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linux/arch/powerpc/kvm/book3s_64_mmu_hv.c

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/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* Copyright 2010 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
*/
#include <linux/types.h>
#include <linux/string.h>
#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <linux/highmem.h>
#include <linux/gfp.h>
#include <linux/slab.h>
#include <linux/hugetlb.h>
#include <linux/vmalloc.h>
#include <linux/srcu.h>
#include <linux/anon_inodes.h>
#include <linux/file.h>
#include <linux/debugfs.h>
#include <asm/tlbflush.h>
#include <asm/kvm_ppc.h>
#include <asm/kvm_book3s.h>
#include <asm/book3s/64/mmu-hash.h>
#include <asm/hvcall.h>
#include <asm/synch.h>
#include <asm/ppc-opcode.h>
#include <asm/cputable.h>
#include <asm/pte-walk.h>
#include "trace_hv.h"
//#define DEBUG_RESIZE_HPT 1
#ifdef DEBUG_RESIZE_HPT
#define resize_hpt_debug(resize, ...) \
do { \
printk(KERN_DEBUG "RESIZE HPT %p: ", resize); \
printk(__VA_ARGS__); \
} while (0)
#else
#define resize_hpt_debug(resize, ...) \
do { } while (0)
#endif
static long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags,
long pte_index, unsigned long pteh,
unsigned long ptel, unsigned long *pte_idx_ret);
struct kvm_resize_hpt {
/* These fields read-only after init */
struct kvm *kvm;
struct work_struct work;
u32 order;
/* These fields protected by kvm->lock */
/* Possible values and their usage:
* <0 an error occurred during allocation,
* -EBUSY allocation is in the progress,
* 0 allocation made successfuly.
*/
int error;
/* Private to the work thread, until error != -EBUSY,
* then protected by kvm->lock.
*/
struct kvm_hpt_info hpt;
};
int kvmppc_allocate_hpt(struct kvm_hpt_info *info, u32 order)
{
unsigned long hpt = 0;
int cma = 0;
struct page *page = NULL;
struct revmap_entry *rev;
unsigned long npte;
if ((order < PPC_MIN_HPT_ORDER) || (order > PPC_MAX_HPT_ORDER))
return -EINVAL;
page = kvm_alloc_hpt_cma(1ul << (order - PAGE_SHIFT));
if (page) {
hpt = (unsigned long)pfn_to_kaddr(page_to_pfn(page));
memset((void *)hpt, 0, (1ul << order));
cma = 1;
}
if (!hpt)
hpt = __get_free_pages(GFP_KERNEL|__GFP_ZERO|__GFP_RETRY_MAYFAIL
|__GFP_NOWARN, order - PAGE_SHIFT);
if (!hpt)
return -ENOMEM;
/* HPTEs are 2**4 bytes long */
npte = 1ul << (order - 4);
/* Allocate reverse map array */
rev = vmalloc(sizeof(struct revmap_entry) * npte);
if (!rev) {
if (cma)
kvm_free_hpt_cma(page, 1 << (order - PAGE_SHIFT));
else
free_pages(hpt, order - PAGE_SHIFT);
return -ENOMEM;
}
info->order = order;
info->virt = hpt;
info->cma = cma;
info->rev = rev;
return 0;
}
void kvmppc_set_hpt(struct kvm *kvm, struct kvm_hpt_info *info)
{
atomic64_set(&kvm->arch.mmio_update, 0);
kvm->arch.hpt = *info;
kvm->arch.sdr1 = __pa(info->virt) | (info->order - 18);
pr_debug("KVM guest htab at %lx (order %ld), LPID %x\n",
info->virt, (long)info->order, kvm->arch.lpid);
}
long kvmppc_alloc_reset_hpt(struct kvm *kvm, int order)
{
long err = -EBUSY;
struct kvm_hpt_info info;
mutex_lock(&kvm->lock);
if (kvm->arch.mmu_ready) {
kvm->arch.mmu_ready = 0;
/* order mmu_ready vs. vcpus_running */
smp_mb();
if (atomic_read(&kvm->arch.vcpus_running)) {
kvm->arch.mmu_ready = 1;
goto out;
}
}
if (kvm_is_radix(kvm)) {
err = kvmppc_switch_mmu_to_hpt(kvm);
if (err)
goto out;
}
if (kvm->arch.hpt.order == order) {
/* We already have a suitable HPT */
/* Set the entire HPT to 0, i.e. invalid HPTEs */
memset((void *)kvm->arch.hpt.virt, 0, 1ul << order);
/*
* Reset all the reverse-mapping chains for all memslots
*/
kvmppc_rmap_reset(kvm);
err = 0;
goto out;
}
if (kvm->arch.hpt.virt) {
kvmppc_free_hpt(&kvm->arch.hpt);
kvmppc_rmap_reset(kvm);
}
err = kvmppc_allocate_hpt(&info, order);
if (err < 0)
goto out;
kvmppc_set_hpt(kvm, &info);
out:
if (err == 0)
/* Ensure that each vcpu will flush its TLB on next entry. */
cpumask_setall(&kvm->arch.need_tlb_flush);
mutex_unlock(&kvm->lock);
return err;
}
void kvmppc_free_hpt(struct kvm_hpt_info *info)
{
vfree(info->rev);
info->rev = NULL;
if (info->cma)
kvm_free_hpt_cma(virt_to_page(info->virt),
1 << (info->order - PAGE_SHIFT));
else if (info->virt)
free_pages(info->virt, info->order - PAGE_SHIFT);
info->virt = 0;
info->order = 0;
}
/* Bits in first HPTE dword for pagesize 4k, 64k or 16M */
static inline unsigned long hpte0_pgsize_encoding(unsigned long pgsize)
{
return (pgsize > 0x1000) ? HPTE_V_LARGE : 0;
}
/* Bits in second HPTE dword for pagesize 4k, 64k or 16M */
static inline unsigned long hpte1_pgsize_encoding(unsigned long pgsize)
{
return (pgsize == 0x10000) ? 0x1000 : 0;
}
void kvmppc_map_vrma(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot,
unsigned long porder)
{
unsigned long i;
unsigned long npages;
unsigned long hp_v, hp_r;
unsigned long addr, hash;
unsigned long psize;
unsigned long hp0, hp1;
unsigned long idx_ret;
long ret;
struct kvm *kvm = vcpu->kvm;
psize = 1ul << porder;
npages = memslot->npages >> (porder - PAGE_SHIFT);
/* VRMA can't be > 1TB */
if (npages > 1ul << (40 - porder))
npages = 1ul << (40 - porder);
/* Can't use more than 1 HPTE per HPTEG */
if (npages > kvmppc_hpt_mask(&kvm->arch.hpt) + 1)
npages = kvmppc_hpt_mask(&kvm->arch.hpt) + 1;
hp0 = HPTE_V_1TB_SEG | (VRMA_VSID << (40 - 16)) |
HPTE_V_BOLTED | hpte0_pgsize_encoding(psize);
hp1 = hpte1_pgsize_encoding(psize) |
HPTE_R_R | HPTE_R_C | HPTE_R_M | PP_RWXX;
for (i = 0; i < npages; ++i) {
addr = i << porder;
/* can't use hpt_hash since va > 64 bits */
hash = (i ^ (VRMA_VSID ^ (VRMA_VSID << 25)))
& kvmppc_hpt_mask(&kvm->arch.hpt);
/*
* We assume that the hash table is empty and no
* vcpus are using it at this stage. Since we create
* at most one HPTE per HPTEG, we just assume entry 7
* is available and use it.
