mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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512b7931ad
Merge misc updates from Andrew Morton: "257 patches. Subsystems affected by this patch series: scripts, ocfs2, vfs, and mm (slab-generic, slab, slub, kconfig, dax, kasan, debug, pagecache, gup, swap, memcg, pagemap, mprotect, mremap, iomap, tracing, vmalloc, pagealloc, memory-failure, hugetlb, userfaultfd, vmscan, tools, memblock, oom-kill, hugetlbfs, migration, thp, readahead, nommu, ksm, vmstat, madvise, memory-hotplug, rmap, zsmalloc, highmem, zram, cleanups, kfence, and damon)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (257 commits) mm/damon: remove return value from before_terminate callback mm/damon: fix a few spelling mistakes in comments and a pr_debug message mm/damon: simplify stop mechanism Docs/admin-guide/mm/pagemap: wordsmith page flags descriptions Docs/admin-guide/mm/damon/start: simplify the content Docs/admin-guide/mm/damon/start: fix a wrong link Docs/admin-guide/mm/damon/start: fix wrong example commands mm/damon/dbgfs: add adaptive_targets list check before enable monitor_on mm/damon: remove unnecessary variable initialization Documentation/admin-guide/mm/damon: add a document for DAMON_RECLAIM mm/damon: introduce DAMON-based Reclamation (DAMON_RECLAIM) selftests/damon: support watermarks mm/damon/dbgfs: support watermarks mm/damon/schemes: activate schemes based on a watermarks mechanism tools/selftests/damon: update for regions prioritization of schemes mm/damon/dbgfs: support prioritization weights mm/damon/vaddr,paddr: support pageout prioritization mm/damon/schemes: prioritize regions within the quotas mm/damon/selftests: support schemes quotas mm/damon/dbgfs: support quotas of schemes ...
519 lines
13 KiB
C
519 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Common Ultravisor functions and initialization
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*
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* Copyright IBM Corp. 2019, 2020
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*/
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#define KMSG_COMPONENT "prot_virt"
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#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
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#include <linux/kernel.h>
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#include <linux/types.h>
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#include <linux/sizes.h>
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#include <linux/bitmap.h>
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#include <linux/memblock.h>
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#include <linux/pagemap.h>
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#include <linux/swap.h>
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#include <asm/facility.h>
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#include <asm/sections.h>
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#include <asm/uv.h>
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/* the bootdata_preserved fields come from ones in arch/s390/boot/uv.c */
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#ifdef CONFIG_PROTECTED_VIRTUALIZATION_GUEST
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int __bootdata_preserved(prot_virt_guest);
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#endif
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struct uv_info __bootdata_preserved(uv_info);
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#if IS_ENABLED(CONFIG_KVM)
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int __bootdata_preserved(prot_virt_host);
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EXPORT_SYMBOL(prot_virt_host);
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EXPORT_SYMBOL(uv_info);
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static int __init uv_init(unsigned long stor_base, unsigned long stor_len)
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{
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struct uv_cb_init uvcb = {
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.header.cmd = UVC_CMD_INIT_UV,
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.header.len = sizeof(uvcb),
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.stor_origin = stor_base,
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.stor_len = stor_len,
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};
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if (uv_call(0, (uint64_t)&uvcb)) {
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pr_err("Ultravisor init failed with rc: 0x%x rrc: 0%x\n",
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uvcb.header.rc, uvcb.header.rrc);
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return -1;
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}
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return 0;
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}
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void __init setup_uv(void)
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{
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unsigned long uv_stor_base;
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if (!is_prot_virt_host())
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return;
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uv_stor_base = (unsigned long)memblock_alloc_try_nid(
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uv_info.uv_base_stor_len, SZ_1M, SZ_2G,
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MEMBLOCK_ALLOC_ACCESSIBLE, NUMA_NO_NODE);
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if (!uv_stor_base) {
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pr_warn("Failed to reserve %lu bytes for ultravisor base storage\n",
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uv_info.uv_base_stor_len);
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goto fail;
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}
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if (uv_init(uv_stor_base, uv_info.uv_base_stor_len)) {
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memblock_phys_free(uv_stor_base, uv_info.uv_base_stor_len);
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goto fail;
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}
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pr_info("Reserving %luMB as ultravisor base storage\n",
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uv_info.uv_base_stor_len >> 20);
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return;
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fail:
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pr_info("Disabling support for protected virtualization");
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prot_virt_host = 0;
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}
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/*
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* Requests the Ultravisor to pin the page in the shared state. This will
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* cause an intercept when the guest attempts to unshare the pinned page.
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*/
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static int uv_pin_shared(unsigned long paddr)
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{
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struct uv_cb_cfs uvcb = {
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.header.cmd = UVC_CMD_PIN_PAGE_SHARED,
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.header.len = sizeof(uvcb),
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.paddr = paddr,
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};
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if (uv_call(0, (u64)&uvcb))
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return -EINVAL;
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return 0;
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}
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/*
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* Requests the Ultravisor to destroy a guest page and make it
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* accessible to the host. The destroy clears the page instead of
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* exporting.
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*
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* @paddr: Absolute host address of page to be destroyed
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*/
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static int uv_destroy_page(unsigned long paddr)
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{
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struct uv_cb_cfs uvcb = {
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.header.cmd = UVC_CMD_DESTR_SEC_STOR,
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.header.len = sizeof(uvcb),
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.paddr = paddr
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};
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if (uv_call(0, (u64)&uvcb)) {
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/*
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* Older firmware uses 107/d as an indication of a non secure
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* page. Let us emulate the newer variant (no-op).
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*/
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if (uvcb.header.rc == 0x107 && uvcb.header.rrc == 0xd)
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return 0;
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return -EINVAL;
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}
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return 0;
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}
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/*
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* The caller must already hold a reference to the page
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*/
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int uv_destroy_owned_page(unsigned long paddr)
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{
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struct page *page = phys_to_page(paddr);
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int rc;
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get_page(page);
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rc = uv_destroy_page(paddr);
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if (!rc)
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clear_bit(PG_arch_1, &page->flags);
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put_page(page);
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return rc;
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}
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/*
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* Requests the Ultravisor to encrypt a guest page and make it
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* accessible to the host for paging (export).
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*
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* @paddr: Absolute host address of page to be exported
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*/
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int uv_convert_from_secure(unsigned long paddr)
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{
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struct uv_cb_cfs uvcb = {
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.header.cmd = UVC_CMD_CONV_FROM_SEC_STOR,
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.header.len = sizeof(uvcb),
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.paddr = paddr
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};
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if (uv_call(0, (u64)&uvcb))
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return -EINVAL;
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return 0;
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}
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/*
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* The caller must already hold a reference to the page
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*/
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int uv_convert_owned_from_secure(unsigned long paddr)
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{
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struct page *page = phys_to_page(paddr);
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int rc;
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get_page(page);
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rc = uv_convert_from_secure(paddr);
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if (!rc)
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clear_bit(PG_arch_1, &page->flags);
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put_page(page);
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return rc;
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}
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/*
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* Calculate the expected ref_count for a page that would otherwise have no
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* further pins. This was cribbed from similar functions in other places in
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* the kernel, but with some slight modifications. We know that a secure
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* page can not be a huge page for example.
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*/
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static int expected_page_refs(struct page *page)
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{
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int res;
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res = page_mapcount(page);
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if (PageSwapCache(page)) {
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res++;
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} else if (page_mapping(page)) {
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res++;
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if (page_has_private(page))
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res++;
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}
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return res;
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}
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static int make_secure_pte(pte_t *ptep, unsigned long addr,
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struct page *exp_page, struct uv_cb_header *uvcb)
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{
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pte_t entry = READ_ONCE(*ptep);
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struct page *page;
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int expected, cc = 0;
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if (!pte_present(entry))
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return -ENXIO;
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if (pte_val(entry) & _PAGE_INVALID)
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return -ENXIO;
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page = pte_page(entry);
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if (page != exp_page)
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return -ENXIO;
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if (PageWriteback(page))
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return -EAGAIN;
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expected = expected_page_refs(page);
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if (!page_ref_freeze(page, expected))
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return -EBUSY;
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set_bit(PG_arch_1, &page->flags);
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/*
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* If the UVC does not succeed or fail immediately, we don't want to
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* loop for long, or we might get stall notifications.
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* On the other hand, this is a complex scenario and we are holding a lot of
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* locks, so we can't easily sleep and reschedule. We try only once,
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* and if the UVC returned busy or partial completion, we return
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* -EAGAIN and we let the callers deal with it.
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*/
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cc = __uv_call(0, (u64)uvcb);
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page_ref_unfreeze(page, expected);
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/*
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* Return -ENXIO if the page was not mapped, -EINVAL for other errors.
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* If busy or partially completed, return -EAGAIN.
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*/
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if (cc == UVC_CC_OK)
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return 0;
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else if (cc == UVC_CC_BUSY || cc == UVC_CC_PARTIAL)
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return -EAGAIN;
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return uvcb->rc == 0x10a ? -ENXIO : -EINVAL;
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}
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/*
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* Requests the Ultravisor to make a page accessible to a guest.
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* If it's brought in the first time, it will be cleared. If
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* it has been exported before, it will be decrypted and integrity
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* checked.
