From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7B8AA1E25F2; Thu, 12 Jun 2025 05:29:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749706188; cv=none; b=YAEwXswNDecVd21x2jtpQpUXHMrWRj9miyKoufEFDzzWbqURpKvgg1Kdb7NX2mbk6XjMHkoCJOya4GoNs4MufjafgpbuQfncwTvwnr4vqe3VFmvpdw0QDUl8dp6maSU2rVeSqFSYoD22Vzysdy5eWyhgNYjQi92wRIYGiVGYSeI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749706188; c=relaxed/simple; bh=AE3+Ai7lW9yV7Ac20q5WllK+ofoz5XA1y3tE02Fp5yI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=gUb5UNkE1Ph8TlNOszSbWtJFXnfUzaDfaVscmYJa+JHovOVYVGkWRYojYypCbUG0u0Pu5etneXJ3Xkkk5v16KoOJkAdaTcS+kk8GNY/pxar2eE3CUwxejD+cnWx4c2CQUMtkWu/0/dgZhh73BADCPmhMFCAhb8TSVKpVmabIcIA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=TT07/vRz; arc=none smtp.client-ip=198.175.65.18 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="TT07/vRz" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1749706186; x=1781242186; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=AE3+Ai7lW9yV7Ac20q5WllK+ofoz5XA1y3tE02Fp5yI=; b=TT07/vRzIBOadGPAjadI8HiMoj5uZjdP+CyrmNO8f1QJKYOI+73Zr9zy 9RuJTGfq4VEi4Gt4SmT9aBjharHmop++VCp+CWgDeBKDl8eEXSItr9af9 H3kusK+h0qYiMqeh5LsF7TBmAGSpknOQufTJE6JauapbJpyQT9ee3q9ce W4K8qzI+gMUmvQJaCWzG6w1apP83jZ82Z5jNgB/8LnfmwohuPYGOVg2dO vLr8EXeH7pW178FHT0fjCIdO4xaywyiyCs6JO2xHN8qpa+TqNKm3RtNhI IEyKDUXc0q6NB7YAlp6nASwGgpdRSai1sCgNS2HtOQiClWQa7BVCUrVlv Q==; X-CSE-ConnectionGUID: eftHv64mS5mUqT+gXxZWxg== X-CSE-MsgGUID: bqpWRNqeSK+mavjAQx3T1A== X-IronPort-AV: E=McAfee;i="6800,10657,11461"; a="52012676" X-IronPort-AV: E=Sophos;i="6.16,230,1744095600"; d="scan'208";a="52012676" Received: from orviesa001.jf.intel.com ([10.64.159.141]) by orvoesa110.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jun 2025 22:29:45 -0700 X-CSE-ConnectionGUID: Iyt6SaMpTViTsFcwh9KemA== X-CSE-MsgGUID: Bs/kYdOYRVOHKLwURPii/A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.16,230,1744095600"; d="scan'208";a="184633000" Received: from xiaoyaol-hp-g830.ccr.corp.intel.com (HELO [10.124.247.1]) ([10.124.247.1]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jun 2025 22:29:43 -0700 Message-ID: Date: Thu, 12 Jun 2025 13:29:40 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] KVM: x86/mmu: Reject direct bits in gpa passed to KVM_PRE_FAULT_MEMORY To: Paolo Bonzini , linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: seanjc@google.com, yan.y.zhao@intel.com References: <20250612044943.151258-1-pbonzini@redhat.com> Content-Language: en-US From: Xiaoyao Li In-Reply-To: <20250612044943.151258-1-pbonzini@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 6/12/2025 12:49 PM, Paolo Bonzini wrote: > Only let userspace pass the same addresses that were used in KVM_SET_USER_MEMORY_REGION > (or KVM_SET_USER_MEMORY_REGION2); gpas in the the upper half of the address space > are an implementation detail of TDX and KVM. > > Extracted from a patch by Sean Christopherson . > > Signed-off-by: Paolo Bonzini > --- > arch/x86/kvm/mmu/mmu.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c > index a4040578b537..4e06e2e89a8f 100644 > --- a/arch/x86/kvm/mmu/mmu.c > +++ b/arch/x86/kvm/mmu/mmu.c > @@ -4903,6 +4903,9 @@ long kvm_arch_vcpu_pre_fault_memory(struct kvm_vcpu *vcpu, > if (!vcpu->kvm->arch.pre_fault_allowed) > return -EOPNOTSUPP; > > + if (kvm_is_gfn_alias(vcpu->kvm, gpa_to_gfn(range->gpa))) > + return -EINVAL; Do we need to worry about the case (range->gpa + range->size) becomes alias? > /* > * reload is efficient when called repeatedly, so we can do it on > * every iteration.