Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
[sfrench/cifs-2.6.git] / arch / s390 / kvm / diag.c
index 1facd9277f38648830165769a1d1e63ad8d99b54..08dfc839a6cfeeb3655f64d850ce1ed6e60d49cc 100644 (file)
@@ -18,6 +18,7 @@
 #include "kvm-s390.h"
 #include "trace.h"
 #include "trace-s390.h"
+#include "gaccess.h"
 
 static int diag_release_pages(struct kvm_vcpu *vcpu)
 {
@@ -47,6 +48,87 @@ static int diag_release_pages(struct kvm_vcpu *vcpu)
        return 0;
 }
 
+static int __diag_page_ref_service(struct kvm_vcpu *vcpu)
+{
+       struct prs_parm {
+               u16 code;
+               u16 subcode;
+               u16 parm_len;
+               u16 parm_version;
+               u64 token_addr;
+               u64 select_mask;
+               u64 compare_mask;
+               u64 zarch;
+       };
+       struct prs_parm parm;
+       int rc;
+       u16 rx = (vcpu->arch.sie_block->ipa & 0xf0) >> 4;
+       u16 ry = (vcpu->arch.sie_block->ipa & 0x0f);
+       unsigned long hva_token = KVM_HVA_ERR_BAD;
+
+       if (vcpu->run->s.regs.gprs[rx] & 7)
+               return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
+       if (copy_from_guest(vcpu, &parm, vcpu->run->s.regs.gprs[rx], sizeof(parm)))
+               return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
+       if (parm.parm_version != 2 || parm.parm_len < 5 || parm.code != 0x258)
+               return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
+
+       switch (parm.subcode) {
+       case 0: /* TOKEN */
+               if (vcpu->arch.pfault_token != KVM_S390_PFAULT_TOKEN_INVALID) {
+                       /*
+                        * If the pagefault handshake is already activated,
+                        * the token must not be changed.  We have to return
+                        * decimal 8 instead, as mandated in SC24-6084.
+                        */
+                       vcpu->run->s.regs.gprs[ry] = 8;
+                       return 0;
+               }
+
+               if ((parm.compare_mask & parm.select_mask) != parm.compare_mask ||
+                   parm.token_addr & 7 || parm.zarch != 0x8000000000000000ULL)
+                       return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
+
+               hva_token = gfn_to_hva(vcpu->kvm, gpa_to_gfn(parm.token_addr));
+               if (kvm_is_error_hva(hva_token))
+                       return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
+
+               vcpu->arch.pfault_token = parm.token_addr;
+               vcpu->arch.pfault_select = parm.select_mask;
+               vcpu->arch.pfault_compare = parm.compare_mask;
+               vcpu->run->s.regs.gprs[ry] = 0;
+               rc = 0;
+               break;
+       case 1: /*
+                * CANCEL
+                * Specification allows to let already pending tokens survive
+                * the cancel, therefore to reduce code complexity, we assume
+                * all outstanding tokens are already pending.
+                */
+               if (parm.token_addr || parm.select_mask ||
+                   parm.compare_mask || parm.zarch)
+                       return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
+
+               vcpu->run->s.regs.gprs[ry] = 0;
+               /*
+                * If the pfault handling was not established or is already
+                * canceled SC24-6084 requests to return decimal 4.
+                */
+               if (vcpu->arch.pfault_token == KVM_S390_PFAULT_TOKEN_INVALID)
+                       vcpu->run->s.regs.gprs[ry] = 4;
+               else
+                       vcpu->arch.pfault_token = KVM_S390_PFAULT_TOKEN_INVALID;
+
+               rc = 0;
+               break;
+       default:
+               rc = -EOPNOTSUPP;
+               break;
+       }
+
+       return rc;
+}
+
 static int __diag_time_slice_end(struct kvm_vcpu *vcpu)
 {
        VCPU_EVENT(vcpu, 5, "%s", "diag time slice end");
@@ -157,6 +239,8 @@ int kvm_s390_handle_diag(struct kvm_vcpu *vcpu)
                return __diag_time_slice_end(vcpu);
        case 0x9c:
                return __diag_time_slice_end_directed(vcpu);
+       case 0x258:
+               return __diag_page_ref_service(vcpu);
        case 0x308:
                return __diag_ipl_functions(vcpu);
        case 0x500: