From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f201.google.com (mail-pf1-f201.google.com [209.85.210.201]) (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 6E41643AD6 for ; Mon, 11 Mar 2024 17:29:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710178144; cv=none; b=GilecorKrxUXm1+XP1JXTplfz6BQuA5dIio3VtjTC98BD7a+hyVRELs6ywm0El5e9PXquiKxx/Y6yrDPukvkHRXacg5+B/FWe6/wSHMzFgIwRP3iewKI+xfBSA0mRuFGkdCOazRwPXtO4QCYUuVmgr47Ro0BTB5XbybrL2h/dBk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710178144; c=relaxed/simple; bh=okoRSz7afbgkoAWXF3XbX78+I1I2fLE58zcbTZyYFWk=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=j9M9llKJBwYsgEKfyD9zAGZcxevqr5p4bvxjUouaa+Crz5xp+zcVqbfd12+gkwt/L5iZDm4ivJZrv2/ewTlsWvQ+Sz7b75H27ABOaUityUOjuXh22i29LWFcZrG1oehXadhR1XoH/9+JzYzrVMCAeB0hK9vAO0q6O6X4emWPUMY= 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=EaLFNKXc; arc=none smtp.client-ip=209.85.210.201 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="EaLFNKXc" Received: by mail-pf1-f201.google.com with SMTP id d2e1a72fcca58-6e678cd2f25so2271417b3a.3 for ; Mon, 11 Mar 2024 10:29:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1710178142; x=1710782942; 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=OEO05PXkfOjTelHZtHuMuwrOVNRkyWhZ+54h8qYt70s=; b=EaLFNKXcXeIut69WO1erXmMTQpeKOVAuJ9HiSFsV7Gp4O9NxAuhM2JllOYg7BkyfTq DIA7QJwetxY7K2NSnhZ1qOJpoGgzj4lyq9lp6KiJyccCXfpXMQMwJgu7ynNB77/QEwjL ke5F9gWfKVaZVrixv1A+v9TbUgkkJ5VSE65joVhlhEDvNubElFLAUIYI1wC7jGHZ7nZD vS7hJRd/vOqLVN1Mpe5c6wE4M+JQKLy9k3svXYDUGwJs4LScUMhN1ku7vfinKcBGVZ/t V9T1y4TxenhUqys6x6HjyCirwhGAV44xNu03IAfFejafjpsss/4P55yL4ozwS4V4ky3M 0N6w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1710178142; x=1710782942; 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=OEO05PXkfOjTelHZtHuMuwrOVNRkyWhZ+54h8qYt70s=; b=XVlV1EaJQvZIILYRBfwLXxe7XU+mGhEEC882VeOud/Yy7+1Ys7IKTjZ/kWpebc/S60 +Ic3Ok9fvBEkC+GjHfvV8ykqg6kQIwQRtxJsaFDHBwWVCdoPJW7CTa2pOMPRsC7c4mSC 7YeHkr9Xio2TFM0tidvhAx7tlfAEupRcEMYLBI5jDdHsaMuIl25EVIWK6GCt6UqdXw+c UAWKGDKqeNPiK22MYaNJGc5qJat+1bFzmkO64479DHstCdwCu1xyneFeNXU78sGbVYeL HWceYxVoBQnkYDLiGZXLpHUHxANGMn3+oW1EhD0btSrjax/+zleB9Z9ZmpL+DbEhofrU yvbw== X-Forwarded-Encrypted: i=1; AJvYcCW6Kib0GFrQJF/K4Zn1auncLuYrpJlyH9l6rtYj1Ev89JeFTsIsDgJV3DXrsavZ5j0+vF91QcH4GMTL+scjwIFjK6CwSXrfP1UIyvkP X-Gm-Message-State: AOJu0YxfBXCd5IsDaKLXnyLpjcyrNAtWuS4jwA4YFrZjJd7R+HHxRTTI HeWZNVVHu5CcOMp/aK9xTxtNzj4dO73uH++468zXGIbkyxyP6Qgjiv6TLG+mQcDwTecDJVV9zdM 4AA== X-Google-Smtp-Source: AGHT+IH/xE2HJF5m/JJewVXuvpdu6o9k/r/j+nQP8U7Ed7EnvWNFWwESSVs39yzjTHjITgxx1z/ymyTWhqY= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a05:6a00:2291:b0:6e5:94b0:68be with SMTP id f17-20020a056a00229100b006e594b068bemr642052pfe.2.1710178142646; Mon, 11 Mar 2024 10:29:02 -0700 (PDT) Date: Mon, 11 Mar 2024 10:29:01 -0700 In-Reply-To: <7b7dd4d56249028aa0b84d439ffdf1b79e67322a.1709288671.git.isaku.yamahata@intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <7b7dd4d56249028aa0b84d439ffdf1b79e67322a.1709288671.git.isaku.yamahata@intel.com> Message-ID: Subject: Re: [RFC PATCH 5/8] KVM: x86/mmu: Introduce kvm_mmu_map_page() for prepopulating guest memory From: Sean Christopherson To: isaku.yamahata@intel.com Cc: kvm@vger.kernel.org, isaku.yamahata@gmail.com, linux-kernel@vger.kernel.org, Paolo Bonzini , Michael Roth , David Matlack , Federico Parola Content-Type: text/plain; charset="us-ascii" On Fri, Mar 01, 2024, isaku.yamahata@intel.com wrote: > From: Isaku Yamahata > > Introduce a helper function to call kvm fault handler. This allows > a new ioctl to invoke kvm fault handler to populate without seeing > RET_PF_* enums or other KVM MMU internal definitions. > > Signed-off-by: Isaku Yamahata > --- > arch/x86/kvm/mmu.h | 3 +++ > arch/x86/kvm/mmu/mmu.c | 30 ++++++++++++++++++++++++++++++ > 2 files changed, 33 insertions(+) > > diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h > index 60f21bb4c27b..48870c5e08ec 100644 > --- a/arch/x86/kvm/mmu.h > +++ b/arch/x86/kvm/mmu.h > @@ -183,6 +183,9 @@ static inline void kvm_mmu_refresh_passthrough_bits(struct kvm_vcpu *vcpu, > __kvm_mmu_refresh_passthrough_bits(vcpu, mmu); > } > > +int kvm_mmu_map_page(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, > + u8 max_level, u8 *goal_level); > + > /* > * Check if a given access (described through the I/D, W/R and U/S bits of a > * page fault error code pfec) causes a permission fault with the given PTE > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c > index e4cc7f764980..7d5e80d17977 100644 > --- a/arch/x86/kvm/mmu/mmu.c > +++ b/arch/x86/kvm/mmu/mmu.c > @@ -4659,6 +4659,36 @@ int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) > return direct_page_fault(vcpu, fault); > } > > +int kvm_mmu_map_page(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, > + u8 max_level, u8 *goal_level) > +{ > + struct kvm_page_fault fault = KVM_PAGE_FAULT_INIT(vcpu, gpa, error_code, > + false, max_level); > + int r; > + > + r = __kvm_mmu_do_page_fault(vcpu, &fault); > + > + if (is_error_noslot_pfn(fault.pfn) || vcpu->kvm->vm_bugged) > + return -EFAULT; This clobbers a non-zero 'r'. And KVM return -EIO if the VM is bugged/dead, not -EFAULT. I also don't see why KVM needs to explicitly check is_error_noslot_pfn(), that should be funneled to RET_PF_EMULATE. > + > + switch (r) { > + case RET_PF_RETRY: > + return -EAGAIN; > + > + case RET_PF_FIXED: > + case RET_PF_SPURIOUS: > + *goal_level = fault.goal_level; > + return 0; > + > + case RET_PF_CONTINUE: > + case RET_PF_EMULATE: -EINVAL woud be more appropriate for RET_PF_EMULATE. > + case RET_PF_INVALID: CONTINUE and INVALID should be WARN conditions. > + default: > + return -EIO; > + } > +} > +EXPORT_SYMBOL_GPL(kvm_mmu_map_page); Unnecessary export. > + > static void nonpaging_init_context(struct kvm_mmu *context) > { > context->page_fault = nonpaging_page_fault; > -- > 2.25.1 >