linux/arch/powerpc/platforms/pseries/svm.c

113 lines
2.5 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Secure VM platform
*
* Copyright 2018 IBM Corporation
* Author: Anshuman Khandual <khandual@linux.vnet.ibm.com>
*/
#include <linux/mm.h>
#include <linux/memblock.h>
#include <asm/machdep.h>
#include <asm/svm.h>
#include <asm/swiotlb.h>
#include <asm/ultravisor.h>
#include <asm/dtl.h>
static int __init init_svm(void)
{
if (!is_secure_guest())
return 0;
/* Don't release the SWIOTLB buffer. */
ppc_swiotlb_enable = 1;
/*
* Since the guest memory is inaccessible to the host, devices always
* need to use the SWIOTLB buffer for DMA even if dma_capable() says
* otherwise.
*/
swiotlb_force = SWIOTLB_FORCE;
/* Share the SWIOTLB buffer with the host. */
swiotlb_update_mem_attributes();
return 0;
}
machine_early_initcall(pseries, init_svm);
/*
* Initialize SWIOTLB. Essentially the same as swiotlb_init(), except that it
* can allocate the buffer anywhere in memory. Since the hypervisor doesn't have
* any addressing limitation, we don't need to allocate it in low addresses.
*/
void __init svm_swiotlb_init(void)
{
unsigned char *vstart;
unsigned long bytes, io_tlb_nslabs;
io_tlb_nslabs = (swiotlb_size_or_default() >> IO_TLB_SHIFT);
io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
bytes = io_tlb_nslabs << IO_TLB_SHIFT;
vstart = memblock_alloc(PAGE_ALIGN(bytes), PAGE_SIZE);
if (vstart && !swiotlb_init_with_tbl(vstart, io_tlb_nslabs, false))
return;
if (io_tlb_start)
memblock_free_early(io_tlb_start,
PAGE_ALIGN(io_tlb_nslabs << IO_TLB_SHIFT));
panic("SVM: Cannot allocate SWIOTLB buffer");
}
int set_memory_encrypted(unsigned long addr, int numpages)
{
if (!PAGE_ALIGNED(addr))
return -EINVAL;
uv_unshare_page(PHYS_PFN(__pa(addr)), numpages);
return 0;
}
int set_memory_decrypted(unsigned long addr, int numpages)
{
if (!PAGE_ALIGNED(addr))
return -EINVAL;
uv_share_page(PHYS_PFN(__pa(addr)), numpages);
return 0;
}
/* There's one dispatch log per CPU. */
#define NR_DTL_PAGE (DISPATCH_LOG_BYTES * CONFIG_NR_CPUS / PAGE_SIZE)
static struct page *dtl_page_store[NR_DTL_PAGE];
static long dtl_nr_pages;
static bool is_dtl_page_shared(struct page *page)
{
long i;
for (i = 0; i < dtl_nr_pages; i++)
if (dtl_page_store[i] == page)
return true;
return false;
}
void dtl_cache_ctor(void *addr)
{
unsigned long pfn = PHYS_PFN(__pa(addr));
struct page *page = pfn_to_page(pfn);
if (!is_dtl_page_shared(page)) {
dtl_page_store[dtl_nr_pages] = page;
dtl_nr_pages++;
WARN_ON(dtl_nr_pages >= NR_DTL_PAGE);
uv_share_page(pfn, 1);
}
}