linux/linux-5.18.11/arch/arm64/kvm/pkvm.c

110 lines
2.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2020 - Google LLC
* Author: Quentin Perret <qperret@google.com>
*/
#include <linux/kvm_host.h>
#include <linux/memblock.h>
#include <linux/sort.h>
#include <asm/kvm_pkvm.h>
#include "hyp_constants.h"
static struct memblock_region *hyp_memory = kvm_nvhe_sym(hyp_memory);
static unsigned int *hyp_memblock_nr_ptr = &kvm_nvhe_sym(hyp_memblock_nr);
phys_addr_t hyp_mem_base;
phys_addr_t hyp_mem_size;
static int cmp_hyp_memblock(const void *p1, const void *p2)
{
const struct memblock_region *r1 = p1;
const struct memblock_region *r2 = p2;
return r1->base < r2->base ? -1 : (r1->base > r2->base);
}
static void __init sort_memblock_regions(void)
{
sort(hyp_memory,
*hyp_memblock_nr_ptr,
sizeof(struct memblock_region),
cmp_hyp_memblock,
NULL);
}
static int __init register_memblock_regions(void)
{
struct memblock_region *reg;
for_each_mem_region(reg) {
if (*hyp_memblock_nr_ptr >= HYP_MEMBLOCK_REGIONS)
return -ENOMEM;
hyp_memory[*hyp_memblock_nr_ptr] = *reg;
(*hyp_memblock_nr_ptr)++;
}
sort_memblock_regions();
return 0;
}
void __init kvm_hyp_reserve(void)
{
u64 nr_pages, prev, hyp_mem_pages = 0;
int ret;
if (!is_hyp_mode_available() || is_kernel_in_hyp_mode())
return;
if (kvm_get_mode() != KVM_MODE_PROTECTED)
return;
ret = register_memblock_regions();
if (ret) {
*hyp_memblock_nr_ptr = 0;
kvm_err("Failed to register hyp memblocks: %d\n", ret);
return;
}
hyp_mem_pages += hyp_s1_pgtable_pages();
hyp_mem_pages += host_s2_pgtable_pages();
/*
* The hyp_vmemmap needs to be backed by pages, but these pages
* themselves need to be present in the vmemmap, so compute the number
* of pages needed by looking for a fixed point.
*/
nr_pages = 0;
do {
prev = nr_pages;
nr_pages = hyp_mem_pages + prev;
nr_pages = DIV_ROUND_UP(nr_pages * STRUCT_HYP_PAGE_SIZE,
PAGE_SIZE);
nr_pages += __hyp_pgtable_max_pages(nr_pages);
} while (nr_pages != prev);
hyp_mem_pages += nr_pages;
/*
* Try to allocate a PMD-aligned region to reduce TLB pressure once
* this is unmapped from the host stage-2, and fallback to PAGE_SIZE.
*/
hyp_mem_size = hyp_mem_pages << PAGE_SHIFT;
hyp_mem_base = memblock_phys_alloc(ALIGN(hyp_mem_size, PMD_SIZE),
PMD_SIZE);
if (!hyp_mem_base)
hyp_mem_base = memblock_phys_alloc(hyp_mem_size, PAGE_SIZE);
else
hyp_mem_size = ALIGN(hyp_mem_size, PMD_SIZE);
if (!hyp_mem_base) {
kvm_err("Failed to reserve hyp memory\n");
return;
}
kvm_info("Reserved %lld MiB at 0x%llx\n", hyp_mem_size >> 20,
hyp_mem_base);
}