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*/
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int gmap_make_secure(struct gmap *gmap, unsigned long gaddr, void *uvcb)
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{
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struct vm_area_struct *vma;
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bool local_drain = false;
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spinlock_t *ptelock;
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unsigned long uaddr;
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struct page *page;
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pte_t *ptep;
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int rc;
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again:
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rc = -EFAULT;
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mmap_read_lock(gmap->mm);
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uaddr = __gmap_translate(gmap, gaddr);
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if (IS_ERR_VALUE(uaddr))
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goto out;
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vma = vma_lookup(gmap->mm, uaddr);
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if (!vma)
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goto out;
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/*
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* Secure pages cannot be huge and userspace should not combine both.
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* In case userspace does it anyway this will result in an -EFAULT for
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* the unpack. The guest is thus never reaching secure mode. If
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* userspace is playing dirty tricky with mapping huge pages later
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* on this will result in a segmentation fault.
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*/
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if (is_vm_hugetlb_page(vma))
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goto out;
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rc = -ENXIO;
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page = follow_page(vma, uaddr, FOLL_WRITE);
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if (IS_ERR_OR_NULL(page))
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goto out;
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lock_page(page);
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ptep = get_locked_pte(gmap->mm, uaddr, &ptelock);
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rc = make_secure_pte(ptep, uaddr, page, uvcb);
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pte_unmap_unlock(ptep, ptelock);
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unlock_page(page);
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out:
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mmap_read_unlock(gmap->mm);
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if (rc == -EAGAIN) {
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/*
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* If we are here because the UVC returned busy or partial
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* completion, this is just a useless check, but it is safe.
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*/
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wait_on_page_writeback(page);
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} else if (rc == -EBUSY) {
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/*
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* If we have tried a local drain and the page refcount
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* still does not match our expected safe value, try with a
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* system wide drain. This is needed if the pagevecs holding
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* the page are on a different CPU.
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*/
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if (local_drain) {
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lru_add_drain_all();
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/* We give up here, and let the caller try again */
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return -EAGAIN;
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}
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/*
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* We are here if the page refcount does not match the
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* expected safe value. The main culprits are usually
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* pagevecs. With lru_add_drain() we drain the pagevecs
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* on the local CPU so that hopefully the refcount will
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* reach the expected safe value.
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*/
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lru_add_drain();
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local_drain = true;
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/* And now we try again immediately after draining */
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goto again;
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} else if (rc == -ENXIO) {
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if (gmap_fault(gmap, gaddr, FAULT_FLAG_WRITE))
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return -EFAULT;
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return -EAGAIN;
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}
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return rc;
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}
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EXPORT_SYMBOL_GPL(gmap_make_secure);
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int gmap_convert_to_secure(struct gmap *gmap, unsigned long gaddr)
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{
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struct uv_cb_cts uvcb = {
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.header.cmd = UVC_CMD_CONV_TO_SEC_STOR,
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.header.len = sizeof(uvcb),
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.guest_handle = gmap->guest_handle,
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.gaddr = gaddr,
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};
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return gmap_make_secure(gmap, gaddr, &uvcb);
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}
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EXPORT_SYMBOL_GPL(gmap_convert_to_secure);
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/*
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* To be called with the page locked or with an extra reference! This will
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* prevent gmap_make_secure from touching the page concurrently. Having 2
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* parallel make_page_accessible is fine, as the UV calls will become a
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* no-op if the page is already exported.
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*/
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int arch_make_page_accessible(struct page *page)
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{
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int rc = 0;
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/* Hugepage cannot be protected, so nothing to do */
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if (PageHuge(page))
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return 0;
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/*
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* PG_arch_1 is used in 3 places:
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* 1. for kernel page tables during early boot
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* 2. for storage keys of huge pages and KVM
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* 3. As an indication that this page might be secure. This can
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* overindicate, e.g. we set the bit before calling
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* convert_to_secure.
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* As secure pages are never huge, all 3 variants can co-exists.
