From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yb1-f202.google.com (mail-yb1-f202.google.com [209.85.219.202]) (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 485381684A7 for ; Fri, 9 Aug 2024 20:52:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723236728; cv=none; b=NMq4RLJaPLP8sKHrgOVM9EbfSyEFOAn1Miav4sK5VVV6Bfk64R+5hteLdTDQ5meVx8r3+tJrViGesprQHeIIunEgyTO9PswNdmYSn7l6x/3RlKJYC1FtF+ZXu4gSJjl5LPF1KFazxUF9fVkW4VgBSLZPJuM7dBLgjPFFugFWc58= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723236728; c=relaxed/simple; bh=UylfwD3oilt2Ap00B9QfJgsS5JbmMx/LZPo5qb2iVKI=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=HJ5vXLO1A5SEx/djcnqxNaUXtVp7YsB+aPh6hlJLiPziEjNItsKuiu22tE5jFC4v2g2PivaPAprfvx7sez+f4nRdjJcgZDItaF3i7mi+deWcVbQWsgOQDaTOy9bcIyCM5QDgW99xgABENnBevVHv0iS0QnJ4j3UGosoMUfCcfZ8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--amoorthy.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=Hzx1HT6J; arc=none smtp.client-ip=209.85.219.202 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--amoorthy.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Hzx1HT6J" Received: by mail-yb1-f202.google.com with SMTP id 3f1490d57ef6-e08bc29c584so4111790276.0 for ; Fri, 09 Aug 2024 13:52:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1723236726; x=1723841526; darn=lists.linux.dev; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=br3FwjgDzPooOiG0lkeIxLVZHvjVaW5LdrLy5p4r3+8=; b=Hzx1HT6J1hngbw+cDOWwD4i3bKkpIGR+O6FtE5mH7gzzTVbDnbWEuQWN2+5dDyu810 OU1h21YZo0zWBdlCwaAED+Y5JO1+R1mX5HPgCLdveEzh57pnSgNdc4unsxoUElT3+O/Y 7Ilshy60IUvo145J2pBTTUbqtQepxfbDibay6ukZ14KEsmtjilY6jNOw8TB2LJgWrdeX mqUzGHfag6wRBnQ7WBuXxuAhoIVGkNeEKlpmQ3rCEmJfLYn2/SVq/ELiJHkr4Uq2dMIX UP8ZGdOH1JhnOCJNrSLfYD5F2175W6x8iA+q7fNloMHphQ6jxZ55G2fhaERg77mFkeYE H/ig== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1723236726; x=1723841526; 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=br3FwjgDzPooOiG0lkeIxLVZHvjVaW5LdrLy5p4r3+8=; b=oTHxqGCMG///IxdAnaQKnhobVEDAXUtzWi0aYBv7vCcphDarGpCB10TjIlpwfWxx67 6pjaxuFseBE21HJR/aPuSSfhMVKKis0U+3V4idN2P6myaVQHh1AKenm7Ppw7gwx4oo7W anJV9M1wV5W8NsDMoI5A6ZbwmYortaVIOv7/dQmQKX9NCeywBfM5MRfoNb89hXwZRieN PaioyjK8tXeGA6/i2leL/6WR03fD3LHFUF53vDLK466gX6xFM+2z1gByDTtT/GvOjIb/ Q9X+W2DxbfRsLwRRjXPrGDwtH8DOC3Fs+VC7vA/WzmnrfgZQuK4pfEv9u+hdem6hvEGk 23CQ== X-Forwarded-Encrypted: i=1; AJvYcCUWnwhY+wNBYlT1hRWidz0vGI4xQ884UfpbOnunxKAXncm7s69br5X9fAUUJng6fraawXMRu8X8Un/RCbS82vzTsUrU5Hyl X-Gm-Message-State: AOJu0YyIMjEuAtENGW1WjCL+51FGUrinPT7BHrQhxnmJsfd2/KsWVKRK r/+gZ1qhAkbqqoiqrx9YUQ02NyLw+byd87dOqHrglXrIsPzto3ql8njlNZb5aukEbj1Zc2IiHh5 +O9p2kK1sog== X-Google-Smtp-Source: AGHT+IEDwdW8UPrl6O8L/dLUe+yB4KqU+io0AFuuQD9m2vE0SJljtoLO2dozJZ1XveNUHCZDlwUWfzVuIHv+5w== X-Received: from laogai.c.googlers.com ([fda3:e722:ac3:cc00:2b:7d90:c0a8:2c9]) (user=amoorthy job=sendgmr) by 2002:a25:ac5d:0:b0:e03:3cfa:1aa7 with SMTP id 3f1490d57ef6-e0eb98c93e5mr4591276.1.1723236726226; Fri, 09 Aug 2024 13:52:06 -0700 (PDT) Date: Fri, 9 Aug 2024 20:51:57 +0000 In-Reply-To: <20240809205158.1340255-1-amoorthy@google.com> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240809205158.1340255-1-amoorthy@google.com> X-Mailer: git-send-email 2.46.0.76.ge559c4bf1a-goog Message-ID: <20240809205158.1340255-3-amoorthy@google.com> Subject: [PATCH v2 2/3] KVM: x86: Do a KVM_MEMORY_FAULT EXIT when stage-2 fault handler EFAULTs From: Anish Moorthy To: seanjc@google.com, oliver.upton@linux.dev, kvm@vger.kernel.org, kvmarm@lists.linux.dev Cc: jthoughton@google.com, amoorthy@google.com, rananta@google.com Content-Type: text/plain; charset="UTF-8" Right now userspace just gets a bare EFAULT when the stage-2 fault handler fails to fault in the relevant page. Set up a memory fault exit when this happens, which at the very least eases debugging and might also let userspace decide on/take some specific action other than crashing the VM. Signed-off-by: Anish Moorthy --- arch/x86/kvm/mmu/mmu.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 901be9e420a4..c22c807696ae 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -3264,6 +3264,7 @@ static int kvm_handle_error_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fa return RET_PF_RETRY; } + kvm_mmu_prepare_memory_fault_exit(vcpu, fault); return -EFAULT; } -- 2.46.0.76.ge559c4bf1a-goog