From nobody Thu Oct 30 23:14:03 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; dkim=pass; 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=pass(p=none dis=none) header.from=gmail.com ARC-Seal: i=1; a=rsa-sha256; t=1758146185; cv=none; d=zohomail.com; s=zohoarc; b=K2rs7yYgfKOu8vrWssFHHUShiivOekbkWkcN724W54rqzkQTHcGd1glRBudtk6fiSD8CUkYUM529dpGc6o9EXIj1RiKxIm6nAzuh+5+QCJEufJ6O1XNMGFFgywubVJXE75dToJbLMrMHIRAFrJR/v53slguS+wiVk1ZZ6JhxHtg= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1758146185; h=Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:Subject:To:To:Message-Id:Reply-To; bh=KISvI+cSCGQuBbffB7BgGhIGyaXm3yteTEaBjxd0dvw=; b=Aw8Jq8t9er3eH/r706+HM1VlHyRrdzV/dXoHvEdkbJC+BTxg8yNO447w/EeDnIHfmH4K/67L55lw7P3RgVFPDbjj4q38xDOp6ohU7Rf16p9Q3MN9WCpx/nvenMy7fqpM6OQa8Ck9Asy8euoAGypflC9wzy/qTHx3glyO2TBGKqo= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; 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=pass header.from= (p=none dis=none) Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1758146185269815.4995217359568; Wed, 17 Sep 2025 14:56:25 -0700 (PDT) Received: from list by lists.xenproject.org with outflank-mailman.1125586.1467523 (Exim 4.92) (envelope-from ) id 1uz089-00006d-Ut; Wed, 17 Sep 2025 21:56:01 +0000 Received: by outflank-mailman (output) from mailman id 1125586.1467523; Wed, 17 Sep 2025 21:56:01 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1uz089-00006M-Qa; Wed, 17 Sep 2025 21:56:01 +0000 Received: by outflank-mailman (input) for mailman id 1125586; Wed, 17 Sep 2025 21:56:00 +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 1uz088-0007Lu-BM for xen-devel@lists.xenproject.org; Wed, 17 Sep 2025 21:56:00 +0000 Received: from mail-pl1-x62c.google.com (mail-pl1-x62c.google.com [2607:f8b0:4864:20::62c]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id 17d37a5c-9411-11f0-9d13-b5c5bf9af7f9; Wed, 17 Sep 2025 23:55:59 +0200 (CEST) Received: by mail-pl1-x62c.google.com with SMTP id d9443c01a7336-2680cf68265so2365365ad.2 for ; Wed, 17 Sep 2025 14:55:59 -0700 (PDT) Received: from fedora ([149.199.65.200]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-26980053da4sm5538095ad.20.2025.09.17.14.55.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 17 Sep 2025 14:55:56 -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: 17d37a5c-9411-11f0-9d13-b5c5bf9af7f9 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1758146157; x=1758750957; darn=lists.xenproject.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=KISvI+cSCGQuBbffB7BgGhIGyaXm3yteTEaBjxd0dvw=; b=hwc+KA/djX59hShLamXAJ8W1Ym6pcbUSk8vGcRXAleDHdbfFtdjWllZjEV5+7M3fXi MQ/u4unguCblMIZkdArAXBFPXppvp4E8cInf6H3han5j7A8vR2MqaQdSF8WPn/XIwBfK t1Xj83sBKcxFxG6QT/9yHnuM9BK40Dp7UpdeZQdtOdz4/RYJzIAir6MRz5/+uZZeFGCA l95xvLGrP2de9q8b2BP7pBtio5M5B4edarT7m4YRr6F3Fl2Wgyjd8n62GK+EQXHRIFmK e2qLHLRvjGc8d8IEDcOJc9bLoFbbmLQC8n4Qz5onMva7RuIcgrOTY4IMt5So9UZ4mVpz BXwg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1758146157; x=1758750957; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=KISvI+cSCGQuBbffB7BgGhIGyaXm3yteTEaBjxd0dvw=; b=I5AlVK4R4XRDJQOcFjrEMl7GqCT5sWxndAlzuDbOWwpgI9aCLPk+wiOBYlwIyAeuK+ V1Vnvnu+KxmMm/uink3d/4g8RtPxvddR5mj+LVWNFMhxFLPzNBas+w7JQzqYYwBdhkcA