*/
hash = (hash << 3) + 7;
hp_v = hp0 | ((addr >> 16) & ~0x7fUL);
hp_r = hp1 | addr;
ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, hash, hp_v, hp_r,
&idx_ret);
if (ret != H_SUCCESS) {
pr_err("KVM: map_vrma at %lx failed, ret=%ld\n",
addr, ret);
break;
}
}
}
int kvmppc_mmu_hv_init(void)
{
unsigned long host_lpid, rsvd_lpid;
if (!cpu_has_feature(CPU_FTR_HVMODE))
return -EINVAL;
/* POWER7 has 10-bit LPIDs (12-bit in POWER8) */
host_lpid = mfspr(SPRN_LPID);
rsvd_lpid = LPID_RSVD;
kvmppc_init_lpid(rsvd_lpid + 1);
kvmppc_claim_lpid(host_lpid);
/* rsvd_lpid is reserved for use in partition switching */
kvmppc_claim_lpid(rsvd_lpid);
return 0;
}
static void kvmppc_mmu_book3s_64_hv_reset_msr(struct kvm_vcpu *vcpu)
{
unsigned long msr = vcpu->arch.intr_msr;
/* If transactional, change to suspend mode on IRQ delivery */
if (MSR_TM_TRANSACTIONAL(vcpu->arch.shregs.msr))
msr |= MSR_TS_S;
else
msr |= vcpu->arch.shregs.msr & MSR_TS_MASK;
kvmppc_set_msr(vcpu, msr);
}
static long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags,
long pte_index, unsigned long pteh,
unsigned long ptel, unsigned long *pte_idx_ret)
{
long ret;
/* Protect linux PTE lookup from page table destruction */
rcu_read_lock_sched(); /* this disables preemption too */
ret = kvmppc_do_h_enter(kvm, flags, pte_index, pteh, ptel,
current->mm->pgd, false, pte_idx_ret);
rcu_read_unlock_sched();
if (ret == H_TOO_HARD) {
/* this can't happen */
pr_err("KVM: Oops, kvmppc_h_enter returned too hard!\n");
ret = H_RESOURCE; /* or something */
}
return ret;
}
static struct kvmppc_slb *kvmppc_mmu_book3s_hv_find_slbe(struct kvm_vcpu *vcpu,
gva_t eaddr)
{
u64 mask;
int i;
for (i = 0; i < vcpu->arch.slb_nr; i++) {
if (!(vcpu->arch.slb[i].orige & SLB_ESID_V))
continue;
if (vcpu->arch.slb[i].origv & SLB_VSID_B_1T)
mask = ESID_MASK_1T;
else
mask = ESID_MASK;
if (((vcpu->arch.slb[i].orige ^ eaddr) & mask) == 0)
return &vcpu->arch.slb[i];
}
return NULL;
}
static unsigned long kvmppc_mmu_get_real_addr(unsigned long v, unsigned long r,
unsigned long ea)
{
unsigned long ra_mask;
ra_mask = kvmppc_actual_pgsz(v, r) - 1;
return (r & HPTE_R_RPN & ~ra_mask) | (ea & ra_mask);
}
static int kvmppc_mmu_book3s_64_hv_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
struct kvmppc_pte *gpte, bool data, bool iswrite)
{
struct kvm *kvm = vcpu->kvm;
struct kvmppc_slb *slbe;
unsigned long slb_v;
unsigned long pp, key;
unsigned long v, orig_v, gr;
__be64 *hptep;
int index;
int virtmode = vcpu->arch.shregs.msr & (data ? MSR_DR : MSR_IR);
if (kvm_is_radix(vcpu->kvm))
return kvmppc_mmu_radix_xlate(vcpu, eaddr, gpte, data, iswrite);
/* Get SLB entry */
if (virtmode) {
slbe = kvmppc_mmu_book3s_hv_find_slbe(vcpu, eaddr);
if (!slbe)
return -EINVAL;
slb_v = slbe->origv;
} else {
/* real mode access */
slb_v = vcpu->kvm->arch.vrma_slb_v;
}
preempt_disable();
/* Find the HPTE in the hash table */
index = kvmppc_hv_find_lock_hpte(kvm, eaddr, slb_v,
HPTE_V_VALID | HPTE_V_ABSENT);
if (index < 0) {
preempt_enable();
return -ENOENT;
}
hptep = (__be64 *)(kvm->arch.hpt.virt + (index << 4));
v = orig_v = be64_to_cpu(hptep[0]) & ~HPTE_V_HVLOCK;
if (cpu_has_feature(CPU_FTR_ARCH_300))
v = hpte_new_to_old_v(v, be64_to_cpu(hptep[1]));
gr = kvm->arch.hpt.rev[index].guest_rpte;
unlock_hpte(hptep, orig_v);
preempt_enable();
gpte->eaddr = eaddr;
gpte->vpage = ((v & HPTE_V_AVPN) << 4) | ((eaddr >> 12) & 0xfff);
/* Get PP bits and key for permission check */
pp = gr & (HPTE_R_PP0 | HPTE_R_PP);
key = (vcpu->arch.shregs.msr & MSR_PR) ? SLB_VSID_KP : SLB_VSID_KS;
key &= slb_v;
/* Calculate permissions */
gpte->may_read = hpte_read_permission(pp, key);
gpte->may_write = hpte_write_permission(pp, key);
gpte->may_execute = gpte->may_read && !(gr & (HPTE_R_N | HPTE_R_G));
/* Storage key permission check for POWER7 */
if (data && virtmode) {
int amrfield = hpte_get_skey_perm(gr, vcpu->arch.amr);
if (amrfield & 1)
gpte->may_read = 0;
if (amrfield & 2)
gpte->may_write = 0;
}
/* Get the guest physical address */
gpte->raddr = kvmppc_mmu_get_real_addr(v, gr, eaddr);
return 0;
}
/*
* Quick test for whether an instruction is a load or a store.
* If the instruction is a load or a store, then this will indicate
* which it is, at least on server processors. (Embedded processors
* have some external PID instructions that don't follow the rule
* embodied here.) If the instruction isn't a load or store, then
* this doesn't return anything useful.
*/
static int instruction_is_store(unsigned int instr)
{
unsigned int mask;
mask = 0x10000000;
if ((instr & 0xfc000000) == 0x7c000000)
mask = 0x100; /* major opcode 31 */
return (instr & mask) != 0;
}
int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu,
unsigned long gpa, gva_t ea, int is_store)
{
u32 last_inst;
/*
* If we fail, we just return to the guest and try executing it again.
*/
if (kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst) !=
EMULATE_DONE)
return RESUME_GUEST;
/*
* WARNING: We do not know for sure whether the instruction we just
* read from memory is the same that caused the fault in the first
* place. If the instruction we read is neither an load or a store,
* then it can't access memory, so we don't need to worry about
* enforcing access permissions. So, assuming it is a load or
* store, we just check that its direction (load or store) is
* consistent with the original fault, since that's what we
* checked the access permissions against. If there is a mismatch
* we just return and retry the instruction.
*/
if (instruction_is_store(last_inst) != !!is_store)
return RESUME_GUEST;
/*
* Emulated accesses are emulated by looking at the hash for
* translation once, then performing the access later. The
* translation could be invalidated in the meantime in which
* point performing the subsequent memory access on the old
* physical address could possibly be a security hole for the
* guest (but not the host).
*
* This is less of an issue for MMIO stores since they aren't
* globally visible. It could be an issue for MMIO loads to
* a certain extent but we'll ignore it for now.
*/
vcpu->arch.paddr_accessed = gpa;
vcpu->arch.vaddr_accessed = ea;
return kvmppc_emulate_mmio(run, vcpu);
}
int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
unsigned long ea, unsigned long dsisr)
{
struct kvm *kvm = vcpu->kvm;
unsigned long hpte[3], r;
unsigned long hnow_v, hnow_r;
__be64 *hptep;
unsigned long mmu_seq, psize, pte_size;
unsigned long gpa_base, gfn_base;
unsigned long gpa, gfn, hva, pfn;
struct kvm_memory_slot *memslot;
unsigned long *rmap;
struct revmap_entry *rev;
struct page *page, *pages[1];
long index, ret, npages;
bool is_ci;
unsigned int writing, write_ok;
struct vm_area_struct *vma;
unsigned long rcbits;
long mmio_update;
if (kvm_is_radix(kvm))
return kvmppc_book3s_radix_page_fault(run, vcpu, ea, dsisr);
/*
* Real-mode code has already searched the HPT and found the
* entry we're interested in. Lock the entry and check that
* it hasn't changed. If it has, just return and re-execute the
* instruction.
