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-rw-r--r--arch/s390/kvm/kvm-s390.c383
1 files changed, 250 insertions, 133 deletions
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 3b7a5151b6a5..91ad4a9425c0 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -172,6 +172,10 @@ static int nested;
module_param(nested, int, S_IRUGO);
MODULE_PARM_DESC(nested, "Nested virtualization support");
+/* allow 1m huge page guest backing, if !nested */
+static int hpage;
+module_param(hpage, int, 0444);
+MODULE_PARM_DESC(hpage, "1m huge page backing support");
/*
* For now we handle at most 16 double words as this is what the s390 base
@@ -475,6 +479,11 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
case KVM_CAP_S390_AIS_MIGRATION:
r = 1;
break;
+ case KVM_CAP_S390_HPAGE_1M:
+ r = 0;
+ if (hpage)
+ r = 1;
+ break;
case KVM_CAP_S390_MEM_OP:
r = MEM_OP_MAX_SIZE;
break;
@@ -511,19 +520,30 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
}
static void kvm_s390_sync_dirty_log(struct kvm *kvm,
- struct kvm_memory_slot *memslot)
+ struct kvm_memory_slot *memslot)
{
+ int i;
gfn_t cur_gfn, last_gfn;
- unsigned long address;
+ unsigned long gaddr, vmaddr;
struct gmap *gmap = kvm->arch.gmap;
+ DECLARE_BITMAP(bitmap, _PAGE_ENTRIES);
- /* Loop over all guest pages */
+ /* Loop over all guest segments */
+ cur_gfn = memslot->base_gfn;
last_gfn = memslot->base_gfn + memslot->npages;
- for (cur_gfn = memslot->base_gfn; cur_gfn <= last_gfn; cur_gfn++) {
- address = gfn_to_hva_memslot(memslot, cur_gfn);
+ for (; cur_gfn <= last_gfn; cur_gfn += _PAGE_ENTRIES) {
+ gaddr = gfn_to_gpa(cur_gfn);
+ vmaddr = gfn_to_hva_memslot(memslot, cur_gfn);
+ if (kvm_is_error_hva(vmaddr))
+ continue;
+
+ bitmap_zero(bitmap, _PAGE_ENTRIES);
+ gmap_sync_dirty_log_pmd(gmap, bitmap, gaddr, vmaddr);
+ for (i = 0; i < _PAGE_ENTRIES; i++) {
+ if (test_bit(i, bitmap))
+ mark_page_dirty(kvm, cur_gfn + i);
+ }
- if (test_and_clear_guest_dirty(gmap->mm, address))
- mark_page_dirty(kvm, cur_gfn);
if (fatal_signal_pending(current))
return;
cond_resched();
@@ -667,6 +687,27 @@ static int kvm_vm_ioctl_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap)
VM_EVENT(kvm, 3, "ENABLE: CAP_S390_GS %s",
r ? "(not available)" : "(success)");
break;
+ case KVM_CAP_S390_HPAGE_1M:
+ mutex_lock(&kvm->lock);
+ if (kvm->created_vcpus)
+ r = -EBUSY;
+ else if (!hpage || kvm->arch.use_cmma)
+ r = -EINVAL;
+ else {
+ r = 0;
+ kvm->mm->context.allow_gmap_hpage_1m = 1;
+ /*
+ * We might have to create fake 4k page
+ * tables. To avoid that the hardware works on
+ * stale PGSTEs, we emulate these instructions.
