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 <asm/machdep.h>
  11 #include <asm/svm.h>
  12 #include <asm/swiotlb.h>
  13 #include <asm/ultravisor.h>
  14
  15 static int __init init_svm(void)
  16 {
  17         if (!is_secure_guest())
  18                 return 0;
  19
  20         /* Don't release the SWIOTLB buffer. */
  21         ppc_swiotlb_enable = 1;
  22
  23         /*
  24          * Since the guest memory is inaccessible to the host, devices always
  25          * need to use the SWIOTLB buffer for DMA even if dma_capable() says
  26          * otherwise.
  27          */
  28         swiotlb_force = SWIOTLB_FORCE;
  29
  30         /* Share the SWIOTLB buffer with the host. */
  31         swiotlb_update_mem_attributes();
  32
  33         return 0;
  34 }
  35 machine_early_initcall(pseries, init_svm);
  36
  37 int set_memory_encrypted(unsigned long addr, int numpages)
  38 {
  39         if (!PAGE_ALIGNED(addr))
  40                 return -EINVAL;
  41
  42         uv_unshare_page(PHYS_PFN(__pa(addr)), numpages);
  43
  44         return 0;
  45 }
  46
  47 int set_memory_decrypted(unsigned long addr, int numpages)
  48 {
  49         if (!PAGE_ALIGNED(addr))
  50                 return -EINVAL;
  51
  52         uv_share_page(PHYS_PFN(__pa(addr)), numpages);
  53
  54         return 0;
  55 }
  56
  57 /* There's one dispatch log per CPU. */
  58 #define NR_DTL_PAGE (DISPATCH_LOG_BYTES * CONFIG_NR_CPUS / PAGE_SIZE)
  59
  60 static struct page *dtl_page_store[NR_DTL_PAGE];
  61 static long dtl_nr_pages;
  62
  63 static bool is_dtl_page_shared(struct page *page)
  64 {
  65         long i;
  66
  67         for (i = 0; i < dtl_nr_pages; i++)
  68                 if (dtl_page_store[i] == page)
  69                         return true;
  70
  71         return false;
  72 }
  73
  74 void dtl_cache_ctor(void *addr)
  75 {
  76         unsigned long pfn = PHYS_PFN(__pa(addr));
  77         struct page *page = pfn_to_page(pfn);
  78
  79         if (!is_dtl_page_shared(page)) {
  80                 dtl_page_store[dtl_nr_pages] = page;
  81                 dtl_nr_pages++;
  82                 WARN_ON(dtl_nr_pages >= NR_DTL_PAGE);
  83                 uv_share_page(pfn, 1);
  84         }
  85 }