*/
if (ea != vcpu->arch.pgfault_addr)
return RESUME_GUEST;
if (vcpu->arch.pgfault_cache) {
mmio_update = atomic64_read(&kvm->arch.mmio_update);
if (mmio_update == vcpu->arch.pgfault_cache->mmio_update) {
r = vcpu->arch.pgfault_cache->rpte;
psize = kvmppc_actual_pgsz(vcpu->arch.pgfault_hpte[0],
r);
gpa_base = r & HPTE_R_RPN & ~(psize - 1);
gfn_base = gpa_base >> PAGE_SHIFT;
gpa = gpa_base | (ea & (psize - 1));
return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea,
dsisr & DSISR_ISSTORE);
}
}
index = vcpu->arch.pgfault_index;
hptep = (__be64 *)(kvm->arch.hpt.virt + (index << 4));
rev = &kvm->arch.hpt.rev[index];
preempt_disable();
while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
cpu_relax();
hpte[0] = be64_to_cpu(hptep[0]) & ~HPTE_V_HVLOCK;
hpte[1] = be64_to_cpu(hptep[1]);
hpte[2] = r = rev->guest_rpte;
unlock_hpte(hptep, hpte[0]);
preempt_enable();
if (cpu_has_feature(CPU_FTR_ARCH_300)) {
hpte[0] = hpte_new_to_old_v(hpte[0], hpte[1]);
hpte[1] = hpte_new_to_old_r(hpte[1]);
}
if (hpte[0] != vcpu->arch.pgfault_hpte[0] ||
hpte[1] != vcpu->arch.pgfault_hpte[1])
return RESUME_GUEST;
/* Translate the logical address and get the page */
psize = kvmppc_actual_pgsz(hpte[0], r);
gpa_base = r & HPTE_R_RPN & ~(psize - 1);
gfn_base = gpa_base >> PAGE_SHIFT;
gpa = gpa_base | (ea & (psize - 1));
gfn = gpa >> PAGE_SHIFT;
memslot = gfn_to_memslot(kvm, gfn);
trace_kvm_page_fault_enter(vcpu, hpte, memslot, ea, dsisr);
/* No memslot means it's an emulated MMIO region */
if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID))
return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea,
dsisr & DSISR_ISSTORE);
/*
* This should never happen, because of the slot_is_aligned()
* check in kvmppc_do_h_enter().
*/
if (gfn_base < memslot->base_gfn)
return -EFAULT;
/* used to check for invalidations in progress */
mmu_seq = kvm->mmu_notifier_seq;
smp_rmb();
ret = -EFAULT;
is_ci = false;
pfn = 0;
page = NULL;
pte_size = PAGE_SIZE;
writing = (dsisr & DSISR_ISSTORE) != 0;
/* If writing != 0, then the HPTE must allow writing, if we get here */
write_ok = writing;
hva = gfn_to_hva_memslot(memslot, gfn);
npages = get_user_pages_fast(hva, 1, writing, pages);
if (npages < 1) {
/* Check if it's an I/O mapping */
down_read(&current->mm->mmap_sem);
vma = find_vma(current->mm, hva);
if (vma && vma->vm_start <= hva && hva + psize <= vma->vm_end &&
(vma->vm_flags & VM_PFNMAP)) {
pfn = vma->vm_pgoff +
((hva - vma->vm_start) >> PAGE_SHIFT);
pte_size = psize;
is_ci = pte_ci(__pte((pgprot_val(vma->vm_page_prot))));
write_ok = vma->vm_flags & VM_WRITE;
}
up_read(&current->mm->mmap_sem);
if (!pfn)
goto out_put;
} else {
page = pages[0];
pfn = page_to_pfn(page);
if (PageHuge(page)) {
page = compound_head(page);
pte_size <<= compound_order(page);
}
/* if the guest wants write access, see if that is OK */
if (!writing && hpte_is_writable(r)) {
pte_t *ptep, pte;
unsigned long flags;
/*
* We need to protect against page table destruction
* hugepage split and collapse.
*/
local_irq_save(flags);
ptep = find_current_mm_pte(current->mm->pgd,
hva, NULL, NULL);
if (ptep) {
pte = kvmppc_read_update_linux_pte(ptep, 1);
if (__pte_write(pte))
write_ok = 1;
}
local_irq_restore(flags);
}
}
if (psize > pte_size)
goto out_put;
/* Check WIMG vs. the actual page we're accessing */
if (!hpte_cache_flags_ok(r, is_ci)) {
if (is_ci)
goto out_put;
/*
* Allow guest to map emulated device memory as
* uncacheable, but actually make it cacheable.
*/
r = (r & ~(HPTE_R_W|HPTE_R_I|HPTE_R_G)) | HPTE_R_M;
}
/*
* Set the HPTE to point to pfn.
* Since the pfn is at PAGE_SIZE granularity, make sure we
* don't mask out lower-order bits if psize < PAGE_SIZE.
*/
if (psize < PAGE_SIZE)
psize = PAGE_SIZE;
r = (r & HPTE_R_KEY_HI) | (r & ~(HPTE_R_PP0 - psize)) |
((pfn << PAGE_SHIFT) & ~(psize - 1));
if (hpte_is_writable(r) && !write_ok)
r = hpte_make_readonly(r);
ret = RESUME_GUEST;
preempt_disable();
while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
cpu_relax();
hnow_v = be64_to_cpu(hptep[0]);
hnow_r = be64_to_cpu(hptep[1]);
if (cpu_has_feature(CPU_FTR_ARCH_300)) {
hnow_v = hpte_new_to_old_v(hnow_v, hnow_r);
hnow_r = hpte_new_to_old_r(hnow_r);
}
/*
* If the HPT is being resized, don't update the HPTE,
* instead let the guest retry after the resize operation is complete.
* The synchronization for mmu_ready test vs. set is provided
* by the HPTE lock.
*/
if (!kvm->arch.mmu_ready)
goto out_unlock;
if ((hnow_v & ~HPTE_V_HVLOCK) != hpte[0] || hnow_r != hpte[1] ||
rev->guest_rpte != hpte[2])
/* HPTE has been changed under us; let the guest retry */
goto out_unlock;
hpte[0] = (hpte[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID;
/* Always put the HPTE in the rmap chain for the page base address */
rmap = &memslot->arch.rmap[gfn_base - memslot->base_gfn];
lock_rmap(rmap);
/* Check if we might have been invalidated; let the guest retry if so */
ret = RESUME_GUEST;
if (mmu_notifier_retry(vcpu->kvm, mmu_seq)) {
unlock_rmap(rmap);
goto out_unlock;
}
/* Only set R/C in real HPTE if set in both *rmap and guest_rpte */
rcbits = *rmap >> KVMPPC_RMAP_RC_SHIFT;
r &= rcbits | ~(HPTE_R_R | HPTE_R_C);
if (be64_to_cpu(hptep[0]) & HPTE_V_VALID) {
/* HPTE was previously valid, so we need to invalidate it */
unlock_rmap(rmap);
hptep[0] |= cpu_to_be64(HPTE_V_ABSENT);
kvmppc_invalidate_hpte(kvm, hptep, index);
/* don't lose previous R and C bits */
r |= be64_to_cpu(hptep[1]) & (HPTE_R_R | HPTE_R_C);
} else {
kvmppc_add_revmap_chain(kvm, rev, rmap, index, 0);
}
if (cpu_has_feature(CPU_FTR_ARCH_300)) {
r = hpte_old_to_new_r(hpte[0], r);
hpte[0] = hpte_old_to_new_v(hpte[0]);
}
hptep[1] = cpu_to_be64(r);
eieio();
__unlock_hpte(hptep, hpte[0]);
asm volatile("ptesync" : : : "memory");
preempt_enable();
if (page && hpte_is_writable(r))
SetPageDirty(page);
out_put:
trace_kvm_page_fault_exit(vcpu, hpte, ret);
if (page) {
/*
* We drop pages[0] here, not page because page might
* have been set to the head page of a compound, but
* we have to drop the reference on the correct tail
* page to match the get inside gup()
*/
put_page(pages[0]);
}
return ret;
out_unlock:
__unlock_hpte(hptep, be64_to_cpu(hptep[0]));
preempt_enable();
goto out_put;
}
void kvmppc_rmap_reset(struct kvm *kvm)
{
struct kvm_memslots *slots;
struct kvm_memory_slot *memslot;
int srcu_idx;
srcu_idx = srcu_read_lock(&kvm->srcu);
slots = kvm_memslots(kvm);
kvm_for_each_memslot(memslot, slots) {
/*
* This assumes it is acceptable to lose reference and
* change bits across a reset.
*/
memset(memslot->arch.rmap, 0,
memslot->npages * sizeof(*memslot->arch.rmap));
}
srcu_read_unlock(&kvm->srcu, srcu_idx);
}
typedef int (*hva_handler_fn)(struct kvm *kvm, struct kvm_memory_slot *memslot,
unsigned long gfn);
static int kvm_handle_hva_range(struct kvm *kvm,
unsigned long start,
unsigned long end,
hva_handler_fn handler)
{
int ret;
int retval = 0;
struct kvm_memslots *slots;
struct kvm_memory_slot *memslot;
slots = kvm_memslots(kvm);
kvm_for_each_memslot(memslot, slots) {
unsigned long hva_start, hva_end;
gfn_t gfn, gfn_end;
hva_start = max(start, memslot->userspace_addr);
hva_end = min(end, memslot->userspace_addr +
(memslot->npages << PAGE_SHIFT));
if (hva_start >= hva_end)
continue;
/*
* {gfn(page) | page intersects with [hva_start, hva_end)} =
* {gfn, gfn+1, ..., gfn_end-1}.