+ */
+ kvm->arch.use_skf = 0;
+ kvm->arch.use_pfmfi = 0;
+ }
+ mutex_unlock(&kvm->lock);
+ VM_EVENT(kvm, 3, "ENABLE: CAP_S390_HPAGE %s",
+ r ? "(not available)" : "(success)");
+ break;
case KVM_CAP_S390_USER_STSI:
VM_EVENT(kvm, 3, "%s", "ENABLE: CAP_S390_USER_STSI");
kvm->arch.user_stsi = 1;
@@ -714,10 +755,13 @@ static int kvm_s390_set_mem_control(struct kvm *kvm, struct kvm_device_attr *att
if (!sclp.has_cmma)
break;
- ret = -EBUSY;
VM_EVENT(kvm, 3, "%s", "ENABLE: CMMA support");
mutex_lock(&kvm->lock);
- if (!kvm->created_vcpus) {
+ if (kvm->created_vcpus)
+ ret = -EBUSY;
+ else if (kvm->mm->context.allow_gmap_hpage_1m)
+ ret = -EINVAL;
+ else {
kvm->arch.use_cmma = 1;
/* Not compatible with cmma. */
kvm->arch.use_pfmfi = 0;
@@ -862,54 +906,37 @@ static void kvm_s390_sync_request_broadcast(struct kvm *kvm, int req)
*/
static int kvm_s390_vm_start_migration(struct kvm *kvm)
{
- struct kvm_s390_migration_state *mgs;
struct kvm_memory_slot *ms;
- /* should be the only one */
struct kvm_memslots *slots;
- unsigned long ram_pages;
+ unsigned long ram_pages = 0;
int slotnr;
/* migration mode already enabled */
- if (kvm->arch.migration_state)
+ if (kvm->arch.migration_mode)
return 0;
-
slots = kvm_memslots(kvm);
if (!slots || !slots->used_slots)
return -EINVAL;
- mgs = kzalloc(sizeof(*mgs), GFP_KERNEL);
- if (!mgs)
- return -ENOMEM;
- kvm->arch.migration_state = mgs;
-
- if (kvm->arch.use_cmma) {
+ if (!kvm->arch.use_cmma) {
+ kvm->arch.migration_mode = 1;
+ return 0;
+ }
+ /* mark all the pages in active slots as dirty */
+ for (slotnr = 0; slotnr < slots->used_slots; slotnr++) {
+ ms = slots->memslots + slotnr;
/*
- * Get the first slot. They are reverse sorted by base_gfn, so
- * the first slot is also the one at the end of the address
- * space. We have verified above that at least one slot is
- * present.
+ * The second half of the bitmap is only used on x86,
+ * and would be wasted otherwise, so we put it to good
+ * use here to keep track of the state of the storage
+ * attributes.
*/
- ms = slots->memslots;
- /* round up so we only use full longs */
- ram_pages = roundup(ms->base_gfn + ms->npages, BITS_PER_LONG);
- /* allocate enough bytes to store all the bits */
- mgs->pgste_bitmap = vmalloc(ram_pages / 8);
- if (!mgs->pgste_bitmap) {
- kfree(mgs);
- kvm->arch.migration_state = NULL;
- return -ENOMEM;
- }
-
- mgs->bitmap_size = ram_pages;
- atomic64_set(&mgs->dirty_pages, ram_pages);
- /* mark all the pages in active slots as dirty */
- for (slotnr = 0; slotnr < slots->used_slots; slotnr++) {
- ms = slots->memslots + slotnr;
- bitmap_set(mgs->pgste_bitmap, ms->base_gfn, ms->npages);
- }
-
- kvm_s390_sync_request_broadcast(kvm, KVM_REQ_START_MIGRATION);
+ memset(kvm_second_dirty_bitmap(ms), 0xff, kvm_dirty_bitmap_bytes(ms));
+ ram_pages += ms->npages;
}
+ atomic64_set(&kvm->arch.cmma_dirty_pages, ram_pages);
+ kvm->arch.migration_mode = 1;
+ kvm_s390_sync_request_broadcast(kvm, KVM_REQ_START_MIGRATION);
return 0;
}
@@ -919,21 +946,12 @@ static int kvm_s390_vm_start_migration(struct kvm *kvm)
*/
static int kvm_s390_vm_stop_migration(struct kvm *kvm)
{
