From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tom Lendacky Subject: [RFC PATCH v1 13/18] x86: DMA support for memory encryption Date: Tue, 26 Apr 2016 17:58:12 -0500 Message-ID: <20160426225812.13567.91220.stgit@tlendack-t1.amdoffice.net> References: <20160426225553.13567.19459.stgit@tlendack-t1.amdoffice.net> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20160426225553.13567.19459.stgit@tlendack-t1.amdoffice.net> Sender: owner-linux-mm@kvack.org To: linux-arch@vger.kernel.org, linux-efi@vger.kernel.org, kvm@vger.kernel.org, linux-doc@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, iommu@lists.linux-foundation.org Cc: Radim =?utf-8?b?S3LEjW3DocWZ?= , Arnd Bergmann , Jonathan Corbet , Matt Fleming , Joerg Roedel , Konrad Rzeszutek Wilk , Paolo Bonzini , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , Andrey Ryabinin , Alexander Potapenko , Thomas Gleixner , Dmitry Vyukov List-Id: linux-efi@vger.kernel.org Since DMA addresses will effectively look like 48-bit addresses when the memory encryption mask is set, SWIOTLB is needed if the DMA mask of the device performing the DMA does not support 48-bits. SWIOTLB will be initialized to create un-encrypted bounce buffers for use by these devices. Signed-off-by: Tom Lendacky --- arch/x86/include/asm/dma-mapping.h | 5 ++- arch/x86/include/asm/mem_encrypt.h | 5 +++ arch/x86/kernel/pci-dma.c | 11 ++++-- arch/x86/kernel/pci-nommu.c | 2 + arch/x86/kernel/pci-swiotlb.c | 8 +++-- arch/x86/mm/mem_encrypt.c | 21 ++++++++++++ include/linux/swiotlb.h | 1 + init/main.c | 6 +++ lib/swiotlb.c | 64 ++++++++++++++++++++++++++++++++---- 9 files changed, 106 insertions(+), 17 deletions(-) diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h index 3a27b93..33a4f6d 100644 --- a/arch/x86/include/asm/dma-mapping.h +++ b/arch/x86/include/asm/dma-mapping.h @@ -13,6 +13,7 @@ #include #include #include +#include #ifdef CONFIG_ISA # define ISA_DMA_BIT_MASK DMA_BIT_MASK(24) @@ -70,12 +71,12 @@ static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size) static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr) { - return paddr; + return paddr | sme_me_mask; } static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr) { - return daddr; + return daddr & ~sme_me_mask; } #endif /* CONFIG_X86_DMA_REMAP */ diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_encrypt.h index 42868f5..d17d8cf 100644 --- a/arch/x86/include/asm/mem_encrypt.h +++ b/arch/x86/include/asm/mem_encrypt.h @@ -37,6 +37,11 @@ void __init *sme_early_memremap(resource_size_t paddr, void __init sme_early_init(void); /* Architecture __weak replacement functions */ +void __init mem_encrypt_init(void); + +unsigned long swiotlb_get_me_mask(void); +void swiotlb_set_mem_dec(void *vaddr, unsigned long size); + void __init *efi_me_early_memremap(resource_size_t paddr, unsigned long size); diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c index 6ba014c..bd1daae 100644 --- a/arch/x86/kernel/pci-dma.c +++ b/arch/x86/kernel/pci-dma.c @@ -92,9 +92,12 @@ again: /* CMA can be used only in the context which permits sleeping */ if (gfpflags_allow_blocking(flag)) { page = dma_alloc_from_contiguous(dev, count, get_order(size)); - if (page && page_to_phys(page) + size > dma_mask) { - dma_release_from_contiguous(dev, page, count); - page = NULL; + if (page) { + addr = phys_to_dma(dev, page_to_phys(page)); + if (addr + size > dma_mask) { + dma_release_from_contiguous(dev, page, count); + page = NULL; + } } } /* fallback */ @@ -103,7 +106,7 @@ again: if (!page) return NULL; - addr = page_to_phys(page); + addr = phys_to_dma(dev, page_to_phys(page)); if (addr + size > dma_mask) { __free_pages(page, get_order(size)); diff --git a/arch/x86/kernel/pci-nommu.c b/arch/x86/kernel/pci-nommu.c index da15918..ca2b820 100644 --- a/arch/x86/kernel/pci-nommu.c +++ b/arch/x86/kernel/pci-nommu.c @@ -30,7 +30,7 @@ static dma_addr_t nommu_map_page(struct device *dev, struct page *page, enum dma_data_direction dir, struct dma_attrs *attrs) { - dma_addr_t bus = page_to_phys(page) + offset; + dma_addr_t bus = phys_to_dma(dev, page_to_phys(page)) + offset; WARN_ON(size == 0); if (!check_addr("map_single", dev, bus, size)) return DMA_ERROR_CODE; diff --git a/arch/x86/kernel/pci-swiotlb.c b/arch/x86/kernel/pci-swiotlb.c index 7c577a1..0ae083d 100644 --- a/arch/x86/kernel/pci-swiotlb.c +++ b/arch/x86/kernel/pci-swiotlb.c @@ -12,6 +12,8 @@ #include #include #include +#include + int swiotlb __read_mostly; void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size, @@ -64,13 +66,15 @@ static struct dma_map_ops swiotlb_dma_ops = { * pci_swiotlb_detect_override - set swiotlb to 1 if necessary * * This returns non-zero if we are forced to use swiotlb (by the boot - * option). + * option). If memory encryption is enabled then swiotlb will be set + * to 1 so that bounce buffers are allocated and used for devices that + * do not support the addressing range required for the encryption mask. */ int __init pci_swiotlb_detect_override(void) { int use_swiotlb = swiotlb | swiotlb_force; - if (swiotlb_force) + if (swiotlb_force || sme_me_mask) swiotlb = 1; return use_swiotlb; diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c index 7d56d1b..594dc65 100644 --- a/arch/x86/mm/mem_encrypt.c +++ b/arch/x86/mm/mem_encrypt.c @@ -12,6 +12,8 @@ #include #include +#include +#include #include #include @@ -168,6 +170,25 @@ void __init sme_early_init(void) } /* Architecture __weak replacement functions */ +void __init mem_encrypt_init(void) +{ + if (!sme_me_mask) + return; + + /* Make SWIOTLB use an unencrypted DMA area */ + swiotlb_clear_encryption(); +} + +unsigned long swiotlb_get_me_mask(void) +{ + return sme_me_mask; +} + +void swiotlb_set_mem_dec(void *vaddr, unsigned long size) +{ + sme_set_mem_dec(vaddr, size); +} + void __init *efi_me_early_memremap(resource_size_t paddr, unsigned long size) { diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h index 017fced..121b9de 100644 --- a/include/linux/swiotlb.h +++ b/include/linux/swiotlb.h @@ -30,6 +30,7 @@ int swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose); extern unsigned long swiotlb_nr_tbl(void); unsigned long swiotlb_size_or_default(void); extern int swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs); +extern void __init swiotlb_clear_encryption(void); /* * Enumeration for sync targets diff --git a/init/main.c b/init/main.c index b3c6e36..1013d1c 100644 --- a/init/main.c +++ b/init/main.c @@ -458,6 +458,10 @@ void __init __weak thread_info_cache_init(void) } #endif +void __init __weak mem_encrypt_init(void) +{ +} + /* * Set up kernel memory allocators */ @@ -597,6 +601,8 @@ asmlinkage __visible void __init start_kernel(void) */ locking_selftest(); + mem_encrypt_init(); + #ifdef CONFIG_BLK_DEV_INITRD if (initrd_start && !initrd_below_start_ok && page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) { diff --git a/lib/swiotlb.c b/lib/swiotlb.c index 76f29ec..339ffdc 100644 --- a/lib/swiotlb.c +++ b/lib/swiotlb.c @@ -131,6 +131,26 @@ unsigned long swiotlb_size_or_default(void) return size ? size : (IO_TLB_DEFAULT_SIZE); } +/* + * Support for memory encryption. If memory encryption is supported, then an + * override to these functions will be provided. + */ +unsigned long __weak swiotlb_get_me_mask(void) +{ + return 0; +} + +void __weak swiotlb_set_mem_dec(void *vaddr, unsigned long size) +{ +} + +/* For swiotlb, clear memory encryption mask from dma addresses */ +static dma_addr_t swiotlb_phys_to_dma(struct device *hwdev, + phys_addr_t address) +{ + return phys_to_dma(hwdev, address) & ~swiotlb_get_me_mask(); +} + /* Note that this doesn't work