From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f51.google.com (mail-wr1-f51.google.com [209.85.221.51]) (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 636EE2BEFFF for ; Wed, 8 Apr 2026 18:43:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.51 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775673807; cv=none; b=bdMdTS+sWs1r5jDYUfqKx4slm3PMIZE8sxkwJkrZjnwCfpUWbkbRKqmdSl4SjY6uTQz0FzWTsL01IkHWuo3vsfd7SihyJJnpdkRPBFOVjND0LE6UMIN1X3F7mXJ8Rp0UGPSNmkVoRad++a+lq7x9cLCbAaOp+AZqPhu6XbeF8WU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775673807; c=relaxed/simple; bh=qlPS0sqMCSOO/GsZqCZjJyLYIRd67O340a8OE0Kzar0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=cOq2Va/jnBSdWfemFimIWLzMWj0Qg8aOhOTM+KP+J/4P70okNj63bSZm5G6E3r00H2L5p9BCrgHlefcRJbXXkELHIPUR1cOADsttI2qzTbZNMYK7/Qr9r0elVP4S8X2SkzQL5Em8r28U5Awkrysz51dJiArFcgc8trPysGzhp/8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=sjeFJdTv; arc=none smtp.client-ip=209.85.221.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="sjeFJdTv" Received: by mail-wr1-f51.google.com with SMTP id ffacd0b85a97d-43cfe71e5d3so28425f8f.0 for ; Wed, 08 Apr 2026 11:43:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1775673805; x=1776278605; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=L7qCTe6ED6FCLce6ISHALUAEngEdutUkIqM/6TQUcGs=; b=sjeFJdTvLVWQIHgInPnNtNvfyop3ieE19tiBxVdNe8GTqPWs3aMONzanYZEy8a0YnB SpceoQiSEvxKeLngIjD+/KDQ8+4aGbtWHWzvXUrJM6N/jUAKNv+F/ZEenHW6pZSYQnr2 UJa38ElkCtaOKN3Yd6cIl3Gd8U0B4+YW5VV6OBoNHa6XKaJrAd6z0ChabW7xRv8mZASY rUXjuuWVhn/mSqBOpjQqdCJNhwN0kW0ghGCHGJS8B5YgPxRgRF7sT2uKDHdT1M1Z8rgz zK7lsfkl/GF1KoN0kF4bL3vv24m/ev4JDMLM6Lkdvzu00R0tZboS5QRfU2Eh8JV0R/yz qoTQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1775673805; x=1776278605; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=L7qCTe6ED6FCLce6ISHALUAEngEdutUkIqM/6TQUcGs=; b=Q7b2ITmnIs52PeGqIxJICjj0c4d1bLcoBrywBWX3dHhuoV2X3Na1D39uYIGq/oCaVm ceNH4yw/bPB90JFXGRO/+/f3XAM2rdIl9FX1VhNzdx1jXe41pMC/XkmQ6rOICbrOUnrv ESEBFvRXzyLlzH67MqxVMAl2NFsrIkk4M2bk9sX2KIl4z6iSvyxeVGGjvf/tsXl4lQjC ckvzQQ2K4jPfgufTO7oOm1r+4P9Z23Uc5zutj6TKPkrN7dW+mnXVkFQpPRF3GFlfW9Cg AEKOtnZklcrPWi960nfP338C468L4XmwpETeqZtLWlxUp2TMA6d3iNG6bgW65e++Fnrm luuQ== X-Forwarded-Encrypted: i=1; AJvYcCUc2oX0vaJ3UYbc1wgL/vKNf3IihU56jxFBGNYe0D4BYjygA8wUKzXmHI+lYjkwBKIz0h1bYPOrSc4Z02I=@vger.kernel.org X-Gm-Message-State: AOJu0YzhnYXdFs5AEs2mo++8YzSfpiXsP7tompB60ta4y5CH5wcAaUYQ Q7y+i1SFqpfGh4CLyfcynNdwKDBAy65RK+HUINy/a56rHefIbNYR/LQrBwbXeIU3Nk4= X-Gm-Gg: AeBDieuUbtr17BmcgCJGHzItwMqcAo/qTy01pUybUWb+WaXOz9KBTVUXrjVhOV1lpIJ gsCFrbZJGFSXLTvU8PkPZEPv8KAn8LDEGmCqi5ZMELuz3pYR93MrRexz7VCsvMRtFN4tJph27Bg WlNcfKLV8blCNAhxlJGa9bPOALWwZ/UfY2WdDzqCL+157IF1fmTSouFTsPq9BVaInT9O00t82g2 TEh7vpUth8Wraicxhi/sE2PZuO1unuBeYv2OAzf1rM9Eu+//Y/Ap3vZjoamJ4p2t/TOOmOHVi98 eygaR4ZVn0YDB9yKJh659VRMVhKx+iwwzkP8qb/WpajUL+1ew0htVuj3Qewp/TXABCpgKFJt5Km v6o+gND7HXKG2Som3Pr6k7Cwh46Aa9xSsrrvWryYmHQCZ6H44KWsuW1qIfJDEZN4YqfLZObsrjn Kp69WPxCLEMB4DAvEJLg== X-Received: by 2002:a05:6000:2586:b0:43c:f8ee:c630 with SMTP id ffacd0b85a97d-43d292db10emr31511798f8f.35.1775673804442; Wed, 08 Apr 2026 11:43:24 -0700 (PDT) Received: from nuna ([154.160.21.43]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-43d1e2a720dsm61267589f8f.4.2026.04.08.11.43.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 08 Apr 2026 11:43:24 -0700 (PDT) From: punixcorn To: seanjc@google.com, pbonzini@redhat.com Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, punixcorn Subject: Re: [BUG] KVM: NULL pointer dereference in kvm_tdp_mmu_map under memory pressure Date: Wed, 8 Apr 2026 18:43:32 +0000 Message-ID: <20260408184332.187482-1-ohyunwoods663@gmail.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: <202604081633.sean.christopherson@intel.com> References: <202604081633.sean.christopherson@intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit To be honest, it could be days. The original crash happened only once in a month of heavy use, though my system has been hitting 100% RAM usage frequently. I suspect a specific transition-like a guest memory zap during high host contention-is the trigger. I am currently trying to reproduce this by scripting a loop that reloads the guest project (Android emulator) while the host is under heavy memory load, as that was the environment when the crash occurred. I’ll keep the current debug patch running. If I can't catch it within the next 48 hours, I’d be very interested in that more elaborate debug patch you mentioned to help track the SPTE lifecycle more closely. Signed-off-by: punixcorn