kMrQffeJum6zuVxayOPbYg/XxaeBrgRTL00XXess1FkUukirIZ6DDnchMgdlFnPIm6AN IyBVcroZL9WG435+lIobjAkFyeK4ZfVyWLi7e+/uLnAADZrwSwo2TiD7g7MesVHorwY/ kdFPhI4nOZf4O7HQXkkcdXChyjo3noSqCuNnIfb4UlsrTIMLl1kMKx/LBLtrcMRgQo/1 yKIw== X-Gm-Message-State: AOJu0YzV9eOzuSWltj2HcBDlGh/HRncGDF7K3gfZNZG4jzRD7Dj1zK8F SnRH9VdVa44GkC++W+DodblAJxmrL4CIFY7+Jmd/Gc9hxoP+7Tai3C7hzD0Bth5feDs= X-Gm-Gg: ASbGncvPH5Cw7jgGvwZR+I6T9ClI0ZIKWPInDM6johiTHaN3b4rEMpYgYNI4Nr5RMmO 6ApyDgnJt1w52iephm2aEayHdyDRzTLtUUyqSc4pL6jRH3PEKl0LaM9kT8wp+6FluoPLB0/PcD4 /g054Xr1hVmqLzG0v2Itz+Pjd0H+5LOn7jK40qwU/8/+aRWxM6bQ6laujXMEw+Gy5BsyLxO794J Pov1tJsEhP7dbzdNwAOS4b6xcWNxUZXJ6j6Dkc+5YN7xiGFtsBWZncozQP9DV4CNTcj1lgKvkiN 3U2P0aCJZWITehRtFX5Wwz/a0mvacG3pCdO7A2RgsF+rVuYZlO4jCgHl1nSfe8E8mVUT/dbbCTc O1lJhgZWpcZ2poJYX6y5VySXpHZlSUweyAnH1pt2vKus3XXtLk13qYrk= X-Google-Smtp-Source: AGHT+IH7EiuupKV2fG/SCMRtQtoVRqq5BxwZOQlRResiuZUa4MT3z9f4dMDqxoKUMA4xzS3nbJZfTA== X-Received: by 2002:a17:902:ec86:b0:24c:7b94:2f53 with SMTP id d9443c01a7336-268119b8394mr52036305ad.6.1758146157270; Wed, 17 Sep 2025 14:55:57 -0700 (PDT) From: Oleksii Kurochko To: xen-devel@lists.xenproject.org Cc: Oleksii Kurochko , Alistair Francis , Bob Eshleman , Connor Davis , Andrew Cooper , Anthony PERARD , Michal Orzel , Jan Beulich , Julien Grall , =?UTF-8?q?Roger=20Pau=20Monn=C3=A9?= , Stefano Stabellini Subject: [PATCH v4 05/18] xen/riscv: add root page table allocation Date: Wed, 17 Sep 2025 23:55:25 +0200 Message-ID: <2b636ea03bf82cae50df87d525e3f58b68f16cb2.1758145428.git.oleksii.kurochko@gmail.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ZohoMail-DKIM: pass (identity @gmail.com) X-ZM-MESSAGEID: 1758146185703116600 Content-Type: text/plain; charset="utf-8" Introduce support for allocating and initializing the root page table required for RISC-V stage-2 address translation. To implement root page table allocation the following is introduced: - p2m_get_clean_page() and p2m_alloc_root_table(), p2m_allocate_root() helpers to allocate and zero a 16 KiB root page table, as mandated by the RISC-V privileged specification for Sv32x4/Sv39x4/Sv48x4/Sv57x4 modes. - Update p2m_init() to inititialize p2m_root_order. - Add maddr_to_page() and page_to_maddr() macros for easier address manipulation. - Introduce paging_ret_pages_to_domheap() to return some pages before allocate 16 KiB pages for root page table. - Allocate root p2m table after p2m pool is initialized. - Add construct_hgatp() to construct the hgatp register value based on p2m->root, p2m->hgatp_mode and VMID. Signed-off-by: Oleksii Kurochko --- Changes in V4: - Drop hgatp_mode from p2m_domain as gstage_mode was introduced and initlialized earlier patch. So use gstage_mode instead. - s/GUEST_ROOT_PAGE_TABLE_SIZE/GSTAGE_ROOT_PAGE_TABLE_SIZE. - Drop p2m_root_order and re-define P2M_ROOT_ORDER: #define P2M_ROOT_ORDER (ilog2(GSTAGE_ROOT_PAGE_TABLE_SIZE) - PAGE_SHI= FT) - Update implementation of construct_hgatp(): use introduced gstage_mode and use MASK_INSRT() to construct ppn value. - Drop nr_root_pages variable inside p2m_alloc_root_table(). - Update the printk's message inside paging_ret_pages_to_domheap(). - Add an introduction of clean_pte member of p2m_domain structure to this