- struct kvm_s390_migration_state *mgs;
-
/* migration mode already disabled */
- if (!kvm->arch.migration_state)
+ if (!kvm->arch.migration_mode)
return 0;
- mgs = kvm->arch.migration_state;
- kvm->arch.migration_state = NULL;
-
- if (kvm->arch.use_cmma) {
+ kvm->arch.migration_mode = 0;
+ if (kvm->arch.use_cmma)
kvm_s390_sync_request_broadcast(kvm, KVM_REQ_STOP_MIGRATION);
- /* We have to wait for the essa emulation to finish */
- synchronize_srcu(&kvm->srcu);
- vfree(mgs->pgste_bitmap);
- }
- kfree(mgs);
return 0;
}
@@ -961,7 +979,7 @@ static int kvm_s390_vm_set_migration(struct kvm *kvm,
static int kvm_s390_vm_get_migration(struct kvm *kvm,
struct kvm_device_attr *attr)
{
- u64 mig = (kvm->arch.migration_state != NULL);
+ u64 mig = kvm->arch.migration_mode;
if (attr->attr != KVM_S390_VM_MIGRATION_STATUS)
return -ENXIO;
@@ -1540,6 +1558,7 @@ static long kvm_s390_set_skeys(struct kvm *kvm, struct kvm_s390_skeys *args)
uint8_t *keys;
uint64_t hva;
int srcu_idx, i, r = 0;
+ bool unlocked;
if (args->flags != 0)
return -EINVAL;
@@ -1564,9 +1583,11 @@ static long kvm_s390_set_skeys(struct kvm *kvm, struct kvm_s390_skeys *args)
if (r)
goto out;
+ i = 0;
down_read(&current->mm->mmap_sem);
srcu_idx = srcu_read_lock(&kvm->srcu);
- for (i = 0; i < args->count; i++) {
+ while (i < args->count) {
+ unlocked = false;
hva = gfn_to_hva(kvm, args->start_gfn + i);
if (kvm_is_error_hva(hva)) {
r = -EFAULT;
@@ -1580,8 +1601,14 @@ static long kvm_s390_set_skeys(struct kvm *kvm, struct kvm_s390_skeys *args)
}
r = set_guest_storage_key(current->mm, hva, keys[i], 0);
- if (r)
- break;
+ if (r) {
+ r = fixup_user_fault(current, current->mm, hva,
+ FAULT_FLAG_WRITE, &unlocked);
+ if (r)
+ break;
+ }
+ if (!r)
+ i++;
}
srcu_read_unlock(&kvm->srcu, srcu_idx);
up_read(&current->mm->mmap_sem);
@@ -1600,6 +1627,134 @@ out:
#define KVM_S390_CMMA_SIZE_MAX ((u32)KVM_S390_SKEYS_MAX)
/*
+ * Similar to gfn_to_memslot, but returns the index of a memslot also when the
+ * address falls in a hole. In that case the index of one of the memslots
+ * bordering the hole is returned.
+ */
+static int gfn_to_memslot_approx(struct kvm_memslots *slots, gfn_t gfn)
+{
+ int start = 0, end = slots->used_slots;
+ int slot = atomic_read(&slots->lru_slot);
+ struct kvm_memory_slot *memslots = slots->memslots;
+
+ if (gfn >= memslots[slot].base_gfn &&
+ gfn < memslots[slot].base_gfn + memslots[slot].npages)
+ return slot;
+
+ while (start < end) {
+ slot = start + (end - start) / 2;
+
+ if (gfn >= memslots[slot].base_gfn)
+ end = slot;
+ else
+ start = slot + 1;
+ }
+
+ if (gfn >= memslots[start].base_gfn &&
+ gfn < memslots[start].base_gfn + memslots[start].npages) {
+ atomic_set(&slots->lru_slot, start);
+ }
+
+ return start;
+}
+
+static int kvm_s390_peek_cmma(struct kvm *kvm, struct kvm_s390_cmma_log *args,
+ u8 *res, unsigned long bufsize)
+{
+ unsigned long pgstev, hva, cur_gfn = args->start_gfn;
+
+ args->count = 0;
+ while (args->count < bufsize) {
+ hva = gfn_to_hva(kvm, cur_gfn);
+ /*
+ * We return an error if the first value was invalid, but we
+ * return successfully if at least one value was copied.
