diff options
| author | Christian Borntraeger <borntraeger@de.ibm.com> | 2011-07-24 10:48:17 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2011-07-24 10:48:20 +0200 |
| commit | bb25b9ba3e33e941dc48048d0a784e6a05e5648a (patch) | |
| tree | 687caacfbe9165dd80d2e29af4b68ce32216e28d /arch/s390/kvm/priv.c | |
| parent | b02f0c2ea25781e0f94b4fc8f6f85582057857b3 (diff) | |
[S390] kvm: handle tprot intercepts
When running a kvm guest we can get intercepts for tprot, if the host
page table is read-only or not populated. This patch implements the
most common case (linux memory detection).
This also allows host copy on write for guest memory on newer systems.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kvm/priv.c')
| -rw-r--r-- | arch/s390/kvm/priv.c | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c index 73c47bd95db3..391626361084 100644 --- a/arch/s390/kvm/priv.c +++ b/arch/s390/kvm/priv.c @@ -326,3 +326,52 @@ int kvm_s390_handle_b2(struct kvm_vcpu *vcpu) } return -EOPNOTSUPP; } + +static int handle_tprot(struct kvm_vcpu *vcpu) +{ + int base1 = (vcpu->arch.sie_block->ipb & 0xf0000000) >> 28; + int disp1 = (vcpu->arch.sie_block->ipb & 0x0fff0000) >> 16; + int base2 = (vcpu->arch.sie_block->ipb & 0xf000) >> 12; + int disp2 = vcpu->arch.sie_block->ipb & 0x0fff; + u64 address1 = disp1 + base1 ? vcpu->arch.guest_gprs[base1] : 0; + u64 address2 = disp2 + base2 ? vcpu->arch.guest_gprs[base2] : 0; + struct vm_area_struct *vma; + + vcpu->stat.instruction_tprot++; + + /* we only handle the Linux memory detection case: + * access key == 0 + * guest DAT == off + * everything else goes to userspace. */ + if (address2 & 0xf0) + return -EOPNOTSUPP; + if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_DAT) + return -EOPNOTSUPP; + + + down_read(¤t->mm->mmap_sem); + vma = find_vma(current->mm, + (unsigned long) __guestaddr_to_user(vcpu, address1)); + if (!vma) { + up_read(¤t->mm->mmap_sem); + return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING); + } + + vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44); + if (!(vma->vm_flags & VM_WRITE) && (vma->vm_flags & VM_READ)) + vcpu->arch.sie_block->gpsw.mask |= (1ul << 44); + if (!(vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_READ)) + vcpu->arch.sie_block->gpsw.mask |= (2ul << 44); + + up_read(¤t->mm->mmap_sem); + return 0; +} + +int kvm_s390_handle_e5(struct kvm_vcpu *vcpu) +{ + /* For e5xx... instructions we only handle TPROT */ + if ((vcpu->arch.sie_block->ipa & 0x00ff) == 0x01) + return handle_tprot(vcpu); + return -EOPNOTSUPP; +} + |