with highmem page */ static dma_addr_t swiotlb_virt_to_bus(struct device *hwdev, volatile void *address) @@ -159,6 +179,30 @@ void swiotlb_print_info(void) bytes >> 20, vstart, vend - 1); } +/* + * If memory encryption is active, the DMA address for an encrypted page may + * be beyond the range of the device. If bounce buffers are required be sure + * that they are not on an encrypted page. This should be called before the + * iotlb area is used. + */ +void __init swiotlb_clear_encryption(void) +{ + void *vaddr; + unsigned long bytes; + + if (no_iotlb_memory || !io_tlb_start || late_alloc) + return; + + vaddr = phys_to_virt(io_tlb_start); + bytes = PAGE_ALIGN(io_tlb_nslabs << IO_TLB_SHIFT); + swiotlb_set_mem_dec(vaddr, bytes); + memset(vaddr, 0, bytes); + + vaddr = phys_to_virt(io_tlb_overflow_buffer); + bytes = PAGE_ALIGN(io_tlb_overflow); + swiotlb_set_mem_dec(vaddr, bytes); +} + int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose) { void *v_overflow_buffer; @@ -294,6 +338,8 @@ swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs) io_tlb_start = virt_to_phys(tlb); io_tlb_end = io_tlb_start + bytes; + /* Keep TLB in unencrypted memory if memory encryption is active */ + swiotlb_set_mem_dec(tlb, bytes); memset(tlb, 0, bytes); /* @@ -304,6 +350,8 @@ swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs) if (!v_overflow_buffer) goto cleanup2; + /* Keep overflow in unencrypted memory if memory encryption is active */ + swiotlb_set_mem_dec(v_overflow_buffer, io_tlb_overflow); io_tlb_overflow_buffer = virt_to_phys(v_overflow_buffer); /* @@ -541,7 +589,7 @@ static phys_addr_t map_single(struct device *hwdev, phys_addr_t phys, size_t size, enum dma_data_direction dir) { - dma_addr_t start_dma_addr = phys_to_dma(hwdev, io_tlb_start); + dma_addr_t start_dma_addr = swiotlb_phys_to_dma(hwdev, io_tlb_start); return swiotlb_tbl_map_single(hwdev, start_dma_addr, phys, size, dir); } @@ -659,7 +707,7 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size, goto err_warn; ret = phys_to_virt(paddr); - dev_addr = phys_to_dma(hwdev, paddr); + dev_addr = swiotlb_phys_to_dma(hwdev, paddr); /* Confirm address can be DMA'd by device */ if (dev_addr + size - 1 > dma_mask) { @@ -758,15 +806,15 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page, map = map_single(dev, phys, size, dir); if (map == SWIOTLB_MAP_ERROR) { swiotlb_full(dev, size, dir, 1); - return phys_to_dma(dev, io_tlb_overflow_buffer); + return swiotlb_phys_to_dma(dev, io_tlb_overflow_buffer); } - dev_addr = phys_to_dma(dev, map); + dev_addr = swiotlb_phys_to_dma(dev, map); /* Ensure that the address returned is DMA'ble */ if (!dma_capable(dev, dev_addr, size)) { swiotlb_tbl_unmap_single(dev, map, size, dir); - return phys_to_dma(dev, io_tlb_overflow_buffer); + return swiotlb_phys_to_dma(dev, io_tlb_overflow_buffer); } return dev_addr; @@ -901,7 +949,7 @@ swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems, sg_dma_len(sgl) = 0; return 0; } - sg->dma_address = phys_to_dma(hwdev, map); + sg->dma_address = swiotlb_phys_to_dma(hwdev, map); } else sg->dma_address = dev_addr; sg_dma_len(sg) = sg->length; @@ -984,7 +1032,7 @@ EXPORT_SYMBOL(swiotlb_sync_sg_for_device); int swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr) { - return (dma_addr == phys_to_dma(hwdev, io_tlb_overflow_buffer)); + return (dma_addr == swiotlb_phys_to_dma(hwdev, io_tlb_overflow_buffer)); } EXPORT_SYMBOL(swiotlb_dma_mapping_error); @@ -997,6 +1045,6 @@ EXPORT_SYMBOL(swiotlb_dma_mapping_error); int swiotlb_dma_supported(struct device *hwdev, u64 mask) { - return phys_to_dma(hwdev, io_tlb_end - 1) <= mask; + return swiotlb_phys_to_dma(hwdev, io_tlb_end - 1) <= mask; } EXPORT_SYMBOL(swiotlb_dma_supported); -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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