+ */
+ if (kvm_is_error_hva(hva))
+ return args->count ? 0 : -EFAULT;
+ if (get_pgste(kvm->mm, hva, &pgstev) < 0)
+ pgstev = 0;
+ res[args->count++] = (pgstev >> 24) & 0x43;
+ cur_gfn++;
+ }
+
+ return 0;
+}
+
+static unsigned long kvm_s390_next_dirty_cmma(struct kvm_memslots *slots,
+ unsigned long cur_gfn)
+{
+ int slotidx = gfn_to_memslot_approx(slots, cur_gfn);
+ struct kvm_memory_slot *ms = slots->memslots + slotidx;
+ unsigned long ofs = cur_gfn - ms->base_gfn;
+
+ if (ms->base_gfn + ms->npages <= cur_gfn) {
+ slotidx--;
+ /* If we are above the highest slot, wrap around */
+ if (slotidx < 0)
+ slotidx = slots->used_slots - 1;
+
+ ms = slots->memslots + slotidx;
+ ofs = 0;
+ }
+ ofs = find_next_bit(kvm_second_dirty_bitmap(ms), ms->npages, ofs);
+ while ((slotidx > 0) && (ofs >= ms->npages)) {
+ slotidx--;
+ ms = slots->memslots + slotidx;
+ ofs = find_next_bit(kvm_second_dirty_bitmap(ms), ms->npages, 0);
+ }
+ return ms->base_gfn + ofs;
+}
+
+static int kvm_s390_get_cmma(struct kvm *kvm, struct kvm_s390_cmma_log *args,
+ u8 *res, unsigned long bufsize)
+{
+ unsigned long mem_end, cur_gfn, next_gfn, hva, pgstev;
+ struct kvm_memslots *slots = kvm_memslots(kvm);
+ struct kvm_memory_slot *ms;
+
+ cur_gfn = kvm_s390_next_dirty_cmma(slots, args->start_gfn);
+ ms = gfn_to_memslot(kvm, cur_gfn);
+ args->count = 0;
+ args->start_gfn = cur_gfn;
+ if (!ms)
+ return 0;
+ next_gfn = kvm_s390_next_dirty_cmma(slots, cur_gfn + 1);
+ mem_end = slots->memslots[0].base_gfn + slots->memslots[0].npages;
+
+ while (args->count < bufsize) {
+ hva = gfn_to_hva(kvm, cur_gfn);
+ if (kvm_is_error_hva(hva))
+ return 0;
+ /* Decrement only if we actually flipped the bit to 0 */
+ if (test_and_clear_bit(cur_gfn - ms->base_gfn, kvm_second_dirty_bitmap(ms)))
+ atomic64_dec(&kvm->arch.cmma_dirty_pages);
+ if (get_pgste(kvm->mm, hva, &pgstev) < 0)
+ pgstev = 0;
+ /* Save the value */
+ res[args->count++] = (pgstev >> 24) & 0x43;
+ /* If the next bit is too far away, stop. */
+ if (next_gfn > cur_gfn + KVM_S390_MAX_BIT_DISTANCE)
+ return 0;
+ /* If we reached the previous "next", find the next one */
+ if (cur_gfn == next_gfn)
+ next_gfn = kvm_s390_next_dirty_cmma(slots, cur_gfn + 1);
+ /* Reached the end of memory or of the buffer, stop */
+ if ((next_gfn >= mem_end) ||
+ (next_gfn - args->start_gfn >= bufsize))
+ return 0;
+ cur_gfn++;
+ /* Reached the end of the current memslot, take the next one. */
+ if (cur_gfn - ms->base_gfn >= ms->npages) {
+ ms = gfn_to_memslot(kvm, cur_gfn);
+ if (!ms)
+ return 0;
+ }
+ }
+ return 0;
+}
+
+/*
