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 | 94 +++++++++++++++++++++++++++++++++++++++++---
1 file changed, 89 insertions(+), 5 deletions(-)
diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c
index 7db022141db3..2db49749e27b 100644
--- a/arch/s390/kvm/vsie.c
+++ b/arch/s390/kvm/vsie.c
@@ -416,11 +416,6 @@ static void unshadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
memcpy((void *)((u64)scb_o + 0xc0),
(void *)((u64)scb_s + 0xc0), 0xf0 - 0xc0);
break;
- case ICPT_PARTEXEC:
- /* MVPG only */
- memcpy((void *)((u64)scb_o + 0xc0),
- (void *)((u64)scb_s + 0xc0), 0xd0 - 0xc0);
- break;
}
if (scb_s->ihcpu != 0xffffU)
@@ -982,6 +977,91 @@ 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 pei1, pei2, src, dest, mask = PAGE_MASK;
+ u64 *pei_block = &vsie_page->scb_o->mcic;
+ int edat, rc1, rc2;
+ union ctlreg0 cr0;
+
+ cr0.val = vcpu->arch.sie_block->gcr[0];
+ edat = cr0.edat && test_kvm_facility(vcpu->kvm, 8);
+ 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;
+
+ dest = vsie_get_register(vcpu, vsie_page, scb_s->ipb >> 16) & mask;
+ src = vsie_get_register(vcpu, vsie_page, scb_s->ipb >> 20) & mask;
+
+ rc1 = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, dest, &pei1);
+ rc2 = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, src, &pei2);
+ /*
+ * Either everything went well, or something non-critical went wrong
+ * e.g. beause of a race. In either case, simply retry.
+ */
+ if (rc1 == -EAGAIN || rc2 == -EAGAIN || (!rc1 && !rc2)) {
+ retry_vsie_icpt(vsie_page);
+ return -EAGAIN;
+ }
+ /* Something more serious went wrong, propagate the error */
+ if (rc1 < 0)
+ return rc1;
+ if (rc2 < 0)
+ return rc2;
+
+ /* The only possible suppressing exception: just deliver it */
+ if (rc1 == PGM_TRANSLATION_SPEC || rc2 == PGM_TRANSLATION_SPEC) {
+ clear_vsie_icpt(vsie_page);
+ rc1 = kvm_s390_inject_program_int(vcpu, PGM_TRANSLATION_SPEC);
+ WARN_ON_ONCE(rc1);
+ return 1;
+ }
+
+ /*
+ * Forward the PEI intercept to the guest if it was a page fault, or
+ * also for segment and region table faults if EDAT applies.
+ */
+ if (edat) {
+ rc1 = rc1 == PGM_ASCE_TYPE ? rc1 : 0;
+ rc2 = rc2 == PGM_ASCE_TYPE ? rc2 : 0;
+ }
+ if ((!rc1 || rc1 == PGM_PAGE_TRANSLATION) && (!rc2 || rc2 == PGM_PAGE_TRANSLATION)) {
+ pei_block[0] = pei1;
+ pei_block[1] = pei2;
+ return 1;
+ }
+
+ retry_vsie_icpt(vsie_page);
+
+ /*
+ * The host has edat, and the guest does not, or it was an ASCE type
+ * exception. The host needs to inject the appropriate DAT interrupts
+ * into the guest.
+ */
+ if (rc1)
+ return inject_fault(vcpu, rc1, dest, 1);
+ if (rc2)
+ return inject_fault(vcpu, rc2, src, 0);
+
+ /* This should never be reached */
+ return 0;
+}
+
/*
* Run the vsie on a shadow scb and a shadow gmap, without any further
* sanity checks, handling SIE faults.
@@ -1068,6 +1148,10 @@ 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
