From nobody Thu Oct 30 23:29:41 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=fail(p=none dis=none) header.from=arm.com Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1751465676356366.28363610728707; Wed, 2 Jul 2025 07:14:36 -0700 (PDT) Received: from list by lists.xenproject.org with outflank-mailman.1031203.1404961 (Exim 4.92) (envelope-from ) id 1uWyEC-0007vr-Gy; Wed, 02 Jul 2025 14:14:24 +0000 Received: by outflank-mailman (output) from mailman id 1031203.1404961; Wed, 02 Jul 2025 14:14:24 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1uWyEC-0007vg-AT; Wed, 02 Jul 2025 14:14:24 +0000 Received: by outflank-mailman (input) for mailman id 1031203; Wed, 02 Jul 2025 14:14:23 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1uWyEB-0007en-1n for xen-devel@lists.xenproject.org; Wed, 02 Jul 2025 14:14:23 +0000 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by se1-gles-flk1.inumbo.com (Halon) with ESMTP id d6e9efb0-574e-11f0-b894-0df219b8e170; Wed, 02 Jul 2025 16:14:17 +0200 (CEST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 25E2B22C7; Wed, 2 Jul 2025 07:14:02 -0700 (PDT) Received: from PWQ0QT7DJ1.arm.com (unknown [10.57.65.245]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id C6A183F6A8; Wed, 2 Jul 2025 07:14:15 -0700 (PDT) X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: d6e9efb0-574e-11f0-b894-0df219b8e170 From: Hari Limaye To: xen-devel@lists.xenproject.org Cc: luca.fancellu@arm.com, Stefano Stabellini , Julien Grall , Bertrand Marquis , Michal Orzel , Volodymyr Babchuk Subject: [PATCH v2 1/6] arm/mpu: Find MPU region by range Date: Wed, 2 Jul 2025 15:13:56 +0100 Message-ID: X-Mailer: git-send-email 2.42.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ZM-MESSAGEID: 1751465677181116600 Content-Type: text/plain; charset="utf-8" From: Luca Fancellu Implement a function to find the index of a MPU region in the xen_mpumap MPU region array. This function will be used in future commits to implement creating and destroying MPU regions. Signed-off-by: Luca Fancellu Signed-off-by: Hari Limaye --- Changes from v1: - Update commit message - Remove internal _index variable - Simplify logic by disallowing NULL index parameter - Use normal printk - Reorder conditional checks - Update some comments --- xen/arch/arm/include/asm/mpu/mm.h | 29 +++++++++++++++++ xen/arch/arm/mpu/mm.c | 52 +++++++++++++++++++++++++++++++ 2 files changed, 81 insertions(+) diff --git a/xen/arch/arm/include/asm/mpu/mm.h b/xen/arch/arm/include/asm/m= pu/mm.h index a7f970b465..81e47b9d0b 100644 --- a/xen/arch/arm/include/asm/mpu/mm.h +++ b/xen/arch/arm/include/asm/mpu/mm.h @@ -10,6 +10,13 @@ #include #include =20 +#define MPUMAP_REGION_OVERLAP -1 +#define MPUMAP_REGION_NOTFOUND 0 +#define MPUMAP_REGION_FOUND 1 +#define MPUMAP_REGION_INCLUSIVE 2 + +#define INVALID_REGION_IDX 0xFFU + extern struct page_info *frame_table; =20 extern uint8_t max_mpu_regions; @@ -75,6 +82,28 @@ void write_protection_region(const pr_t *pr_write, uint8= _t sel); */ pr_t pr_of_addr(paddr_t base, paddr_t limit, unsigned int flags); =20 +/* + * Checks whether a given memory range is present in the provided table of + * MPU protection regions. + * + * @param table Array of pr_t protection regions. + * @param r_regions Number of elements in `table`. + * @param base Start of the memory region to be checked (inclusiv= e). + * @param limit End of the memory region to be checked (exclusive). + * @param index Set to the index of the region if an exact or incl= usive + * match is found, and INVALID_REGION