From nobody Tue Dec 16 13:48:11 2025 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 65707C6FA8F for ; Thu, 24 Aug 2023 22:38:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243908AbjHXWiI (ORCPT ); Thu, 24 Aug 2023 18:38:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53280 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243937AbjHXWhr (ORCPT ); Thu, 24 Aug 2023 18:37:47 -0400 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B44F9E77 for ; Thu, 24 Aug 2023 15:37:45 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-58c8cbf0a0dso29043407b3.1 for ; Thu, 24 Aug 2023 15:37:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1692916665; x=1693521465; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=UMFl4tquwwjAqS1w3i0zThSN3MgU1gooXrvOwfPzxiY=; b=Dl/FB9cQAooD+5xmfvVkbd+RWJKasgFxWZ2KnhM7gWtqQS2A+Th+gfhgfoVdw+yGBD mYbzABOrt/V+AYVwlcDMGJkT3fWxPaNC5WDQ3oUtROEpYeiNRHJJVzBaoW/HI3wQybTv Y8p/5T7hLQ1GJ9TCE4PBEunEGsBjvOu0GH6hwVMDXSHGwuXTV7FZTU0zH6ixYJhS8zhD X9lFj+ZI/5OvoJ/+DxT5hjWkaC0rwH+BPS8PIoTrkiPnjdWxgQNE/2LQo2Uo6qeCkkDB Vchv+Sh4SesvmENbHOtNekx8pvUbPjDtfXT6xuB5SSWi5b38xG3rMzWsL9O4zquBpoDF JALA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1692916665; x=1693521465; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=UMFl4tquwwjAqS1w3i0zThSN3MgU1gooXrvOwfPzxiY=; b=FqHuAZVhNWzkzQwmAeZBaKr2MrsxdClh8q9KujDJrGBpKVNaQkoW4QSPt+k6paBWce 1C3jkQHJBEysRb9mWrYPfpGxJPV7YS4+hUvSUlzKwF2skTB6mC+HzjK7gZuhwDnrwcuC xHrxISqUD1VX02++nSAJQ/gbKN9WglO6lcV793hrDDhTfM7ohBH5pLiV09zseTXnB3a8 DhLaJiSnfn3kAewLmybGn0kLPHTybV05+CrcKhFDUAeRTn/lLZxfQc6GxNo1TZvHsiaI pkTUuI64MxFS81wg1byBTafPPzkqkqhYGIe7M/YHceg1HWkk+lrTJDhpCPBTrdYW9Dph 41Wg== X-Gm-Message-State: AOJu0Yx47VohmN5/qHWZeOHf7FjbF6ziV8YMZWilPxo0m2WG/kKNvmvN uLAuDEQSzEt8dq/JKLTAIBf0wfSkI4uF6qyNbg== X-Google-Smtp-Source: AGHT+IEcNoYWlkJCqJb3cVnMqS2O4oLgeTyN2sbLgckZMBtD7aJFOXZZEaU0dUzbpAUrKO56nFA29Ob66DhkUhC/HA== X-Received: from riemann.sea.corp.google.com ([2620:15c:100:201:1fdc:3cc3:587a:93c9]) (user=srutherford job=sendgmr) by 2002:a05:690c:2712:b0:57a:6019:62aa with SMTP id dy18-20020a05690c271200b0057a601962aamr329028ywb.5.1692916665017; Thu, 24 Aug 2023 15:37:45 -0700 (PDT) Date: Thu, 24 Aug 2023 15:37:31 -0700 Mime-Version: 1.0 X-Mailer: git-send-email 2.42.0.rc1.204.g551eb34607-goog Message-ID: <20230824223731.2055016-1-srutherford@google.com> Subject: [PATCH v3] x86/sev: Make enc_dec_hypercall() accept a size instead of npages From: Steve Rutherford To: Borislav Petkov , Thomas Gleixner , thomas.lendacky@amd.com, pankaj.gupta@amd.com Cc: Paolo Bonzini , Wanpeng Li , Vitaly Kuznetsov , Ingo Molnar , Dave Hansen , x86@kernel.org, "H . Peter Anvin" , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, David.Kaplan@amd.com, jacobhxu@google.com, patelsvishal@google.com, bhillier@google.com, Steve Rutherford , stable@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" enc_dec_hypercall() accepted a page count instead of a size, which forced its callers to round up. As a result, non-page aligned vaddrs caused pages to be spuriously marked as decrypted via the encryption status hypercall, which in turn caused consistent corruption of pages during live migration. Live migration requires accurate encryption status information to avoid migrating pages from the wrong perspective. Cc: stable@vger.kernel.org Fixes: 064ce6c550a0 ("mm: x86: Invoke hypercall when page encryption status= is changed") Signed-off-by: Steve Rutherford Reviewed-by: Tom Lendacky Reviewed-by: Pankaj Gupta Tested-by: Ben Hillier --- arch/x86/include/asm/mem_encrypt.h | 6 +++--- arch/x86/kernel/kvm.c | 4 +--- arch/x86/mm/mem_encrypt_amd.c | 13 ++++++------- 3 files changed, 10 insertions(+), 13 deletions(-) diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_= encrypt.h index 7f97a8a97e24..473b16d73b47 100644 --- a/arch/x86/include/asm/mem_encrypt.h +++ b/arch/x86/include/asm/mem_encrypt.h @@ -50,8 +50,8 @@ void __init sme_enable(struct boot_params *bp); =20 int __init early_set_memory_decrypted(unsigned long vaddr, unsigned long s= ize); int __init early_set_memory_encrypted(unsigned long vaddr, unsigned long s= ize); -void __init early_set_mem_enc_dec_hypercall(unsigned long vaddr, int npage= s, - bool enc); +void __init early_set_mem_enc_dec_hypercall(unsigned long vaddr, + unsigned long size, bool enc); =20 void __init mem_encrypt_free_decrypted_mem(void); =20 @@ -85,7 +85,7 @@ early_set_memory_decrypted(unsigned long vaddr, unsigned = long size) { return 0; static inline int __init early_set_memory_encrypted(unsigned long vaddr, unsigned long size) { retu= rn 0; } static inline void __init -early_set_mem_enc_dec_hypercall(unsigned long vaddr, int npages, bool enc)= {} +early_set_mem_enc_dec_hypercall(unsigned long vaddr, unsigned long size, b= ool enc) {} =20 static inline void mem_encrypt_free_decrypted_mem(void) { } =20 diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index 6a36db4f79fd..b8ab9ee5896c 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -966,10 +966,8 @@ static void __init kvm_init_platform(void) * Ensure that _bss_decrypted section is marked as decrypted in the * shared pages list. */ - nr_pages =3D DIV_ROUND_UP(__end_bss_decrypted - __start_bss_decrypted, - PAGE_SIZE); early_set_mem_enc_dec_hypercall((unsigned long)__start_bss_decrypted, - nr_pages, 0); + __end_bss_decrypted - __start_bss_decrypted, 0); =20 /* * If not booted using EFI, enable Live migration support. diff --git a/arch/x86/mm/mem_encrypt_amd.c b/arch/x86/mm/mem_encrypt_amd.c index 54bbd5163e8d..6faea41e99b6 100644 --- a/arch/x86/mm/mem_encrypt_amd.c +++ b/arch/x86/mm/mem_encrypt_amd.c @@ -288,11 +288,10 @@ static bool amd_enc_cache_flush_required(void) return !cpu_feature_enabled(X86_FEATURE_SME_COHERENT); } =20 -static void enc_dec_hypercall(unsigned long vaddr, int npages, bool enc) +static void enc_dec_hypercall(unsigned long vaddr, unsigned long size, boo= l enc) { #ifdef CONFIG_PARAVIRT - unsigned long sz =3D npages << PAGE_SHIFT; - unsigned long vaddr_end =3D vaddr + sz; + unsigned long vaddr_end =3D vaddr + size; =20 while (vaddr < vaddr_end) { int psize, pmask, level; @@ -342,7 +341,7 @@ static bool amd_enc_status_change_finish(unsigned long = vaddr, int npages, bool e snp_set_memory_private(vaddr, npages); =20 if (!cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT)) - enc_dec_hypercall(vaddr, npages, enc); + enc_dec_hypercall(vaddr, npages << PAGE_SHIFT, enc); =20 return true; } @@ -466,7 +465,7 @@ static int __init early_set_memory_enc_dec(unsigned lon= g vaddr, =20 ret =3D 0; =20 - early_set_mem_enc_dec_hypercall(start, PAGE_ALIGN(size) >> PAGE_SHIFT, en= c); + early_set_mem_enc_dec_hypercall(start, size, enc); out: __flush_tlb_all(); return ret; @@ -482,9 +481,9 @@ int __init early_set_memory_encrypted(unsigned long vad= dr, unsigned long size) return early_set_memory_enc_dec(vaddr, size, true); } =20 -void __init early_set_mem_enc_dec_hypercall(unsigned long vaddr, int npage= s, bool enc) +void __init early_set_mem_enc_dec_hypercall(unsigned long vaddr, unsigned = long size, bool enc) { - enc_dec_hypercall(vaddr, npages, enc); + enc_dec_hypercall(vaddr, size, enc); } =20 void __init sme_early_init(void) --=20 2.42.0.rc1.204.g551eb34607-goog