* This function searches for the next page with dirty CMMA attributes, and
* saves the attributes in the buffer up to either the end of the buffer or
* until a block of at least KVM_S390_MAX_BIT_DISTANCE clean bits is found;
@@ -1610,22 +1765,18 @@ out:
static int kvm_s390_get_cmma_bits(struct kvm *kvm,
struct kvm_s390_cmma_log *args)
{
- struct kvm_s390_migration_state *s = kvm->arch.migration_state;
- unsigned long bufsize, hva, pgstev, i, next, cur;
- int srcu_idx, peek, r = 0, rr;
- u8 *res;
-
- cur = args->start_gfn;
- i = next = pgstev = 0;
+ unsigned long bufsize;
+ int srcu_idx, peek, ret;
+ u8 *values;
- if (unlikely(!kvm->arch.use_cmma))
+ if (!kvm->arch.use_cmma)
return -ENXIO;
/* Invalid/unsupported flags were specified */
if (args->flags & ~KVM_S390_CMMA_PEEK)
return -EINVAL;
/* Migration mode query, and we are not doing a migration */
peek = !!(args->flags & KVM_S390_CMMA_PEEK);
- if (!peek && !s)
+ if (!peek && !kvm->arch.migration_mode)
return -EINVAL;
/* CMMA is disabled or was not used, or the buffer has length zero */
bufsize = min(args->count, KVM_S390_CMMA_SIZE_MAX);
@@ -1633,74 +1784,35 @@ static int kvm_s390_get_cmma_bits(struct kvm *kvm,
memset(args, 0, sizeof(*args));
return 0;
}
-
- if (!peek) {
- /* We are not peeking, and there are no dirty pages */
- if (!atomic64_read(&s->dirty_pages)) {
- memset(args, 0, sizeof(*args));
- return 0;
- }
- cur = find_next_bit(s->pgste_bitmap, s->bitmap_size,
- args->start_gfn);
- if (cur >= s->bitmap_size) /* nothing found, loop back */
- cur = find_next_bit(s->pgste_bitmap, s->bitmap_size, 0);
- if (cur >= s->bitmap_size) { /* again! (very unlikely) */
- memset(args, 0, sizeof(*args));
- return 0;
- }
- next = find_next_bit(s->pgste_bitmap, s->bitmap_size, cur + 1);
+ /* We are not peeking, and there are no dirty pages */
+ if (!peek && !atomic64_read(&kvm->arch.cmma_dirty_pages)) {
+ memset(args, 0, sizeof(*args));
+ return 0;
}
- res = vmalloc(bufsize);
- if (!res)
+ values = vmalloc(bufsize);
+ if (!values)
return -ENOMEM;
- args->start_gfn = cur;
-
down_read(&kvm->mm->mmap_sem);
srcu_idx = srcu_read_lock(&kvm->srcu);
- while (i < bufsize) {
- hva = gfn_to_hva(kvm, cur);
- if (kvm_is_error_hva(hva)) {
- r = -EFAULT;
- break;
- }
- /* decrement only if we actually flipped the bit to 0 */
- if (!peek && test_and_clear_bit(cur, s->pgste_bitmap))
- atomic64_dec(&s->dirty_pages);
- r = get_pgste(kvm->mm, hva, &pgstev);
- if (r < 0)
- pgstev = 0;
- /* save the value */
- res[i++] = (pgstev >> 24) & 0x43;
- /*
- * if the next bit is too far away, stop.