otherwise. + * @return: Return code indicating the result of the search: + * MPUMAP_REGION_NOTFOUND: no part of the range is present in `ta= ble` + * MPUMAP_REGION_FOUND: found an exact match in `table` + * MPUMAP_REGION_INCLUSIVE: found an inclusive match in `table` + * MPUMAP_REGION_OVERLAP: found an overlap with a mapping in `tab= le` + * + * Note: make sure that the range [`base`, `limit`) refers to the memory r= egion + * inclusive of `base` and exclusive of `limit`. + */ +int mpumap_contains_region(pr_t *table, uint8_t nr_regions, paddr_t base, + paddr_t limit, uint8_t *index); + #endif /* __ARM_MPU_MM_H__ */ =20 /* diff --git a/xen/arch/arm/mpu/mm.c b/xen/arch/arm/mpu/mm.c index ccfb37a67b..25e7f36c1e 100644 --- a/xen/arch/arm/mpu/mm.c +++ b/xen/arch/arm/mpu/mm.c @@ -110,6 +110,58 @@ pr_t pr_of_addr(paddr_t base, paddr_t limit, unsigned = int flags) return region; } =20 +int mpumap_contains_region(pr_t *table, uint8_t nr_regions, paddr_t base, + paddr_t limit, uint8_t *index) +{ + ASSERT(index); + *index =3D INVALID_REGION_IDX; + + /* Convert [base, limit) to [base, limit - 1] for inclusive comparison= */ + limit =3D limit - 1; + + if ( limit < base ) + { + printk("Base address %#"PRIpaddr" must be smaller than limit addre= ss %#"PRIpaddr"\n", + base, limit); + return -EINVAL; + } + + for (uint8_t i =3D 0; i < nr_regions; i++ ) + { + paddr_t iter_base =3D pr_get_base(&table[i]); + paddr_t iter_limit =3D pr_get_limit(&table[i]); + + /* Skip invalid (disabled) regions */ + if ( !region_is_valid(&table[i]) ) + continue; + + /* No match */ + if ( (iter_limit < base) || (iter_base > limit) ) + continue; + + /* Exact match */ + if ( (iter_base =3D=3D base) && (iter_limit =3D=3D limit) ) + { + *index =3D i; + return MPUMAP_REGION_FOUND; + } + + /* Inclusive match */ + if ( (base >=3D iter_base) && (limit <=3D iter_limit) ) + { + *index =3D i; + return MPUMAP_REGION_INCLUSIVE; + } + + /* Overlap */ + printk("Range %#"PRIpaddr" - %#"PRIpaddr" overlaps with the existi= ng region %#"PRIpaddr" - %#"PRIpaddr"\n", + base, limit + 1, iter_base, iter_limit + 1); + return MPUMAP_REGION_OVERLAP; + } + + return MPUMAP_REGION_NOTFOUND; +} + void __init setup_mm(void) { BUG_ON("unimplemented"); --=20 2.34.1 From nobody Thu Oct 30 23:29:41 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; 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Wed, 02 Jul 2025 16:14:20 +0200 (CEST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id EC73E22D9; Wed, 2 Jul 2025 07:14:04 -0700 (PDT) Received: from PWQ0QT7DJ1.arm.com (unknown [10.57.65.245]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7D9003F6A8; Wed, 2 Jul 2025 07:14:18 -0700 (PDT) X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: d8a116f6-574e-11f0-b894-0df219b8e170 From: Hari Limaye To: xen-devel@lists.xenproject.org Cc: luca.fancellu@arm.com, Stefano Stabellini , Julien Grall , Bertrand Marquis , Michal Orzel , Volodymyr Babchuk , Ayan Kumar Halder Subject: [PATCH v2 2/6] xen/arm: Introduce flags_has_rwx helper Date: Wed, 2 Jul 2025 15:13:57 +0100 Message-ID: X-Mailer: git-send-email 2.42.