KVM: s390: pfmf: support conditional-sske facility

We already indicate that facility but don't implement it in our pfmf
interception handler. Let's add a new storage key handling function for
conditionally setting the guest storage key.

As we will reuse this function later on, let's directly implement returning
the old key via parameter and indicating if any change happened via rc.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

1 files changed, 14 insertions, 4 deletions

diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
index 71fa603034d0..752a1ac1aab6 100644
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -654,8 +654,10 @@ static int handle_epsw(struct kvm_vcpu *vcpu)
 
 static int handle_pfmf(struct kvm_vcpu *vcpu)
 {
+        bool mr = false, mc = false, nq;
         int reg1, reg2;
         unsigned long start, end;
+        unsigned char key;
 
         vcpu->stat.instruction_pfmf++;
 
@@ -675,6 +677,15 @@ static int handle_pfmf(struct kvm_vcpu *vcpu)
             !test_kvm_facility(vcpu->kvm, 14))
                 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
 
+        /* Only provide conditional-SSKE support if enabled for the guest */
+        if (vcpu->run->s.regs.gprs[reg1] & PFMF_SK &&
+            test_kvm_facility(vcpu->kvm, 10)) {
+                mr = vcpu->run->s.regs.gprs[reg1] & PFMF_MR;
+                mc = vcpu->run->s.regs.gprs[reg1] & PFMF_MC;
+        }
+
+        nq = vcpu->run->s.regs.gprs[reg1] & PFMF_NQ;
+        key = vcpu->run->s.regs.gprs[reg1] & PFMF_KEY;
         start = vcpu->run->s.regs.gprs[reg2] & PAGE_MASK;
         start = kvm_s390_logical_to_effective(vcpu, start);
 
@@ -723,11 +734,10 @@ static int handle_pfmf(struct kvm_vcpu *vcpu)
                         if (rc)
                                 return rc;
                         down_read(&current->mm->mmap_sem);
-                        rc = set_guest_storage_key(current->mm, useraddr,
-                                        vcpu->run->s.regs.gprs[reg1] & PFMF_KEY,
-                                        vcpu->run->s.regs.gprs[reg1] & PFMF_NQ);
+                        rc = cond_set_guest_storage_key(current->mm, useraddr,
+                                                        key, NULL, nq, mr, mc);
                         up_read(&current->mm->mmap_sem);
-                        if (rc)
+                        if (rc < 0)
                                 return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
                 }