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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2012,2013 - ARM Ltd
* Author: Marc Zyngier <marc.zyngier@arm.com>
*/
#ifndef __ARM64_KVM_MMU_H__
#define __ARM64_KVM_MMU_H__
#include <asm/page.h>
#include <asm/memory.h>
#include <asm/mmu.h>
#include <asm/cpufeature.h>
/*
* As ARMv8.0 only has the TTBR0_EL2 register, we cannot express
* "negative" addresses. This makes it impossible to directly share
* mappings with the kernel.
*
* Instead, give the HYP mode its own VA region at a fixed offset from
* the kernel by just masking the top bits (which are all ones for a
* kernel address). We need to find out how many bits to mask.
*
* We want to build a set of page tables that cover both parts of the
* idmap (the trampoline page used to initialize EL2), and our normal
* runtime VA space, at the same time.
*
* Given that the kernel uses VA_BITS for its entire address space,
* and that half of that space (VA_BITS - 1) is used for the linear
* mapping, we can also limit the EL2 space to (VA_BITS - 1).
*
* The main question is "Within the VA_BITS space, does EL2 use the
* top or the bottom half of that space to shadow the kernel's linear
* mapping?". As we need to idmap the trampoline page, this is
* determined by the range in which this page lives.
*
* If the page is in the bottom half, we have to use the top half. If
* the page is in the top half, we have to use the bottom half:
*
* T = __pa_symbol(__hyp_idmap_text_start)
* if (T & BIT(VA_BITS - 1))
* HYP_VA_MIN = 0 //idmap in upper half
* else
* HYP_VA_MIN = 1 << (VA_BITS - 1)
* HYP_VA_MAX = HYP_VA_MIN + (1 << (VA_BITS - 1)) - 1
*
* When using VHE, there are no separate hyp mappings and all KVM
* functionality is already mapped as part of the main kernel
* mappings, and none of this applies in that case.
*/
#ifdef __ASSEMBLY__
#include <asm/alternative.h>
/*
* Convert a kernel VA into a HYP VA.
* reg: VA to be converted.
*
* The actual code generation takes place in kvm_update_va_mask, and
* the instructions below are only there to reserve the space and
* perform the register allocation (kvm_update_va_mask uses the
* specific registers encoded in the instructions).
*/
.macro kern_hyp_va reg
#ifndef __KVM_VHE_HYPERVISOR__
alternative_cb ARM64_ALWAYS_SYSTEM, kvm_update_va_mask
and \reg, \reg, #1 /* mask with va_mask */
ror \reg, \reg, #1 /* rotate to the first tag bit */
add \reg, \reg, #0 /* insert the low 12 bits of the tag */
add \reg, \reg, #0, lsl 12 /* insert the top 12 bits of the tag */
ror \reg, \reg, #63 /* rotate back */
alternative_cb_end
#endif
.endm
/*
* Convert a hypervisor VA to a PA
* reg: hypervisor address to be converted in place
* tmp: temporary register
*/
.macro hyp_pa reg, tmp
ldr_l \tmp, hyp_physvirt_offset
add \reg, \reg, \tmp
.endm
/*
* Convert a hypervisor VA to a kernel image address
* reg: hypervisor address to be converted in place
* tmp: temporary register
*
* The actual code generation takes place in kvm_get_kimage_voffset, and
* the instructions below are only there to reserve the space and
* perform the register allocation (kvm_get_kimage_voffset uses the
* specific registers encoded in the instructions).
*/
.macro hyp_kimg_va reg, tmp
/* Convert hyp VA -> PA. */
hyp_pa \reg, \tmp
/* Load kimage_voffset. */
alternative_cb ARM64_ALWAYS_SYSTEM, kvm_get_kimage_voffset
movz \tmp, #0
movk \tmp, #0, lsl #16
movk \tmp, #0, lsl #32
movk \tmp, #0, lsl #48
alternative_cb_end
/* Convert PA -> kimg VA. */
add \reg, \reg, \tmp
.endm
#else
#include <linux/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/cache.h>
#include <asm/cacheflush.h>
#include <asm/mmu_context.h>
#include <asm/kvm_emulate.h>
#include <asm/kvm_host.h>
void kvm_update_va_mask(struct alt_instr *alt,
__le32 *origptr, __le32 *updptr, int nr_inst);
void kvm_compute_layout(void);
void kvm_apply_hyp_relocations(void);
#define __hyp_pa(x) (((phys_addr_t)(x)) + hyp_physvirt_offset)
static __always_inline unsigned long __kern_hyp_va(unsigned long v)
{
#ifndef __KVM_VHE_HYPERVISOR__
asm volatile(ALTERNATIVE_CB("and %0, %0, #1\n"
"ror %0, %0, #1\n"
"add %0, %0, #0\n"
"add %0, %0, #0, lsl 12\n"
"ror %0, %0, #63\n",
ARM64_ALWAYS_SYSTEM,
kvm_update_va_mask)
: "+r" (v));
#endif
return v;
}
#define kern_hyp_va(v) ((typeof(v))(__kern_hyp_va((unsigned long)(v))))
/*
* We currently support using a VM-specified IPA size. For backward
* compatibility, the default IPA size is fixed to 40bits.
*/
#define KVM_PHYS_SHIFT (40)
#define kvm_phys_shift(mmu) VTCR_EL2_IPA((mmu)->vtcr)
#define kvm_phys_size(mmu) (_AC(1, ULL) << kvm_phys_shift(mmu))
#define kvm_phys_mask(mmu) (kvm_phys_size(mmu) - _AC(1, ULL))
#include <asm/kvm_pgtable.h>
#include <asm/stage2_pgtable.h>
int kvm_share_hyp(void *from, void *to);
void kvm_unshare_hyp(void *from, void *to);
int create_hyp_mappings(void *from, void *to, enum kvm_pgtable_prot prot);
int __create_hyp_mappings(unsigned long start, unsigned long size,
unsigned long phys, enum kvm_pgtable_prot prot);
int hyp_alloc_private_va_range(size_t size, unsigned long *haddr);
int create_hyp_io_mappings(phys_addr_t phys_addr, size_t size,
void __iomem **kaddr,
void __iomem **haddr);
int create_hyp_exec_mappings(phys_addr_t phys_addr, size_t size,
void **haddr);
int create_hyp_stack(phys_addr_t phys_addr, unsigned long *haddr);
void __init free_hyp_pgds(void);
void stage2_unmap_vm(struct kvm *kvm);
int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu, unsigned long type);
void kvm_uninit_stage2_mmu(struct kvm *kvm);
void kvm_free_stage2_pgd(struct kvm_s2_mmu *mmu);
int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
phys_addr_t pa, unsigned long size, bool writable);
int kvm_handle_guest_abort(struct kvm_vcpu *vcpu);
phys_addr_t kvm_mmu_get_httbr(void);
phys_addr_t kvm_get_idmap_vector(void);
int __init kvm_mmu_init(u32 *hyp_va_bits);
static inline void *__kvm_vector_slot2addr(void *base,
enum arm64_hyp_spectre_vector slot)
{
int idx = slot - (slot != HYP_VECTOR_DIRECT);
return base + (idx * SZ_2K);
}
struct kvm;
#define kvm_flush_dcache_to_poc(a,l) \
dcache_clean_inval_poc((unsigned long)(a), (unsigned long)(a)+(l))
static inline bool vcpu_has_cache_enabled(struct kvm_vcpu *vcpu)
{
u64 cache_bits = SCTLR_ELx_M | SCTLR_ELx_C;
int reg;
if (vcpu_is_el2(vcpu))
reg = SCTLR_EL2;
else
reg = SCTLR_EL1;
return (vcpu_read_sys_reg(vcpu, reg) & cache_bits) == cache_bits;
}
static inline void __clean_dcache_guest_page(void *va, size_t size)
{
/*
* With FWB, we ensure that the guest always accesses memory using
* cacheable attributes, and we don't have to clean to PoC when
* faulting in pages. Furthermore, FWB implies IDC, so cleaning to
* PoU is not required either in this case.
*/
if (cpus_have_final_cap(ARM64_HAS_STAGE2_FWB))
return;
kvm_flush_dcache_to_poc(va, size);
}
static inline size_t __invalidate_icache_max_range(void)
{
u8 iminline;
u64 ctr;
asm volatile(ALTERNATIVE_CB("movz %0, #0\n"
"movk %0, #0, lsl #16\n"
"movk %0, #0, lsl #32\n"
"movk %0, #0, lsl #48\n",
ARM64_ALWAYS_SYSTEM,
kvm_compute_final_ctr_el0)
: "=r" (ctr));
iminline = SYS_FIELD_GET(CTR_EL0, IminLine, ctr) + 2;
return MAX_DVM_OPS << iminline;
}
static inline void __invalidate_icache_guest_page(void *va, size_t size)
{
/*
* Blow the whole I-cache if it is aliasing (i.e. VIPT) or the
* invalidation range exceeds our arbitrary limit on invadations by
* cache line.
*/
if (icache_is_aliasing() || size > __invalidate_icache_max_range())
icache_inval_all_pou();
else
icache_inval_pou((unsigned long)va, (unsigned long)va + size);
}
void kvm_set_way_flush(struct kvm_vcpu *vcpu);
void kvm_toggle_cache(struct kvm_vcpu *vcpu, bool was_enabled);
static inline unsigned int kvm_get_vmid_bits(void)
{
int reg = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1);
return get_vmid_bits(reg);
}
/*
* We are not in the kvm->srcu critical section most of the time, so we take
* the SRCU read lock here. Since we copy the data from the user page, we
* can immediately drop the lock again.
*/
static inline int kvm_read_guest_lock(struct kvm *kvm,
gpa_t gpa, void *data, unsigned long len)
{
int srcu_idx = srcu_read_lock(&kvm->srcu);
int ret = kvm_read_guest(kvm, gpa, data, len);
srcu_read_unlock(&kvm->srcu, srcu_idx);
return ret;
}
static inline int kvm_write_guest_lock(struct kvm *kvm, gpa_t gpa,
const void *data, unsigned long len)
{
int srcu_idx = srcu_read_lock(&kvm->srcu);
int ret = kvm_write_guest(kvm, gpa, data, len);
srcu_read_unlock(&kvm->srcu, srcu_idx);
return ret;
}
#define kvm_phys_to_vttbr(addr) phys_to_ttbr(addr)
/*
* When this is (directly or indirectly) used on the TLB invalidation
* path, we rely on a previously issued DSB so that page table updates
* and VMID reads are correctly ordered.
*/
static __always_inline u64 kvm_get_vttbr(struct kvm_s2_mmu *mmu)
{
struct kvm_vmid *vmid = &mmu->vmid;
u64 vmid_field, baddr;
u64 cnp = system_supports_cnp() ? VTTBR_CNP_BIT : 0;
baddr = mmu->pgd_phys;
vmid_field = atomic64_read(&vmid->id) << VTTBR_VMID_SHIFT;
vmid_field &= VTTBR_VMID_MASK(kvm_arm_vmid_bits);
return kvm_phys_to_vttbr(baddr) | vmid_field | cnp;
}
/*
* Must be called from hyp code running at EL2 with an updated VTTBR
* and interrupts disabled.
*/
static __always_inline void __load_stage2(struct kvm_s2_mmu *mmu,
struct kvm_arch *arch)
{
write_sysreg(mmu->vtcr, vtcr_el2);
write_sysreg(kvm_get_vttbr(mmu), vttbr_el2);
/*
* ARM errata 1165522 and 1530923 require the actual execution of the
* above before we can switch to the EL1/EL0 translation regime used by
* the guest.
*/
asm(ALTERNATIVE("nop", "isb", ARM64_WORKAROUND_SPECULATIVE_AT));
}
static inline struct kvm *kvm_s2_mmu_to_kvm(struct kvm_s2_mmu *mmu)
{
return container_of(mmu->arch, struct kvm, arch);
}
#endif /* __ASSEMBLY__ */
#endif /* __ARM64_KVM_MMU_H__ */