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 DCFF934D387 for ; Thu, 30 Oct 2025 20:28:32 +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=1761856115; cv=none; b=Wc5SXwocF2cVmsxCGwIL5ACzEaX0wr6qjuHKBPuLCIN5hFwzEqrqScmoBe49kg7LfPsbCoPDNg7JszTXvgVStJzlw/ypik4Nx2iNY26d4+fOxfcSNXPCofA0ZOAxDYnu60cTphzMU9kCdR3ltTlAaXNhCFTwPInR5YcU/o4NLYk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761856115; c=relaxed/simple; bh=H9/xXV6vFX4ZJCIqIxmxB3nw141jB+d1HVL8gk8S4gw=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=CiJK9qksc9KixS5V/faORq9qe0oazu8m2V5puBxgbmtNTUhWPXhF9FWSbYErLQ+f2m28qVXVemM34XuTn6zR2QzIqtkpPQ/OI8/PeLzaedob1XyLH3n1++HOWKkTxTS6dgdVe04ahZO6lCMUhmf+yB/tZucSB18/dTMJNCi7KcI= 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=JXXxgKNO; 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="JXXxgKNO" Received: by mail-pg1-f201.google.com with SMTP id 41be03b00d2f7-b6d0014d416so1057816a12.1 for ; Thu, 30 Oct 2025 13:28:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1761856112; x=1762460912; darn=vger.kernel.org; h=content-transfer-encoding:cc:to:from:subject:message-id:references :mime-version:in-reply-to:date:from:to:cc:subject:date:message-id :reply-to; bh=JYy3lGD2M24oZtXLBqYQjcEVOzmXVwbJ6uDSdSZV2P0=; b=JXXxgKNOSKYHM+LYbEADTlCzoih3ty+Om9hFt0vYbjF9SOsQAPcRWd4ENjcFffNfsX SYiUDkgQg0YgH2vP1lBk8W0cSXH+uJoOica7XxdgaPohWClJmtCRJaJYTORPA5gzedHd vRUwrPOg5IHCrNzPOUxhj8bFjjAXKrCPukPNTYsJt0wpwKYACfuBwVvthdg3OTHQzLsx 6WqWYZNUhgu1M5HSkxmIhUkWSBg278LWMY6mDvU3cV/Stst81Cpr81J3jDHxV22Tl6rf SFiyglwCLMBrS9usvosShv66/ndjPmIMdh3DACf2TT+iKtZd3YlD6qVJrMMJ06rBVipG 7YgA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1761856112; x=1762460912; h=content-transfer-encoding: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=JYy3lGD2M24oZtXLBqYQjcEVOzmXVwbJ6uDSdSZV2P0=; b=NA8E7iqOSmLWyuiBpinCGPd4k5huMvJXlClbh22ltLvvqmWHYbvoXGMhC5a9OeJzYS tUKDjp6gzKQobLypZXOI5hdNRWP2M0eB+rHWBuCULUf/RTwWAQiq9LHFjyWgo2Gb/YSb vqvYNFnq2b+UHg9C3lXFPiUgRR5bE924/jwGCBoVV7BWdzKYn9iXK+wwFFauZD3Qlb6L z8e91erJ+uOzhpBRMEvq69v3tSIuFyCopizbxAJssdLcnFYsIfxdE1ytWXc0HqDo3Bkh ZUMdWYvzZ9CZ3U10Z/cd3MI6Eq07WE6PjEGW8Kv4TCwBo0szdDTvQm4DUl5NYFHo60tX RwWw== X-Forwarded-Encrypted: i=1; AJvYcCXnKyiMvku0wjtye1WF+gptov33rA5+pjgOEsfzEuCv1xoiLBZeozDlPWd+c55Aj0UVGdc=@vger.kernel.org X-Gm-Message-State: AOJu0YxGb0DIo0eRQZpQrj4byEaEZsC8jl6s4jfzaIMkaX6QKU6JTvfF Tb6RINYROQXOd4k/Dx3B3wB4C+O+2VtnozgL8P7W8mQ1VhCu+G6gJHFGVf0tTZvga0S9RfuZwA5 DmQljnA== X-Google-Smtp-Source: AGHT+IE9NYAhKnrJM4tsNmEx9VXdiQTQGHzgV2EPdW1C58528xQJxYi4ip5iQMGXcxcQwvbRV5MRMFrhxxc= X-Received: from pfez17.prod.google.com ([2002:aa7:8891:0:b0:792:f698:fda2]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a21:3290:b0:340:cc06:9514 with SMTP id adf61e73a8af0-348cd90d3b8mr1272183637.57.1761856112060; Thu, 30 Oct 2025 13:28:32 -0700 (PDT) Date: Thu, 30 Oct 2025 13:28:30 -0700 In-Reply-To: Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250813192313.132431-1-mlevitsk@redhat.com> <20250813192313.132431-3-mlevitsk@redhat.com> <7c7a5a75-a786-4a05-a836-4368582ca4c2@redhat.com> <23f11dc1-4fd1-4286-a69a-3892a869ed33@redhat.com> Message-ID: Subject: Re: [PATCH 2/3] KVM: x86: Fix a semi theoretical bug in kvm_arch_async_page_present_queued From: Sean Christopherson To: mlevitsk@redhat.com Cc: Paolo Bonzini , kvm@vger.kernel.org, Dave Hansen , "H. Peter Anvin" , Ingo Molnar , Thomas Gleixner , x86@kernel.org, Borislav Petkov , linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable On Thu, Oct 30, 2025, mlevitsk@redhat.com wrote: > On Mon, 2025-10-27 at 08:00 -0700, Sean Christopherson wrote: > > On Tue, Sep 23, 2025, Sean Christopherson wrote: > > > On x86, the "page ready" IRQ is only injected from vCPU context, so A= FAICT nothing > > > is guarnateed wake the vCPU in the above sequence. > >=20 > > Gah, KVM checks async_pf.done instead of the request.=C2=A0 So I don't = think there's > > a bug, just weird code. >=20 > Hi! >=20 > Note that I posted a v2 of this patch series. I got 'em, and looked at them in depth (which is how I figured out the abov= e weirdness with async_pf.done). They're sitting in my "for_next" folder, I = just haven't spent any time on applying+testing upstream patches this week (I ex= pect to get to your series tomorrow, or early next week). > Do I need to drop this patch or its better to keep it (the patch should s= till > be correct, but maybe an overkill I think). It's probably overkill, but there's no real downside, so I'm inclined to ap= ply the v2 version (and am planning on doing so).