From patchwork Thu May 19 13:40:43 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Will Deacon X-Patchwork-Id: 12854989 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 154D9C43217 for ; Thu, 19 May 2022 13:44:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238992AbiESNnX (ORCPT ); Thu, 19 May 2022 09:43:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47834 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231290AbiESNm7 (ORCPT ); Thu, 19 May 2022 09:42:59 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EB4BF3EF02 for ; Thu, 19 May 2022 06:42:57 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 6E7F76179A for ; Thu, 19 May 2022 13:42:57 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5E564C34117; Thu, 19 May 2022 13:42:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1652967776; bh=c8lrI2T7pA2HznSihwDmJJiSD07lpb1MnUvgkAjomMg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pRsZdFFnh8NypPazxOFE0eXARXvA7MuCC5zvD3FoqqdeXRLO/lRvHPLavJYJxpOm2 xGYAYajpy4VQzCPwE9VzPm56PXyCt8pxJ2MvUlMbQ3S+CzRr8HjCS1kh0Dn/ue3e6Z 6VwIAbj5yOMWFgwssw+MzeFBdRLF0F1KbVo3ORQE//+ItNjOEZJ8JL5C3wVjqodjFB f6f9qGE1uMKW1JUJA4fg44F4vK/S34z24TCL9iJtS0SzrDL/Qz+BO62As95H5Uy/th iA4KC15lE0qo+/2e9NnbILqKmTvdaWoeozK5TaRMOVEHXyXPTYNF8N8DV0P173Em9l /C2LugrD+e6+A== From: Will Deacon To: kvmarm@lists.cs.columbia.edu Cc: Will Deacon , Ard Biesheuvel , Sean Christopherson , Alexandru Elisei , Andy Lutomirski , Catalin Marinas , James Morse , Chao Peng , Quentin Perret , Suzuki K Poulose , Michael Roth , Mark Rutland , Fuad Tabba , Oliver Upton , Marc Zyngier , kernel-team@android.com, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH 08/89] KVM: arm64: Back hyp_vmemmap for all of memory Date: Thu, 19 May 2022 14:40:43 +0100 Message-Id: <20220519134204.5379-9-will@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20220519134204.5379-1-will@kernel.org> References: <20220519134204.5379-1-will@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Quentin Perret The EL2 vmemmap in nVHE Protected mode is currently very sparse: only memory pages owned by the hypervisor itself have a matching struct hyp_page. But since the size of these structs has been reduced significantly, it appears that we can afford backing the vmemmap for all of memory. This will simplify a lot memory tracking as the hypervisor will have a place to store metadata (e.g. refcounts) that wouldn't otherwise fit in the 4 SW bits we have in the host stage-2 page-table for instance. Signed-off-by: Quentin Perret --- arch/arm64/include/asm/kvm_pkvm.h | 26 +++++++++++++++++++++++ arch/arm64/kvm/hyp/include/nvhe/mm.h | 14 +------------ arch/arm64/kvm/hyp/nvhe/mm.c | 31 ++++++++++++++++++++++++---- arch/arm64/kvm/hyp/nvhe/page_alloc.c | 4 +--- arch/arm64/kvm/hyp/nvhe/setup.c | 7 +++---- arch/arm64/kvm/pkvm.c | 18 ++-------------- 6 files changed, 60 insertions(+), 40 deletions(-) diff --git a/arch/arm64/include/asm/kvm_pkvm.h b/arch/arm64/include/asm/kvm_pkvm.h index 9f4ad2a8df59..8f7b8a2314bb 100644 --- a/arch/arm64/include/asm/kvm_pkvm.h +++ b/arch/arm64/include/asm/kvm_pkvm.h @@ -14,6 +14,32 @@ extern struct memblock_region kvm_nvhe_sym(hyp_memory)[]; extern unsigned int kvm_nvhe_sym(hyp_memblock_nr); +static inline unsigned long +hyp_vmemmap_memblock_size(struct memblock_region *reg, size_t vmemmap_entry_size) +{ + unsigned long nr_pages = reg->size >> PAGE_SHIFT; + unsigned long start, end; + + start = (reg->base >> PAGE_SHIFT) * vmemmap_entry_size; + end = start + nr_pages * vmemmap_entry_size; + start = ALIGN_DOWN(start, PAGE_SIZE); + end = ALIGN(end, PAGE_SIZE); + + return end - start; +} + +static inline unsigned long hyp_vmemmap_pages(size_t vmemmap_entry_size) +{ + unsigned long res = 0, i; + + for (i = 0; i < kvm_nvhe_sym(hyp_memblock_nr); i++) { + res += hyp_vmemmap_memblock_size(&kvm_nvhe_sym(hyp_memory)[i], + vmemmap_entry_size); + } + + return res >> PAGE_SHIFT; +} + static inline unsigned long __hyp_pgtable_max_pages(unsigned long nr_pages) { unsigned long total = 0, i; diff --git a/arch/arm64/kvm/hyp/include/nvhe/mm.h b/arch/arm64/kvm/hyp/include/nvhe/mm.h index 2d08510c6cc1..73309ccc192e 100644 --- a/arch/arm64/kvm/hyp/include/nvhe/mm.h +++ b/arch/arm64/kvm/hyp/include/nvhe/mm.h @@ -15,23 +15,11 @@ extern hyp_spinlock_t pkvm_pgd_lock; int hyp_create_idmap(u32 hyp_va_bits); int hyp_map_vectors(void); -int hyp_back_vmemmap(phys_addr_t phys, unsigned long size, phys_addr_t back); +int hyp_back_vmemmap(phys_addr_t back); int pkvm_cpu_set_vector(enum arm64_hyp_spectre_vector slot); int pkvm_create_mappings(void *from, void *to, enum kvm_pgtable_prot prot); int pkvm_create_mappings_locked(void *from, void *to, enum kvm_pgtable_prot prot); unsigned long __pkvm_create_private_mapping(phys_addr_t phys, size_t size, enum kvm_pgtable_prot prot); -static inline void hyp_vmemmap_range(phys_addr_t phys, unsigned long size, - unsigned long *start, unsigned long *end) -{ - unsigned long nr_pages = size >> PAGE_SHIFT; - struct hyp_page *p = hyp_phys_to_page(phys); - - *start = (unsigned long)p; - *end = *start + nr_pages * sizeof(struct hyp_page); - *start = ALIGN_DOWN(*start, PAGE_SIZE); - *end = ALIGN(*end, PAGE_SIZE); -} - #endif /* __KVM_HYP_MM_H */ diff --git a/arch/arm64/kvm/hyp/nvhe/mm.c b/arch/arm64/kvm/hyp/nvhe/mm.c index cdbe8e246418..168e7fbe9a3c 100644 --- a/arch/arm64/kvm/hyp/nvhe/mm.c +++ b/arch/arm64/kvm/hyp/nvhe/mm.c @@ -105,13 +105,36 @@ int pkvm_create_mappings(void *from, void *to, enum kvm_pgtable_prot prot) return ret; } -int hyp_back_vmemmap(phys_addr_t phys, unsigned long size, phys_addr_t back) +int hyp_back_vmemmap(phys_addr_t back) { - unsigned long start, end; + unsigned long i, start, size, end = 0; + int ret; - hyp_vmemmap_range(phys, size, &start, &end); + for (i = 0; i < hyp_memblock_nr; i++) { + start = hyp_memory[i].base; + start = ALIGN_DOWN((u64)hyp_phys_to_page(start), PAGE_SIZE); + /* + * The begining of the hyp_vmemmap region for the current + * memblock may already be backed by the page backing the end + * the previous region, so avoid mapping it twice. + */ + start = max(start, end); + + end = hyp_memory[i].base + hyp_memory[i].size; + end = PAGE_ALIGN((u64)hyp_phys_to_page(end)); + if (start >= end) + continue; + + size = end - start; + ret = __pkvm_create_mappings(start, size, back, PAGE_HYP); + if (ret) + return ret; + + memset(hyp_phys_to_virt(back), 0, size); + back += size; + } - return __pkvm_create_mappings(start, end - start, back, PAGE_HYP); + return 0; } static void *__hyp_bp_vect_base; diff --git a/arch/arm64/kvm/hyp/nvhe/page_alloc.c b/arch/arm64/kvm/hyp/nvhe/page_alloc.c index 1ded09fc9b10..dc87589440b8 100644 --- a/arch/arm64/kvm/hyp/nvhe/page_alloc.c +++ b/arch/arm64/kvm/hyp/nvhe/page_alloc.c @@ -230,10 +230,8 @@ int hyp_pool_init(struct hyp_pool *pool, u64 pfn, unsigned int nr_pages, /* Init the vmemmap portion */ p = hyp_phys_to_page(phys); - for (i = 0; i < nr_pages; i++) { - p[i].order = 0; + for (i = 0; i < nr_pages; i++) hyp_set_page_refcounted(&p[i]); - } /* Attach the unused pages to the buddy tree */ for (i = reserved_pages; i < nr_pages; i++) diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c index 27af337f9fea..7d2b325efb50 100644 --- a/arch/arm64/kvm/hyp/nvhe/setup.c +++ b/arch/arm64/kvm/hyp/nvhe/setup.c @@ -31,12 +31,11 @@ static struct hyp_pool hpool; static int divide_memory_pool(void *virt, unsigned long size) { - unsigned long vstart, vend, nr_pages; + unsigned long nr_pages; hyp_early_alloc_init(virt, size); - hyp_vmemmap_range(__hyp_pa(virt), size, &vstart, &vend); - nr_pages = (vend - vstart) >> PAGE_SHIFT; + nr_pages = hyp_vmemmap_pages(sizeof(struct hyp_page)); vmemmap_base = hyp_early_alloc_contig(nr_pages); if (!vmemmap_base) return -ENOMEM; @@ -78,7 +77,7 @@ static int recreate_hyp_mappings(phys_addr_t phys, unsigned long size, if (ret) return ret; - ret = hyp_back_vmemmap(phys, size, hyp_virt_to_phys(vmemmap_base)); + ret = hyp_back_vmemmap(hyp_virt_to_phys(vmemmap_base)); if (ret) return ret; diff --git a/arch/arm64/kvm/pkvm.c b/arch/arm64/kvm/pkvm.c index ebecb7c045f4..34229425b25d 100644 --- a/arch/arm64/kvm/pkvm.c +++ b/arch/arm64/kvm/pkvm.c @@ -53,7 +53,7 @@ static int __init register_memblock_regions(void) void __init kvm_hyp_reserve(void) { - u64 nr_pages, prev, hyp_mem_pages = 0; + u64 hyp_mem_pages = 0; int ret; if (!is_hyp_mode_available() || is_kernel_in_hyp_mode()) @@ -71,21 +71,7 @@ void __init kvm_hyp_reserve(void) hyp_mem_pages += hyp_s1_pgtable_pages(); hyp_mem_pages += host_s2_pgtable_pages(); - - /* - * The hyp_vmemmap needs to be backed by pages, but these pages - * themselves need to be present in the vmemmap, so compute the number - * of pages needed by looking for a fixed point. - */ - nr_pages = 0; - do { - prev = nr_pages; - nr_pages = hyp_mem_pages + prev; - nr_pages = DIV_ROUND_UP(nr_pages * STRUCT_HYP_PAGE_SIZE, - PAGE_SIZE); - nr_pages += __hyp_pgtable_max_pages(nr_pages); - } while (nr_pages != prev); - hyp_mem_pages += nr_pages; + hyp_mem_pages += hyp_vmemmap_pages(STRUCT_HYP_PAGE_SIZE); /* * Try to allocate a PMD-aligned region to reduce TLB pressure once