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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2020 Google LLC
* Author: Quentin Perret <qperret@google.com>
*/
#include <linux/kvm_host.h>
#include <asm/kvm_hyp.h>
#include <asm/kvm_mmu.h>
#include <asm/kvm_pgtable.h>
#include <nvhe/early_alloc.h>
#include <nvhe/gfp.h>
#include <nvhe/memory.h>
#include <nvhe/mem_protect.h>
#include <nvhe/mm.h>
#include <nvhe/trap_handler.h>
struct hyp_pool hpool;
struct kvm_pgtable_mm_ops pkvm_pgtable_mm_ops;
unsigned long hyp_nr_cpus;
#define hyp_percpu_size ((unsigned long)__per_cpu_end - \
(unsigned long)__per_cpu_start)
static void *vmemmap_base;
static void *hyp_pgt_base;
static void *host_s2_mem_pgt_base;
static void *host_s2_dev_pgt_base;
static int divide_memory_pool(void *virt, unsigned long size)
{
unsigned long vstart, vend, nr_pages;
hyp_early_alloc_init(virt, size);
hyp_vmemmap_range(__hyp_pa(virt), size, &vstart, &vend);
nr_pages = (vend - vstart) >> PAGE_SHIFT;
vmemmap_base = hyp_early_alloc_contig(nr_pages);
if (!vmemmap_base)
return -ENOMEM;
nr_pages = hyp_s1_pgtable_pages();
hyp_pgt_base = hyp_early_alloc_contig(nr_pages);
if (!hyp_pgt_base)
return -ENOMEM;
nr_pages = host_s2_mem_pgtable_pages();
host_s2_mem_pgt_base = hyp_early_alloc_contig(nr_pages);
if (!host_s2_mem_pgt_base)
return -ENOMEM;
nr_pages = host_s2_dev_pgtable_pages();
host_s2_dev_pgt_base = hyp_early_alloc_contig(nr_pages);
if (!host_s2_dev_pgt_base)
return -ENOMEM;
return 0;
}
static int recreate_hyp_mappings(phys_addr_t phys, unsigned long size,
unsigned long *per_cpu_base,
u32 hyp_va_bits)
{
void *start, *end, *virt = hyp_phys_to_virt(phys);
unsigned long pgt_size = hyp_s1_pgtable_pages() << PAGE_SHIFT;
int ret, i;
/* Recreate the hyp page-table using the early page allocator */
hyp_early_alloc_init(hyp_pgt_base, pgt_size);
ret = kvm_pgtable_hyp_init(&pkvm_pgtable, hyp_va_bits,
&hyp_early_alloc_mm_ops);
if (ret)
return ret;
ret = hyp_create_idmap(hyp_va_bits);
if (ret)
return ret;
ret = hyp_map_vectors();
if (ret)
return ret;
ret = hyp_back_vmemmap(phys, size, hyp_virt_to_phys(vmemmap_base));
if (ret)
return ret;
ret = pkvm_create_mappings(__hyp_text_start, __hyp_text_end, PAGE_HYP_EXEC);
if (ret)
return ret;
ret = pkvm_create_mappings(__start_rodata, __end_rodata, PAGE_HYP_RO);
if (ret)
return ret;
ret = pkvm_create_mappings(__hyp_rodata_start, __hyp_rodata_end, PAGE_HYP_RO);
if (ret)
return ret;
ret = pkvm_create_mappings(__hyp_bss_start, __hyp_bss_end, PAGE_HYP);
if (ret)
return ret;
ret = pkvm_create_mappings(__hyp_bss_end, __bss_stop, PAGE_HYP_RO);
if (ret)
return ret;
ret = pkvm_create_mappings(virt, virt + size, PAGE_HYP);
if (ret)
return ret;
for (i = 0; i < hyp_nr_cpus; i++) {
start = (void *)kern_hyp_va(per_cpu_base[i]);
end = start + PAGE_ALIGN(hyp_percpu_size);
ret = pkvm_create_mappings(start, end, PAGE_HYP);
if (ret)
return ret;
end = (void *)per_cpu_ptr(&kvm_init_params, i)->stack_hyp_va;
start = end - PAGE_SIZE;
ret = pkvm_create_mappings(start, end, PAGE_HYP);
if (ret)
return ret;
}
return 0;
}
static void update_nvhe_init_params(void)
{
struct kvm_nvhe_init_params *params;
unsigned long i;
for (i = 0; i < hyp_nr_cpus; i++) {
params = per_cpu_ptr(&kvm_init_params, i);
params->pgd_pa = __hyp_pa(pkvm_pgtable.pgd);
__flush_dcache_area(params, sizeof(*params));
}
}
static void *hyp_zalloc_hyp_page(void *arg)
{
return hyp_alloc_pages(&hpool, 0);
}
void __noreturn __pkvm_init_finalise(void)
{
struct kvm_host_data *host_data = this_cpu_ptr(&kvm_host_data);
struct kvm_cpu_context *host_ctxt = &host_data->host_ctxt;
unsigned long nr_pages, reserved_pages, pfn;
int ret;
/* Now that the vmemmap is backed, install the full-fledged allocator */
pfn = hyp_virt_to_pfn(hyp_pgt_base);
nr_pages = hyp_s1_pgtable_pages();
reserved_pages = hyp_early_alloc_nr_used_pages();
ret = hyp_pool_init(&hpool, pfn, nr_pages, reserved_pages);
if (ret)
goto out;
ret = kvm_host_prepare_stage2(host_s2_mem_pgt_base, host_s2_dev_pgt_base);
if (ret)
goto out;
pkvm_pgtable_mm_ops = (struct kvm_pgtable_mm_ops) {
.zalloc_page = hyp_zalloc_hyp_page,
.phys_to_virt = hyp_phys_to_virt,
.virt_to_phys = hyp_virt_to_phys,
.get_page = hyp_get_page,
.put_page = hyp_put_page,
};
pkvm_pgtable.mm_ops = &pkvm_pgtable_mm_ops;
out:
/*
* We tail-called to here from handle___pkvm_init() and will not return,
* so make sure to propagate the return value to the host.
*/
cpu_reg(host_ctxt, 1) = ret;
__host_enter(host_ctxt);
}
int __pkvm_init(phys_addr_t phys, unsigned long size, unsigned long nr_cpus,
unsigned long *per_cpu_base, u32 hyp_va_bits)
{
struct kvm_nvhe_init_params *params;
void *virt = hyp_phys_to_virt(phys);
void (*fn)(phys_addr_t params_pa, void *finalize_fn_va);
int ret;
if (!PAGE_ALIGNED(phys) || !PAGE_ALIGNED(size))
return -EINVAL;
hyp_spin_lock_init(&pkvm_pgd_lock);
hyp_nr_cpus = nr_cpus;
ret = divide_memory_pool(virt, size);
if (ret)
return ret;
ret = recreate_hyp_mappings(phys, size, per_cpu_base, hyp_va_bits);
if (ret)
return ret;
update_nvhe_init_params();
/* Jump in the idmap page to switch to the new page-tables */
params = this_cpu_ptr(&kvm_init_params);
fn = (typeof(fn))__hyp_pa(__pkvm_init_switch_pgd);
fn(__hyp_pa(params), __pkvm_init_finalise);
unreachable();
}
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