Commit 55531b74 authored by Janosch Frank's avatar Janosch Frank Committed by Christian Borntraeger
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KVM: s390: Add storage key facility interpretation control



Up to now we always expected to have the storage key facility
available for our (non-VSIE) KVM guests. For huge page support, we
need to be able to disable it, so let's introduce that now.

We add the use_skf variable to manage KVM storage key facility
usage. Also we rename use_skey in the mm context struct to uses_skeys
to make it more clear that it is an indication that the vm actively
uses storage keys.

Signed-off-by: default avatarJanosch Frank <frankja@linux.vnet.ibm.com>
Reviewed-by: default avatarFarhan Ali <alifm@linux.vnet.ibm.com>
Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
Acked-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
parent 75bc37fe
......@@ -812,6 +812,7 @@ struct kvm_arch{
int use_irqchip;
int use_cmma;
int use_pfmfi;
int use_skf;
int user_cpu_state_ctrl;
int user_sigp;
int user_stsi;
......
......@@ -21,7 +21,7 @@ typedef struct {
/* The mmu context uses extended page tables. */
unsigned int has_pgste:1;
/* The mmu context uses storage keys. */
unsigned int use_skey:1;
unsigned int uses_skeys:1;
/* The mmu context uses CMM. */
unsigned int uses_cmm:1;
} mm_context_t;
......
......@@ -30,7 +30,7 @@ static inline int init_new_context(struct task_struct *tsk,
test_thread_flag(TIF_PGSTE) ||
(current->mm && current->mm->context.alloc_pgste);
mm->context.has_pgste = 0;
mm->context.use_skey = 0;
mm->context.uses_skeys = 0;
mm->context.uses_cmm = 0;
#endif
switch (mm->context.asce_limit) {
......
......@@ -507,10 +507,10 @@ static inline int mm_alloc_pgste(struct mm_struct *mm)
* faults should no longer be backed by zero pages
*/
#define mm_forbids_zeropage mm_has_pgste
static inline int mm_use_skey(struct mm_struct *mm)
static inline int mm_uses_skeys(struct mm_struct *mm)
{
#ifdef CONFIG_PGSTE
if (mm->context.use_skey)
if (mm->context.uses_skeys)
return 1;
#endif
return 0;
......
......@@ -1493,7 +1493,7 @@ static long kvm_s390_get_skeys(struct kvm *kvm, struct kvm_s390_skeys *args)
return -EINVAL;
/* Is this guest using storage keys? */
if (!mm_use_skey(current->mm))
if (!mm_uses_skeys(current->mm))
return KVM_S390_GET_SKEYS_NONE;
/* Enforce sane limit on memory allocation */
......@@ -2066,6 +2066,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
kvm->arch.css_support = 0;
kvm->arch.use_irqchip = 0;
kvm->arch.use_pfmfi = sclp.has_pfmfi;
kvm->arch.use_skf = sclp.has_skey;
kvm->arch.epoch = 0;
spin_lock_init(&kvm->arch.start_stop_lock);
......
......@@ -205,24 +205,28 @@ static int handle_store_cpu_address(struct kvm_vcpu *vcpu)
int kvm_s390_skey_check_enable(struct kvm_vcpu *vcpu)
{
int rc = 0;
int rc;
struct kvm_s390_sie_block *sie_block = vcpu->arch.sie_block;
trace_kvm_s390_skey_related_inst(vcpu);
if (!(sie_block->ictl & (ICTL_ISKE | ICTL_SSKE | ICTL_RRBE)) &&
/* Already enabled? */
if (vcpu->kvm->arch.use_skf &&
!(sie_block->ictl & (ICTL_ISKE | ICTL_SSKE | ICTL_RRBE)) &&
!kvm_s390_test_cpuflags(vcpu, CPUSTAT_KSS))
return rc;
return 0;
rc = s390_enable_skey();
VCPU_EVENT(vcpu, 3, "enabling storage keys for guest: %d", rc);
if (!rc) {
if (kvm_s390_test_cpuflags(vcpu, CPUSTAT_KSS))
kvm_s390_clear_cpuflags(vcpu, CPUSTAT_KSS);
else
sie_block->ictl &= ~(ICTL_ISKE | ICTL_SSKE |
ICTL_RRBE);
}
return rc;
if (rc)
return rc;
if (kvm_s390_test_cpuflags(vcpu, CPUSTAT_KSS))
kvm_s390_clear_cpuflags(vcpu, CPUSTAT_KSS);
if (!vcpu->kvm->arch.use_skf)
sie_block->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE;
else
sie_block->ictl &= ~(ICTL_ISKE | ICTL_SSKE | ICTL_RRBE);
return 0;
}
static int try_handle_skey(struct kvm_vcpu *vcpu)
......@@ -232,7 +236,7 @@ static int try_handle_skey(struct kvm_vcpu *vcpu)
rc = kvm_s390_skey_check_enable(vcpu);
if (rc)
return rc;
if (sclp.has_skey) {
if (vcpu->kvm->arch.use_skf) {
/* with storage-key facility, SIE interprets it for us */
kvm_s390_retry_instr(vcpu);
VCPU_EVENT(vcpu, 4, "%s", "retrying storage key operation");
......
......@@ -2184,14 +2184,14 @@ int s390_enable_skey(void)
int rc = 0;
down_write(&mm->mmap_sem);
if (mm_use_skey(mm))
if (mm_uses_skeys(mm))
goto out_up;
mm->context.use_skey = 1;
mm->context.uses_skeys = 1;
for (vma = mm->mmap; vma; vma = vma->vm_next) {
if (ksm_madvise(vma, vma->vm_start, vma->vm_end,
MADV_UNMERGEABLE, &vma->vm_flags)) {
mm->context.use_skey = 0;
mm->context.uses_skeys = 0;
rc = -ENOMEM;
goto out_up;
}
......
......@@ -158,7 +158,7 @@ static inline pgste_t pgste_update_all(pte_t pte, pgste_t pgste,
#ifdef CONFIG_PGSTE
unsigned long address, bits, skey;
if (!mm_use_skey(mm) || pte_val(pte) & _PAGE_INVALID)
if (!mm_uses_skeys(mm) || pte_val(pte) & _PAGE_INVALID)
return pgste;
address = pte_val(pte) & PAGE_MASK;
skey = (unsigned long) page_get_storage_key(address);
......@@ -180,7 +180,7 @@ static inline void pgste_set_key(pte_t *ptep, pgste_t pgste, pte_t entry,
unsigned long address;
unsigned long nkey;
if (!mm_use_skey(mm) || pte_val(entry) & _PAGE_INVALID)
if (!mm_uses_skeys(mm) || pte_val(entry) & _PAGE_INVALID)
return;
VM_BUG_ON(!(pte_val(*ptep) & _PAGE_INVALID));
address = pte_val(entry) & PAGE_MASK;
......
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