From patchwork Thu Jun 3 22:58:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lai Jiangshan X-Patchwork-Id: 12299127 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=-14.2 required=3.0 tests=BAYES_00,DATE_IN_PAST_06_12, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 29BF0C07E94 for ; Fri, 4 Jun 2021 08:43:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0C9016140F for ; Fri, 4 Jun 2021 08:43:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230162AbhFDIpg (ORCPT ); Fri, 4 Jun 2021 04:45:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56620 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230139AbhFDIpf (ORCPT ); Fri, 4 Jun 2021 04:45:35 -0400 Received: from mail-pg1-x52c.google.com (mail-pg1-x52c.google.com [IPv6:2607:f8b0:4864:20::52c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E6913C06174A for ; Fri, 4 Jun 2021 01:43:49 -0700 (PDT) Received: by mail-pg1-x52c.google.com with SMTP id 29so7286724pgu.11 for ; Fri, 04 Jun 2021 01:43:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=FigIGmRIu5SYFHKn/ZPvBuA0AvniqiVs7gd/RP2sOog=; b=Iq5t2MILAMIw8b8me94GQifcgT+ECntTBGCLZyHEylAOqmmBt+SycqWSyi4Vz0s+fE L8iy4GU82U56VWRWFxZfRPv4/sAZIvdFbaEDnpWUjnWCayHjg0DY42WxeZ9nhfuloegW y28Hnx/Qs8GAQ5WOumRRHkTzb/vNHDX75Rm/z245h0khyE29LV/EUX9k/IKgWJ35RCZz 8zGIRdQDmldTnQFxyawmi6v5QWszJM5KW1fepuwGw7gNGrUoP09GfMyeNUiAAXhEsuCU gA0N+gLuUnLqdhIio2WAwXvCO1FMIHaC2Ip2FkfUNusefBvYCbQIJwGicVyvD0ausDmV uHBg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=FigIGmRIu5SYFHKn/ZPvBuA0AvniqiVs7gd/RP2sOog=; b=B6D8pTlGVB2GJbgm8jUeykNxbkFyVKAB/hedsjCBdj+NDuzKgWnWEErjoY8USSHVMn 1gIghqM4kFYbQy2ZkLuLDjXFWCt9a2E3WrBmQiv9HQAJqh5LRpWT2Wprs780JYMPYGlf ZgNM+geDyxJaGjRR9sbRp4XD7ieHYQsThbJHVw0OVwevtswUyD1yLqBT5qbNDOEWOHgv XXim6k4gISoQk5fR7mtXx4YSolrd3Hqx9Fs3F66lBrNeRT3kbBX/g3M4nB017RHw6k0G 9EurFMRyhmys+hyj4n7Y03tgAO7oCs99q2+zIsfOnqfujsXbTNAw7JIZ7U2QKRpJLsrt CjNQ== X-Gm-Message-State: AOAM530FD7T4/eviebsc5XX4yXa50SdGqDqW8tTMioajX3k+qprrKZi8 XTvg0TBdLhdIS0IkI9GXT0vvqlLixnU= X-Google-Smtp-Source: ABdhPJyhKs2Bau/r3KMYNFiAm0MxyjIS1LT3PZt1obBV7dgBYZHqg2ZQcsBma6BGDdRC2HfKVQ+y9Q== X-Received: by 2002:a65:4d03:: with SMTP id i3mr3851077pgt.422.1622796229253; Fri, 04 Jun 2021 01:43:49 -0700 (PDT) Received: from localhost ([47.251.4.198]) by smtp.gmail.com with ESMTPSA id cl2sm4080250pjb.31.2021.06.04.01.43.48 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Fri, 04 Jun 2021 01:43:48 -0700 (PDT) From: Lai Jiangshan To: kvm@vger.kernel.org Cc: Paolo Bonzini , Sean Christopherson , Hou Wenlong , Lai Jiangshan Subject: [kvm-unit-tests PATCH V2] x86: Add a test to check effective permissions Date: Fri, 4 Jun 2021 06:58:51 +0800 Message-Id: <20210603225851.26621-1-jiangshanlai@gmail.com> X-Mailer: git-send-email 2.19.1.6.gb485710b In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Lai Jiangshan Add a test to verify that KVM correctly handles the case where two or more non-leaf page table entries point at the same table gfn, but with different parent