patch as it is started to be used here. Rename clean_pte to clean_dcache. - Drop p2m_allocate_root() function as it is going to be used only in one place. - Propogate rc from p2m_alloc_root_table() in p2m_set_allocation(). - Return P2M_ROOT_PAGES to freelist in case of allocation of root page table failed. - Add allocated root tables pages to p2m->pages pool so a usage of pages could be properly taken into account. --- Changes in v3: - Drop insterting of p2m->vmid in hgatp_from_page() as now vmid is allocat= ed per-CPU, not per-domain, so it will be inserted later somewhere in context_switch or before returning control to a guest. - use BIT() to init nr_pages in p2m_allocate_root() instead of open-code BIT() macros. - Fix order in clear_and_clean_page(). - s/panic("Specify more xen,domain-p2m-mem-mb\n")/return NULL. - Use lock around a procedure of returning back pages necessary for p2m root table. - Update the comment about allocation of page for root page table. - Update an argument of hgatp_from_page() to "struct page_info *p2m_root_p= age" to be consistent with the function name. - Use p2m_get_hostp2m(d) instead of open-coding it. - Update the comment above the call of p2m_alloc_root_table(). - Update the comments in p2m_allocate_root(). - Move part which returns some page to domheap before root page table allo= cation to paging.c. - Pass p2m_domain * instead of struct domain * for p2m_alloc_root_table(). - Introduce construct_hgatp() instead of hgatp_from_page(). - Add vmid and hgatp_mode member of struct p2m_domain. - Add explanatory comment above clean_dcache_va_range() in clear_and_clean_page(). - Introduce P2M_ROOT_ORDER and P2M_ROOT_PAGES. - Drop vmid member from p2m_domain as now we are using per-pCPU VMID allocation. - Update a declaration of construct_hgatp() to recieve VMID as it isn't per-VM anymore. - Drop hgatp member of p2m_domain struct as with the new VMID scheme allocation construction of hgatp will be needed more often. - Drop is_hardware_domain() case in p2m_allocate_root(), just always allocate root using p2m pool pages. - Refactor p2m_alloc_root_table() and p2m_alloc_table(). --- Changes in v2: - This patch was created from "xen/riscv: introduce things necessary for p= 2m initialization" with the following changes: - [clear_and_clean_page()] Add missed call of clean_dcache_va_range(). - Drop p2m_get_clean_page() as it is going to be used only once to alloc= ate root page table. Open-code it explicittly in p2m_allocate_root(). Also, it will help avoid duplication of the code connected to order and nr_p= ages of p2m root page table. - Instead of using order 2 for alloc_domheap_pages(), use get_order_from_bytes(KB(16)). - Clear and clean a proper amount of allocated pages in p2m_allocate_roo= t(). - Drop _info from the function name hgatp_from_page_info() and its argum= ent page_info. - Introduce HGATP_MODE_MASK and use MASK_INSR() instead of shift to calc= ulate value of hgatp. - Drop unnecessary parentheses in definition of page_to_maddr(). - Add support of VMID. - Drop TLB flushing in p2m_alloc_root_table() and do that once when VMID is re-used. [Look at p2m_alloc_vmid()] - Allocate p2m root table after p2m pool is fully