From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CC0E6C433FE for ; Tue, 21 Dec 2021 15:14:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239266AbhLUPOK (ORCPT ); Tue, 21 Dec 2021 10:14:10 -0500 Received: from mga09.intel.com ([134.134.136.24]:56050 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239203AbhLUPOE (ORCPT ); Tue, 21 Dec 2021 10:14:04 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1640099644; x=1671635644; h=from:to:cc:subject:date:message-id:in-reply-to: references; bh=We7gK/h+jEknZOV42LJTALD74jcdTiL5CfglrMRHFxI=; b=agCPuVx8JsdpkpYpKJR3WvUNB+rjROd49vaYMAbyCuq3I2bQStc/S4cM mXuiAY3Uc034Mn5EZutFf4KZtOovUUHVwgI0wFDfwlTYvd1XXtRlRwD/2 p2XIjGoe0RGqqJfPUtv3WD5tq7Ox4ZAXxlCk4zki/WLwW4lYB7YBuHXFT TmIpaEY6YJ8Wbrx2NZCP23nhR4az/henWGp43C9m+lhr5Zwm7OK3BGD6T ga+8xmLHOP12U9VwR1yOpyG5pbi5jLPjCaREqnDkpD6+oMDpYuAQZuyMd lzTFa2rw89j8fFo4kCAY/h+YJ2Fm+dAoArBP4Rlng/CTb0CA5MkJMwYXT A==; X-IronPort-AV: E=McAfee;i="6200,9189,10204"; a="240216779" X-IronPort-AV: E=Sophos;i="5.88,223,1635231600"; d="scan'208";a="240216779" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Dec 2021 07:14:03 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.88,223,1635231600"; d="scan'208";a="684688711" Received: from chaop.bj.intel.com ([10.240.192.101]) by orsmga005.jf.intel.com with ESMTP; 21 Dec 2021 07:13:56 -0800 From: Chao Peng To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, qemu-devel@nongnu.org Cc: Paolo Bonzini , Jonathan Corbet , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H . Peter Anvin" , Hugh Dickins , Jeff Layton , "J . Bruce Fields" , Andrew Morton , Yu Zhang , Chao Peng , "Kirill A . Shutemov" , luto@kernel.org, john.ji@intel.com, susie.li@intel.com, jun.nakajima@intel.com, dave.hansen@intel.com, ak@linux.intel.com, david@redhat.com Subject: [PATCH v3 15/15] KVM: Register/unregister private memory slot to memfd Date: Tue, 21 Dec 2021 23:11:25 +0800 Message-Id: <20211221151125.19446-16-chao.p.peng@linux.intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20211221151125.19446-1-chao.p.peng@linux.intel.com> References: <20211221151125.19446-1-chao.p.peng@linux.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Expose KVM_MEM_PRIVATE flag and register/unregister private memory slot to memfd when userspace sets the flag. KVM_MEM_PRIVATE is disallowed by default but architecture code can turn it on by implementing kvm_arch_private_memory_supported(). Signed-off-by: Yu Zhang Signed-off-by: Chao Peng --- include/linux/kvm_host.h | 2 ++ virt/kvm/kvm_main.c | 35 +++++++++++++++++++++++++++++++---- 2 files changed, 33 insertions(+), 4 deletions(-) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 0c53df0a6b2e..0f0e24f19892 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -1096,6 +1096,8 @@ int kvm_arch_post_init_vm(struct kvm *kvm); void kvm_arch_pre_destroy_vm(struct kvm *kvm); int kvm_arch_create_vm_debugfs(struct kvm *kvm); bool kvm_arch_dirty_log_supported(struct kvm *kvm); +bool kvm_arch_private_memory_supported(struct kvm *kvm); + #ifndef __KVM_HAVE_ARCH_VM_ALLOC /* diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 79313c549fb9..6eb0d86abdcf 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1509,6 +1509,11 @@ bool __weak kvm_arch_dirty_log_supported(struct kvm *kvm) return true; } +bool __weak kvm_arch_private_memory_supported(struct kvm *kvm) +{ + return false; +} + static int check_memory_region_flags(struct kvm *kvm, const struct kvm_userspace_memory_region_ext *mem) { @@ -1517,6 +1522,9 @@ static int check_memory_region_flags(struct kvm *kvm, if (kvm_arch_dirty_log_supported(kvm)) valid_flags |= KVM_MEM_LOG_DIRTY_PAGES; + if (kvm_arch_private_memory_supported(kvm)) + valid_flags |= KVM_MEM_PRIVATE; + #ifdef __KVM_HAVE_READONLY_MEM valid_flags |= KVM_MEM_READONLY; #endif @@ -1708,9 +1716,21 @@ static int kvm_set_memslot(struct kvm *kvm, /* Copy the arch-specific data, again after (re)acquiring