This patch introduces an interface to access the guest visible
storage keys. It supports three operations that model the behavior
that SSKE/ISKE/RRBE instructions would have if they were issued by
the guest. These instructions are all documented in the z architecture
principles of operation book.
Signed-off-by: Carsten Otte <cotte@xxxxxxxxxx>
---
Index: linux-2.5-cecsim/arch/s390/include/asm/kvm_host.h
===================================================================
--- linux-2.5-cecsim.orig/arch/s390/include/asm/kvm_host.h
+++ linux-2.5-cecsim/arch/s390/include/asm/kvm_host.h
@@ -25,6 +25,9 @@
#define KVM_PRIVATE_MEM_SLOTS 4
#define KVM_SIE_PAGE_OFFSET 1
+#define KVM_S390_KEYOP_SSKE 0x01
+#define KVM_S390_KEYOP_ISKE 0x02
+#define KVM_S390_KEYOP_RRBE 0x03
struct sca_entry {
atomic_t scn;
Index: linux-2.5-cecsim/arch/s390/kvm/kvm-s390.c
===================================================================
--- linux-2.5-cecsim.orig/arch/s390/kvm/kvm-s390.c
+++ linux-2.5-cecsim/arch/s390/kvm/kvm-s390.c
@@ -112,13 +112,144 @@ void kvm_arch_exit(void)
{
}
+pte_t *ptep_for_addr(unsigned long addr)
+{
+ struct vm_area_struct *vma;
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *rc;
+
+ down_read(¤t->mm->mmap_sem);
+
+ rc = NULL;
+ vma = find_vma(current->mm, addr);
+ if (!vma)
+ goto up_out;
+
+ pgd = pgd_offset(current->mm, addr);
+ pud = pud_alloc(current->mm, pgd, addr);
+ if (!pud)
+ goto up_out;
+
+ pmd = pmd_alloc(current->mm, pud, addr);
+ if (!pmd)
+ goto up_out;
+
+ if (!pmd_present(*pmd) &&
+ __pte_alloc(current->mm, vma, pmd, addr))
+ goto up_out;
+
+ rc = pte_offset(pmd, addr);
+up_out:
+ up_read(¤t->mm->mmap_sem);
+ return rc;
+}
+
+static long kvm_s390_keyop(struct kvm_s390_keyop *kop)
+{
+ unsigned long addr = kop->user_addr;
+ pte_t *ptep;
+ pgste_t pgste;
+ int r;
+ unsigned long skey;
+ unsigned long bits;
+
+ /* make sure this process is a hypervisor */
+ r = -EINVAL;
+ if (!mm_has_pgste(current->mm))
+ goto out;
+
+ r = -ENXIO;
+ if (addr >= PGDIR_SIZE)
+ goto out;
+
+ spin_lock(¤t->mm->page_table_lock);
+ ptep = ptep_for_addr(addr);
+ if (!ptep)
+ goto out_unlock;
+
+ pgste = pgste_get_lock(ptep);
+
+ switch (kop->operation) {
+ case KVM_S390_KEYOP_SSKE:
+ pgste = pgste_update_all(ptep, pgste);
+ /* set the real key back w/o rc bits */
+ skey = kop->key & (_PAGE_ACC_BITS | _PAGE_FP_BIT);
+ if (pte_present(*ptep))
+ page_set_storage_key(pte_val(*ptep), skey, 1);
+ /* put acc+f plus guest refereced and changed into the pgste */
+ pgste_val(pgste) &= ~(RCP_ACC_BITS | RCP_FP_BIT | RCP_GR_BIT
+ | RCP_GC_BIT);
+ bits = (kop->key & (_PAGE_ACC_BITS | _PAGE_FP_BIT));
+ pgste_val(pgste) |= bits << 56;
+ bits = (kop->key & (_PAGE_CHANGED | _PAGE_REFERENCED));
+ pgste_val(pgste) |= bits << 48;
+ r = 0;
+ break;
+ case KVM_S390_KEYOP_ISKE:
+ if (pte_present(*ptep)) {
+ skey = page_get_storage_key(pte_val(*ptep));
+ kop->key = skey & (_PAGE_ACC_BITS | _PAGE_FP_BIT);
+ } else {
+ skey = 0;
+ kop->key = (pgste_val(pgste) >> 56) &
+ (_PAGE_ACC_BITS | _PAGE_FP_BIT);
+ }
+ kop->key |= skey & (_PAGE_CHANGED | _PAGE_REFERENCED);
+ kop->key |= (pgste_val(pgste) >> 48) &
+ (_PAGE_CHANGED | _PAGE_REFERENCED);
+ r = 0;
+ break;
+ case KVM_S390_KEYOP_RRBE:
+ pgste = pgste_update_all(ptep, pgste);
+ kop->key = 0;
+ if (pgste_val(pgste) & RCP_GR_BIT)
+ kop->key |= _PAGE_REFERENCED;
+ pgste_val(pgste) &= ~RCP_GR_BIT;
+ r = 0;
+ break;
+ default:
+ r = -EINVAL;
+ }
+ pgste_set_unlock(ptep, pgste);
+
+out_unlock:
+ spin_unlock(¤t->mm->page_table_lock);
+out:
+ return r;
+}
+
/* Section: device related */
long kvm_arch_dev_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
- if (ioctl == KVM_S390_ENABLE_SIE)
- return s390_enable_sie();
- return -EINVAL;
+ void __user *argp = (void __user *)arg;
+ int r;
+
+ switch (ioctl) {
+ case KVM_S390_ENABLE_SIE:
+ r = s390_enable_sie();
+ break;
+ case KVM_S390_KEYOP: {
+ struct kvm_s390_keyop kop;
+ r = -EFAULT;
+ if (copy_from_user(&kop, argp, sizeof(struct kvm_s390_keyop)))
+ break;
+ r = kvm_s390_keyop(&kop);
+ if (r)
+ break;
+ r = -EFAULT;
+ if (copy_to_user(argp, &kop, sizeof(struct kvm_s390_keyop)))
+ break;
+ r = 0;
+ break;
+ }
+ default:
+ r = -ENOTTY;
+ }
+
+ return r;
}
int kvm_dev_ioctl_check_extension(long ext)
Index: linux-2.5-cecsim/include/linux/kvm.h
===================================================================
--- linux-2.5-cecsim.orig/include/linux/kvm.h
+++ linux-2.5-cecsim/include/linux/kvm.h
@@ -445,6 +445,13 @@ struct kvm_ppc_pvinfo {
#define KVM_GET_MSR_INDEX_LIST _IOWR(KVMIO, 0x02, struct kvm_msr_list)
#define KVM_S390_ENABLE_SIE _IO(KVMIO, 0x06)
+
+struct kvm_s390_keyop {
+ __u64 user_addr;
+ __u8 key;
+ __u8 operation;
+};
+#define KVM_S390_KEYOP _IOWR(KVMIO, 0x09, struct kvm_s390_keyop)
/*
* Check if a kvm extension is available. Argument is extension number,
* return is 1 (yes) or 0 (no, sorry).
--
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