mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-28 11:18:45 +07:00
ae7eb82a92
Secure Encrypted Virtualization is an x86-specific feature, so it shouldn't appear in generic kernel code because it forces non-x86 architectures to define the sev_active() function, which doesn't make a lot of sense. To solve this problem, add an x86 elfcorehdr_read() function to override the generic weak implementation. To do that, it's necessary to make read_from_oldmem() public so that it can be used outside of vmcore.c. Also, remove the export for sev_active() since it's only used in files that won't be built as modules. Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Lianbo Jiang <lijiang@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190806044919.10622-6-bauerman@linux.ibm.com
78 lines
2.2 KiB
C
78 lines
2.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Memory preserving reboot related code.
|
|
*
|
|
* Created by: Hariprasad Nellitheertha (hari@in.ibm.com)
|
|
* Copyright (C) IBM Corporation, 2004. All rights reserved
|
|
*/
|
|
|
|
#include <linux/errno.h>
|
|
#include <linux/crash_dump.h>
|
|
#include <linux/uaccess.h>
|
|
#include <linux/io.h>
|
|
|
|
static ssize_t __copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
|
|
unsigned long offset, int userbuf,
|
|
bool encrypted)
|
|
{
|
|
void *vaddr;
|
|
|
|
if (!csize)
|
|
return 0;
|
|
|
|
if (encrypted)
|
|
vaddr = (__force void *)ioremap_encrypted(pfn << PAGE_SHIFT, PAGE_SIZE);
|
|
else
|
|
vaddr = (__force void *)ioremap_cache(pfn << PAGE_SHIFT, PAGE_SIZE);
|
|
|
|
if (!vaddr)
|
|
return -ENOMEM;
|
|
|
|
if (userbuf) {
|
|
if (copy_to_user((void __user *)buf, vaddr + offset, csize)) {
|
|
iounmap((void __iomem *)vaddr);
|
|
return -EFAULT;
|
|
}
|
|
} else
|
|
memcpy(buf, vaddr + offset, csize);
|
|
|
|
set_iounmap_nonlazy();
|
|
iounmap((void __iomem *)vaddr);
|
|
return csize;
|
|
}
|
|
|
|
/**
|
|
* copy_oldmem_page - copy one page of memory
|
|
* @pfn: page frame number to be copied
|
|
* @buf: target memory address for the copy; this can be in kernel address
|
|
* space or user address space (see @userbuf)
|
|
* @csize: number of bytes to copy
|
|
* @offset: offset in bytes into the page (based on pfn) to begin the copy
|
|
* @userbuf: if set, @buf is in user address space, use copy_to_user(),
|
|
* otherwise @buf is in kernel address space, use memcpy().
|
|
*
|
|
* Copy a page from the old kernel's memory. For this page, there is no pte
|
|
* mapped in the current kernel. We stitch up a pte, similar to kmap_atomic.
|
|
*/
|
|
ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
|
|
unsigned long offset, int userbuf)
|
|
{
|
|
return __copy_oldmem_page(pfn, buf, csize, offset, userbuf, false);
|
|
}
|
|
|
|
/**
|
|
* copy_oldmem_page_encrypted - same as copy_oldmem_page() above but ioremap the
|
|
* memory with the encryption mask set to accommodate kdump on SME-enabled
|
|
* machines.
|
|
*/
|
|
ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf, size_t csize,
|
|
unsigned long offset, int userbuf)
|
|
{
|
|
return __copy_oldmem_page(pfn, buf, csize, offset, userbuf, true);
|
|
}
|
|
|
|
ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos)
|
|
{
|
|
return read_from_oldmem(buf, count, ppos, 0, sev_active());
|
|
}
|