slots_arch_lock. */ memcpy(&new->arch, &old.arch, sizeof(old.arch)); + if (mem->flags & KVM_MEM_PRIVATE && change == KVM_MR_CREATE) { + r = kvm_memfd_register(kvm, mem, new); + if (r) + goto out_slots; + } + r = kvm_arch_prepare_memory_region(kvm, new, mem, change); - if (r) + if (r) { + if (mem->flags & KVM_MEM_PRIVATE && change == KVM_MR_CREATE) + kvm_memfd_unregister(kvm, new); goto out_slots; + } + + if (mem->flags & KVM_MEM_PRIVATE && change == KVM_MR_DELETE) + kvm_memfd_unregister(kvm, new); update_memslots(slots, new, change); slots = install_new_memslots(kvm, as_id, slots); @@ -1786,10 +1806,12 @@ int __kvm_set_memory_region(struct kvm *kvm, return -EINVAL; if (mem->guest_phys_addr & (PAGE_SIZE - 1)) return -EINVAL; - /* We can read the guest memory with __xxx_user() later on. */ if ((mem->userspace_addr & (PAGE_SIZE - 1)) || - (mem->userspace_addr != untagged_addr(mem->userspace_addr)) || - !access_ok((void __user *)(unsigned long)mem->userspace_addr, + (mem->userspace_addr != untagged_addr(mem->userspace_addr))) + return -EINVAL; + /* We can read the guest memory with __xxx_user() later on. */ + if (!(mem->flags & KVM_MEM_PRIVATE) && + !access_ok((void __user *)(unsigned long)mem->userspace_addr, mem->memory_size)) return -EINVAL; if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_MEM_SLOTS_NUM) @@ -1821,6 +1843,8 @@ int __kvm_set_memory_region(struct kvm *kvm, new.npages = mem->memory_size >> PAGE_SHIFT; new.flags = mem->flags; new.userspace_addr = mem->userspace_addr; + new.file = NULL; + new.file_ofs = 0; if (new.npages > KVM_MEM_MAX_NR_PAGES) return -EINVAL; @@ -1829,6 +1853,9 @@ int __kvm_set_memory_region(struct kvm *kvm, change = KVM_MR_CREATE; new.dirty_bitmap = NULL; } else { /* Modify an existing slot. */ + /* Private memslots are immutable, they can only be deleted. */ + if (mem->flags & KVM_MEM_PRIVATE) + return -EINVAL; if ((new.userspace_addr != old.userspace_addr) || (new.npages != old.npages) || ((new.flags ^ old.flags) & KVM_MEM_READONLY)) -- 2.17.1 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4AB7DC433F5 for ; Tue, 21 Dec 2021 15:27:12 +0000 (UTC) Received: from localhost ([::1]:42248 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mzh2l-000357-94 for qemu-devel@archiver.kernel.org; Tue, 21 Dec 2021 10:27:11 -0500 Received: from eggs.gnu.org ([209.51.188.92]:46454) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mzgq7-0001Iy-Kj for qemu-devel@nongnu.org; Tue, 21 Dec 2021 10:14:07 -0500 Received: from mga11.intel.com ([192.55.52.93]:41795) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mzgq5-0008Qo-TC for qemu-devel@nongnu.org; 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21 Dec 2021 07:13:56 -0800 From: Chao Peng To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, qemu-devel@nongnu.org Subject: [PATCH v3 15/15] KVM: Register/unregister private memory slot to memfd Date: Tue, 21 Dec 2021 23:11:25 +0800 Message-Id: <20211221151125.19446-16-chao.p.peng@linux.intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20211221151125.19446-1-chao.p.peng@linux.intel.com> References: <20211221151125.19446-1-chao.p.peng@linux.intel.com> Received-SPF: none client-ip=192.55.52.93; envelope-from=chao.p.peng@linux.intel.com; helo=mga11.intel.com X-Spam_score_int: -71 X-Spam_score: -7.2 X-Spam_bar: ------- X-Spam_report: (-7.