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*/
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if (!test_bit(PG_arch_1, &page->flags))
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return 0;
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rc = uv_pin_shared(page_to_phys(page));
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if (!rc) {
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clear_bit(PG_arch_1, &page->flags);
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return 0;
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}
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rc = uv_convert_from_secure(page_to_phys(page));
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if (!rc) {
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clear_bit(PG_arch_1, &page->flags);
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return 0;
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}
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return rc;
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}
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EXPORT_SYMBOL_GPL(arch_make_page_accessible);
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#endif
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#if defined(CONFIG_PROTECTED_VIRTUALIZATION_GUEST) || IS_ENABLED(CONFIG_KVM)
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static ssize_t uv_query_facilities(struct kobject *kobj,
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struct kobj_attribute *attr, char *page)
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{
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return scnprintf(page, PAGE_SIZE, "%lx\n%lx\n%lx\n%lx\n",
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uv_info.inst_calls_list[0],
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uv_info.inst_calls_list[1],
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uv_info.inst_calls_list[2],
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uv_info.inst_calls_list[3]);
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}
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static struct kobj_attribute uv_query_facilities_attr =
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__ATTR(facilities, 0444, uv_query_facilities, NULL);
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static ssize_t uv_query_feature_indications(struct kobject *kobj,
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struct kobj_attribute *attr, char *buf)
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{
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return sysfs_emit(buf, "%lx\n", uv_info.uv_feature_indications);
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}
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static struct kobj_attribute uv_query_feature_indications_attr =
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__ATTR(feature_indications, 0444, uv_query_feature_indications, NULL);
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static ssize_t uv_query_max_guest_cpus(struct kobject *kobj,
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struct kobj_attribute *attr, char *page)
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{
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return scnprintf(page, PAGE_SIZE, "%d\n",
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uv_info.max_guest_cpu_id + 1);
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}
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static struct kobj_attribute uv_query_max_guest_cpus_attr =
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__ATTR(max_cpus, 0444, uv_query_max_guest_cpus, NULL);
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static ssize_t uv_query_max_guest_vms(struct kobject *kobj,
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struct kobj_attribute *attr, char *page)
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{
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return scnprintf(page, PAGE_SIZE, "%d\n",
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uv_info.max_num_sec_conf);
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}
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static struct kobj_attribute uv_query_max_guest_vms_attr =
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__ATTR(max_guests, 0444, uv_query_max_guest_vms, NULL);
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static ssize_t uv_query_max_guest_addr(struct kobject *kobj,
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struct kobj_attribute *attr, char *page)
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{
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return scnprintf(page, PAGE_SIZE, "%lx\n",
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uv_info.max_sec_stor_addr);
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}
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static struct kobj_attribute uv_query_max_guest_addr_attr =
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__ATTR(max_address, 0444, uv_query_max_guest_addr, NULL);
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static struct attribute *uv_query_attrs[] = {
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&uv_query_facilities_attr.attr,
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&uv_query_feature_indications_attr.attr,
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&uv_query_max_guest_cpus_attr.attr,
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&uv_query_max_guest_vms_attr.attr,
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&uv_query_max_guest_addr_attr.attr,
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NULL,
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};
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static struct attribute_group uv_query_attr_group = {
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.attrs = uv_query_attrs,
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};
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static ssize_t uv_is_prot_virt_guest(struct kobject *kobj,
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struct kobj_attribute *attr, char *page)
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{
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int val = 0;
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#ifdef CONFIG_PROTECTED_VIRTUALIZATION_GUEST
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val = prot_virt_guest;
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#endif
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return scnprintf(page, PAGE_SIZE, "%d\n", val);
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}
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static ssize_t uv_is_prot_virt_host(struct kobject *kobj,
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struct kobj_attribute *attr, char *page)
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{
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int val = 0;
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#if IS_ENABLED(CONFIG_KVM)
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val = prot_virt_host;
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#endif
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return scnprintf(page, PAGE_SIZE, "%d\n", val);
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}
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static struct kobj_attribute uv_prot_virt_guest =
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__ATTR(prot_virt_guest, 0444, uv_is_prot_virt_guest, NULL);
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static struct kobj_attribute uv_prot_virt_host =
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__ATTR(prot_virt_host, 0444, uv_is_prot_virt_host, NULL);
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|
|
static const struct attribute *uv_prot_virt_attrs[] = {
|
|
&uv_prot_virt_guest.attr,
|
|
&uv_prot_virt_host.attr,
|
|
NULL,
|
|
};
|
|
|
|
static struct kset *uv_query_kset;
|
|
static struct kobject *uv_kobj;
|
|
|
|
static int __init uv_info_init(void)
|
|
{
|
|
int rc = -ENOMEM;
|
|
|
|
if (!test_facility(158))
|
|
return 0;
|
|
|
|
uv_kobj = kobject_create_and_add("uv", firmware_kobj);
|
|
if (!uv_kobj)
|
|
return -ENOMEM;
|
|
|
|
rc = sysfs_create_files(uv_kobj, uv_prot_virt_attrs);
|
|
if (rc)
|
|
goto out_kobj;
|
|
|
|
uv_query_kset = kset_create_and_add("query", NULL, uv_kobj);
|
|
if (!uv_query_kset) {
|
|
rc = -ENOMEM;
|
|
goto out_ind_files;
|
|
}
|
|
|
|
rc = sysfs_create_group(&uv_query_kset->kobj, &uv_query_attr_group);
|
|
if (!rc)
|
|
return 0;
|
|
|
|
kset_unregister(uv_query_kset);
|
|
out_ind_files:
|
|
sysfs_remove_files(uv_kobj, uv_prot_virt_attrs);
|
|
out_kobj:
|
|
kobject_del(uv_kobj);
|
|
kobject_put(uv_kobj);
|
|
return rc;
|
|
}
|
|
device_initcall(uv_info_init);
|
|
#endif
|