Merge tag 'hlp_stage1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into kvms390/next

KVM: s390: initial host large page support

- must be enabled via module parameter hpage=1
- cannot be used together with nested
- does support migration
- does support hugetlbfs
- no THP yet
This commit is contained in:
Janosch Frank
2018-07-30 23:20:00 +02:00
13 changed files with 756 additions and 120 deletions

View File

@@ -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;
@@ -1514,6 +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;
@@ -1538,9 +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;
@@ -1554,8 +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);
@@ -4141,6 +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);