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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 <asm/kvm_pkvm.h>
#include <asm/spectre.h>
#include <nvhe/early_alloc.h>
#include <nvhe/gfp.h>
#include <nvhe/memory.h>
#include <nvhe/mm.h>
#include <nvhe/spinlock.h>
struct kvm_pgtable pkvm_pgtable;
hyp_spinlock_t pkvm_pgd_lock;
struct memblock_region hyp_memory[HYP_MEMBLOCK_REGIONS];
unsigned int hyp_memblock_nr;
static u64 __io_map_base;
static int __pkvm_create_mappings(unsigned long start, unsigned long size,
unsigned long phys, enum kvm_pgtable_prot prot)
{
int err;
hyp_spin_lock(&pkvm_pgd_lock);
err = kvm_pgtable_hyp_map(&pkvm_pgtable, start, size, phys, prot);
hyp_spin_unlock(&pkvm_pgd_lock);
return err;
}
unsigned long __pkvm_create_private_mapping(phys_addr_t phys, size_t size,
enum kvm_pgtable_prot prot)
{
unsigned long addr;
int err;
hyp_spin_lock(&pkvm_pgd_lock);
size = PAGE_ALIGN(size + offset_in_page(phys));
addr = __io_map_base;
__io_map_base += size;
/* Are we overflowing on the vmemmap ? */
if (__io_map_base > __hyp_vmemmap) {
__io_map_base -= size;
addr = (unsigned long)ERR_PTR(-ENOMEM);
goto out;
}
err = kvm_pgtable_hyp_map(&pkvm_pgtable, addr, size, phys, prot);
if (err) {
addr = (unsigned long)ERR_PTR(err);
goto out;
}
addr = addr + offset_in_page(phys);
out:
hyp_spin_unlock(&pkvm_pgd_lock);
return addr;
}
int pkvm_create_mappings_locked(void *from, void *to, enum kvm_pgtable_prot prot)
{
unsigned long start = (unsigned long)from;
unsigned long end = (unsigned long)to;
unsigned long virt_addr;
phys_addr_t phys;
hyp_assert_lock_held(&pkvm_pgd_lock);
start = start & PAGE_MASK;
end = PAGE_ALIGN(end);
for (virt_addr = start; virt_addr < end; virt_addr += PAGE_SIZE) {
int err;
phys = hyp_virt_to_phys((void *)virt_addr);
err = kvm_pgtable_hyp_map(&pkvm_pgtable, virt_addr, PAGE_SIZE,
phys, prot);
if (err)
return err;
}
return 0;
}
int pkvm_create_mappings(void *from, void *to, enum kvm_pgtable_prot prot)
{
int ret;
hyp_spin_lock(&pkvm_pgd_lock);
ret = pkvm_create_mappings_locked(from, to, prot);
hyp_spin_unlock(&pkvm_pgd_lock);
return ret;
}
int hyp_back_vmemmap(phys_addr_t phys, unsigned long size, phys_addr_t back)
{
unsigned long start, end;
hyp_vmemmap_range(phys, size, &start, &end);
return __pkvm_create_mappings(start, end - start, back, PAGE_HYP);
}
static void *__hyp_bp_vect_base;
int pkvm_cpu_set_vector(enum arm64_hyp_spectre_vector slot)
{
void *vector;
switch (slot) {
case HYP_VECTOR_DIRECT: {
vector = __kvm_hyp_vector;
break;
}
case HYP_VECTOR_SPECTRE_DIRECT: {
vector = __bp_harden_hyp_vecs;
break;
}
case HYP_VECTOR_INDIRECT:
case HYP_VECTOR_SPECTRE_INDIRECT: {
vector = (void *)__hyp_bp_vect_base;
break;
}
default:
return -EINVAL;
}
vector = __kvm_vector_slot2addr(vector, slot);
*this_cpu_ptr(&kvm_hyp_vector) = (unsigned long)vector;
return 0;
}
int hyp_map_vectors(void)
{
phys_addr_t phys;
void *bp_base;
if (!cpus_have_const_cap(ARM64_SPECTRE_V3A))
return 0;
phys = __hyp_pa(__bp_harden_hyp_vecs);
bp_base = (void *)__pkvm_create_private_mapping(phys,
__BP_HARDEN_HYP_VECS_SZ,
PAGE_HYP_EXEC);
if (IS_ERR_OR_NULL(bp_base))
return PTR_ERR(bp_base);
__hyp_bp_vect_base = bp_base;
return 0;
}
int hyp_create_idmap(u32 hyp_va_bits)
{
unsigned long start, end;
start = hyp_virt_to_phys((void *)__hyp_idmap_text_start);
start = ALIGN_DOWN(start, PAGE_SIZE);
end = hyp_virt_to_phys((void *)__hyp_idmap_text_end);
end = ALIGN(end, PAGE_SIZE);
/*
* One half of the VA space is reserved to linearly map portions of
* memory -- see va_layout.c for more details. The other half of the VA
* space contains the trampoline page, and needs some care. Split that
* second half in two and find the quarter of VA space not conflicting
* with the idmap to place the IOs and the vmemmap. IOs use the lower
* half of the quarter and the vmemmap the upper half.
*/
__io_map_base = start & BIT(hyp_va_bits - 2);
__io_map_base ^= BIT(hyp_va_bits - 2);
__hyp_vmemmap = __io_map_base | BIT(hyp_va_bits - 3);
return __pkvm_create_mappings(start, end - start, start, PAGE_HYP_EXEC);
}
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