access permissions. For example, here is a shared pagetable: pgd[] pud[] pmd[] virtual address pointers /->pmd1(u--)->pte1(uw-)->page1 <- ptr1 (u--) /->pud1(uw-)--->pmd2(uw-)->pte2(uw-)->page2 <- ptr2 (uw-) pgd-| (shared pmd[] as above) \->pud2(u--)--->pmd1(u--)->pte1(uw-)->page1 <- ptr3 (u--) \->pmd2(uw-)->pte2(uw-)->page2 <- ptr4 (u--) pud1 and pud2 point to the same pmd table The test is useful when TDP is not enabled. Co-Developed-by: Hou Wenlong Signed-off-by: Hou Wenlong Signed-off-by: Lai Jiangshan --- x86/access.c | 106 ++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 100 insertions(+), 6 deletions(-) diff --git a/x86/access.c b/x86/access.c index 7dc9eb6..98b8545 100644 --- a/x86/access.c +++ b/x86/access.c @@ -60,6 +60,12 @@ enum { AC_PDE_BIT36_BIT, AC_PDE_BIT13_BIT, + /* + * special test case to DISABLE writable bit on page directory + * pointer table entry. + */ + AC_PDPTE_NO_WRITABLE_BIT, + AC_PKU_AD_BIT, AC_PKU_WD_BIT, AC_PKU_PKEY_BIT, @@ -97,6 +103,8 @@ enum { #define AC_PDE_BIT36_MASK (1 << AC_PDE_BIT36_BIT) #define AC_PDE_BIT13_MASK (1 << AC_PDE_BIT13_BIT) +#define AC_PDPTE_NO_WRITABLE_MASK (1 << AC_PDPTE_NO_WRITABLE_BIT) + #define AC_PKU_AD_MASK (1 << AC_PKU_AD_BIT) #define AC_PKU_WD_MASK (1 << AC_PKU_WD_BIT) #define AC_PKU_PKEY_MASK (1 << AC_PKU_PKEY_BIT) @@ -130,6 +138,7 @@ const char *ac_names[] = { [AC_PDE_BIT51_BIT] = "pde.51", [AC_PDE_BIT36_BIT] = "pde.36", [AC_PDE_BIT13_BIT] = "pde.13", + [AC_PDPTE_NO_WRITABLE_BIT] = "pdpte.ro", [AC_PKU_AD_BIT] = "pkru.ad", [AC_PKU_WD_BIT] = "pkru.wd", [AC_PKU_PKEY_BIT] = "pkey=1", @@ -326,6 +335,7 @@ static pt_element_t ac_test_alloc_pt(ac_pool_t *pool) { pt_element_t ret = pool->pt_pool + pool->pt_pool_current; pool->pt_pool_current += PAGE_SIZE; + memset(va(ret), 0, PAGE_SIZE); return ret; } @@ -408,7 +418,7 @@ static void ac_emulate_access(ac_test_t *at, unsigned flags) goto fault; } - writable = F(AC_PDE_WRITABLE); + writable = !F(AC_PDPTE_NO_WRITABLE) && F(AC_PDE_WRITABLE); user = F(AC_PDE_USER); executable = !F(AC_PDE_NX); @@ -471,7 +481,7 @@ static void ac_set_expected_status(ac_test_t *at) ac_emulate_access(at, at->flags); } -static void __ac_setup_specific_pages(ac_test_t *at, ac_pool_t *pool, +static void __ac_setup_specific_pages(ac_test_t *at, ac_pool_t *pool, bool reuse, u64 pd_page, u64 pt_page) { @@ -496,13 +506,29 @@ static void __ac_setup_specific_pages(ac_test_t *at, ac_pool_t *pool, goto next; } skip = false; + if (reuse && vroot[index]) { + switch (i) { + case 2: + at->pdep = &vroot[index]; + break; + case 1: + at->ptep = &vroot[index]; + break; + } + goto next; + } switch (i) { case 5: case 4: + pte = ac_test_alloc_pt(pool); + pte |= PT_PRESENT_MASK | PT_WRITABLE_MASK | PT_USER_MASK; + break; case 3: pte = pd_page ? pd_page : ac_test_alloc_pt(pool); - pte |= PT_PRESENT_MASK | PT_WRITABLE_MASK | PT_USER_MASK; + pte |= PT_PRESENT_MASK | PT_USER_MASK; + if (!F(AC_PDPTE_NO_WRITABLE)) + pte |= PT_WRITABLE_MASK; break; case 2: if (!F(AC_PDE_PSE)) { @@ -568,13 +594,13 @@ static void __ac_setup_specific_pages(ac_test_t *at, ac_pool_t *pool, static void ac_test_setup_pte(ac_test_t *at, ac_pool_t *pool) { - __ac_setup_specific_pages(at, pool, 0, 0); + __ac_setup_specific_pages(at, pool, false, 0, 0); } static void ac_setup_specific_pages(ac_test_t *at, ac_pool_t *pool, u64 pd_page, u64 pt_page) { - return __ac_setup_specific_pages(at, pool, pd_page, pt_page); + return __ac_setup_specific_pages(at, pool, false, pd_page, pt_page); } static void dump_mapping(ac_test_t *at) @@ -930,6 +956,73 @@ err: return 0; } +static int check_effective_sp_permissions(ac_pool_t *pool) +{ + unsigned long ptr1 = 0x123480000000; + unsigned long ptr2 = ptr1 + 2 * 1024 * 1024; + unsigned long ptr3 = ptr1 + 1 * 1024 * 1024 * 1024; + unsigned long ptr4 = ptr3 + 2 * 1024 * 1024; + pt_element_t pmd = ac_test_alloc_pt(pool); + ac_test_t at1, at2, at3, at4; + int err_read_at1, err_write_at2; + int err_read_at3, err_write_at4; + + /* + * pgd[] pud[] pmd[] virtual address pointers + * /->pmd1(u--)->pte1(uw-)->page1 <- ptr1 (u--) + * /->pud1(uw-)--->pmd2(uw-)->pte2(uw-)->page2 <- ptr2 (uw-) + * pgd-| (shared pmd[] as above) + * \->pud2(u--)--->pmd1(u--)->pte1(uw-)->page1 <- ptr3 (u--) + * \->pmd2(uw-)->pte2(uw-)->page2 <- ptr4 (u--) + * pud1 and pud2 point to the same pmd page. + */ + + ac_test_init(&at1, (void *)(ptr1)); + at1.flags = AC_PDE_PRESENT_MASK | AC_PTE_PRESENT_MASK | + AC_PDE_USER_MASK | AC_PTE_USER_MASK | + AC_PDE_ACCESSED_MASK | AC_PTE_ACCESSED_MASK | + AC_PTE_WRITABLE_MASK | AC_ACCESS_USER_MASK; + __ac_setup_specific_pages(&at1, pool, false, pmd, 0); + + ac_test_init(&at2, (void *)(ptr2)); + at2.flags = at1.flags | AC_PDE_WRITABLE_MASK | AC_PTE_DIRTY_MASK | AC_ACCESS_WRITE_MASK; + __ac_setup_specific_pages(&at2, pool, true, pmd, 0); + + ac_test_init(&at3, (void *)(ptr3)); + at3.flags = AC_PDPTE_NO_WRITABLE_MASK | at1.flags; + __ac_setup_specific_pages(&at3, pool, true, pmd, 0); + + ac_test_init(&at4, (void *)(ptr4)); + at4.flags = AC_PDPTE_NO_WRITABLE_MASK | at2.flags; + __ac_setup_specific_pages(&at4, pool, true, pmd, 0); + + err_read_at1 = ac_test_do_access(&at1); + if (!err_read_at1) { + printf("%s: read access at1 fail\n", __FUNCTION__); + return 0; + } + + err_write_at2 = ac_test_do_access(&at2); + if (!err_write_at2) { + printf("%s: write access at2 fail\n", __FUNCTION__); + return 0; + } + + err_read_at3 = ac_test_do_access(&at3); + if (!err_read_at3) { + printf("%s: read access at3 fail\n", __FUNCTION__); + return 0; + } + + err_write_at4 = ac_test_do_access(&at4); + if (!err_write_at4) { + printf("%s: write access at4 should fail\n", __FUNCTION__); + return 0; + } + + return 1; +} + static int ac_test_exec(ac_test_t *at, ac_pool_t *pool) { int r; @@ -948,7 +1041,8 @@ const ac_test_fn ac_test_cases[] = corrupt_hugepage_triger, check_pfec_on_prefetch_pte, check_large_pte_dirty_for_nowp, - check_smep_andnot_wp + check_smep_andnot_wp, + check_effective_sp_permissions, }; static int ac_test_run(void)