initialized: first return pages to p2m pool them allocate p2m root table. --- xen/arch/riscv/include/asm/mm.h | 4 + xen/arch/riscv/include/asm/p2m.h | 15 +++ xen/arch/riscv/include/asm/paging.h | 3 + xen/arch/riscv/include/asm/riscv_encoding.h | 2 + xen/arch/riscv/p2m.c | 90 +++++++++++++++- xen/arch/riscv/paging.c | 108 +++++++++++++++----- 6 files changed, 193 insertions(+), 29 deletions(-) diff --git a/xen/arch/riscv/include/asm/mm.h b/xen/arch/riscv/include/asm/m= m.h index 9283616c02..dd8cdc9782 100644 --- a/xen/arch/riscv/include/asm/mm.h +++ b/xen/arch/riscv/include/asm/mm.h @@ -167,6 +167,10 @@ extern struct page_info *frametable_virt_start; #define mfn_to_page(mfn) (frametable_virt_start + mfn_x(mfn)) #define page_to_mfn(pg) _mfn((pg) - frametable_virt_start) =20 +/* Convert between machine addresses and page-info structures. */ +#define maddr_to_page(ma) mfn_to_page(maddr_to_mfn(ma)) +#define page_to_maddr(pg) mfn_to_maddr(page_to_mfn(pg)) + static inline void *page_to_virt(const struct page_info *pg) { return mfn_to_virt(mfn_x(page_to_mfn(pg))); diff --git a/xen/arch/riscv/include/asm/p2m.h b/xen/arch/riscv/include/asm/= p2m.h index 2672dcdecb..7b263cb354 100644 --- a/xen/arch/riscv/include/asm/p2m.h +++ b/xen/arch/riscv/include/asm/p2m.h @@ -2,6 +2,7 @@ #ifndef ASM__RISCV__P2M_H #define ASM__RISCV__P2M_H =20 +#include #include #include #include @@ -11,6 +12,9 @@ =20 extern unsigned long gstage_mode; =20 +#define P2M_ROOT_ORDER (ilog2(GSTAGE_ROOT_PAGE_TABLE_SIZE) - PAGE_SHIFT) +#define P2M_ROOT_PAGES BIT(P2M_ROOT_ORDER, U) + #define paddr_bits PADDR_BITS =20 /* Get host p2m table */ @@ -26,6 +30,9 @@ struct p2m_domain { /* Pages used to construct the p2m */ struct page_list_head pages; =20 + /* The root of the p2m tree. May be concatenated */ + struct page_info *root; + /* Back pointer to domain */ struct domain *domain; =20 @@ -39,6 +46,12 @@ struct p2m_domain { * shattered), call p2m_tlb_flush_sync(). */ bool need_flush; + + /* + * Indicate if it is required to clean the cache when writing an entry= or + * when a page is needed to be fully cleared and cleaned. + */ + bool clean_dcache; }; =20 /* @@ -125,6 +138,8 @@ void gstage_mode_detect(void); =20 int p2m_init(struct domain *d); =20 +unsigned long construct_hgatp(struct p2m_domain *p2m, uint16_t vmid); + #endif /* ASM__RISCV__P2M_H */ =20 /* diff --git a/xen/arch/riscv/include/asm/paging.h b/xen/arch/riscv/include/a= sm/paging.h index 98d8b06d45..befad14f82 100644 --- a/xen/arch/riscv/include/asm/paging.h +++ b/xen/arch/riscv/include/asm/paging.h @@ -10,4 +10,7 @@ int paging_domain_init(struct domain *d); int paging_freelist_adjust(struct domain *d, unsigned long pages, bool *preempted); =20 +int paging_ret_pages_to_domheap(struct domain *d, unsigned int nr_pages); +int paging_ret_pages_to_freelist(struct domain *d, unsigned int nr_pages); + #endif /* ASM_RISCV_PAGING_H */ diff --git a/xen/arch/riscv/include/asm/riscv_encoding.h b/xen/arch/riscv/i= nclude/asm/riscv_encoding.h index b15f5ad0b4..8890b903e1 100644 --- a/xen/arch/riscv/include/asm/riscv_encoding.h +++ b/xen/arch/riscv/include/asm/riscv_encoding.h @@ -188,6 +188,8 @@ #define HGATP_MODE_MASK HGATP32_MODE_MASK #endif =20 +#define GSTAGE_ROOT_PAGE_TABLE_SIZE KB(16) + #define TOPI_IID_SHIFT 16 #define TOPI_IID_MASK 0xfff #define TOPI_IPRIO_MASK 0xff diff --git a/xen/arch/riscv/p2m.c b/xen/arch/riscv/p2m.c index dc0f2b2a23..ad0478f155 100644 --- a/xen/arch/riscv/p2m.c +++ b/xen/arch/riscv/p2m.c @@ -3,6 +3,7 @@ #include #include #include +#include #include #include #include @@ -95,6 +96,70 @@ void __init gstage_mode_detect(void) local_hfence_gvma_all(); } =20 +static void clear_and_clean_page(struct page_info *page, bool clean_dcache) +{ + clear_domain_page(page_to_mfn(page)); + + /* + * If the IOMMU doesn't support coherent walks and the p2m tables are + * shared between the CPU and IOMMU, it is necessary to clean the + * d-cache. + */ + if ( clean_dcache ) + clean_dcache_va_range(page, PAGE_SIZE); +} + +unsigned long construct_hgatp(struct p2m_domain *p2m, uint16_t vmid) +{ + return MASK_INSR(mfn_x(page_to_mfn(p2m->root)), HGATP_PPN) | + MASK_INSR(gstage_mode, HGATP_MODE_MASK) | + MASK_INSR(vmid, HGATP_VMID_MASK); +} + +static int p2m_alloc_root_table(struct p2m_domain *p2m) +{ + struct domain *d =3D p2m->domain; + struct page_info *page; + int rc; + + /* + * Return back P2M_ROOT_PAGES to assure the root table memory is also + * accounted against the P2M pool of the domain. + */ + if ( (rc =3D paging_ret_pages_to_domheap(d, P2M_ROOT_PAGES)) ) + return rc; + + /* + * As mentioned in the Priviliged Architecture Spec (version 20240411) + * in Section 18.5.1, for the paged virtual-memory schemes (Sv32x4, + * Sv39x4, Sv48x4, and Sv57x4), the root page table is 16 KiB and must + * be aligned to a 16-KiB boundary. + */ + page =3D alloc_domheap_pages(d, P2M_ROOT_ORDER, MEMF_no_owner); + if ( !page ) + { + /* + * If allocation of root table pages fails, the pages acquired abo= ve + * must be returned to the freelist to maintain proper freelist + * balance. + */ + paging_ret_pages_to_freelist(d, P2M_ROOT_PAGES); + + return -ENOMEM; + } + + for ( unsigned int i =3D 0; i < P2M_ROOT_PAGES; i++ ) + { + clear_and_clean_page(page + i, p2m->clean_dcache); + + page_list_add(page + i, &p2m->pages); + } + + p2m->root =3D page; + + return 0; +} + int p2m_init(struct domain *d) { struct p2m_domain *p2m =3D p2m_get_hostp2m(d); @@ -110,6 +175,19 @@ int p2m_init(struct domain *d) rwlock_init(&p2m->lock); INIT_PAGE_LIST_HEAD(&p2m->pages); =20 + /* + * Currently, the infrastructure required to enable CONFIG_HAS_PASSTHR= OUGH + * is not ready for RISC-V support. + * + * When CONFIG_HAS_PASSTHROUGH=3Dy, p2m->clean_dcache must be properly + * initialized. + * At the moment, it defaults to false because the p2m structure is + * zero-initialized. + */ +#ifdef CONFIG_HAS_PASSTHROUGH +# error "Add init of p2m->clean_dcache" +#endif + return 0; } =20 @@ -120,10 +198,20 @@ int p2m_init(struct domain *d) */ int p2m_set_allocation(struct domain *d, unsigned long pages, bool *preemp= ted) { + struct p2m_domain *p2m =3D p2m_get_hostp2m(d); int rc; =20 if ( (rc =3D paging_freelist_adjust(d, pages, preempted)) ) return rc; =20 - return 0; + /* + * First, initialize p2m pool. Then allocate the root + * table so that the necessary pages can be returned from the p2m pool, + * since the root table must be allocated using alloc_domheap_pages(..