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.203, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_HI=-5, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_NONE=0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Wanpeng Li , jun.nakajima@intel.com, david@redhat.com, "J . Bruce Fields" , dave.hansen@intel.com, "H . Peter Anvin" , Chao Peng , ak@linux.intel.com, Jonathan Corbet , Joerg Roedel , x86@kernel.org, Hugh Dickins , Ingo Molnar , Borislav Petkov , luto@kernel.org, Thomas Gleixner , Vitaly Kuznetsov , Jim Mattson , Sean Christopherson , susie.li@intel.com, Jeff Layton , john.ji@intel.com, Yu Zhang , Paolo Bonzini , Andrew Morton , "Kirill A . Shutemov" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Expose KVM_MEM_PRIVATE flag and register/unregister private memory slot to memfd when userspace sets the flag. KVM_MEM_PRIVATE is disallowed by default but architecture code can turn it on by implementing kvm_arch_private_memory_supported(). Signed-off-by: Yu Zhang Signed-off-by: Chao Peng --- include/linux/kvm_host.h | 2 ++ virt/kvm/kvm_main.c | 35 +++++++++++++++++++++++++++++++---- 2 files changed, 33 insertions(+), 4 deletions(-) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 0c53df0a6b2e..0f0e24f19892 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -1096,6 +1096,8 @@ int kvm_arch_post_init_vm(struct kvm *kvm); void kvm_arch_pre_destroy_vm(struct kvm *kvm); int kvm_arch_create_vm_debugfs(struct kvm *kvm); bool kvm_arch_dirty_log_supported(struct kvm *kvm); +bool kvm_arch_private_memory_supported(struct kvm *kvm); + #ifndef __KVM_HAVE_ARCH_VM_ALLOC /* diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 79313c549fb9..6eb0d86abdcf 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1509,6 +1509,11 @@ bool __weak kvm_arch_dirty_log_supported(struct kvm *kvm) return true; } +bool __weak kvm_arch_private_memory_supported(struct kvm *kvm) +{ + return false; +} + static int check_memory_region_flags(struct kvm *kvm, const struct kvm_userspace_memory_region_ext *mem) { @@ -1517,6 +1522,9 @@ static int check_memory_region_flags(struct kvm *kvm, if (kvm_arch_dirty_log_supported(kvm)) valid_flags |= KVM_MEM_LOG_DIRTY_PAGES; + if (kvm_arch_private_memory_supported(kvm)) + valid_flags |= KVM_MEM_PRIVATE; + #ifdef __KVM_HAVE_READONLY_MEM valid_flags |= KVM_MEM_READONLY; #endif @@ -1708,9 +1716,21 @@ static int kvm_set_memslot(struct kvm *kvm, /* Copy the arch-specific data, again after (re)acquiring slots_arch_lock. */ memcpy(&new->arch, &old.arch, sizeof(old.arch)); + if (mem->flags & KVM_MEM_PRIVATE && change == KVM_MR_CREATE) { + r = kvm_memfd_register(kvm, mem, new); + if (r) + goto out_slots; + } + r = kvm_arch_prepare_memory_region(kvm, new, mem, change); - if (r) + if (r) { + if (mem->flags & KVM_MEM_PRIVATE && change == KVM_MR_CREATE) + kvm_memfd_unregister(kvm, new); goto out_slots; + } + + if (mem->flags & KVM_MEM_PRIVATE && change == KVM_MR_DELETE) + kvm_memfd_unregister(kvm, new); update_memslots(slots, new, change); slots = install_new_memslots(kvm, as_id, slots); @@ -1786,10 +1806,12 @@ int __kvm_set_memory_region(struct kvm *kvm, return -EINVAL; if (mem->guest_phys_addr & (PAGE_SIZE - 1)) return -EINVAL; - /* We can read the guest memory with __xxx_user() later on. */ if ((mem->userspace_addr & (PAGE_SIZE - 1)) || - (mem->userspace_addr != untagged_addr(mem->userspace_addr)) || - !access_ok((void __user *)(unsigned long)mem->userspace_addr, + (mem->userspace_addr != untagged_addr(mem->userspace_addr))) + return -EINVAL; + /* We can read the guest memory with __xxx_user() later on. */ + if (!(mem->flags & KVM_MEM_PRIVATE) && + !access_ok((void __user *)(unsigned long)mem->userspace_addr, mem->memory_size)) return -EINVAL; if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_MEM_SLOTS_NUM) @@ -1821,6 +1843,8 @@ int __kvm_set_memory_region(struct kvm *kvm, new.npages = mem->memory_size >> PAGE_SHIFT; new.flags = mem->flags; new.userspace_addr = mem->userspace_addr; + new.file = NULL; + new.file_ofs = 0; if (new.npages > KVM_MEM_MAX_NR_PAGES) return -EINVAL; @@ -1829,6 +1853,9 @@ int __kvm_set_memory_region(struct kvm *kvm, change = KVM_MR_CREATE; new.dirty_bitmap = NULL; } else { /* Modify an existing slot. */ + /* Private memslots are immutable, they can only be deleted. */ + if (mem->flags & KVM_MEM_PRIVATE) + return -EINVAL; if ((new.userspace_addr != old.userspace_addr) || (new.npages != old.npages) || ((new.flags ^ old.flags) & KVM_MEM_READONLY)) -- 2.17.1