cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

svm.c (1946B)

      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
     18static 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}
     38machine_early_initcall(pseries, init_svm);
     39
     40int 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
     53int 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
     69static struct page *dtl_page_store[NR_DTL_PAGE];
     70static long dtl_nr_pages;
     71
     72static 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
     83void 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}