From patchwork Tue Dec 7 07:19:37 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tianyu Lan X-Patchwork-Id: 12661165 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 77C94C433F5 for ; Tue, 7 Dec 2021 07:20:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229876AbhLGHXd (ORCPT ); Tue, 7 Dec 2021 02:23:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55524 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229743AbhLGHXa (ORCPT ); Tue, 7 Dec 2021 02:23:30 -0500 Received: from mail-pl1-x62b.google.com (mail-pl1-x62b.google.com [IPv6:2607:f8b0:4864:20::62b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7F33EC061746; Mon, 6 Dec 2021 23:20:00 -0800 (PST) Received: by mail-pl1-x62b.google.com with SMTP id o14so8802010plg.5; Mon, 06 Dec 2021 23:20:00 -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=wues2SqUPRv0oUKBbTR72tAwqhwqv49+w2re/gGhWqk=; b=MmgsetIfrScftpEdcxFdlZ4uOpXeK+/Eso5NGaaLHIBWe0KHh+5pRTO5TuCNot6UfL yo7SuJgY3X51fDzalf8xlfR/WDqg5iJ5qgIgDI5hBCriig7s6Q/74W52IjF1FyH+Ezn4 t96C8qDcIs4MAR8Xrnn6IxvOUHMKAUNbmJntc+X+EUlZOA9qvWuqiGYJXlB/igBhGOBY ridi/iG4hQOByLGHGVnAFoiM+hlHxBdc20ySc81GKQmmjYdHnqQEyq5FOmdroqI3LQeh dpHD0pO1+/dY/Mcqc9VGRrRbqSK1kiCi4rkwDtEhaOSx6fePj/VhoF2xfrTQUyHkPvcJ alrA== 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=wues2SqUPRv0oUKBbTR72tAwqhwqv49+w2re/gGhWqk=; b=jj86IulQTVPw2WZQ8URR2/u+ct0bBIYMa2CUvBg7kz4XgCWvqnyqahfx4h7hXMjwP5 /4QI1XYLen0ZYOheErAcRViBfcxyB1jUxL+2FYOJCj3zwzxTEjqLuasMFHu3WHKA+OiN s6wKWfgV/x+PgFXAJXEiIls6OOm+jy4FGIbhJSm64duY/fBo3V2G2sxltN++lV4MiSTP OSbBGyqaaeXMhikkNbqYbjaOShml7dJ5YviDk37CLa30Vf1xshwl8BgmcSxb6PvRtu7a 7UNlGlvJdexvjiZVdkKLnoQ65qMbnbZFWySbnY689eDidcZvCeiagsHUlROCDqM5JwrN y33w== X-Gm-Message-State: AOAM533yXbN7qjUG4Q89MA6R2qyDibpKB/0cZBbCmn5VeKzwrf+IsxAv 50cngJm7+VHtIqQM/IN/vOI= X-Google-Smtp-Source: ABdhPJzTmN+YBZb3GufD6ZLZulwl9R2hECfW7zdqRXNP8FkEs/A422ELJYyHP8ZDZsYYOlPMVepI/A== X-Received: by 2002:a17:902:6b47:b0:142:82e1:6c92 with SMTP id g7-20020a1709026b4700b0014282e16c92mr49161237plt.84.1638861599998; Mon, 06 Dec 2021 23:19:59 -0800 (PST) Received: from ubuntu-Virtual-Machine.corp.microsoft.com ([2001:4898:80e8:38:e747:5b78:1904:a4ed]) by smtp.gmail.com with ESMTPSA id u12sm2081789pfk.71.2021.12.06.23.19.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 06 Dec 2021 23:19:59 -0800 (PST) From: Tianyu Lan To: kys@microsoft.com, haiyangz@microsoft.com, sthemmin@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, davem@davemloft.net, kuba@kernel.org, jejb@linux.ibm.com, martin.petersen@oracle.com, arnd@arndb.de, hch@infradead.org, m.szyprowski@samsung.com, robin.murphy@arm.com, Tianyu.Lan@microsoft.com, thomas.lendacky@amd.com, michael.h.kelley@microsoft.com Cc: iommu@lists.linux-foundation.org, linux-arch@vger.kernel.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, hch@lst.de, joro@8bytes.org, parri.andrea@gmail.com, dave.hansen@intel.com Subject: [PATCH V6 1/5] swiotlb: Add swiotlb bounce buffer remap function for HV IVM Date: Tue, 7 Dec 2021 02:19:37 -0500 Message-Id: <20211207071942.472442-2-ltykernel@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211207071942.472442-1-ltykernel@gmail.com> References: <20211207071942.472442-1-ltykernel@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@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. Acked-by: Christoph Hellwig Signed-off-by: Tianyu Lan --- Change since v3: * Fix boot up failure on the host with mem_encrypt=on. Move calloing of set_memory_decrypted() back from swiotlb_init_io_tlb_mem to swiotlb_late_init_with_tbl() and rmem_swiotlb_device_init(). Change since v2: * Leave mem->vaddr with phys_to_virt(mem->start) when fail to remap swiotlb memory. 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 | 43 +++++++++++++++++++++++++++++++++++++++-- 2 files changed, 47 insertions(+), 2 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..34e6ade4f73c 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 +158,27 @@ 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 = NULL; + + 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 vaddr; +} + /* * Early SWIOTLB allocation may be too early to allow an architecture to * perform the desired operations. This function allows the architecture to @@ -172,7 +196,12 @@ 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) + mem->vaddr = vaddr; + + memset(mem->vaddr, 0, bytes); } static void swiotlb_init_io_tlb_mem(struct io_tlb_mem *mem, phys_addr_t start, @@ -196,7 +225,17 @@ 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; + memset(vaddr, 0, bytes); + mem->vaddr = vaddr; + return; } int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose) @@ -371,7 +410,7 @@ 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)