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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 A1839C43461 for ; Wed, 21 Apr 2021 10:07:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6CFAD61448 for ; Wed, 21 Apr 2021 10:07:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237987AbhDUKH7 (ORCPT ); Wed, 21 Apr 2021 06:07:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55750 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234768AbhDUKH5 (ORCPT ); Wed, 21 Apr 2021 06:07:57 -0400 Received: from mail.skyhub.de (mail.skyhub.de [IPv6:2a01:4f8:190:11c2::b:1457]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 46833C06174A; Wed, 21 Apr 2021 03:07:24 -0700 (PDT) Received: from zn.tnic (p2e584d0d.dip0.t-ipconnect.de [46.88.77.13]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 8F3561EC02FE; Wed, 21 Apr 2021 12:07:22 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1618999642; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=nlWh21zVm9wXf6lmbj/qjCQYJOgoa0PKTSSc0HqTslI=; b=RqA3aml/cZyDqGPFABn1m49TskGG/uQch5cv2gIPodJ1q6Oe11Ya1UlEgcRfSN6PPxBMIv Lh7vqD8Nv1Ob86DJfprMlP+1lUV71AuK3nRak1ULGlKkLOiKWxgXXNLHPRejfP4kvnmtGf VsQX22r0FmYNFDWEmyswoa4q/MAE7Sc= Date: Wed, 21 Apr 2021 12:05:08 +0200 From: Borislav Petkov To: Ashish Kalra Cc: pbonzini@redhat.com, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, joro@8bytes.org, thomas.lendacky@amd.com, x86@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, srutherford@google.com, seanjc@google.com, venu.busireddy@oracle.com, brijesh.singh@amd.com Subject: Re: [PATCH v13 09/12] mm: x86: Invoke hypercall when page encryption status is changed Message-ID: <20210421100508.GA11234@zn.tnic> References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 15, 2021 at 03:57:26PM +0000, Ashish Kalra wrote: > +static inline void page_encryption_changed(unsigned long vaddr, int npages, > + bool enc) When you see a function name "page_encryption_changed", what does that tell you about what that function does? Dunno but it doesn't tell me a whole lot. Now look at the other function names in struct pv_mmu_ops. See the difference? > +static void set_memory_enc_dec_hypercall(unsigned long vaddr, int npages, If I had to guess what that function does just by reading its name, it sets a memory encryption/decryption hypercall. Am I close? > + bool enc) > +{ > + unsigned long sz = npages << PAGE_SHIFT; > + unsigned long vaddr_end, vaddr_next; > + > + vaddr_end = vaddr + sz; > + > + for (; vaddr < vaddr_end; vaddr = vaddr_next) { > + int psize, pmask, level; > + unsigned long pfn; > + pte_t *kpte; > + > + kpte = lookup_address(vaddr, &level); > + if (!kpte || pte_none(*kpte)) > + return; > + > + switch (level) { > + case PG_LEVEL_4K: > + pfn = pte_pfn(*kpte); > + break; > + case PG_LEVEL_2M: > + pfn = pmd_pfn(*(pmd_t *)kpte); > + break; > + case PG_LEVEL_1G: > + pfn = pud_pfn(*(pud_t *)kpte); > + break; > + default: > + return; > + } Pretty much that same thing is in __set_clr_pte_enc(). Make a helper function pls. > + > + psize = page_level_size(level); > + pmask = page_level_mask(level); > + > + kvm_sev_hypercall3(KVM_HC_PAGE_ENC_STATUS, > + pfn << PAGE_SHIFT, psize >> PAGE_SHIFT, enc); > + > + vaddr_next = (vaddr & pmask) + psize; > + } As with other patches from Brijesh, that should be a while loop. :) > +} > + > static void __init __set_clr_pte_enc(pte_t *kpte, int level, bool enc) > { > pgprot_t old_prot, new_prot; > @@ -286,12 +329,13 @@ static void __init __set_clr_pte_enc(pte_t *kpte, int level, bool enc) > static int __init early_set_memory_enc_dec(unsigned long vaddr, > unsigned long size, bool enc) > { > - unsigned long vaddr_end, vaddr_next; > + unsigned long vaddr_end, vaddr_next, start; > unsigned long psize, pmask; > int split_page_size_mask; > int level, ret; > pte_t *kpte; > > + start = vaddr; > vaddr_next = vaddr; > vaddr_end = vaddr + size; > > @@ -346,6 +390,8 @@ static int __init early_set_memory_enc_dec(unsigned long vaddr, > > ret = 0; > > + set_memory_enc_dec_hypercall(start, PAGE_ALIGN(size) >> PAGE_SHIFT, > + enc); > out: > __flush_tlb_all(); > return ret; > @@ -481,6 +527,15 @@ void __init mem_encrypt_init(void) > if (sev_active() && !sev_es_active()) > static_branch_enable(&sev_enable_key); > > +#ifdef CONFIG_PARAVIRT > + /* > + * With SEV, we need to make a hypercall when page encryption state is > + * changed. > + */ > + if (sev_active()) > + pv_ops.mmu.page_encryption_changed = set_memory_enc_dec_hypercall; > +#endif There's already a sev_active() check above it. Merge the two pls. > + > print_mem_encrypt_feature_info(); > } > > diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c > index 16f878c26667..3576b583ac65 100644 > --- a/arch/x86/mm/pat/set_memory.c > +++ b/arch/x86/mm/pat/set_memory.c > @@ -27,6 +27,7 @@ > #include > #include > #include > +#include > > #include "../mm_internal.h" > > @@ -2012,6 +2013,12 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc) > */ > cpa_flush(&cpa, 0); > > + /* Notify hypervisor that a given memory range is mapped encrypted > + * or decrypted. The hypervisor will use this information during the > + * VM migration. > + */ Kernel comments style is: /* * A sentence ending with a full-stop. * Another sentence. ... * More sentences. ... */ -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette