swh:1:snp:49cd9498d6cccc5e78252c27dcb645bcf7bf0c91
Tip revision: 6efb943b8616ec53a5e444193dccf1af9ad627b5 authored by Linus Torvalds on 09 May 2021, 21:17:44 UTC
Linux 5.13-rc1
Linux 5.13-rc1
Tip revision: 6efb943
book3s_64_mmu_host.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2009 SUSE Linux Products GmbH. All rights reserved.
*
* Authors:
* Alexander Graf <agraf@suse.de>
* Kevin Wolf <mail@kevin-wolf.de>
*/
#include <linux/kvm_host.h>
#include <linux/pkeys.h>
#include <asm/kvm_ppc.h>
#include <asm/kvm_book3s.h>
#include <asm/book3s/64/mmu-hash.h>
#include <asm/machdep.h>
#include <asm/mmu_context.h>
#include <asm/hw_irq.h>
#include "trace_pr.h"
#include "book3s.h"
#define PTE_SIZE 12
void kvmppc_mmu_invalidate_pte(struct kvm_vcpu *vcpu, struct hpte_cache *pte)
{
mmu_hash_ops.hpte_invalidate(pte->slot, pte->host_vpn,
pte->pagesize, pte->pagesize,
MMU_SEGSIZE_256M, false);
}
/* We keep 512 gvsid->hvsid entries, mapping the guest ones to the array using
* a hash, so we don't waste cycles on looping */
static u16 kvmppc_sid_hash(struct kvm_vcpu *vcpu, u64 gvsid)
{
return (u16)(((gvsid >> (SID_MAP_BITS * 7)) & SID_MAP_MASK) ^
((gvsid >> (SID_MAP_BITS * 6)) & SID_MAP_MASK) ^
((gvsid >> (SID_MAP_BITS * 5)) & SID_MAP_MASK) ^
((gvsid >> (SID_MAP_BITS * 4)) & SID_MAP_MASK) ^
((gvsid >> (SID_MAP_BITS * 3)) & SID_MAP_MASK) ^
((gvsid >> (SID_MAP_BITS * 2)) & SID_MAP_MASK) ^
((gvsid >> (SID_MAP_BITS * 1)) & SID_MAP_MASK) ^
((gvsid >> (SID_MAP_BITS * 0)) & SID_MAP_MASK));
}
static struct kvmppc_sid_map *find_sid_vsid(struct kvm_vcpu *vcpu, u64 gvsid)
{
struct kvmppc_sid_map *map;
u16 sid_map_mask;
if (kvmppc_get_msr(vcpu) & MSR_PR)
gvsid |= VSID_PR;
sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
map = &to_book3s(vcpu)->sid_map[sid_map_mask];
if (map->valid && (map->guest_vsid == gvsid)) {
trace_kvm_book3s_slb_found(gvsid, map->host_vsid);
return map;
}
map = &to_book3s(vcpu)->sid_map[SID_MAP_MASK - sid_map_mask];
if (map->valid && (map->guest_vsid == gvsid)) {
trace_kvm_book3s_slb_found(gvsid, map->host_vsid);
return map;
}
trace_kvm_book3s_slb_fail(sid_map_mask, gvsid);
return NULL;
}
int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte,
bool iswrite)
{
unsigned long vpn;
kvm_pfn_t hpaddr;
ulong hash, hpteg;
u64 vsid;
int ret;
int rflags = 0x192;
int vflags = 0;
int attempt = 0;
struct kvmppc_sid_map *map;
int r = 0;
int hpsize = MMU_PAGE_4K;
bool writable;
unsigned long mmu_seq;
struct kvm *kvm = vcpu->kvm;
struct hpte_cache *cpte;
unsigned long gfn = orig_pte->raddr >> PAGE_SHIFT;
unsigned long pfn;
/* used to check for invalidations in progress */
mmu_seq = kvm->mmu_notifier_seq;
smp_rmb();
/* Get host physical address for gpa */
pfn = kvmppc_gpa_to_pfn(vcpu, orig_pte->raddr, iswrite, &writable);
if (is_error_noslot_pfn(pfn)) {
printk(KERN_INFO "Couldn't get guest page for gpa %lx!\n",
orig_pte->raddr);
r = -EINVAL;
goto out;
}
hpaddr = pfn << PAGE_SHIFT;
/* and write the mapping ea -> hpa into the pt */
vcpu->arch.mmu.esid_to_vsid(vcpu, orig_pte->eaddr >> SID_SHIFT, &vsid);
map = find_sid_vsid(vcpu, vsid);
if (!map) {
ret = kvmppc_mmu_map_segment(vcpu, orig_pte->eaddr);
WARN_ON(ret < 0);
map = find_sid_vsid(vcpu, vsid);
}
if (!map) {
printk(KERN_ERR "KVM: Segment map for 0x%llx (0x%lx) failed\n",
vsid, orig_pte->eaddr);
WARN_ON(true);
r = -EINVAL;
goto out;
}
vpn = hpt_vpn(orig_pte->eaddr, map->host_vsid, MMU_SEGSIZE_256M);
kvm_set_pfn_accessed(pfn);
if (!orig_pte->may_write || !writable)
rflags |= PP_RXRX;
else {
mark_page_dirty(vcpu->kvm, gfn);
kvm_set_pfn_dirty(pfn);
}
if (!orig_pte->may_execute)
rflags |= HPTE_R_N;
else
kvmppc_mmu_flush_icache(pfn);
rflags |= pte_to_hpte_pkey_bits(0, HPTE_USE_KERNEL_KEY);
rflags = (rflags & ~HPTE_R_WIMG) | orig_pte->wimg;
/*
* Use 64K pages if possible; otherwise, on 64K page kernels,
* we need to transfer 4 more bits from guest real to host real addr.
*/
if (vsid & VSID_64K)
hpsize = MMU_PAGE_64K;
else
hpaddr |= orig_pte->raddr & (~0xfffULL & ~PAGE_MASK);
hash = hpt_hash(vpn, mmu_psize_defs[hpsize].shift, MMU_SEGSIZE_256M);
cpte = kvmppc_mmu_hpte_cache_next(vcpu);
spin_lock(&kvm->mmu_lock);
if (!cpte || mmu_notifier_retry(kvm, mmu_seq)) {
r = -EAGAIN;
goto out_unlock;
}
map_again:
hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
/* In case we tried normal mapping already, let's nuke old entries */
if (attempt > 1)
if (mmu_hash_ops.hpte_remove(hpteg) < 0) {
r = -1;
goto out_unlock;
}
ret = mmu_hash_ops.hpte_insert(hpteg, vpn, hpaddr, rflags, vflags,
hpsize, hpsize, MMU_SEGSIZE_256M);
if (ret == -1) {
/* If we couldn't map a primary PTE, try a secondary */
hash = ~hash;
vflags ^= HPTE_V_SECONDARY;
attempt++;
goto map_again;
} else if (ret < 0) {
r = -EIO;
goto out_unlock;
} else {
trace_kvm_book3s_64_mmu_map(rflags, hpteg,
vpn, hpaddr, orig_pte);
/*
* The mmu_hash_ops code may give us a secondary entry even
* though we asked for a primary. Fix up.
*/
if ((ret & _PTEIDX_SECONDARY) && !(vflags & HPTE_V_SECONDARY)) {
hash = ~hash;
hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
}
cpte->slot = hpteg + (ret & 7);
cpte->host_vpn = vpn;
cpte->pte = *orig_pte;
cpte->pfn = pfn;
cpte->pagesize = hpsize;
kvmppc_mmu_hpte_cache_map(vcpu, cpte);
cpte = NULL;
}
out_unlock:
spin_unlock(&kvm->mmu_lock);
kvm_release_pfn_clean(pfn);
if (cpte)
kvmppc_mmu_hpte_cache_free(cpte);
out:
return r;
}
void kvmppc_mmu_unmap_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *pte)
{
u64 mask = 0xfffffffffULL;
u64 vsid;
vcpu->arch.mmu.esid_to_vsid(vcpu, pte->eaddr >> SID_SHIFT, &vsid);
if (vsid & VSID_64K)
mask = 0xffffffff0ULL;
kvmppc_mmu_pte_vflush(vcpu, pte->vpage, mask);
}
static struct kvmppc_sid_map *create_sid_map(struct kvm_vcpu *vcpu, u64 gvsid)
{
unsigned long vsid_bits = VSID_BITS_65_256M;
struct kvmppc_sid_map *map;
struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
u16 sid_map_mask;
static int backwards_map = 0;
if (kvmppc_get_msr(vcpu) & MSR_PR)
gvsid |= VSID_PR;
/* We might get collisions that trap in preceding order, so let's
map them differently */
sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
if (backwards_map)
sid_map_mask = SID_MAP_MASK - sid_map_mask;
map = &to_book3s(vcpu)->sid_map[sid_map_mask];
/* Make sure we're taking the other map next time */
backwards_map = !backwards_map;
/* Uh-oh ... out of mappings. Let's flush! */
if (vcpu_book3s->proto_vsid_next == vcpu_book3s->proto_vsid_max) {
vcpu_book3s->proto_vsid_next = vcpu_book3s->proto_vsid_first;
memset(vcpu_book3s->sid_map, 0,
sizeof(struct kvmppc_sid_map) * SID_MAP_NUM);
kvmppc_mmu_pte_flush(vcpu, 0, 0);
kvmppc_mmu_flush_segments(vcpu);
}
if (mmu_has_feature(MMU_FTR_68_BIT_VA))
vsid_bits = VSID_BITS_256M;
map->host_vsid = vsid_scramble(vcpu_book3s->proto_vsid_next++,
VSID_MULTIPLIER_256M, vsid_bits);
map->guest_vsid = gvsid;
map->valid = true;
trace_kvm_book3s_slb_map(sid_map_mask, gvsid, map->host_vsid);
return map;
}
static int kvmppc_mmu_next_segment(struct kvm_vcpu *vcpu, ulong esid)
{
struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
int i;
int max_slb_size = 64;
int found_inval = -1;
int r;
/* Are we overwriting? */
for (i = 0; i < svcpu->slb_max; i++) {
if (!(svcpu->slb[i].esid & SLB_ESID_V))
found_inval = i;
else if ((svcpu->slb[i].esid & ESID_MASK) == esid) {
r = i;
goto out;
}
}
/* Found a spare entry that was invalidated before */
if (found_inval >= 0) {
r = found_inval;
goto out;
}
/* No spare invalid entry, so create one */
if (mmu_slb_size < 64)
max_slb_size = mmu_slb_size;
/* Overflowing -> purge */
if ((svcpu->slb_max) == max_slb_size)
kvmppc_mmu_flush_segments(vcpu);
r = svcpu->slb_max;
svcpu->slb_max++;
out:
svcpu_put(svcpu);
return r;
}
int kvmppc_mmu_map_segment(struct kvm_vcpu *vcpu, ulong eaddr)
{
struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
u64 esid = eaddr >> SID_SHIFT;
u64 slb_esid = (eaddr & ESID_MASK) | SLB_ESID_V;
u64 slb_vsid = SLB_VSID_USER;
u64 gvsid;
int slb_index;
struct kvmppc_sid_map *map;
int r = 0;
slb_index = kvmppc_mmu_next_segment(vcpu, eaddr & ESID_MASK);
if (vcpu->arch.mmu.esid_to_vsid(vcpu, esid, &gvsid)) {
/* Invalidate an entry */
svcpu->slb[slb_index].esid = 0;
r = -ENOENT;
goto out;
}
map = find_sid_vsid(vcpu, gvsid);
if (!map)
map = create_sid_map(vcpu, gvsid);
map->guest_esid = esid;
slb_vsid |= (map->host_vsid << 12);
slb_vsid &= ~SLB_VSID_KP;
slb_esid |= slb_index;
#ifdef CONFIG_PPC_64K_PAGES
/* Set host segment base page size to 64K if possible */
if (gvsid & VSID_64K)
slb_vsid |= mmu_psize_defs[MMU_PAGE_64K].sllp;
#endif
svcpu->slb[slb_index].esid = slb_esid;
svcpu->slb[slb_index].vsid = slb_vsid;
trace_kvm_book3s_slbmte(slb_vsid, slb_esid);
out:
svcpu_put(svcpu);
return r;
}
void kvmppc_mmu_flush_segment(struct kvm_vcpu *vcpu, ulong ea, ulong seg_size)
{
struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
ulong seg_mask = -seg_size;
int i;
for (i = 0; i < svcpu->slb_max; i++) {
if ((svcpu->slb[i].esid & SLB_ESID_V) &&
(svcpu->slb[i].esid & seg_mask) == ea) {
/* Invalidate this entry */
svcpu->slb[i].esid = 0;
}
}
svcpu_put(svcpu);
}
void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu)
{
struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
svcpu->slb_max = 0;
svcpu->slb[0].esid = 0;
svcpu_put(svcpu);
}
void kvmppc_mmu_destroy_pr(struct kvm_vcpu *vcpu)
{
kvmppc_mmu_hpte_destroy(vcpu);
__destroy_context(to_book3s(vcpu)->context_id[0]);
}
int kvmppc_mmu_init_pr(struct kvm_vcpu *vcpu)
{
struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
int err;
err = hash__alloc_context_id();
if (err < 0)
return -1;
vcpu3s->context_id[0] = err;
vcpu3s->proto_vsid_max = ((u64)(vcpu3s->context_id[0] + 1)
<< ESID_BITS) - 1;
vcpu3s->proto_vsid_first = (u64)vcpu3s->context_id[0] << ESID_BITS;
vcpu3s->proto_vsid_next = vcpu3s->proto_vsid_first;
kvmppc_mmu_hpte_init(vcpu);
return 0;
}