Correctly handle the MVPG instruction when issued by a VSIE guest.
Fixes: a3508fbe9dc6d ("KVM: s390: vsie: initial support for nested virtualization")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>
---
arch/s390/kvm/vsie.c | 73 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 73 insertions(+)
diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c
index ada49583e530..6c3069868acd 100644
--- a/arch/s390/kvm/vsie.c
+++ b/arch/s390/kvm/vsie.c
@@ -977,6 +977,75 @@ static int handle_stfle(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
return 0;
}
+static u64 vsie_get_register(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page, u8 reg)
+{
+ reg &= 0xf;
+ switch (reg) {
+ case 15:
+ return vsie_page->scb_s.gg15;
+ case 14:
+ return vsie_page->scb_s.gg14;
+ default:
+ return vcpu->run->s.regs.gprs[reg];
+ }
+}
+
+static int vsie_handle_mvpg(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
+{
+ struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
+ unsigned long r1, r2, mask = PAGE_MASK;
+ int rc;
+
+ if (psw_bits(scb_s->gpsw).eaba == PSW_BITS_AMODE_24BIT)
+ mask = 0xfff000;
+ else if (psw_bits(scb_s->gpsw).eaba == PSW_BITS_AMODE_31BIT)
+ mask = 0x7ffff000;
+
+ r1 = vsie_get_register(vcpu, vsie_page, scb_s->ipb >> 20) & mask;
+ r2 = vsie_get_register(vcpu, vsie_page, scb_s->ipb >> 16) & mask;
+ rc = kvm_s390_vsie_mvpg_check(vcpu, r1, r2, &vsie_page->scb_o->mcic);
+
+ /*
+ * Guest translation was not successful. The host needs to forward
+ * the intercept to the guest and let the guest fix its page tables.
+ * The guest needs then to retry the instruction.
+ */
+ if (rc == -ENOENT)
+ return 1;
+
+ retry_vsie_icpt(vsie_page);
+
+ /*
+ * Guest translation was not successful. The page tables of the guest
+ * are broken. Try again and let the hardware deliver the fault.
+ */
+ if (rc == -EFAULT)
+ return 0;
+
+ /*
+ * Guest translation was successful. The host needs to fix up its
+ * page tables and retry the instruction in the nested guest.
+ * In case of failure, the instruction will intercept again, and
+ * a different path will be taken.
+ */
+ if (!rc) {
+ kvm_s390_shadow_fault(vcpu, vsie_page->gmap, r2);
+ kvm_s390_shadow_fault(vcpu, vsie_page->gmap, r1);
+ return 0;
+ }
+
+ /*
+ * An exception happened during guest translation, it needs to be
+ * delivered to the guest. This can happen if the host has EDAT1
+ * enabled and the guest has not, or for other causes. The guest
+ * needs to process the exception and return to the nested guest.
+ */
+ if (rc > 0)
+ return kvm_s390_inject_prog_cond(vcpu, rc);
+
+ return 1;
+}
+
/*
* Run the vsie on a shadow scb and a shadow gmap, without any further
* sanity checks, handling SIE faults.
@@ -1063,6 +1132,10 @@ static int do_vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
if ((scb_s->ipa & 0xf000) != 0xf000)
scb_s->ipa += 0x1000;
break;
+ case ICPT_PARTEXEC:
+ if (scb_s->ipa == 0xb254)
+ rc = vsie_handle_mvpg(vcpu, vsie_page);
+ break;
}
return rc;
}
--
2.26.2
