LXR linux/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 <asm/machdep.h>
  12#include <asm/svm.h>
  13#include <asm/swiotlb.h>
  14#include <asm/ultravisor.h>
  15#include <asm/dtl.h>
  16
  17static int __init init_svm(void)
  18{
  19        if (!is_secure_guest())
  20                return 0;
  21
  22        /* Don't release the SWIOTLB buffer. */
  23        ppc_swiotlb_enable = 1;
  24
  25        /*
  26         * Since the guest memory is inaccessible to the host, devices always
  27         * need to use the SWIOTLB buffer for DMA even if dma_capable() says
  28         * otherwise.
  29         */
  30        swiotlb_force = SWIOTLB_FORCE;
  31
  32        /* Share the SWIOTLB buffer with the host. */
  33        swiotlb_update_mem_attributes();
  34
  35        return 0;
  36}
  37machine_early_initcall(pseries, init_svm);
  38
  39/*
  40 * Initialize SWIOTLB. Essentially the same as swiotlb_init(), except that it
  41 * can allocate the buffer anywhere in memory. Since the hypervisor doesn't have
  42 * any addressing limitation, we don't need to allocate it in low addresses.
  43 */
  44void __init svm_swiotlb_init(void)
  45{
  46        unsigned char *vstart;
  47        unsigned long bytes, io_tlb_nslabs;
  48
  49        io_tlb_nslabs = (swiotlb_size_or_default() >> IO_TLB_SHIFT);
  50        io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
  51
  52        bytes = io_tlb_nslabs << IO_TLB_SHIFT;
  53
  54        vstart = memblock_alloc(PAGE_ALIGN(bytes), PAGE_SIZE);
  55        if (vstart && !swiotlb_init_with_tbl(vstart, io_tlb_nslabs, false))
  56                return;
  57
  58
  59        memblock_free_early(__pa(vstart),
  60                            PAGE_ALIGN(io_tlb_nslabs << IO_TLB_SHIFT));
  61        panic("SVM: Cannot allocate SWIOTLB buffer");
  62}
  63
  64int set_memory_encrypted(unsigned long addr, int numpages)
  65{
  66        if (!mem_encrypt_active())
  67                return 0;
  68
  69        if (!PAGE_ALIGNED(addr))
  70                return -EINVAL;
  71
  72        uv_unshare_page(PHYS_PFN(__pa(addr)), numpages);
  73
  74        return 0;
  75}
  76
  77int set_memory_decrypted(unsigned long addr, int numpages)
  78{
  79        if (!mem_encrypt_active())
  80                return 0;
  81
  82        if (!PAGE_ALIGNED(addr))
  83                return -EINVAL;
  84
  85        uv_share_page(PHYS_PFN(__pa(addr)), numpages);
  86
  87        return 0;
  88}
  89
  90/* There's one dispatch log per CPU. */
  91#define NR_DTL_PAGE (DISPATCH_LOG_BYTES * CONFIG_NR_CPUS / PAGE_SIZE)
  92
  93static struct page *dtl_page_store[NR_DTL_PAGE];
  94static long dtl_nr_pages;
  95
  96static bool is_dtl_page_shared(struct page *page)
  97{
  98        long i;
  99
 100        for (i = 0; i < dtl_nr_pages; i++)
 101                if (dtl_page_store[i] == page)
 102                        return true;
 103
 104        return false;
 105}
 106
 107void dtl_cache_ctor(void *addr)
 108{
 109        unsigned long pfn = PHYS_PFN(__pa(addr));
 110        struct page *page = pfn_to_page(pfn);
 111
 112        if (!is_dtl_page_shared(page)) {
 113                dtl_page_store[dtl_nr_pages] = page;
 114                dtl_nr_pages++;
 115                WARN_ON(dtl_nr_pages >= NR_DTL_PAGE);
 116                uv_share_page(pfn, 1);
 117        }
 118}
 119