*/
gfn = hva_to_gfn_memslot(hva_start, memslot);
gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot);
for (; gfn < gfn_end; ++gfn) {
ret = handler(kvm, memslot, gfn);
retval |= ret;
}
}
return retval;
}
static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
hva_handler_fn handler)
{
return kvm_handle_hva_range(kvm, hva, hva + 1, handler);
}
/* Must be called with both HPTE and rmap locked */
static void kvmppc_unmap_hpte(struct kvm *kvm, unsigned long i,
struct kvm_memory_slot *memslot,
unsigned long *rmapp, unsigned long gfn)
{
__be64 *hptep = (__be64 *) (kvm->arch.hpt.virt + (i << 4));
struct revmap_entry *rev = kvm->arch.hpt.rev;
unsigned long j, h;
unsigned long ptel, psize, rcbits;
j = rev[i].forw;
if (j == i) {
/* chain is now empty */
*rmapp &= ~(KVMPPC_RMAP_PRESENT | KVMPPC_RMAP_INDEX);
} else {
/* remove i from chain */
h = rev[i].back;
rev[h].forw = j;
rev[j].back = h;
rev[i].forw = rev[i].back = i;
*rmapp = (*rmapp & ~KVMPPC_RMAP_INDEX) | j;
}
/* Now check and modify the HPTE */
ptel = rev[i].guest_rpte;
psize = kvmppc_actual_pgsz(be64_to_cpu(hptep[0]), ptel);
if ((be64_to_cpu(hptep[0]) & HPTE_V_VALID) &&
hpte_rpn(ptel, psize) == gfn) {
hptep[0] |= cpu_to_be64(HPTE_V_ABSENT);
kvmppc_invalidate_hpte(kvm, hptep, i);
hptep[1] &= ~cpu_to_be64(HPTE_R_KEY_HI | HPTE_R_KEY_LO);
/* Harvest R and C */
rcbits = be64_to_cpu(hptep[1]) & (HPTE_R_R | HPTE_R_C);
*rmapp |= rcbits << KVMPPC_RMAP_RC_SHIFT;
if ((rcbits & HPTE_R_C) && memslot->dirty_bitmap)
kvmppc_update_dirty_map(memslot, gfn, psize);
if (rcbits & ~rev[i].guest_rpte) {
rev[i].guest_rpte = ptel | rcbits;
note_hpte_modification(kvm, &rev[i]);
}
}
}
static int kvm_unmap_rmapp(struct kvm *kvm, struct kvm_memory_slot *memslot,
unsigned long gfn)
{
unsigned long i;
__be64 *hptep;
unsigned long *rmapp;
rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
for (;;) {
lock_rmap(rmapp);
if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
unlock_rmap(rmapp);
break;
}
/*
* To avoid an ABBA deadlock with the HPTE lock bit,
* we can't spin on the HPTE lock while holding the
* rmap chain lock.
*/
i = *rmapp & KVMPPC_RMAP_INDEX;
hptep = (__be64 *) (kvm->arch.hpt.virt + (i << 4));
if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
/* unlock rmap before spinning on the HPTE lock */
unlock_rmap(rmapp);
while (be64_to_cpu(hptep[0]) & HPTE_V_HVLOCK)
cpu_relax();
continue;
}
kvmppc_unmap_hpte(kvm, i, memslot, rmapp, gfn);
unlock_rmap(rmapp);
__unlock_hpte(hptep, be64_to_cpu(hptep[0]));
}
return 0;
}
int kvm_unmap_hva_range_hv(struct kvm *kvm, unsigned long start, unsigned long end)
{
hva_handler_fn handler;
handler = kvm_is_radix(kvm) ? kvm_unmap_radix : kvm_unmap_rmapp;
kvm_handle_hva_range(kvm, start, end, handler);
return 0;
}
void kvmppc_core_flush_memslot_hv(struct kvm *kvm,
struct kvm_memory_slot *memslot)
{
unsigned long gfn;
unsigned long n;
unsigned long *rmapp;
gfn = memslot->base_gfn;
rmapp = memslot->arch.rmap;
for (n = memslot->npages; n; --n, ++gfn) {
if (kvm_is_radix(kvm)) {
kvm_unmap_radix(kvm, memslot, gfn);
continue;
}
/*
* Testing the present bit without locking is OK because
* the memslot has been marked invalid already, and hence
* no new HPTEs referencing this page can be created,
* thus the present bit can't go from 0 to 1.
*/
if (*rmapp & KVMPPC_RMAP_PRESENT)
kvm_unmap_rmapp(kvm, memslot, gfn);
++rmapp;
}
}
static int kvm_age_rmapp(struct kvm *kvm, struct kvm_memory_slot *memslot,
unsigned long gfn)
{
struct revmap_entry *rev = kvm->arch.hpt.rev;
unsigned long head, i, j;
__be64 *hptep;
int ret = 0;
unsigned long *rmapp;
rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
retry:
lock_rmap(rmapp);
if (*rmapp & KVMPPC_RMAP_REFERENCED) {
*rmapp &= ~KVMPPC_RMAP_REFERENCED;
ret = 1;
}
if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
unlock_rmap(rmapp);
return ret;
}
i = head = *rmapp & KVMPPC_RMAP_INDEX;
do {
hptep = (__be64 *) (kvm->arch.hpt.virt + (i << 4));
j = rev[i].forw;
/* If this HPTE isn't referenced, ignore it */
if (!(be64_to_cpu(hptep[1]) & HPTE_R_R))
continue;
if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
/* unlock rmap before spinning on the HPTE lock */
unlock_rmap(rmapp);
while (be64_to_cpu(hptep[0]) & HPTE_V_HVLOCK)
cpu_relax();
goto retry;
}
/* Now check and modify the HPTE */
if ((be64_to_cpu(hptep[0]) & HPTE_V_VALID) &&
(be64_to_cpu(hptep[1]) & HPTE_R_R)) {
kvmppc_clear_ref_hpte(kvm, hptep, i);
if (!(rev[i].guest_rpte & HPTE_R_R)) {
rev[i].guest_rpte |= HPTE_R_R;
note_hpte_modification(kvm, &rev[i]);
}
ret = 1;
}
__unlock_hpte(hptep, be64_to_cpu(hptep[0]));
} while ((i = j) != head);
unlock_rmap(rmapp);
return ret;
}
int kvm_age_hva_hv(struct kvm *kvm, unsigned long start, unsigned long end)
{
hva_handler_fn handler;
handler = kvm_is_radix(kvm) ? kvm_age_radix : kvm_age_rmapp;
return kvm_handle_hva_range(kvm, start, end, handler);
}
static int kvm_test_age_rmapp(struct kvm *kvm, struct kvm_memory_slot *memslot,
unsigned long gfn)
{
struct revmap_entry *rev = kvm->arch.hpt.rev;
unsigned long head, i, j;
unsigned long *hp;
int ret = 1;
unsigned long *rmapp;
rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
if (*rmapp & KVMPPC_RMAP_REFERENCED)
return 1;
lock_rmap(rmapp);
if (*rmapp & KVMPPC_RMAP_REFERENCED)
goto out;
if (*rmapp & KVMPPC_RMAP_PRESENT) {
i = head = *rmapp & KVMPPC_RMAP_INDEX;
do {
hp = (unsigned long *)(kvm->arch.hpt.virt + (i << 4));
j = rev[i].forw;
if (be64_to_cpu(hp[1]) & HPTE_R_R)
goto out;
} while ((i = j) != head);
}
ret = 0;
out:
unlock_rmap(rmapp);
return ret;
}
int kvm_test_age_hva_hv(struct kvm *kvm, unsigned long hva)
{
hva_handler_fn handler;
handler = kvm_is_radix(kvm) ? kvm_test_age_radix : kvm_test_age_rmapp;
return kvm_handle_hva(kvm, hva, handler);
}
void kvm_set_spte_hva_hv(struct kvm *kvm, unsigned long hva, pte_t pte)
{
hva_handler_fn handler;
handler = kvm_is_radix(kvm) ? kvm_unmap_radix : kvm_unmap_rmapp;
kvm_handle_hva(kvm, hva, handler);
}
static int vcpus_running(struct kvm *kvm)
{
return atomic_read(&kvm->arch.vcpus_running) != 0;
}
/*
* Returns the number of system pages that are dirty.
