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 <[email protected]> --- 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). -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