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ZM-MESSAGEID: 1751465675311116600 Content-Type: text/plain; charset="utf-8" From: Luca Fancellu Introduce flags_has_rwx() function that will check if a mapping is both writable and executable when modifying or updating the mapping. This check was already present in pt.c but since it will be used also for MPU systems, it's wrapped into a function now. Signed-off-by: Luca Fancellu Signed-off-by: Hari Limaye Reviewed-by: Ayan Kumar Halder Reviewed-by: Michal Orzel --- Changes from v1: - Add Ayan and Michal's R-b - Fix typos - Don't use extern for function prototype --- xen/arch/arm/include/asm/mm.h | 2 ++ xen/arch/arm/mm.c | 15 +++++++++++++++ xen/arch/arm/mmu/pt.c | 9 +-------- 3 files changed, 18 insertions(+), 8 deletions(-) diff --git a/xen/arch/arm/include/asm/mm.h b/xen/arch/arm/include/asm/mm.h index 011bc1fd30..fb79aeb088 100644 --- a/xen/arch/arm/include/asm/mm.h +++ b/xen/arch/arm/include/asm/mm.h @@ -192,6 +192,8 @@ extern unsigned long frametable_base_pdx; =20 /* Boot-time pagetable setup */ extern void setup_pagetables(void); +/* Check that the mapping flag has no W and X together */ +bool flags_has_rwx(unsigned int flags); /* Map FDT in boot pagetable */ extern void *early_fdt_map(paddr_t fdt_paddr); /* Remove early mappings */ diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c index 0613c19169..77e21f5f29 100644 --- a/xen/arch/arm/mm.c +++ b/xen/arch/arm/mm.c @@ -24,6 +24,21 @@ =20 unsigned long frametable_base_pdx __read_mostly; =20 +bool flags_has_rwx(unsigned int flags) +{ + /* + * The hardware was configured to forbid mapping both writable and + * executable. + * When modifying/creating mapping (i.e _PAGE_PRESENT is set), + * prevent any update if this happen. + */ + if ( (flags & _PAGE_PRESENT) && !PAGE_RO_MASK(flags) && + !PAGE_XN_MASK(flags) ) + return true; + else + return false; +} + void flush_page_to_ram(unsigned long mfn, bool sync_icache) { void *v =3D map_domain_page(_mfn(mfn)); diff --git a/xen/arch/arm/mmu/pt.c b/xen/arch/arm/mmu/pt.c index 4726e713ef..621b47dbf5 100644 --- a/xen/arch/arm/mmu/pt.c +++ b/xen/arch/arm/mmu/pt.c @@ -610,14 +610,7 @@ static int xen_pt_update(unsigned long virt, */ const mfn_t root =3D maddr_to_mfn(READ_SYSREG64(TTBR0_EL2)); =20 - /* - * The hardware was configured to forbid mapping both writeable and - * executable. - * When modifying/creating mapping (i.e _PAGE_PRESENT is set), - * prevent any update if this happen. - */ - if ( (flags & _PAGE_PRESENT) && !PAGE_RO_MASK(flags) && - !PAGE_XN_MASK(flags) ) + if ( flags_has_rwx(flags) ) { mm_printk("Mappings should not be both Writeable and Executable.\n= "); return -EINVAL; --=20 2.34.1 From nobody Thu Oct 30 23:29:41 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=fail(p=none dis=none) header.from=arm.com Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1751465679214542.8969477150239; Wed, 2 Jul 2025 07:14:39 -0700 (PDT) Received: from list by lists.xenproject.org with outflank-mailman.1031204.1404971 (Exim 4.92) (envelope-from ) id 1uWyED-0008By-MI; Wed, 02 Jul 2025 14:14:25 +0000 Received: by outflank-mailman (output) from mailman id 1031204.1404971; Wed, 02 Jul 2025 14:14:25 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1uWyED-0008Bl-I0; 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charset="utf-8" From: Penny Zheng Introduce map_pages_to_xen() that is implemented using a new helper, xen_mpumap_update(), which is responsible for updating Xen MPU memory mapping table(xen_mpumap), including creating a new entry, updating or destroying an existing one, it is equivalent to xen_pt_update in MMU. This commit only implements populating a new entry in Xen MPU memory mapping table(xen_mpumap). Signed-off-by: Penny Zheng Signed-off-by: Wei Chen Signed-off-by: Luca Fancellu Signed-off-by: Hari Limaye --- Changes from v1: - Simplify if condition - Use normal printk - Use %# over 0x% - Add same asserts as in Patch 4 --- xen/arch/arm/include/asm/mpu/mm.h | 12 ++++ xen/arch/arm/mpu/mm.c | 100 ++++++++++++++++++++++++++++++ 2 files changed, 112 insertions(+) diff --git a/xen/arch/arm/include/asm/mpu/mm.h b/xen/arch/arm/include/asm/m= pu/mm.h index 81e47b9d0b..101002f7d4 100644 --- a/xen/arch/arm/include/asm/mpu/mm.h +++ b/xen/arch/arm/include/asm/mpu/mm.h @@ -64,6 +64,7 @@ static inline void context_sync_mpu(void) * The following API requires context_sync_mpu() after being used to modif= y MPU * regions: * - write_protection_region + * - xen_mpumap_update */ =20 /* Reads the MPU region (into @pr_read) with index @sel from the HW */ @@ -72,6 +73,17 @@ void read_protection_region(pr_t *pr_read, uint8_t sel); /* Writes the MPU region (from @pr_write) with index @sel to the HW */ void write_protection_region(const pr_t *pr_write, uint8_t sel); =20 +/* + * Maps an address range into the MPU data structure and updates the HW. + * Equivalent to xen_pt_update in an MMU system. + * + * @param base Base address of the range to map (inclusive). + * @param limit Limit address of the range to map (exclusive). + * @param flags Flags for the memory range to map. + * @return 0 on success, negative on error. + */ +int xen_mpumap_update(paddr_t base, paddr_t limit, unsigned int flags); + /* * Creates a pr_t structure describing a protection region. * diff --git a/xen/arch/arm/mpu/mm.c b/xen/arch/arm/mpu/mm.c index 25e7f36c1e..dd54b66901 100644 --- a/xen/arch/arm/mpu/mm.c +++ b/xen/arch/arm/mpu/mm.c @@ -6,6 +6,7 @@ #include #include #include +#include #include #include #include @@ -29,6 +30,8 @@ DECLARE_BITMAP(xen_mpumap_mask, MAX_MPU_REGION_NR) \ /* EL2 Xen MPU memory region mapping table. */ pr_t __cacheline_aligned __section(".data") xen_mpumap[MAX_MPU_REGION_NR]; =20 +static DEFINE_SPINLOCK(xen_mpumap_lock); + static void __init __maybe_unused build_assertions(void) { /* @@ -162,6 +165,103 @@ int mpumap_contains_region(pr_t *table, uint8_t nr_re= gions, paddr_t base, return MPUMAP_REGION_NOTFOUND; } =20 +/* + * Allocate a new free EL2 MPU memory region, based on bitmap xen_mpumap_m= ask. + * @param idx Set to the index of the allocated EL2 MPU region on succes= s. + * @return 0 on success, otherwise -ENOENT on failure. + */ +static int xen_mpumap_alloc_entry(uint8_t *idx) +{ + ASSERT(spin_is_locked(&xen_mpumap_lock)); + + *idx =3D find_first_zero_bit(xen_mpumap_mask, max_mpu_regions); + if ( *idx =3D=3D max_mpu_regions ) + { + printk(XENLOG_ERR "mpu: EL2 MPU memory region mapping pool exhaust= ed\n"); + return -ENOENT; + } + + set_bit(*idx, xen_mpumap_mask); + return 0; +} + +/* + * Update the entry in the MPU memory region mapping table (xen_mpumap) fo= r the + * given memory range and flags, creating one if none exists. + * + * @param base Base address (inclusive). + * @param limit Limit address (exclusive). + * @param flags Region attributes (a combination of PAGE_HYPERVISOR_XXX) + * @return 0 on success, otherwise negative on error. + */ +static int xen_mpumap_update_entry(paddr_t base, paddr_t limit, + unsigned int flags) +{ + uint8_t idx; + int rc; + + ASSERT(spin_is_locked(&xen_mpumap_lock)); + + rc =3D mpumap_contains_region(xen_mpumap, max_mpu_regions, base, limit= , &idx); + if ( !