* This can be more than 1 if we find a huge-page HPTE.
*/
static int kvm_test_clear_dirty_npages(struct kvm *kvm, unsigned long *rmapp)
{
struct revmap_entry *rev = kvm->arch.hpt.rev;
unsigned long head, i, j;
unsigned long n;
unsigned long v, r;
__be64 *hptep;
int npages_dirty = 0;
retry:
lock_rmap(rmapp);
if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
unlock_rmap(rmapp);
return npages_dirty;
}
i = head = *rmapp & KVMPPC_RMAP_INDEX;
do {
unsigned long hptep1;
hptep = (__be64 *) (kvm->arch.hpt.virt + (i << 4));
j = rev[i].forw;
/*
* Checking the C (changed) bit here is racy since there
* is no guarantee about when the hardware writes it back.
* If the HPTE is not writable then it is stable since the
* page can't be written to, and we would have done a tlbie
* (which forces the hardware to complete any writeback)
* when making the HPTE read-only.
* If vcpus are running then this call is racy anyway
* since the page could get dirtied subsequently, so we
* expect there to be a further call which would pick up
* any delayed C bit writeback.
* Otherwise we need to do the tlbie even if C==0 in
* order to pick up any delayed writeback of C.
*/
hptep1 = be64_to_cpu(hptep[1]);
if (!(hptep1 & HPTE_R_C) &&
(!hpte_is_writable(hptep1) || vcpus_running(kvm)))
continue;
if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
/* unlock rmap before spinning on the HPTE lock */
unlock_rmap(rmapp);
while (hptep[0] & cpu_to_be64(HPTE_V_HVLOCK))
cpu_relax();
goto retry;
}
/* Now check and modify the HPTE */
if (!(hptep[0] & cpu_to_be64(HPTE_V_VALID))) {
__unlock_hpte(hptep, be64_to_cpu(hptep[0]));
continue;
}
/* need to make it temporarily absent so C is stable */
hptep[0] |= cpu_to_be64(HPTE_V_ABSENT);
kvmppc_invalidate_hpte(kvm, hptep, i);
v = be64_to_cpu(hptep[0]);
r = be64_to_cpu(hptep[1]);
if (r & HPTE_R_C) {
hptep[1] = cpu_to_be64(r & ~HPTE_R_C);
if (!(rev[i].guest_rpte & HPTE_R_C)) {
rev[i].guest_rpte |= HPTE_R_C;
note_hpte_modification(kvm, &rev[i]);
}
n = kvmppc_actual_pgsz(v, r);
n = (n + PAGE_SIZE - 1) >> PAGE_SHIFT;
if (n > npages_dirty)
npages_dirty = n;
eieio();
}
v &= ~HPTE_V_ABSENT;
v |= HPTE_V_VALID;
__unlock_hpte(hptep, v);
} while ((i = j) != head);
unlock_rmap(rmapp);
return npages_dirty;
}
void kvmppc_harvest_vpa_dirty(struct kvmppc_vpa *vpa,
struct kvm_memory_slot *memslot,
unsigned long *map)
{
unsigned long gfn;
if (!vpa->dirty || !vpa->pinned_addr)
return;
gfn = vpa->gpa >> PAGE_SHIFT;
if (gfn < memslot->base_gfn ||
gfn >= memslot->base_gfn + memslot->npages)
return;
vpa->dirty = false;
if (map)
__set_bit_le(gfn - memslot->base_gfn, map);
}
long kvmppc_hv_get_dirty_log_hpt(struct kvm *kvm,
struct kvm_memory_slot *memslot, unsigned long *map)
{
unsigned long i;
unsigned long *rmapp;
preempt_disable();
rmapp = memslot->arch.rmap;
for (i = 0; i < memslot->npages; ++i) {
int npages = kvm_test_clear_dirty_npages(kvm, rmapp);
/*
* Note that if npages > 0 then i must be a multiple of npages,
* since we always put huge-page HPTEs in the rmap chain
* corresponding to their page base address.
*/
if (npages)
set_dirty_bits(map, i, npages);
++rmapp;
}
preempt_enable();
return 0;
}
void *kvmppc_pin_guest_page(struct kvm *kvm, unsigned long gpa,
unsigned long *nb_ret)
{
struct kvm_memory_slot *memslot;
unsigned long gfn = gpa >> PAGE_SHIFT;
struct page *page, *pages[1];
int npages;
unsigned long hva, offset;
int srcu_idx;
srcu_idx = srcu_read_lock(&kvm->srcu);
memslot = gfn_to_memslot(kvm, gfn);
if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID))
goto err;
hva = gfn_to_hva_memslot(memslot, gfn);
npages = get_user_pages_fast(hva, 1, 1, pages);
if (npages < 1)
goto err;
page = pages[0];
srcu_read_unlock(&kvm->srcu, srcu_idx);
offset = gpa & (PAGE_SIZE - 1);
if (nb_ret)
*nb_ret = PAGE_SIZE - offset;
return page_address(page) + offset;
err:
srcu_read_unlock(&kvm->srcu, srcu_idx);
return NULL;
}
void kvmppc_unpin_guest_page(struct kvm *kvm, void *va, unsigned long gpa,
bool dirty)
{
struct page *page = virt_to_page(va);
struct kvm_memory_slot *memslot;
unsigned long gfn;
int srcu_idx;
put_page(page);
if (!dirty)
return;
/* We need to mark this page dirty in the memslot dirty_bitmap, if any */
gfn = gpa >> PAGE_SHIFT;
srcu_idx = srcu_read_lock(&kvm->srcu);
memslot = gfn_to_memslot(kvm, gfn);
if (memslot && memslot->dirty_bitmap)
set_bit_le(gfn - memslot->base_gfn, memslot->dirty_bitmap);
srcu_read_unlock(&kvm->srcu, srcu_idx);
}
/*
* HPT resizing
*/
static int resize_hpt_allocate(struct kvm_resize_hpt *resize)
{
int rc;
rc = kvmppc_allocate_hpt(&resize->hpt, resize->order);
if (rc < 0)
return rc;
resize_hpt_debug(resize, "resize_hpt_allocate(): HPT @ 0x%lx\n",
resize->hpt.virt);
return 0;
}
static unsigned long resize_hpt_rehash_hpte(struct kvm_resize_hpt *resize,
unsigned long idx)
{
struct kvm *kvm = resize->kvm;
struct kvm_hpt_info *old = &kvm->arch.hpt;
struct kvm_hpt_info *new = &resize->hpt;
unsigned long old_hash_mask = (1ULL << (old->order - 7)) - 1;
unsigned long new_hash_mask = (1ULL << (new->order - 7)) - 1;
__be64 *hptep, *new_hptep;
unsigned long vpte, rpte, guest_rpte;
int ret;
struct revmap_entry *rev;
unsigned long apsize, avpn, pteg, hash;
unsigned long new_idx, new_pteg, replace_vpte;
int pshift;
hptep = (__be64 *)(old->virt + (idx << 4));
/* Guest is stopped, so new HPTEs can't be added or faulted
* in, only unmapped or altered by host actions. So, it's
* safe to check this before we take the HPTE lock */
vpte = be64_to_cpu(hptep[0]);
if (!(vpte & HPTE_V_VALID) && !(vpte & HPTE_V_ABSENT))
return 0; /* nothing to do */
while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
cpu_relax();
vpte = be64_to_cpu(hptep[0]);
ret = 0;
if (!(vpte & HPTE_V_VALID) && !(vpte & HPTE_V_ABSENT))
/* Nothing to do */
goto out;
if (cpu_has_feature(CPU_FTR_ARCH_300)) {
rpte = be64_to_cpu(hptep[1]);
vpte = hpte_new_to_old_v(vpte, rpte);
}
/* Unmap */
rev = &old->rev[idx];
guest_rpte = rev->guest_rpte;
ret = -EIO;
apsize = kvmppc_actual_pgsz(vpte, guest_rpte);
if (!apsize)
goto out;
if (vpte & HPTE_V_VALID) {
unsigned long gfn = hpte_rpn(guest_rpte, apsize);
int srcu_idx = srcu_read_lock(&kvm->srcu);
struct kvm_memory_slot *memslot =
__gfn_to_memslot(kvm_memslots(kvm), gfn);
if (memslot) {
unsigned long *rmapp;
rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
lock_rmap(rmapp);
kvmppc_unmap_hpte(kvm, idx, memslot, rmapp, gfn);
unlock_rmap(rmapp);
}
srcu_read_unlock(&kvm->srcu, srcu_idx);
}
/* Reload PTE after unmap */
vpte = be64_to_cpu(hptep[0]);
