From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tom Lendacky Subject: [PATCH v5 22/32] x86, swiotlb: DMA support for memory encryption Date: Tue, 18 Apr 2017 16:20:10 -0500 Message-ID: <20170418212010.10190.78119.stgit@tlendack-t1.amdoffice.net> References: <20170418211612.10190.82788.stgit@tlendack-t1.amdoffice.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20170418211612.10190.82788.stgit-qCXWGYdRb2BnqfbPTmsdiZQ+2ll4COg0XqFh9Ls21Oc@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: linux-arch-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, kexec-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kasan-dev-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Cc: Thomas Gleixner , Rik van Riel , Brijesh Singh , Toshimitsu Kani , Arnd Bergmann , Jonathan Corbet , Matt Fleming , Radim =?utf-8?b?S3LEjW3DocWZ?= , Andrey Ryabinin , Ingo Molnar , "Michael S. Tsirkin" , Andy Lutomirski , "H. Peter Anvin" , Borislav Petkov , Paolo Bonzini , Alexander Potapenko , Dave Young , Larry Woodman , 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 decrypted 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 | 22 ++++++++++++++ include/linux/mem_encrypt.h | 10 ++++++ include/linux/swiotlb.h | 1 + init/main.c | 13 ++++++++ lib/swiotlb.c | 56 +++++++++++++++++++++++++++++++----- 10 files changed, 116 insertions(+), 17 deletions(-) diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h index 08a0838..d75430a 100644 --- a/arch/x86/include/asm/dma-mapping.h +++ b/arch/x86/include/asm/dma-mapping.h @@ -12,6 +12,7 @@ #include #include #include +#include #ifdef CONFIG_ISA # define ISA_DMA_BIT_MASK DMA_BIT_MASK(24) @@ -62,12 +63,12 @@ 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 __sme_set(paddr); } static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr) { - return daddr; + return __sme_clr(daddr); } #endif /* CONFIG_X86_DMA_REMAP */ diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_encrypt.h index 130d7fe..0637b4b 100644 --- a/arch/x86/include/asm/mem_encrypt.h +++ b/arch/x86/include/asm/mem_encrypt.h @@ -36,6 +36,11 @@ void __init sme_early_decrypt(resource_size_t paddr, void __init sme_early_init(void); +/* Architecture __weak replacement functions */ +void __init mem_encrypt_init(void); + +void swiotlb_set_mem_attributes(void *vaddr, unsigned long size); + #else /* !CONFIG_AMD_MEM_ENCRYPT */ #ifndef sme_me_mask diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c index 3a216ec..72d96d4 100644 --- a/arch/x86/kernel/pci-dma.c +++ b/arch/x86/kernel/pci-dma.c @@ -93,9 +93,12 @@ void *dma_generic_alloc_coherent(struct device *dev, size_t size, if (gfpflags_allow_blocking(flag)) { page = dma_alloc_from_contiguous(dev, count, get_order(size), flag); - 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 */ @@ -104,7 +107,7 @@ void *dma_generic_alloc_coherent(struct device *dev, size_t size, 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 a88952e..98b576a 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, unsigned long 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 1e23577..a75fee7 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, @@ -64,11 +66,13 @@ void x86_swiotlb_free_coherent(struct device *dev, size_t size, * 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) { - if (swiotlb_force == SWIOTLB_FORCE) + if ((swiotlb_force == SWIOTLB_FORCE) || sme_active()) swiotlb = 1; return swiotlb; diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c index 2321f05..30b07a3 100644 --- a/arch/x86/mm/mem_encrypt.c +++ b/arch/x86/mm/mem_encrypt.c @@ -16,11 +16,14 @@ #ifdef CONFIG_AMD_MEM_ENCRYPT #include +#include +#include #include #include #include #include +#include /* * Since SME related variables are set early in the boot process they must @@ -194,6 +197,25 @@ void __init sme_early_init(void) protection_map[i] = pgprot_encrypted(protection_map[i]); } +/* Architecture __weak replacement functions */ +void __init mem_encrypt_init(void) +{ + if (!sme_me_mask) + return; + + /* Call into SWIOTLB to update the SWIOTLB DMA buffers */ + swiotlb_update_mem_attributes(); +} + +void swiotlb_set_mem_attributes(void *vaddr, unsigned long size) +{ + WARN(PAGE_ALIGN(size) != size, + "size is not page-aligned (%#lx)\n", size); + + /* Make the SWIOTLB buffer area decrypted */ + set_memory_decrypted((unsigned long)vaddr, size >> PAGE_SHIFT); +} + void __init sme_encrypt_kernel(void) { } diff --git a/include/linux/mem_encrypt.h b/include/linux/mem_encrypt.h index 14a7b9f..3c384d1 100644 --- a/include/linux/mem_encrypt.h +++ b/include/linux/mem_encrypt.h @@ -32,6 +32,16 @@ static inline bool sme_active(void) #endif /* CONFIG_AMD_MEM_ENCRYPT */ +#ifndef __sme_set +/* + * The __sme_set() and __sme_clr() macros are useful for adding or removing + * the encryption mask from a value (e.g. when dealing with pagetable + * entries). + */ +#define __sme_set(x) ((unsigned long)(x) | sme_me_mask) +#define __sme_clr(x) ((unsigned long)(x) & ~sme_me_mask) +#endif + #endif /* __ASSEMBLY__ */ #endif /* __MEM_ENCRYPT_H__ */ diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h index 4ee479f..15e7160 100644 --- a/include/linux/swiotlb.h +++ b/include/linux/swiotlb.h @@ -35,6 +35,7 @@ enum swiotlb_force { 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_update_mem_attributes(void); /* * Enumeration for sync targets diff --git a/init/main.c b/init/main.c index b0c11cb..e5b4fb7 100644 --- a/init/main.c +++ b/init/main.c @@ -467,6 +467,10 @@ void __init __weak thread_stack_cache_init(void) } #endif +void __init __weak mem_encrypt_init(void) +{ +} + /* * Set up kernel memory allocators */ @@ -614,6 +618,15 @@ asmlinkage __visible void __init start_kernel(void) */ locking_selftest(); + /* + * This needs to be called before any devices perform DMA + * operations that might use the SWIOTLB bounce buffers. + * This call will mark the bounce buffers as decrypted so + * that their usage will not cause "plain-text" data to be + * decrypted when accessed. + */ + 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 a8d74a7..74d6557 100644 --- a/lib/swiotlb.c +++ b/lib/swiotlb.c @@ -30,6 +30,7 @@ #include #include #include +#include #include #include @@ -155,6 +156,17 @@ unsigned long swiotlb_size_or_default(void) return size ? size : (IO_TLB_DEFAULT_SIZE); } +void __weak swiotlb_set_mem_attributes(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 __sme_clr(phys_to_dma(hwdev, address)); +} + /* Note that this doesn't work with highmem page */ static dma_addr_t swiotlb_virt_to_bus(struct device *hwdev, volatile void *address) @@ -183,6 +195,31 @@ void swiotlb_print_info(void) bytes >> 20, vstart, vend - 1); } +/* + * Early SWIOTLB allocation may be too early to allow an architecture to + * perform the desired operations. This function allows the architecture to + * call SWIOTLB when the operations are possible. It needs to be called + * before the SWIOTLB memory is used. + */ +void __init swiotlb_update_mem_attributes(void) +{ + void *vaddr; + unsigned long bytes; + + if (no_iotlb_memory || late_alloc) + return; + + vaddr = phys_to_virt(io_tlb_start); + bytes = PAGE_ALIGN(io_tlb_nslabs << IO_TLB_SHIFT); + swiotlb_set_mem_attributes(vaddr, bytes); + memset(vaddr, 0, bytes); + + vaddr = phys_to_virt(io_tlb_overflow_buffer); + bytes = PAGE_ALIGN(io_tlb_overflow); + swiotlb_set_mem_attributes(vaddr, bytes); + memset(vaddr, 0, bytes); +} + int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose) { void *v_overflow_buffer; @@ -320,6 +357,7 @@ int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose) io_tlb_start = virt_to_phys(tlb); io_tlb_end = io_tlb_start + bytes; + swiotlb_set_mem_attributes(tlb, bytes); memset(tlb, 0, bytes); /* @@ -330,6 +368,8 @@ int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose) if (!v_overflow_buffer) goto cleanup2; + swiotlb_set_mem_attributes(v_overflow_buffer, io_tlb_overflow); + memset(v_overflow_buffer, 0, io_tlb_overflow); io_tlb_overflow_buffer = virt_to_phys(v_overflow_buffer); /* @@ -581,7 +621,7 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, return SWIOTLB_MAP_ERROR; } - start_dma_addr = phys_to_dma(hwdev, io_tlb_start); + start_dma_addr = swiotlb_phys_to_dma(hwdev, io_tlb_start); return swiotlb_tbl_map_single(hwdev, start_dma_addr, phys, size, dir, attrs); } @@ -702,7 +742,7 @@ void swiotlb_tbl_sync_single(struct device *hwdev, phys_addr_t tlb_addr, 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) { @@ -812,10 +852,10 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page, map = map_single(dev, phys, size, dir, attrs); 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)) @@ -824,7 +864,7 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page, attrs |= DMA_ATTR_SKIP_CPU_SYNC; swiotlb_tbl_unmap_single(dev, map, size, dir, attrs); - return phys_to_dma(dev, io_tlb_overflow_buffer); + return swiotlb_phys_to_dma(dev, io_tlb_overflow_buffer); } EXPORT_SYMBOL_GPL(swiotlb_map_page); @@ -958,7 +998,7 @@ void swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr, 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; @@ -1026,7 +1066,7 @@ void swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr, 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); @@ -1039,6 +1079,6 @@ void swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr, 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);