(rc =3D=3D MPUMAP_REGION_NOTFOUND) ) + return -EINVAL; + + /* We are inserting a mapping =3D> Create new region. */ + if ( flags & _PAGE_PRESENT ) + { + rc =3D xen_mpumap_alloc_entry(&idx); + if ( rc ) + return -ENOENT; + + xen_mpumap[idx] =3D pr_of_addr(base, limit, flags); + + write_protection_region(&xen_mpumap[idx], idx); + } + + return 0; +} + +int xen_mpumap_update(paddr_t base, paddr_t limit, unsigned int flags) +{ + int rc; + + ASSERT(IS_ALIGNED(base, PAGE_SIZE)); + ASSERT(IS_ALIGNED(limit, PAGE_SIZE)); + ASSERT(base <=3D limit); + + if ( flags_has_rwx(flags) ) + { + printk("Mappings should not be both Writeable and Executable\n"); + return -EINVAL; + } + + if ( !IS_ALIGNED(base, PAGE_SIZE) || !IS_ALIGNED(limit, PAGE_SIZE) ) + { + printk("base address %#"PRIpaddr", or limit address %#"PRIpaddr" i= s not page aligned\n", + base, limit); + return -EINVAL; + } + + spin_lock(&xen_mpumap_lock); + + rc =3D xen_mpumap_update_entry(base, limit, flags); + + spin_unlock(&xen_mpumap_lock); + + return rc; +} + +int map_pages_to_xen(unsigned long virt, mfn_t mfn, unsigned long nr_mfns, + unsigned int flags) +{ + int rc =3D xen_mpumap_update(mfn_to_maddr(mfn), + mfn_to_maddr(mfn_add(mfn, nr_mfns)), flags); + if ( !rc ) + context_sync_mpu(); + + return rc; +} + void __init setup_mm(void) { BUG_ON("unimplemented"); --=20 2.34.1 From nobody Thu Oct 30 23:29:41 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=fail(p=none dis=none) header.from=arm.com Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1751465682591968.4831716219096; 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Wed, 2 Jul 2025 07:14:10 -0700 (PDT) Received: from PWQ0QT7DJ1.arm.com (unknown [10.57.65.245]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D6E233F6A8; Wed, 2 Jul 2025 07:14:23 -0700 (PDT) X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: dbed749b-574e-11f0-a313-13f23c93f187 From: Hari Limaye To: xen-devel@lists.xenproject.org Cc: luca.fancellu@arm.com, Penny Zheng , Stefano Stabellini , Julien Grall , Bertrand Marquis , Michal Orzel , Volodymyr Babchuk , Penny Zheng , Wei Chen Subject: [PATCH v2 4/6] arm/mpu: Destroy an existing entry in Xen MPU memory mapping table Date: Wed, 2 Jul 2025 15:13:59 +0100 Message-ID: X-Mailer: git-send-email 2.42.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ZM-MESSAGEID: 1751465683315116600 Content-Type: text/plain; charset="utf-8" From: Penny Zheng This commit expands xen_mpumap_update/xen_mpumap_update_entry to include destroying an existing entry. We define a new helper "disable_mpu_region_from_index" to disable the MPU region based on index. If region is within [0, 31], we could quickly disable the MPU region through PRENR_EL2 which provides direct access to the PRLAR_EL2.EN bits of EL2 MPU regions. Rignt now, we only support destroying a *WHOLE* MPU memory region, part-region removing is not supported, as in worst case, it will leave two fragments behind. Signed-off-by: Penny Zheng Signed-off-by: Wei Chen Signed-off-by: Luca Fancellu Signed-off-by: Hari Limaye --- Changes from v1: - Move check for part-region removal outside if condition - Use normal printk --- xen/arch/arm/include/asm/mpu.h | 2 + xen/arch/arm/include/asm/mpu/cpregs.h | 4 ++ xen/arch/arm/mpu/mm.c | 69 ++++++++++++++++++++++++++- 3 files changed, 73 insertions(+), 2 deletions(-) diff --git a/xen/arch/arm/include/asm/mpu.h b/xen/arch/arm/include/asm/mpu.h index 63560c613b..5053edaf63 100644 --- a/xen/arch/arm/include/asm/mpu.h +++ b/xen/arch/arm/include/asm/mpu.h @@ -23,6 +23,8 @@ #define NUM_MPU_REGIONS_MASK (NUM_MPU_REGIONS - 1) #define MAX_MPU_REGION_NR NUM_MPU_REGIONS_MASK =20 +#define PRENR_MASK GENMASK(31, 0) + #ifndef __ASSEMBLY__ =20 /* diff --git a/xen/arch/arm/include/asm/mpu/cpregs.h b/xen/arch/arm/include/a= sm/mpu/cpregs.h index bb15e02df6..9f3b32acd7 100644 --- a/xen/arch/arm/include/asm/mpu/cpregs.h +++ b/xen/arch/arm/include/asm/mpu/cpregs.h @@ -6,6 +6,9 @@ /* CP15 CR0: MPU Type Register */ #define HMPUIR p15,4,c0,c0,4 =20 +/* CP15 CR6: Protection Region Enable Register */ +#define HPRENR p15,4,c6,c1,1 + /* CP15 CR6: MPU Protection Region Base/Limit/Select Address Register */ #define HPRSELR p15,4,c6,c2,1 #define HPRBAR p15,4,c6,c3,0 @@ -82,6 +85,7 @@ /* Alphabetically... */ #define MPUIR_EL2 HMPUIR #define PRBAR_EL2 HPRBAR +#define PRENR_EL2 HPRENR #define PRLAR_EL2 HPRLAR #define PRSELR_EL2 HPRSELR #endif /* CONFIG_ARM_32 */ diff --git a/xen/arch/arm/mpu/mm.c b/xen/arch/arm/mpu/mm.c index dd54b66901..2e88c467d5 100644 --- a/xen/arch/arm/mpu/mm.c +++ b/xen/arch/arm/mpu/mm.c @@ -185,6 +185,42 @@ static int xen_mpumap_alloc_entry(uint8_t *idx) return 0; } =20 +/* + * Disable and remove an MPU region from the data structure and MPU regist= ers. + * + * @param index Index of the MPU region to be disabled. + */ +static void disable_mpu_region_from_index(uint8_t index) +{ + ASSERT(spin_is_locked(&xen_mpumap_lock)); + ASSERT(index !=3D INVALID_REGION_IDX); + + if ( !region_is_valid(&xen_mpumap[index]) ) + { + printk(XENLOG_WARNING + "mpu: MPU memory region[%u] is already disabled\n", index); + return; + } + + /* Zeroing the region will also zero the region enable */ + memset(&xen_mpumap[index], 0, sizeof(pr_t)); + clear_bit(index, xen_mpumap_mask); + + /* + * Both Armv8-R AArch64 and AArch32 have direct access to the enable b= it for + * MPU regions numbered from 0 to 31. + */ + if ( (index & PRENR_MASK) !=3D 0 ) + { + /* Clear respective bit */ + uint64_t val =3D READ_SYSREG(PRENR_EL2) & (~(1UL << index)); + + WRITE_SYSREG(val, PRENR_EL2); + } + else + write_protection_region(&xen_mpumap[index], index); +} + /* * Update the entry in the MPU memory region mapping table (xen_mpumap) fo= r the * given memory range and flags, creating one if none exists. @@ -203,11 +239,11 @@ static int xen_mpumap_update_entry(paddr_t base, padd= r_t limit, ASSERT(spin_is_locked(&xen_mpumap_lock)); =20 rc =3D mpumap_contains_region(xen_mpumap, max_mpu_regions, base, limit= , &idx); - if ( !(rc =3D=3D MPUMAP_REGION_NOTFOUND) ) + if ( rc < 0 ) return -EINVAL; =20 /* We are inserting a mapping =3D> Create new region. */ - if ( flags & _PAGE_PRESENT ) + if ( (flags & _PAGE_PRESENT) && (MPUMAP_REGION_NOTFOUND =3D=3D rc) ) { rc =3D xen_mpumap_alloc_entry(&idx); if ( rc ) @@ -218,6 +254,20 @@ static int xen_mpumap_update_entry(paddr_t base, paddr= _t limit, write_protection_region(&xen_mpumap[idx], idx); } =20 + /* + * Currently, we only support destroying a *WHOLE* MPU memory region. + * Part-region removal is not supported as in the worst case it will l= eave + * two fragments behind. + */ + if ( rc =3D=3D MPUMAP_REGION_INCLUSIVE ) + { + printk("mpu: part-region removal is not supported\n"); + return -EINVAL; + } + + if ( !(flags & _PAGE_PRESENT) && (rc >=3D MPUMAP_REGION_FOUND) ) + disable_mpu_region_from_index(idx); + return 0; } =20 @@ -251,6 +301,21 @@ int xen_mpumap_update(paddr_t base, paddr_t limit, uns= igned int flags) return rc; } =20 +int destroy_xen_mappings(unsigned long s, unsigned long e) +{ + int rc; + + ASSERT(IS_ALIGNED(s, PAGE_SIZE)); + ASSERT(IS_ALIGNED(e, PAGE_SIZE)); + ASSERT(s <=3D e); + + rc =3D xen_mpumap_update(virt_to_maddr(s), virt_to_maddr(e), 0); + if ( !rc ) + context_sync_mpu(); + + return rc; +} + int map_pages_to_xen(unsigned long virt, mfn_t mfn, unsigned long nr_mfns, unsigned int flags) { --=20 2.34.1 From nobody Thu Oct 30 23:29:41 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=fail(p=none