BUG_ON(vpte & HPTE_V_VALID);
BUG_ON(!(vpte & HPTE_V_ABSENT));
ret = 0;
if (!(vpte & HPTE_V_BOLTED))
goto out;
rpte = be64_to_cpu(hptep[1]);
if (cpu_has_feature(CPU_FTR_ARCH_300)) {
vpte = hpte_new_to_old_v(vpte, rpte);
rpte = hpte_new_to_old_r(rpte);
}
pshift = kvmppc_hpte_base_page_shift(vpte, rpte);
avpn = HPTE_V_AVPN_VAL(vpte) & ~(((1ul << pshift) - 1) >> 23);
pteg = idx / HPTES_PER_GROUP;
if (vpte & HPTE_V_SECONDARY)
pteg = ~pteg;
if (!(vpte & HPTE_V_1TB_SEG)) {
unsigned long offset, vsid;
/* We only have 28 - 23 bits of offset in avpn */
offset = (avpn & 0x1f) << 23;
vsid = avpn >> 5;
/* We can find more bits from the pteg value */
if (pshift < 23)
offset |= ((vsid ^ pteg) & old_hash_mask) << pshift;
hash = vsid ^ (offset >> pshift);
} else {
unsigned long offset, vsid;
/* We only have 40 - 23 bits of seg_off in avpn */
offset = (avpn & 0x1ffff) << 23;
vsid = avpn >> 17;
if (pshift < 23)
offset |= ((vsid ^ (vsid << 25) ^ pteg) & old_hash_mask) << pshift;
hash = vsid ^ (vsid << 25) ^ (offset >> pshift);
}
new_pteg = hash & new_hash_mask;
if (vpte & HPTE_V_SECONDARY)
new_pteg = ~hash & new_hash_mask;
new_idx = new_pteg * HPTES_PER_GROUP + (idx % HPTES_PER_GROUP);
new_hptep = (__be64 *)(new->virt + (new_idx << 4));
replace_vpte = be64_to_cpu(new_hptep[0]);
if (cpu_has_feature(CPU_FTR_ARCH_300)) {
unsigned long replace_rpte = be64_to_cpu(new_hptep[1]);
replace_vpte = hpte_new_to_old_v(replace_vpte, replace_rpte);
}
if (replace_vpte & (HPTE_V_VALID | HPTE_V_ABSENT)) {
BUG_ON(new->order >= old->order);
if (replace_vpte & HPTE_V_BOLTED) {
if (vpte & HPTE_V_BOLTED)
/* Bolted collision, nothing we can do */
ret = -ENOSPC;
/* Discard the new HPTE */
goto out;
}
/* Discard the previous HPTE */
}
if (cpu_has_feature(CPU_FTR_ARCH_300)) {
rpte = hpte_old_to_new_r(vpte, rpte);
vpte = hpte_old_to_new_v(vpte);
}
new_hptep[1] = cpu_to_be64(rpte);
new->rev[new_idx].guest_rpte = guest_rpte;
/* No need for a barrier, since new HPT isn't active */
new_hptep[0] = cpu_to_be64(vpte);
unlock_hpte(new_hptep, vpte);
out:
unlock_hpte(hptep, vpte);
return ret;
}
static int resize_hpt_rehash(struct kvm_resize_hpt *resize)
{
struct kvm *kvm = resize->kvm;
unsigned long i;
int rc;
for (i = 0; i < kvmppc_hpt_npte(&kvm->arch.hpt); i++) {
rc = resize_hpt_rehash_hpte(resize, i);
if (rc != 0)
return rc;
}
return 0;
}
static void resize_hpt_pivot(struct kvm_resize_hpt *resize)
{
struct kvm *kvm = resize->kvm;
struct kvm_hpt_info hpt_tmp;
/* Exchange the pending tables in the resize structure with
* the active tables */
resize_hpt_debug(resize, "resize_hpt_pivot()\n");
spin_lock(&kvm->mmu_lock);
asm volatile("ptesync" : : : "memory");
hpt_tmp = kvm->arch.hpt;
kvmppc_set_hpt(kvm, &resize->hpt);
resize->hpt = hpt_tmp;
spin_unlock(&kvm->mmu_lock);
synchronize_srcu_expedited(&kvm->srcu);
if (cpu_has_feature(CPU_FTR_ARCH_300))
kvmppc_setup_partition_table(kvm);
resize_hpt_debug(resize, "resize_hpt_pivot() done\n");
}
static void resize_hpt_release(struct kvm *kvm, struct kvm_resize_hpt *resize)
{
if (WARN_ON(!mutex_is_locked(&kvm->lock)))
return;
if (!resize)
return;
if (resize->error != -EBUSY) {
if (resize->hpt.virt)
kvmppc_free_hpt(&resize->hpt);
kfree(resize);
}
if (kvm->arch.resize_hpt == resize)
kvm->arch.resize_hpt = NULL;
}
static void resize_hpt_prepare_work(struct work_struct *work)
{
struct kvm_resize_hpt *resize = container_of(work,
struct kvm_resize_hpt,
work);
struct kvm *kvm = resize->kvm;
int err = 0;
if (WARN_ON(resize->error != -EBUSY))
return;
mutex_lock(&kvm->lock);
/* Request is still current? */
if (kvm->arch.resize_hpt == resize) {
/* We may request large allocations here:
* do not sleep with kvm->lock held for a while.
*/
mutex_unlock(&kvm->lock);
resize_hpt_debug(resize, "resize_hpt_prepare_work(): order = %d\n",
resize->order);
err = resize_hpt_allocate(resize);
/* We have strict assumption about -EBUSY
* when preparing for HPT resize.
*/
if (WARN_ON(err == -EBUSY))
err = -EINPROGRESS;
mutex_lock(&kvm->lock);
/* It is possible that kvm->arch.resize_hpt != resize
* after we grab kvm->lock again.
*/
}
resize->error = err;
if (kvm->arch.resize_hpt != resize)
resize_hpt_release(kvm, resize);
mutex_unlock(&kvm->lock);
}
long kvm_vm_ioctl_resize_hpt_prepare(struct kvm *kvm,
struct kvm_ppc_resize_hpt *rhpt)
{
unsigned long flags = rhpt->flags;
unsigned long shift = rhpt->shift;
struct kvm_resize_hpt *resize;
int ret;
if (flags != 0 || kvm_is_radix(kvm))
return -EINVAL;
if (shift && ((shift < 18) || (shift > 46)))
return -EINVAL;
mutex_lock(&kvm->lock);
resize = kvm->arch.resize_hpt;
if (resize) {
if (resize->order == shift) {
/* Suitable resize in progress? */
ret = resize->error;
if (ret == -EBUSY)
ret = 100; /* estimated time in ms */
else if (ret)
resize_hpt_release(kvm, resize);
goto out;
}
/* not suitable, cancel it */
resize_hpt_release(kvm, resize);
}
ret = 0;
if (!shift)
goto out; /* nothing to do */
/* start new resize */
resize = kzalloc(sizeof(*resize), GFP_KERNEL);
if (!resize) {
ret = -ENOMEM;
goto out;
}
resize->error = -EBUSY;
resize->order = shift;
resize->kvm = kvm;
INIT_WORK(&resize->work, resize_hpt_prepare_work);
kvm->arch.resize_hpt = resize;
schedule_work(&resize->work);
ret = 100; /* estimated time in ms */
out:
mutex_unlock(&kvm->lock);
return ret;
}
static void resize_hpt_boot_vcpu(void *opaque)
{
/* Nothing to do, just force a KVM exit */
}
long kvm_vm_ioctl_resize_hpt_commit(struct kvm *kvm,
struct kvm_ppc_resize_hpt *rhpt)
{
unsigned long flags = rhpt->flags;
unsigned long shift = rhpt->shift;
struct kvm_resize_hpt *resize;
long ret;
if (flags != 0 || kvm_is_radix(kvm))
return -EINVAL;
if (shift && ((shift < 18) || (shift > 46)))
return -EINVAL;
mutex_lock(&kvm->lock);
resize = kvm->arch.resize_hpt;
/* This shouldn't be possible */
ret = -EIO;
if (WARN_ON(!kvm->arch.mmu_ready))
goto out_no_hpt;
/* Stop VCPUs from running while we mess with the HPT */
kvm->arch.mmu_ready = 0;
smp_mb();
/* Boot all CPUs out of the guest so they re-read
* mmu_ready */
on_each_cpu(resize_hpt_boot_vcpu, NULL, 1);
ret = -ENXIO;
if (!resize || (resize->order != shift))
goto out;
ret = resize->error;
if (ret)
goto out;
ret = resize_hpt_rehash(resize);
if (ret)
goto out;
resize_hpt_pivot(resize);
out:
/* Let VCPUs run again */
kvm->arch.mmu_ready = 1;
smp_mb();
out_no_hpt:
resize_hpt_release(kvm, resize);
mutex_unlock(&kvm->lock);
return ret;
}
/*
* Functions for reading and writing the hash table via reads and
* writes on a file descriptor.