= .) + * to meet its specific requirements. + */ + if ( !p2m->root ) + rc =3D p2m_alloc_root_table(p2m); + + return rc; } diff --git a/xen/arch/riscv/paging.c b/xen/arch/riscv/paging.c index 2df8de033b..ed537fee07 100644 --- a/xen/arch/riscv/paging.c +++ b/xen/arch/riscv/paging.c @@ -4,46 +4,67 @@ #include #include =20 +static int paging_ret_page_to_domheap(struct domain *d) +{ + struct page_info *page; + + ASSERT(spin_is_locked(&d->arch.paging.lock)); + + /* Return memory to domheap. */ + page =3D page_list_remove_head(&d->arch.paging.freelist); + if( page ) + { + ACCESS_ONCE(d->arch.paging.total_pages)--; + free_domheap_page(page); + } + else + { + printk(XENLOG_ERR + "Failed to free P2M pages, P2M freelist is empty.\n"); + return -ENOMEM; + } + + return 0; +} + +static int paging_ret_page_to_freelist(struct domain *d) +{ + struct page_info *page; + + ASSERT(spin_is_locked(&d->arch.paging.lock)); + + /* Need to allocate more memory from domheap */ + page =3D alloc_domheap_page(d, MEMF_no_owner); + if ( page =3D=3D NULL ) + { + printk(XENLOG_ERR "Failed to allocate pages.\n"); + return -ENOMEM; + } + ACCESS_ONCE(d->arch.paging.total_pages)++; + page_list_add_tail(page, &d->arch.paging.freelist); + + return 0; +} + int paging_freelist_adjust(struct domain *d, unsigned long pages, bool *preempted) { - struct page_info *pg; - ASSERT(spin_is_locked(&d->arch.paging.lock)); =20 for ( ; ; ) { + int rc =3D 0; + if ( d->arch.paging.total_pages < pages ) - { - /* Need to allocate more memory from domheap */ - pg =3D alloc_domheap_page(d, MEMF_no_owner); - if ( pg =3D=3D NULL ) - { - printk(XENLOG_ERR "Failed to allocate pages.\n"); - return -ENOMEM; - } - ACCESS_ONCE(d->arch.paging.total_pages)++; - page_list_add_tail(pg, &d->arch.paging.freelist); - } + rc =3D paging_ret_page_to_freelist(d); else if ( d->arch.paging.total_pages > pages ) - { - /* Need to return memory to domheap */ - pg =3D page_list_remove_head(&d->arch.paging.freelist); - if ( pg ) - { - ACCESS_ONCE(d->arch.paging.total_pages)--; - free_domheap_page(pg); - } - else - { - printk(XENLOG_ERR - "Failed to free pages, freelist is empty.\n"); - return -ENOMEM; - } - } + rc =3D paging_ret_page_to_domheap(d); else break; =20 + if ( rc ) + return rc; + /* Check to see if we need to yield and try again */ if ( preempted && general_preempt_check() ) { @@ -55,6 +76,37 @@ int paging_freelist_adjust(struct domain *d, unsigned lo= ng pages, return 0; } =20 +int paging_ret_pages_to_freelist(struct domain *d, unsigned int nr_pages) +{ + ASSERT(spin_is_locked(&d->arch.paging.lock)); + + for ( unsigned int i =3D 0; i < nr_pages; i++ ) + { + int rc =3D paging_ret_page_to_freelist(d); + if ( rc ) + return rc; + } + + return 0; +} + +int paging_ret_pages_to_domheap(struct domain *d, unsigned int nr_pages) +{ + ASSERT(spin_is_locked(&d->arch.paging.lock)); + + if ( ACCESS_ONCE(d->arch.paging.total_pages) < nr_pages ) + return false; + + for ( unsigned int i =3D 0; i < nr_pages; i++ ) + { + int rc =3D paging_ret_page_to_domheap(d); + if ( rc ) + return rc; + } + + return 0; +} + /* Domain paging struct initialization. */ int paging_domain_init(struct domain *d) { --=20 2.51.0