dis=none) header.from=arm.com Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1751465686662519.6493125293531; 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Wed, 2 Jul 2025 07:14:13 -0700 (PDT) Received: from PWQ0QT7DJ1.arm.com (unknown [10.57.65.245]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id AC0063F6A8; Wed, 2 Jul 2025 07:14:26 -0700 (PDT) X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: dd7d27f9-574e-11f0-b894-0df219b8e170 From: Hari Limaye To: xen-devel@lists.xenproject.org Cc: luca.fancellu@arm.com, Stefano Stabellini , Julien Grall , Bertrand Marquis , Michal Orzel , Volodymyr Babchuk , Ayan Kumar Halder Subject: [PATCH v2 5/6] arm/mpu: Implement early_fdt_map support in MPU systems Date: Wed, 2 Jul 2025 15:14:00 +0100 Message-ID: <100cc63353021067e3eae68d092ebd73f484f416.1751464757.git.hari.limaye@arm.com> X-Mailer: git-send-email 2.42.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ZM-MESSAGEID: 1751465687405116600 Content-Type: text/plain; charset="utf-8" From: Luca Fancellu Implement the function early_fdt_map(), which is responsible for mapping the Device Tree Blob in the early stages of the boot process, for MPU systems. We make use of the map_pages_to_xen() and destroy_xen_mappings() APIs. In particular the latter function is necessary in the case that the initial mapping of the fdt_header is insufficient to cover the entire DTB, as we must destroy and then remap the region due to the APIs no providing support for extending the size of an existing region. Signed-off-by: Luca Fancellu Signed-off-by: Hari Limaye Reviewed-by: Ayan Kumar Halder --- Changes from v1: - Add Ayan's R-b --- xen/arch/arm/mpu/setup.c | 74 ++++++++++++++++++++++++++++++++++++++-- 1 file changed, 72 insertions(+), 2 deletions(-) diff --git a/xen/arch/arm/mpu/setup.c b/xen/arch/arm/mpu/setup.c index b4da77003f..ab00cb944b 100644 --- a/xen/arch/arm/mpu/setup.c +++ b/xen/arch/arm/mpu/setup.c @@ -1,17 +1,87 @@ /* SPDX-License-Identifier: GPL-2.0-only */ =20 +#include #include #include +#include #include +#include #include #include =20 +static paddr_t __initdata mapped_fdt_paddr =3D INVALID_PADDR; +static paddr_t __initdata mapped_fdt_limit =3D INVALID_PADDR; + void __init setup_pagetables(void) {} =20 void * __init early_fdt_map(paddr_t fdt_paddr) { - BUG_ON("unimplemented"); - return NULL; + /* Map at least a page containing the DTB address, exclusive range */ + paddr_t base =3D round_pgdown(fdt_paddr); + paddr_t limit =3D round_pgup(fdt_paddr + sizeof(struct fdt_header)); + unsigned int flags =3D PAGE_HYPERVISOR_RO; + void *fdt_virt =3D (void *)fdt_paddr; /* virt =3D=3D paddr for MPU */ + int rc; + unsigned long nr_mfns; + + /* + * Check whether the physical FDT address is set and meets the minimum + * alignment requirement. Since we are relying on MIN_FDT_ALIGN to be = at + * least 8 bytes so that we always access the magic and size fields + * of the FDT header after mapping the first chunk, double check if + * that is indeed the case. + */ + BUILD_BUG_ON(MIN_FDT_ALIGN < 8); + if ( !fdt_paddr || fdt_paddr % MIN_FDT_ALIGN ) + return NULL; + + /* DTB starting at this address has already been mapped. */ + if ( mapped_fdt_paddr =3D=3D fdt_paddr ) + return fdt_virt; + + /* + * DTB starting at a different address has been mapped, so destroy this + * before continuing. + */ + if ( mapped_fdt_paddr !=3D INVALID_PADDR ) + { + rc =3D destroy_xen_mappings(round_pgdown(mapped_fdt_paddr), + mapped_fdt_limit); + if ( rc ) + panic("Unable to unmap existing device-tree.