*
* Reads return the guest view of the hash table, which has to be
* pieced together from the real hash table and the guest_rpte
* values in the revmap array.
*
* On writes, each HPTE written is considered in turn, and if it
* is valid, it is written to the HPT as if an H_ENTER with the
* exact flag set was done. When the invalid count is non-zero
* in the header written to the stream, the kernel will make
* sure that that many HPTEs are invalid, and invalidate them
* if not.
*/
struct kvm_htab_ctx {
unsigned long index;
unsigned long flags;
struct kvm *kvm;
int first_pass;
};
#define HPTE_SIZE (2 * sizeof(unsigned long))
/*
* Returns 1 if this HPT entry has been modified or has pending
* R/C bit changes.
*/
static int hpte_dirty(struct revmap_entry *revp, __be64 *hptp)
{
unsigned long rcbits_unset;
if (revp->guest_rpte & HPTE_GR_MODIFIED)
return 1;
/* Also need to consider changes in reference and changed bits */
rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C);
if ((be64_to_cpu(hptp[0]) & HPTE_V_VALID) &&
(be64_to_cpu(hptp[1]) & rcbits_unset))
return 1;
return 0;
}
static long record_hpte(unsigned long flags, __be64 *hptp,
unsigned long *hpte, struct revmap_entry *revp,
int want_valid, int first_pass)
{
unsigned long v, r, hr;
unsigned long rcbits_unset;
int ok = 1;
int valid, dirty;
/* Unmodified entries are uninteresting except on the first pass */
dirty = hpte_dirty(revp, hptp);
if (!first_pass && !dirty)
return 0;
valid = 0;
if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT)) {
valid = 1;
if ((flags & KVM_GET_HTAB_BOLTED_ONLY) &&
!(be64_to_cpu(hptp[0]) & HPTE_V_BOLTED))
valid = 0;
}
if (valid != want_valid)
return 0;
v = r = 0;
if (valid || dirty) {
/* lock the HPTE so it's stable and read it */
preempt_disable();
while (!try_lock_hpte(hptp, HPTE_V_HVLOCK))
cpu_relax();
v = be64_to_cpu(hptp[0]);
hr = be64_to_cpu(hptp[1]);
if (cpu_has_feature(CPU_FTR_ARCH_300)) {
v = hpte_new_to_old_v(v, hr);
hr = hpte_new_to_old_r(hr);
}
/* re-evaluate valid and dirty from synchronized HPTE value */
valid = !!(v & HPTE_V_VALID);
dirty = !!(revp->guest_rpte & HPTE_GR_MODIFIED);
/* Harvest R and C into guest view if necessary */
rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C);
if (valid && (rcbits_unset & hr)) {
revp->guest_rpte |= (hr &
(HPTE_R_R | HPTE_R_C)) | HPTE_GR_MODIFIED;
dirty = 1;
}
if (v & HPTE_V_ABSENT) {
v &= ~HPTE_V_ABSENT;
v |= HPTE_V_VALID;
valid = 1;
}
if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && !(v & HPTE_V_BOLTED))
valid = 0;
r = revp->guest_rpte;
/* only clear modified if this is the right sort of entry */
if (valid == want_valid && dirty) {
r &= ~HPTE_GR_MODIFIED;
revp->guest_rpte = r;
}
unlock_hpte(hptp, be64_to_cpu(hptp[0]));
preempt_enable();
if (!(valid == want_valid && (first_pass || dirty)))
ok = 0;
}
hpte[0] = cpu_to_be64(v);
hpte[1] = cpu_to_be64(r);
return ok;
}
static ssize_t kvm_htab_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
struct kvm_htab_ctx *ctx = file->private_data;
struct kvm *kvm = ctx->kvm;
struct kvm_get_htab_header hdr;
__be64 *hptp;
struct revmap_entry *revp;
unsigned long i, nb, nw;
unsigned long __user *lbuf;
struct kvm_get_htab_header __user *hptr;
unsigned long flags;
int first_pass;
unsigned long hpte[2];
if (!access_ok(VERIFY_WRITE, buf, count))
return -EFAULT;
if (kvm_is_radix(kvm))
return 0;
first_pass = ctx->first_pass;
flags = ctx->flags;
i = ctx->index;
hptp = (__be64 *)(kvm->arch.hpt.virt + (i * HPTE_SIZE));
revp = kvm->arch.hpt.rev + i;
lbuf = (unsigned long __user *)buf;
nb = 0;
while (nb + sizeof(hdr) + HPTE_SIZE < count) {
/* Initialize header */
hptr = (struct kvm_get_htab_header __user *)buf;
hdr.n_valid = 0;
hdr.n_invalid = 0;
nw = nb;
nb += sizeof(hdr);
lbuf = (unsigned long __user *)(buf + sizeof(hdr));
/* Skip uninteresting entries, i.e. clean on not-first pass */
if (!first_pass) {
while (i < kvmppc_hpt_npte(&kvm->arch.hpt) &&
!hpte_dirty(revp, hptp)) {
++i;
hptp += 2;
++revp;
}
}
hdr.index = i;
/* Grab a series of valid entries */
while (i < kvmppc_hpt_npte(&kvm->arch.hpt) &&
hdr.n_valid < 0xffff &&
nb + HPTE_SIZE < count &&
record_hpte(flags, hptp, hpte, revp, 1, first_pass)) {
/* valid entry, write it out */
++hdr.n_valid;
if (__put_user(hpte[0], lbuf) ||
__put_user(hpte[1], lbuf + 1))
return -EFAULT;
nb += HPTE_SIZE;
lbuf += 2;
++i;
hptp += 2;
++revp;
}
/* Now skip invalid entries while we can */
while (i < kvmppc_hpt_npte(&kvm->arch.hpt) &&
hdr.n_invalid < 0xffff &&
record_hpte(flags, hptp, hpte, revp, 0, first_pass)) {
/* found an invalid entry */
++hdr.n_invalid;
++i;
hptp += 2;
++revp;
}
if (hdr.n_valid || hdr.n_invalid) {
/* write back the header */
if (__copy_to_user(hptr, &hdr, sizeof(hdr)))
return -EFAULT;
nw = nb;
buf = (char __user *)lbuf;
} else {
nb = nw;
}
/* Check if we've wrapped around the hash table */
if (i >= kvmppc_hpt_npte(&kvm->arch.hpt)) {
i = 0;
ctx->first_pass = 0;
break;
}
}
ctx->index = i;
return nb;
}
static ssize_t kvm_htab_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
struct kvm_htab_ctx *ctx = file->private_data;
struct kvm *kvm = ctx->kvm;
struct kvm_get_htab_header hdr;
unsigned long i, j;
unsigned long v, r;
unsigned long __user *lbuf;
__be64 *hptp;
unsigned long tmp[2];
ssize_t nb;
long int err, ret;
int mmu_ready;
int pshift;
if (!access_ok(VERIFY_READ, buf, count))
return -EFAULT;
if (kvm_is_radix(kvm))
return -EINVAL;
/* lock out vcpus from running while we're doing this */
mutex_lock(&kvm->lock);
mmu_ready = kvm->arch.mmu_ready;
if (mmu_ready) {
kvm->arch.mmu_ready = 0; /* temporarily */
/* order mmu_ready vs. vcpus_running */
smp_mb();
if (atomic_read(&kvm->arch.vcpus_running)) {
kvm->arch.mmu_ready = 1;
mutex_unlock(&kvm->lock);
return -EBUSY;
}
}
err = 0;
for (nb = 0; nb + sizeof(hdr) <= count; ) {
err = -EFAULT;
if (__copy_from_user(&hdr, buf, sizeof(hdr)))
break;
err = 0;
if (nb + hdr.n_valid * HPTE_SIZE > count)
break;
