bvhEJ//tEnACAxPnU/iy2938KDK7FI40FcOS 0xV4AYVOGVFG6bogvQdj+psgq6ypwUbbVlj8pcpN4e4TcGcbMaK7+l70uxTFTZyGIr6M DvLFxZrDtibw6oBSB/pz8KVklX57K2xqJsRv9rZrkPcNDCYqh3X7cUGZolcSRPV71ciC Bm7w== X-Forwarded-Encrypted: i=1; AJvYcCUXEssv/Te9shUet8FoYgfzaCal8V4MJlHLgXHLa7der75O2I5ZBg69ZI3wfWirS6QuGZ5OTpkK0I82W/E=@vger.kernel.org X-Gm-Message-State: AOJu0YyWYpHDBz48mMXlcGuowGbIH7eJx0aAiaeEDgLwDWXc4k2aq/pk lDa4vwMk6K0wOsyR0/qgtZ2LmHartgWzRH/GK8VceG5TP0yMwEOI/RFMtCWONsTGl4fIH1Gzbqh 15ewSUQ== X-Google-Smtp-Source: AGHT+IEfJBrBNRQn8+cn6fgmQOnDkh3t6dmbXJnUtpRU+T1/SW9hG6iOheIivj/skyPPBe7GkdNTpM1ILXI= X-Received: from pjzj22.prod.google.com ([2002:a17:90a:eb16:b0:338:3770:a496]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a21:32a3:b0:32d:95f2:1fe with SMTP id adf61e73a8af0-334a786492fmr18401737637.2.1760978082232; Mon, 20 Oct 2025 09:34:42 -0700 (PDT) Date: Mon, 20 Oct 2025 09:33:11 -0700 In-Reply-To: <20250919005955.1366256-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250919005955.1366256-1-seanjc@google.com> X-Mailer: git-send-email 2.51.0.869.ge66316f041-goog Message-ID: <176097600449.438961.7346944615480363146.b4-ty@google.com> Subject: Re: [PATCH 0/9] KVM: VMX: EPTP cleanups and nVMX fixes From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" On Thu, 18 Sep 2025 17:59:46 -0700, Sean Christopherson wrote: > This started as a trivial series to cleanup KVM's handling of EPTPs in > anticipation of eliding TLB flushes on task migration[*], but then I made the > mistake of trying to test the nested_early_check change, and things snowballed. > > Long story short, nested_early_check is obviously not being used as it's been > broken for years, and it's not adding value. E.g. doesn't help us find KVM > bugs, and doesn't provide any meaningful protection for KVM (especially since > no one is using it). > > [...] Applied to kvm-x86 vmx, thanks! [1/9] KVM: VMX: Hoist construct_eptp() "up" in vmx.c https://github.com/kvm-x86/linux/commit/f48888bb8ad1 [2/9] KVM: nVMX: Hardcode dummy EPTP used for early nested consistency checks https://github.com/kvm-x86/linux/commit/a8749281e4c6 [3/9] KVM: x86/mmu: Move "dummy root" helpers to spte.h https://github.com/kvm-x86/linux/commit/a10f5cc3ac9b [4/9] KVM: VMX: Use kvm_mmu_page role to construct EPTP, not current vCPU state https://github.com/kvm-x86/linux/commit/2f723a863423 [5/9] KVM: nVMX: Add consistency check for TPR_THRESHOLD[31:4]!=0 without VID https://github.com/kvm-x86/linux/commit/15fe455dd1a0 [6/9] KVM: nVMX: Add consistency check for TSC_MULTIPLIER=0 https://github.com/kvm-x86/linux/commit/ae8e6ad84177 [7/9] KVM: nVMX: Stuff vmcs02.TSC_MULTIPLIER early on for nested early checks https://github.com/kvm-x86/linux/commit/f91699d5692d [8/9] KVM: nVMX: Remove support for "early" consistency checks via hardware https://github.com/kvm-x86/linux/commit/a175da6d430e [9/9] KVM: nVMX: Add an off-by-default module param to WARN on missed consistency checks https://github.com/kvm-x86/linux/commit/1100e4910ad2 -- https://github.com/kvm-x86/linux/tree/next