From patchwork Tue Nov 23 14:30:32 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tianyu Lan X-Patchwork-Id: 12634425 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 C94A7C433FE for ; Tue, 23 Nov 2021 14:36:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238241AbhKWOkE (ORCPT ); Tue, 23 Nov 2021 09:40:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36732 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238223AbhKWOkD (ORCPT ); Tue, 23 Nov 2021 09:40:03 -0500 Received: from mail-pj1-x1031.google.com (mail-pj1-x1031.google.com [IPv6:2607:f8b0:4864:20::1031]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E6534C061574; Tue, 23 Nov 2021 06:36:55 -0800 (PST) Received: by mail-pj1-x1031.google.com with SMTP id y14-20020a17090a2b4e00b001a5824f4918so2242106pjc.4; Tue, 23 Nov 2021 06:36:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=ZLZVOIJvkNfO78QMd8KmGxzLi6165uI7/yB2dxT/Ykk=; b=gqnaX3y9BYxnolIAz6ohPiMx1+uWA+HB/7pfL/hta47mhZY1SESuVh6AyO6OrBvHl4 /npGN7awBKNSRQFcgIEBAnGQLe1TLQvX5fWEjykeGyOCPelkp+IbfbQTIgCNlY5OeAD+ eVdYJFoj6/DSB36poZtkhDU8kI/BioBEeklOVgEjpy6HVmrGKC3iurU9Am5/L4pKcVQo 9HwmXweKaCVV+o0dnMKeqaMyEJBq/18jyvil0UQJaUHJwzq84trc9n7cG5YlBsDNaByO nmFEsY5HrfMbnqBJoHTKUUSzYWMoT5zH1nz7N3YVt/hbwdgqDBDxMpSC2gh1veDdQaDJ hKnA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=ZLZVOIJvkNfO78QMd8KmGxzLi6165uI7/yB2dxT/Ykk=; b=Ei1D0SuIzVrejV7J2f0r6h0Me42gQtNuXnFEczi0w0aPivhPWWjbfJmOsZn2nZhB13 HLzegQxC11zttW8kv8lsfBfp89nwssBF4R0XUeTm3LZR/vlLkn8MrCUyGvWNf4gyzTgx Pmm0vAeX/f89l1eN+h8pBwAIWygzezynI22dILcq4X2RJOTpj1qSy2IC1lu6maOF7WFo SleLVne6Zo8madbT3V5eGP7ys3SEVmGClbe+Alg7QPgXJIChM4VGd2c9zGTK8YFdft+4 ARad5UotE5XcoUfRR3VQ3vwQ2dVSI5vRKLSGFj8dqcPX/bEZFGaRQXmCFbrESf9tZWgh EpJg== X-Gm-Message-State: AOAM532Ig1GRk6UchO2TEusClO53zwAEHpirylsaRf6gQDxI8bpvStWa bAntZdMER4VEaclJ7AJXxNk= X-Google-Smtp-Source: ABdhPJw6FmBtePaEKtdoENI4y3Ha3Tjj5xx6DbA0cDTOhxNZa7Gb4JErBed6/HhU6blkX6qlJforYg== X-Received: by 2002:a17:90b:4d92:: with SMTP id oj18mr3481484pjb.188.1637678215409; Tue, 23 Nov 2021 06:36:55 -0800 (PST) Received: from ubuntu-Virtual-Machine.corp.microsoft.com ([2001:4898:80e8:1:af65:c3d4:6df:5a8b]) by smtp.gmail.com with ESMTPSA id j13sm11926127pfc.151.2021.11.23.06.36.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 Nov 2021 06:36:54 -0800 (PST) From: Tianyu Lan To: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, luto@kernel.org, peterz@infradead.org, jgross@suse.com, sstabellini@kernel.org, boris.ostrovsky@oracle.com, kys@microsoft.com, haiyangz@microsoft.com, sthemmin@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, joro@8bytes.org, will@kernel.org, davem@davemloft.net, kuba@kernel.org, jejb@linux.ibm.com, martin.petersen@oracle.com, hch@lst.de, m.szyprowski@samsung.com, robin.murphy@arm.com, Tianyu.Lan@microsoft.com, thomas.lendacky@amd.com, xen-devel@lists.xenproject.org, michael.h.kelley@microsoft.com Cc: iommu@lists.linux-foundation.org, linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, netdev@vger.kernel.org, vkuznets@redhat.com, brijesh.singh@amd.com, konrad.wilk@oracle.com, parri.andrea@gmail.com, dave.hansen@intel.com Subject: [PATCH V2 1/6] Swiotlb: Add Swiotlb bounce buffer remap function for HV IVM Date: Tue, 23 Nov 2021 09:30:32 -0500 Message-Id: <20211123143039.331929-2-ltykernel@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211123143039.331929-1-ltykernel@gmail.com> References: <20211123143039.331929-1-ltykernel@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org From: Tianyu Lan In Isolation VM with AMD SEV, bounce buffer needs to be accessed via extra address space which is above shared_gpa_boundary (E.G 39 bit address line) reported by Hyper-V CPUID ISOLATION_CONFIG. The access physical address will be original physical address + shared_gpa_boundary. The shared_gpa_boundary in the AMD SEV SNP spec is called virtual top of memory(vTOM). Memory addresses below vTOM are automatically treated as private while memory above vTOM is treated as shared. Expose swiotlb_unencrypted_base for platforms to set unencrypted memory base offset and platform calls swiotlb_update_mem_attributes() to remap swiotlb mem to unencrypted address space. memremap() can not be called in the early stage and so put remapping code into swiotlb_update_mem_attributes(). Store remap address and use it to copy data from/to swiotlb bounce buffer. Signed-off-by: Tianyu Lan --- Change since v1: * Rework comment in the swiotlb_init_io_tlb_mem() * Make swiotlb_init_io_tlb_mem() back to return void. --- include/linux/swiotlb.h | 6 +++++ kernel/dma/swiotlb.c | 53 +++++++++++++++++++++++++++++++++++++---- 2 files changed, 54 insertions(+), 5 deletions(-) diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h index 569272871375..f6c3638255d5 100644 --- a/include/linux/swiotlb.h +++ b/include/linux/swiotlb.h @@ -73,6 +73,9 @@ extern enum swiotlb_force swiotlb_force; * @end: The end address of the swiotlb memory pool. Used to do a quick * range check to see if the memory was in fact allocated by this * API. + * @vaddr: The vaddr of the swiotlb memory pool. The swiotlb memory pool + * may be remapped in the memory encrypted case and store virtual + * address for bounce buffer operation. * @nslabs: The number of IO TLB blocks (in groups of 64) between @start and * @end. For default swiotlb, this is command line adjustable via * setup_io_tlb_npages. @@ -92,6 +95,7 @@ extern enum swiotlb_force swiotlb_force; struct io_tlb_mem { phys_addr_t start; phys_addr_t end; + void *vaddr; unsigned long nslabs; unsigned long used; unsigned int index; @@ -186,4 +190,6 @@ static inline bool is_swiotlb_for_alloc(struct device *dev) } #endif /* CONFIG_DMA_RESTRICTED_POOL */ +extern phys_addr_t swiotlb_unencrypted_base; + #endif /* __LINUX_SWIOTLB_H */ diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 8e840fbbed7c..c303fdeba82f 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -50,6 +50,7 @@ #include #include +#include #include #include #include @@ -72,6 +73,8 @@ enum swiotlb_force swiotlb_force; struct io_tlb_mem io_tlb_default_mem; +phys_addr_t swiotlb_unencrypted_base; + /* * Max segment that we can provide which (if pages are contingous) will * not be bounced (unless SWIOTLB_FORCE is set). @@ -155,6 +158,31 @@ static inline unsigned long nr_slots(u64 val) return DIV_ROUND_UP(val, IO_TLB_SIZE); } +/* + * Remap swioltb memory in the unencrypted physical address space + * when swiotlb_unencrypted_base is set. (e.g. for Hyper-V AMD SEV-SNP + * Isolation VMs). + */ +void *swiotlb_mem_remap(struct io_tlb_mem *mem, unsigned long bytes) +{ + void *vaddr; + + if (swiotlb_unencrypted_base) { + phys_addr_t paddr = mem->start + swiotlb_unencrypted_base; + + vaddr = memremap(paddr, bytes, MEMREMAP_WB); + if (!vaddr) { + pr_err("Failed to map the unencrypted memory %llx size %lx.\n", + paddr, bytes); + return NULL; + } + + return vaddr; + } + + return phys_to_virt(mem->start); +} + /* * Early SWIOTLB allocation may be too early to allow an architecture to * perform the desired operations. This function allows the architecture to @@ -172,7 +200,14 @@ void __init swiotlb_update_mem_attributes(void) vaddr = phys_to_virt(mem->start); bytes = PAGE_ALIGN(mem->nslabs << IO_TLB_SHIFT); set_memory_decrypted((unsigned long)vaddr, bytes >> PAGE_SHIFT); - memset(vaddr, 0, bytes); + + mem->vaddr = swiotlb_mem_remap(mem, bytes); + if (!mem->vaddr) { + pr_err("Fail to remap swiotlb mem.\n"); + return; + } + + memset(mem->vaddr, 0, bytes); } static void swiotlb_init_io_tlb_mem(struct io_tlb_mem *mem, phys_addr_t start, @@ -196,7 +231,18 @@ static void swiotlb_init_io_tlb_mem(struct io_tlb_mem *mem, phys_addr_t start, mem->slots[i].orig_addr = INVALID_PHYS_ADDR; mem->slots[i].alloc_size = 0; } + + /* + * If swiotlb_unencrypted_base is set, the bounce buffer memory will + * be remapped and cleared in swiotlb_update_mem_attributes. + */ + if (swiotlb_unencrypted_base) + return; + + set_memory_decrypted((unsigned long)vaddr, bytes >> PAGE_SHIFT); memset(vaddr, 0, bytes); + mem->vaddr = vaddr; + return; } int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose) @@ -318,7 +364,6 @@ swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs) if (!mem->slots) return -ENOMEM; - set_memory_decrypted((unsigned long)tlb, bytes >> PAGE_SHIFT); swiotlb_init_io_tlb_mem(mem, virt_to_phys(tlb), nslabs, true); swiotlb_print_info(); @@ -371,7 +416,7 @@ static void swiotlb_bounce(struct device *dev, phys_addr_t tlb_addr, size_t size phys_addr_t orig_addr = mem->slots[index].orig_addr; size_t alloc_size = mem->slots[index].alloc_size; unsigned long pfn = PFN_DOWN(orig_addr); - unsigned char *vaddr = phys_to_virt(tlb_addr); + unsigned char *vaddr = mem->vaddr + tlb_addr - mem->start; unsigned int tlb_offset, orig_addr_offset; if (orig_addr == INVALID_PHYS_ADDR) @@ -806,8 +851,6 @@ static int rmem_swiotlb_device_init(struct reserved_mem *rmem, return -ENOMEM; } - set_memory_decrypted((unsigned long)phys_to_virt(rmem->base), - rmem->size >> PAGE_SHIFT); swiotlb_init_io_tlb_mem(mem, rmem->base, nslabs, false); mem->force_bounce = true; mem->for_alloc = true;