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 X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9E233C388F9 for ; Fri, 23 Oct 2020 12:37:28 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1EC8C21D43 for ; Fri, 23 Oct 2020 12:37:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="yQDZVDnq" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1EC8C21D43 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 559646B0068; Fri, 23 Oct 2020 08:37:27 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 532196B006C; Fri, 23 Oct 2020 08:37:27 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 41FED6B006E; Fri, 23 Oct 2020 08:37:27 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0073.hostedemail.com [216.40.44.73]) by kanga.kvack.org (Postfix) with ESMTP id 1666E6B0068 for ; Fri, 23 Oct 2020 08:37:27 -0400 (EDT) Received: from smtpin18.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id A49431EE6 for ; Fri, 23 Oct 2020 12:37:26 +0000 (UTC) X-FDA: 77403140892.18.mist68_2b0ffdb27259 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin18.hostedemail.com (Postfix) with ESMTP id 7E6771021B005 for ; Fri, 23 Oct 2020 12:37:26 +0000 (UTC) X-HE-Tag: mist68_2b0ffdb27259 X-Filterd-Recvd-Size: 7851 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf10.hostedemail.com (Postfix) with ESMTP for ; Fri, 23 Oct 2020 12:37:25 +0000 (UTC) Received: from kernel.org (unknown [87.70.96.83]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0709E2085B; Fri, 23 Oct 2020 12:37:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603456644; bh=6bYTWe4ruS8+LB8nHf1nJspiMoagfv9P4NHAjSqQuV0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=yQDZVDnq7DkgFwnpnRIYjaxLg96l7qBfzqLCRkSwWprLsiscmOLA9f8qTbncBhiat vmM8FdlrJrjlEfGNU3iw7mFWERgPpl7r3ak+h40UUiXk7upNByy7433tMNYYo2EN4E WhAsTsr6WqadQX3pKMtlTdCf4QpzPdJLLYg8+Qa8= Date: Fri, 23 Oct 2020 15:37:12 +0300 From: Mike Rapoport To: "Kirill A. Shutemov" Cc: Dave Hansen , Andy Lutomirski , Peter Zijlstra , Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , David Rientjes , Andrea Arcangeli , Kees Cook , Will Drewry , "Edgecombe, Rick P" , "Kleen, Andi" , Liran Alon , x86@kernel.org, kvm@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: Re: [RFCv2 15/16] KVM: Unmap protected pages from direct mapping Message-ID: <20201023123712.GC392079@kernel.org> References: <20201020061859.18385-1-kirill.shutemov@linux.intel.com> <20201020061859.18385-16-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201020061859.18385-16-kirill.shutemov@linux.intel.com> X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Oct 20, 2020 at 09:18:58AM +0300, Kirill A. Shutemov wrote: > If the protected memory feature enabled, unmap guest memory from > kernel's direct mappings. > > Migration and KSM is disabled for protected memory as it would require a > special treatment. > > Signed-off-by: Kirill A. Shutemov > --- > include/linux/mm.h | 3 +++ > mm/huge_memory.c | 8 ++++++++ > mm/ksm.c | 2 ++ > mm/memory.c | 12 ++++++++++++ > mm/rmap.c | 4 ++++ > virt/lib/mem_protected.c | 21 +++++++++++++++++++++ > 6 files changed, 50 insertions(+) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index ee274d27e764..74efc51e63f0 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -671,6 +671,9 @@ static inline bool vma_is_kvm_protected(struct vm_area_struct *vma) > return vma->vm_flags & VM_KVM_PROTECTED; > } > > +void kvm_map_page(struct page *page, int nr_pages); > +void kvm_unmap_page(struct page *page, int nr_pages); This still does not seem right ;-) And I still think that map/unmap primitives shoud be a part of the generic mm rather than exported by KVM. > + > #ifdef CONFIG_SHMEM > /* > * The vma_is_shmem is not inline because it is used only by slow > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index ec8cf9a40cfd..40974656cb43 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -627,6 +627,10 @@ static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf, > spin_unlock(vmf->ptl); > count_vm_event(THP_FAULT_ALLOC); > count_memcg_event_mm(vma->vm_mm, THP_FAULT_ALLOC); > + > + /* Unmap page from direct mapping */ > + if (vma_is_kvm_protected(vma)) > + kvm_unmap_page(page, HPAGE_PMD_NR); > } > > return 0; > @@ -1689,6 +1693,10 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, > page_remove_rmap(page, true); > VM_BUG_ON_PAGE(page_mapcount(page) < 0, page); > VM_BUG_ON_PAGE(!PageHead(page), page); > + > + /* Map the page back to the direct mapping */ > + if (vma_is_kvm_protected(vma)) > + kvm_map_page(page, HPAGE_PMD_NR); > } else if (thp_migration_supported()) { > swp_entry_t entry; > > diff --git a/mm/ksm.c b/mm/ksm.c > index 9afccc36dbd2..c720e271448f 100644 > --- a/mm/ksm.c > +++ b/mm/ksm.c > @@ -528,6 +528,8 @@ static struct vm_area_struct *find_mergeable_vma(struct mm_struct *mm, > return NULL; > if (!(vma->vm_flags & VM_MERGEABLE) || !vma->anon_vma) > return NULL; > + if (vma_is_kvm_protected(vma)) > + return NULL; > return vma; > } > > diff --git a/mm/memory.c b/mm/memory.c > index 2c9756b4e52f..e28bd5f902a7 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -1245,6 +1245,11 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb, > likely(!(vma->vm_flags & VM_SEQ_READ))) > mark_page_accessed(page); > } > + > + /* Map the page back to the direct mapping */ > + if (vma_is_anonymous(vma) && vma_is_kvm_protected(vma)) > + kvm_map_page(page, 1); > + > rss[mm_counter(page)]--; > page_remove_rmap(page, false); > if (unlikely(page_mapcount(page) < 0)) > @@ -3466,6 +3471,7 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf) > struct page *page; > vm_fault_t ret = 0; > pte_t entry; > + bool set = false; > > /* File mapping without ->vm_ops ? */ > if (vma->vm_flags & VM_SHARED) > @@ -3554,6 +3560,7 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf) > inc_mm_counter_fast(vma->vm_mm, MM_ANONPAGES); > page_add_new_anon_rmap(page, vma, vmf->address, false); > lru_cache_add_inactive_or_unevictable(page, vma); > + set = true; > setpte: > set_pte_at(vma->vm_mm, vmf->address, vmf->pte, entry); > > @@ -3561,6 +3568,11 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf) > update_mmu_cache(vma, vmf->address, vmf->pte); > unlock: > pte_unmap_unlock(vmf->pte, vmf->ptl); > + > + /* Unmap page from direct mapping */ > + if (vma_is_kvm_protected(vma) && set) > + kvm_unmap_page(page, 1); > + > return ret; > release: > put_page(page); > diff --git a/mm/rmap.c b/mm/rmap.c > index 9425260774a1..247548d6d24b 100644 > --- a/mm/rmap.c > +++ b/mm/rmap.c > @@ -1725,6 +1725,10 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma, > > static bool invalid_migration_vma(struct vm_area_struct *vma, void *arg) > { > + /* TODO */ > + if (vma_is_kvm_protected(vma)) > + return true; > + > return vma_is_temporary_stack(vma); > } > > diff --git a/virt/lib/mem_protected.c b/virt/lib/mem_protected.c > index 1dfe82534242..9d2ef99285e5 100644 > --- a/virt/lib/mem_protected.c > +++ b/virt/lib/mem_protected.c > @@ -30,6 +30,27 @@ void kvm_unmap_page_atomic(void *vaddr) > } > EXPORT_SYMBOL_GPL(kvm_unmap_page_atomic); > > +void kvm_map_page(struct page *page, int nr_pages) > +{ > + int i; > + > + /* Clear page before returning it to the direct mapping */ > + for (i = 0; i < nr_pages; i++) { > + void *p = kvm_map_page_atomic(page + i); > + memset(p, 0, PAGE_SIZE); > + kvm_unmap_page_atomic(p); > + } > + > + kernel_map_pages(page, nr_pages, 1); > +} > +EXPORT_SYMBOL_GPL(kvm_map_page); > + > +void kvm_unmap_page(struct page *page, int nr_pages) > +{ > + kernel_map_pages(page, nr_pages, 0); > +} > +EXPORT_SYMBOL_GPL(kvm_unmap_page); > + > int kvm_init_protected_memory(void) > { > guest_map_ptes = kmalloc_array(num_possible_cpus(), > -- > 2.26.2 > > -- Sincerely yours, Mike.