arch/powerpc/platforms/pseries/svm.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Secure VM platform
   4  *
   5  * Copyright 2018 IBM Corporation
   6  * Author: Anshuman Khandual <khandual@linux.vnet.ibm.com>
   7  */
   8
   9 #include <linux/mm.h>
  10 #include <linux/memblock.h>
  11 #include <linux/cc_platform.h>
  12 #include <asm/machdep.h>
  13 #include <asm/svm.h>
  14 #include <asm/swiotlb.h>
  15 #include <asm/ultravisor.h>
  16 #include <asm/dtl.h>
  17
  18 static int __init init_svm(void)
  19 {
  20         if (!is_secure_guest())
  21                 return 0;
  22
  23         /* Don't release the SWIOTLB buffer. */
  24         ppc_swiotlb_enable = 1;
  25
  26         /*
  27          * Since the guest memory is inaccessible to the host, devices always
  28          * need to use the SWIOTLB buffer for DMA even if dma_capable() says
  29          * otherwise.
  30          */
  31         ppc_swiotlb_flags |= SWIOTLB_ANY | SWIOTLB_FORCE;
  32
  33         /* Share the SWIOTLB buffer with the host. */
  34         swiotlb_update_mem_attributes();
  35
  36         return 0;
  37 }
  38 machine_early_initcall(pseries, init_svm);
  39
  40 int set_memory_encrypted(unsigned long addr, int numpages)
  41 {
  42         if (!cc_platform_has(CC_ATTR_MEM_ENCRYPT))
  43                 return 0;
  44
  45         if (!PAGE_ALIGNED(addr))
  46                 return -EINVAL;
  47
  48         uv_unshare_page(PHYS_PFN(__pa(addr)), numpages);
  49
  50         return 0;
  51 }
  52
  53 int set_memory_decrypted(unsigned long addr, int numpages)
  54 {
  55         if (!cc_platform_has(CC_ATTR_MEM_ENCRYPT))
  56                 return 0;
  57
  58         if (!PAGE_ALIGNED(addr))
  59                 return -EINVAL;
  60
  61         uv_share_page(PHYS_PFN(__pa(addr)), numpages);
  62
  63         return 0;
  64 }
  65
  66 /* There's one dispatch log per CPU. */
  67 #define NR_DTL_PAGE (DISPATCH_LOG_BYTES * CONFIG_NR_CPUS / PAGE_SIZE)
  68
  69 static struct page *dtl_page_store[NR_DTL_PAGE];
  70 static long dtl_nr_pages;
  71
  72 static bool is_dtl_page_shared(struct page *page)
  73 {
  74         long i;
  75
  76         for (i = 0; i < dtl_nr_pages; i++)
  77                 if (dtl_page_store[i] == page)
  78                         return true;
  79
  80         return false;
  81 }
  82
  83 void dtl_cache_ctor(void *addr)
  84 {
  85         unsigned long pfn = PHYS_PFN(__pa(addr));
  86         struct page *page = pfn_to_page(pfn);
  87
  88         if (!is_dtl_page_shared(page)) {
  89                 dtl_page_store[dtl_nr_pages] = page;
  90                 dtl_nr_pages++;
  91                 WARN_ON(dtl_nr_pages >= NR_DTL_PAGE);
  92                 uv_share_page(pfn, 1);
  93         }
  94 }