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[192.237.175.120]) by mx.google.com with ESMTPS id g15-v6si9911701itf.85.2018.07.16.10.29.45 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 16 Jul 2018 10:29:45 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of xen-devel-bounces@lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of xen-devel-bounces@lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1ff7HZ-0006XR-9r; Mon, 16 Jul 2018 17:27:33 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1ff7HY-0006Vs-4W for xen-devel@lists.xenproject.org; Mon, 16 Jul 2018 17:27:32 +0000 X-Inumbo-ID: 8a5dcb62-891d-11e8-a6a9-d7ebe60f679a Received: from foss.arm.com (unknown [217.140.101.70]) by us1-amaz-eas1.inumbo.com (Halon) with ESMTP id 8a5dcb62-891d-11e8-a6a9-d7ebe60f679a; Mon, 16 Jul 2018 17:27:40 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C60237A9; Mon, 16 Jul 2018 10:27:30 -0700 (PDT) Received: from e108454-lin.cambridge.arm.com (e108454-lin.cambridge.arm.com [10.1.206.53]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0B3753F5B1; Mon, 16 Jul 2018 10:27:29 -0700 (PDT) From: Julien Grall To: xen-devel@lists.xenproject.org Date: Mon, 16 Jul 2018 18:27:08 +0100 Message-Id: <20180716172712.20294-12-julien.grall@arm.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20180716172712.20294-1-julien.grall@arm.com> References: <20180716172712.20294-1-julien.grall@arm.com> Subject: [Xen-devel] [PATCH 11/15] xen/arm: Allow lpae_is_{table, mapping} helpers to work on invalid entry X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Julien Grall , sstabellini@kernel.org MIME-Version: 1.0 Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" Currently, lpae_is_{table, mapping} helpers will always return false on entry with the valid bit unset. However, it would be useful to have them operating on any entry. For instance to store information in advance but still request a fault. With that change, the p2m is now providing an overlay for *_is_{table, mapping} that will check the valid bit of the entry. Signed-off-by: Julien Grall --- xen/arch/arm/guest_walk.c | 2 +- xen/arch/arm/mm.c | 2 +- xen/arch/arm/p2m.c | 22 ++++++++++++++++++---- xen/include/asm-arm/lpae.h | 11 +++++++---- 4 files changed, 27 insertions(+), 10 deletions(-) diff --git a/xen/arch/arm/guest_walk.c b/xen/arch/arm/guest_walk.c index e3e21bdad3..4a1b4cf2c8 100644 --- a/xen/arch/arm/guest_walk.c +++ b/xen/arch/arm/guest_walk.c @@ -566,7 +566,7 @@ static int guest_walk_ld(const struct vcpu *v, * PTE is invalid or holds a reserved entry (PTE<1:0> == x0)) or if the PTE * maps a memory block at level 3 (PTE<1:0> == 01). */ - if ( !lpae_is_mapping(pte, level) ) + if ( !lpae_is_valid(pte) || !lpae_is_mapping(pte, level) ) return -EFAULT; /* Make sure that the lower bits of the PTE's base address are zero. */ diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c index e3dafe5fd7..52e57fef2f 100644 --- a/xen/arch/arm/mm.c +++ b/xen/arch/arm/mm.c @@ -996,7 +996,7 @@ static int create_xen_entries(enum xenmap_operation op, for(; addr < addr_end; addr += PAGE_SIZE, mfn = mfn_add(mfn, 1)) { entry = &xen_second[second_linear_offset(addr)]; - if ( !lpae_is_table(*entry, 2) ) + if ( !lpae_is_valid(*entry) || !lpae_is_table(*entry, 2) ) { rc = create_xen_table(entry); if ( rc < 0 ) { diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c index ec3fdcb554..07925a1be4 100644 --- a/xen/arch/arm/p2m.c +++ b/xen/arch/arm/p2m.c @@ -219,6 +219,20 @@ static p2m_access_t p2m_mem_access_radix_get(struct p2m_domain *p2m, gfn_t gfn) return radix_tree_ptr_to_int(ptr); } +/* + * lpae_is_* helpers don't check whether the valid bit is set in the + * PTE. Provide our own overlay to check the valid bit. + */ +static inline bool p2m_is_mapping(lpae_t pte, unsigned int level) +{ + return lpae_is_valid(pte) && lpae_is_mapping(pte, level); +} + +static inline bool p2m_is_superpage(lpae_t pte, unsigned int level) +{ + return lpae_is_valid(pte) && lpae_is_superpage(pte, level); +} + #define GUEST_TABLE_MAP_FAILED 0 #define GUEST_TABLE_SUPER_PAGE 1 #define GUEST_TABLE_NORMAL_PAGE 2 @@ -262,7 +276,7 @@ static int p2m_next_level(struct p2m_domain *p2m, bool read_only, /* The function p2m_next_level is never called at the 3rd level */ ASSERT(level < 3); - if ( lpae_is_mapping(*entry, level) ) + if ( p2m_is_mapping(*entry, level) ) return GUEST_TABLE_SUPER_PAGE; mfn = lpae_to_mfn(*entry); @@ -642,7 +656,7 @@ static void p2m_free_entry(struct p2m_domain *p2m, return; /* Nothing to do but updating the stats if the entry is a super-page. */ - if ( lpae_is_superpage(entry, level) ) + if ( p2m_is_superpage(entry, level) ) { p2m->stats.mappings[level]--; return; @@ -697,7 +711,7 @@ static bool p2m_split_superpage(struct p2m_domain *p2m, lpae_t *entry, * a superpage. */ ASSERT(level < target); - ASSERT(lpae_is_superpage(*entry, level)); + ASSERT(p2m_is_superpage(*entry, level)); page = alloc_domheap_page(NULL, 0); if ( !page ) @@ -834,7 +848,7 @@ static int __p2m_set_entry(struct p2m_domain *p2m, /* We need to split the original page. */ lpae_t split_pte = *entry; - ASSERT(lpae_is_superpage(*entry, level)); + ASSERT(p2m_is_superpage(*entry, level)); if ( !p2m_split_superpage(p2m, &split_pte, level, target, offsets) ) { diff --git a/xen/include/asm-arm/lpae.h b/xen/include/asm-arm/lpae.h index 05c87a8f48..88f30fc917 100644 --- a/xen/include/asm-arm/lpae.h +++ b/xen/include/asm-arm/lpae.h @@ -133,16 +133,19 @@ static inline bool lpae_is_valid(lpae_t pte) return pte.walk.valid; } +/* + * lpae_is_* don't check the valid bit. This gives an opportunity for the + * callers to operate on the entry even if they are not valid. For + * instance to store information in advance. + */ static inline bool lpae_is_table(lpae_t pte, unsigned int level) { - return (level < 3) && lpae_is_valid(pte) && pte.walk.table; + return (level < 3) && pte.walk.table; } static inline bool lpae_is_mapping(lpae_t pte, unsigned int level) { - if ( !lpae_is_valid(pte) ) - return false; - else if ( level == 3 ) + if ( level == 3 ) return pte.walk.table; else return !pte.walk.table;