diff options
| -rw-r--r-- | arch/x86/mm/mem_encrypt.c | 86 | ||||
| -rw-r--r-- | lib/swiotlb.c | 5 |
2 files changed, 89 insertions, 2 deletions
diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c index add836d3d174..e8bfad75ba29 100644 --- a/arch/x86/mm/mem_encrypt.c +++ b/arch/x86/mm/mem_encrypt.c @@ -192,6 +192,70 @@ void __init sme_early_init(void) /* Update the protection map with memory encryption mask */ for (i = 0; i < ARRAY_SIZE(protection_map); i++) protection_map[i] = pgprot_encrypted(protection_map[i]); + + if (sev_active()) + swiotlb_force = SWIOTLB_FORCE; +} + +static void *sev_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, + gfp_t gfp, unsigned long attrs) +{ + unsigned long dma_mask; + unsigned int order; + struct page *page; + void *vaddr = NULL; + + dma_mask = dma_alloc_coherent_mask(dev, gfp); + order = get_order(size); + + /* + * Memory will be memset to zero after marking decrypted, so don't + * bother clearing it before. + */ + gfp &= ~__GFP_ZERO; + + page = alloc_pages_node(dev_to_node(dev), gfp, order); + if (page) { + dma_addr_t addr; + + /* + * Since we will be clearing the encryption bit, check the + * mask with it already cleared. + */ + addr = __sme_clr(phys_to_dma(dev, page_to_phys(page))); + if ((addr + size) > dma_mask) { + __free_pages(page, get_order(size)); + } else { + vaddr = page_address(page); + *dma_handle = addr; + } + } + + if (!vaddr) + vaddr = swiotlb_alloc_coherent(dev, size, dma_handle, gfp); + + if (!vaddr) + return NULL; + + /* Clear the SME encryption bit for DMA use if not swiotlb area */ + if (!is_swiotlb_buffer(dma_to_phys(dev, *dma_handle))) { + set_memory_decrypted((unsigned long)vaddr, 1 << order); + memset(vaddr, 0, PAGE_SIZE << order); + *dma_handle = __sme_clr(*dma_handle); + } + + return vaddr; +} + +static void sev_free(struct device *dev, size_t size, void *vaddr, + dma_addr_t dma_handle, unsigned long attrs) +{ + /* Set the SME encryption bit for re-use if not swiotlb area */ + if (!is_swiotlb_buffer(dma_to_phys(dev, dma_handle))) + set_memory_encrypted((unsigned long)vaddr, + 1 << get_order(size)); + + swiotlb_free_coherent(dev, size, vaddr, dma_handle); } /* @@ -218,6 +282,20 @@ bool sev_active(void) } EXPORT_SYMBOL_GPL(sev_active); +static const struct dma_map_ops sev_dma_ops = { + .alloc = sev_alloc, + .free = sev_free, + .map_page = swiotlb_map_page, + .unmap_page = swiotlb_unmap_page, + .map_sg = swiotlb_map_sg_attrs, + .unmap_sg = swiotlb_unmap_sg_attrs, + .sync_single_for_cpu = swiotlb_sync_single_for_cpu, + .sync_single_for_device = swiotlb_sync_single_for_device, + .sync_sg_for_cpu = swiotlb_sync_sg_for_cpu, + .sync_sg_for_device = swiotlb_sync_sg_for_device, + .mapping_error = swiotlb_dma_mapping_error, +}; + /* Architecture __weak replacement functions */ void __init mem_encrypt_init(void) { @@ -227,6 +305,14 @@ void __init mem_encrypt_init(void) /* Call into SWIOTLB to update the SWIOTLB DMA buffers */ swiotlb_update_mem_attributes(); + /* + * With SEV, DMA operations cannot use encryption. New DMA ops + * are required in order to mark the DMA areas as decrypted or + * to use bounce buffers. + */ + if (sev_active()) + dma_ops = &sev_dma_ops; + pr_info("AMD Secure Memory Encryption (SME) active\n"); } diff --git a/lib/swiotlb.c b/lib/swiotlb.c index 8c6c83ef57a4..cea19aaf303c 100644 --- a/lib/swiotlb.c +++ b/lib/swiotlb.c @@ -507,8 +507,9 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, if (no_iotlb_memory) panic("Can not allocate SWIOTLB buffer earlier and can't now provide you with the DMA bounce buffer"); - if (sme_active()) - pr_warn_once("SME is active and system is using DMA bounce buffers\n"); + if (mem_encrypt_active()) + pr_warn_once("%s is active and system is using DMA bounce buffers\n", + sme_active() ? "SME" : "SEV"); mask = dma_get_seg_boundary(hwdev); |