nb += sizeof(hdr);
buf += sizeof(hdr);
err = -EINVAL;
i = hdr.index;
if (i >= kvmppc_hpt_npte(&kvm->arch.hpt) ||
i + hdr.n_valid + hdr.n_invalid > kvmppc_hpt_npte(&kvm->arch.hpt))
break;
hptp = (__be64 *)(kvm->arch.hpt.virt + (i * HPTE_SIZE));
lbuf = (unsigned long __user *)buf;
for (j = 0; j < hdr.n_valid; ++j) {
__be64 hpte_v;
__be64 hpte_r;
err = -EFAULT;
if (__get_user(hpte_v, lbuf) ||
__get_user(hpte_r, lbuf + 1))
goto out;
v = be64_to_cpu(hpte_v);
r = be64_to_cpu(hpte_r);
err = -EINVAL;
if (!(v & HPTE_V_VALID))
goto out;
pshift = kvmppc_hpte_base_page_shift(v, r);
if (pshift <= 0)
goto out;
lbuf += 2;
nb += HPTE_SIZE;
if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT))
kvmppc_do_h_remove(kvm, 0, i, 0, tmp);
err = -EIO;
ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, i, v, r,
tmp);
if (ret != H_SUCCESS) {
pr_err("kvm_htab_write ret %ld i=%ld v=%lx "
"r=%lx\n", ret, i, v, r);
goto out;
}
if (!mmu_ready && is_vrma_hpte(v)) {
unsigned long senc, lpcr;
senc = slb_pgsize_encoding(1ul << pshift);
kvm->arch.vrma_slb_v = senc | SLB_VSID_B_1T |
(VRMA_VSID << SLB_VSID_SHIFT_1T);
if (!cpu_has_feature(CPU_FTR_ARCH_300)) {
lpcr = senc << (LPCR_VRMASD_SH - 4);
kvmppc_update_lpcr(kvm, lpcr,
LPCR_VRMASD);
} else {
kvmppc_setup_partition_table(kvm);
}
mmu_ready = 1;
}
++i;
hptp += 2;
}
for (j = 0; j < hdr.n_invalid; ++j) {
if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT))
kvmppc_do_h_remove(kvm, 0, i, 0, tmp);
++i;
hptp += 2;
}
err = 0;
}
out:
/* Order HPTE updates vs. mmu_ready */
smp_wmb();
kvm->arch.mmu_ready = mmu_ready;
mutex_unlock(&kvm->lock);
if (err)
return err;
return nb;
}
static int kvm_htab_release(struct inode *inode, struct file *filp)
{
struct kvm_htab_ctx *ctx = filp->private_data;
filp->private_data = NULL;
if (!(ctx->flags & KVM_GET_HTAB_WRITE))
atomic_dec(&ctx->kvm->arch.hpte_mod_interest);
kvm_put_kvm(ctx->kvm);
kfree(ctx);
return 0;
}
static const struct file_operations kvm_htab_fops = {
.read = kvm_htab_read,
.write = kvm_htab_write,
.llseek = default_llseek,
.release = kvm_htab_release,
};
int kvm_vm_ioctl_get_htab_fd(struct kvm *kvm, struct kvm_get_htab_fd *ghf)
{
int ret;
struct kvm_htab_ctx *ctx;
int rwflag;
/* reject flags we don't recognize */
if (ghf->flags & ~(KVM_GET_HTAB_BOLTED_ONLY | KVM_GET_HTAB_WRITE))
return -EINVAL;
ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
if (!ctx)
return -ENOMEM;
kvm_get_kvm(kvm);
ctx->kvm = kvm;
ctx->index = ghf->start_index;
ctx->flags = ghf->flags;
ctx->first_pass = 1;
rwflag = (ghf->flags & KVM_GET_HTAB_WRITE) ? O_WRONLY : O_RDONLY;
ret = anon_inode_getfd("kvm-htab", &kvm_htab_fops, ctx, rwflag | O_CLOEXEC);
if (ret < 0) {
kfree(ctx);
kvm_put_kvm(kvm);
return ret;
}
if (rwflag == O_RDONLY) {
mutex_lock(&kvm->slots_lock);
atomic_inc(&kvm->arch.hpte_mod_interest);
/* make sure kvmppc_do_h_enter etc. see the increment */
synchronize_srcu_expedited(&kvm->srcu);
mutex_unlock(&kvm->slots_lock);
}
return ret;
}
struct debugfs_htab_state {
struct kvm *kvm;
struct mutex mutex;
unsigned long hpt_index;
int chars_left;
int buf_index;
char buf[64];
};
static int debugfs_htab_open(struct inode *inode, struct file *file)
{
struct kvm *kvm = inode->i_private;
struct debugfs_htab_state *p;
p = kzalloc(sizeof(*p), GFP_KERNEL);
if (!p)
return -ENOMEM;
kvm_get_kvm(kvm);
p->kvm = kvm;
mutex_init(&p->mutex);
file->private_data = p;
return nonseekable_open(inode, file);
}
static int debugfs_htab_release(struct inode *inode, struct file *file)
{
struct debugfs_htab_state *p = file->private_data;
kvm_put_kvm(p->kvm);
kfree(p);
return 0;
}
static ssize_t debugfs_htab_read(struct file *file, char __user *buf,
size_t len, loff_t *ppos)
{
struct debugfs_htab_state *p = file->private_data;
ssize_t ret, r;
unsigned long i, n;
unsigned long v, hr, gr;
struct kvm *kvm;
__be64 *hptp;
kvm = p->kvm;
if (kvm_is_radix(kvm))
return 0;
ret = mutex_lock_interruptible(&p->mutex);
if (ret)
return ret;
if (p->chars_left) {
n = p->chars_left;
if (n > len)
n = len;
r = copy_to_user(buf, p->buf + p->buf_index, n);
n -= r;
p->chars_left -= n;
p->buf_index += n;
buf += n;
len -= n;
ret = n;
if (r) {
if (!n)
ret = -EFAULT;
goto out;
}
}
i = p->hpt_index;
hptp = (__be64 *)(kvm->arch.hpt.virt + (i * HPTE_SIZE));
for (; len != 0 && i < kvmppc_hpt_npte(&kvm->arch.hpt);
++i, hptp += 2) {
if (!(be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT)))
continue;
/* lock the HPTE so it's stable and read it */
preempt_disable();
while (!try_lock_hpte(hptp, HPTE_V_HVLOCK))
cpu_relax();
v = be64_to_cpu(hptp[0]) & ~HPTE_V_HVLOCK;
hr = be64_to_cpu(hptp[1]);
gr = kvm->arch.hpt.rev[i].guest_rpte;
unlock_hpte(hptp, v);
preempt_enable();
if (!(v & (HPTE_V_VALID | HPTE_V_ABSENT)))
continue;
n = scnprintf(p->buf, sizeof(p->buf),
"%6lx %.16lx %.16lx %.16lx\n",
i, v, hr, gr);
p->chars_left = n;
if (n > len)
n = len;
r = copy_to_user(buf, p->buf, n);
n -= r;
p->chars_left -= n;
p->buf_index = n;
buf += n;
len -= n;
ret += n;
if (r) {
if (!ret)
ret = -EFAULT;
goto out;
}
}
p->hpt_index = i;
out:
mutex_unlock(&p->mutex);
return ret;
}
static ssize_t debugfs_htab_write(struct file *file, const char __user *buf,
size_t len, loff_t *ppos)
{
return -EACCES;
}
static const struct file_operations debugfs_htab_fops = {
.owner = THIS_MODULE,
.open = debugfs_htab_open,
.release = debugfs_htab_release,
.read = debugfs_htab_read,
.write = debugfs_htab_write,
.llseek = generic_file_llseek,
};
void kvmppc_mmu_debugfs_init(struct kvm *kvm)
{
kvm->arch.htab_dentry = debugfs_create_file("htab", 0400,
kvm->arch.debugfs_dir, kvm,
&debugfs_htab_fops);
}
void kvmppc_mmu_book3s_hv_init(struct kvm_vcpu *vcpu)
{
struct kvmppc_mmu *mmu = &vcpu->arch.mmu;
vcpu->arch.slb_nr = 32; /* POWER7/POWER8 */
mmu->xlate = kvmppc_mmu_book3s_64_hv_xlate;
mmu->reset_msr = kvmppc_mmu_book3s_64_hv_reset_msr;
vcpu->arch.hflags |= BOOK3S_HFLAG_SLB;
}
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