- * if we reached the previous "next", find the next one
- */
- if (!peek) {
- if (next > cur + KVM_S390_MAX_BIT_DISTANCE)
- break;
- if (cur == next)
- next = find_next_bit(s->pgste_bitmap,
- s->bitmap_size, cur + 1);
- /* reached the end of the bitmap or of the buffer, stop */
- if ((next >= s->bitmap_size) ||
- (next >= args->start_gfn + bufsize))
- break;
- }
- cur++;
- }
+ if (peek)
+ ret = kvm_s390_peek_cmma(kvm, args, values, bufsize);
+ else
+ ret = kvm_s390_get_cmma(kvm, args, values, bufsize);
srcu_read_unlock(&kvm->srcu, srcu_idx);
up_read(&kvm->mm->mmap_sem);
- args->count = i;
- args->remaining = s ? atomic64_read(&s->dirty_pages) : 0;
- rr = copy_to_user((void __user *)args->values, res, args->count);
- if (rr)
- r = -EFAULT;
+ if (kvm->arch.migration_mode)
+ args->remaining = atomic64_read(&kvm->arch.cmma_dirty_pages);
+ else
+ args->remaining = 0;
- vfree(res);
- return r;
+ if (copy_to_user((void __user *)args->values, values, args->count))
+ ret = -EFAULT;
+
+ vfree(values);
+ return ret;
}
/*
@@ -2139,10 +2251,6 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
kvm_s390_destroy_adapters(kvm);
kvm_s390_clear_float_irqs(kvm);
kvm_s390_vsie_destroy(kvm);
- if (kvm->arch.migration_state) {
- vfree(kvm->arch.migration_state->pgste_bitmap);
- kfree(kvm->arch.migration_state);
- }
KVM_EVENT(3, "vm 0x%pK destroyed", kvm);
}
@@ -2300,6 +2408,8 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
vcpu->run->kvm_valid_regs |= KVM_SYNC_BPBC;
if (test_kvm_facility(vcpu->kvm, 133))
vcpu->run->kvm_valid_regs |= KVM_SYNC_GSCB;
+ if (test_kvm_facility(vcpu->kvm, 156))
+ vcpu->run->kvm_valid_regs |= KVM_SYNC_ETOKEN;
/* fprs can be synchronized via vrs, even if the guest has no vx. With
* MACHINE_HAS_VX, (load|store)_fpu_regs() will work with vrs format.
*/
@@ -2549,7 +2659,8 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
}
if (test_kvm_facility(vcpu->kvm, 139))
vcpu->arch.sie_block->ecd |= ECD_MEF;
-
+ if (test_kvm_facility(vcpu->kvm, 156))
+ vcpu->arch.sie_block->ecd |= ECD_ETOKENF;
if (vcpu->arch.sie_block->gd) {
vcpu->arch.sie_block->eca |= ECA_AIV;
VCPU_EVENT(vcpu, 3, "AIV gisa format-%u enabled for cpu %03u",
@@ -3467,6 +3578,7 @@ static void sync_regs(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
}
preempt_enable();
}
+ /* SIE will load etoken directly from SDNX and therefore kvm_run */
kvm_run->kvm_dirty_regs = 0;
}
@@ -3506,7 +3618,7 @@ static void store_regs(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
__ctl_clear_bit(2, 4);
vcpu->arch.host_gscb = NULL;
}
-
+ /* SIE will save etoken directly into SDNX and therefore kvm_run */
}
int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
@@ -4082,6 +4194,11 @@ static int __init kvm_s390_init(void)
return -ENODEV;
}
+ if (nested && hpage) {
+ pr_info("nested (vSIE) and hpage (huge page backing) can currently not be activated concurrently");
+ return -EINVAL;
+ }
+
for (i = 0; i < 16; i++)
kvm_s390_fac_base[i] |=
S390_lowcore.stfle_fac_list[i] & nonhyp_mask(i);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.