\n"); + } + + nr_mfns =3D (limit - base) >> PAGE_SHIFT; + + rc =3D map_pages_to_xen(base, maddr_to_mfn(base), nr_mfns, flags); + if ( rc ) + panic("Unable to map the device-tree.\n"); + + mapped_fdt_paddr =3D fdt_paddr; + mapped_fdt_limit =3D limit; + + if ( fdt_magic(fdt_virt) !=3D FDT_MAGIC ) + return NULL; + + limit =3D round_pgup(fdt_paddr + fdt_totalsize(fdt_virt)); + + /* If the mapped range is not enough, map the rest of the DTB. */ + if ( limit > mapped_fdt_limit ) + { + rc =3D destroy_xen_mappings(base, mapped_fdt_limit); + if ( rc ) + panic("Unable to unmap the device-tree header.\n"); + + nr_mfns =3D (limit - base) >> PAGE_SHIFT; + + rc =3D map_pages_to_xen(base, maddr_to_mfn(base), nr_mfns, flags); + if ( rc ) + panic("Unable to map the device-tree.\n"); + + mapped_fdt_limit =3D limit; + } + + return fdt_virt; } =20 /* --=20 2.34.1 From nobody Thu Oct 30 23:29:41 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=fail(p=none dis=none) header.from=arm.com Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1751465686217196.2545721578481; Wed, 2 Jul 2025 07:14:46 -0700 (PDT) Received: from list by lists.xenproject.org with outflank-mailman.1031210.1405001 (Exim 4.92) (envelope-from ) id 1uWyEL-0000iy-Mg; Wed, 02 Jul 2025 14:14:33 +0000 Received: by outflank-mailman (output) from mailman id 1031210.1405001; Wed, 02 Jul 2025 14:14:33 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1uWyEL-0000il-Ha; Wed, 02 Jul 2025 14:14:33 +0000 Received: by outflank-mailman (input) for mailman id 1031210; Wed, 02 Jul 2025 14:14:32 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1uWyEK-0007Ob-IF for xen-devel@lists.xenproject.org; Wed, 02 Jul 2025 14:14:32 +0000 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by se1-gles-sth1.inumbo.com (Halon) with ESMTP id df6aa2d3-574e-11f0-a313-13f23c93f187; Wed, 02 Jul 2025 16:14:31 +0200 (CEST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 68EA122C7; Wed, 2 Jul 2025 07:14:16 -0700 (PDT) Received: from PWQ0QT7DJ1.arm.com (unknown [10.57.65.245]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DC3EF3F6A8; Wed, 2 Jul 2025 07:14:29 -0700 (PDT) X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: df6aa2d3-574e-11f0-a313-13f23c93f187 From: Hari Limaye To: xen-devel@lists.xenproject.org Cc: luca.fancellu@arm.com, Stefano Stabellini , Julien Grall , Bertrand Marquis , Michal Orzel , Volodymyr Babchuk , Ayan Kumar Halder Subject: [PATCH v2 6/6] arm/mpu: Implement remove_early_mappings for MPU systems Date: Wed, 2 Jul 2025 15:14:01 +0100 Message-ID: <540b3b9ea598a63b31ffe4165bd791d4b8151863.1751464757.git.hari.limaye@arm.com> X-Mailer: git-send-email 2.42.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ZM-MESSAGEID: 1751465687302116600 Content-Type: text/plain; charset="utf-8" From: Luca Fancellu Implement remove_early_mappings for MPU systems. Signed-off-by: Luca Fancellu Signed-off-by: Hari Limaye Reviewed-by: Ayan Kumar Halder --- Changes from v1: - Add Ayan's R-b --- xen/arch/arm/mpu/setup.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/xen/arch/arm/mpu/setup.c b/xen/arch/arm/mpu/setup.c index ab00cb944b..5928b534d5 100644 --- a/xen/arch/arm/mpu/setup.c +++ b/xen/arch/arm/mpu/setup.c @@ -97,7 +97,14 @@ void __init copy_from_paddr(void *dst, paddr_t paddr, un= signed long len) =20 void __init remove_early_mappings(void) { - BUG_ON("unimplemented"); + int rc; + + if ( mapped_fdt_paddr =3D=3D INVALID_PADDR ) + return; + + rc =3D destroy_xen_mappings(round_pgdown(mapped_fdt_paddr), mapped_fdt= _limit); + if ( rc ) + panic("Unable to unmap the device-tree.\n"); } =20 /* --=20 2.34.1