If the guest runs with bp isolation when doing a SIE instruction,
we must also run the nested guest with bp isolation when emulating
that SIE instruction.
Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
---
arch/s390/kvm/vsie.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c
index ec772700ff96..b8e7660d7207 100644
--- a/arch/s390/kvm/vsie.c
+++ b/arch/s390/kvm/vsie.c
@@ -821,6 +821,7 @@ static int do_vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
{
struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
+ int guest_bp_isolation;
int rc;
handle_last_fault(vcpu, vsie_page);
@@ -831,6 +832,15 @@ static int do_vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
s390_handle_mcck();
srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
+
+ /* save current guest state of bp isolation override */
+ guest_bp_isolation = test_thread_flag(TIF_ISOLATE_BP_GUEST);
+
+ /* if guest runs with bp isolation force it on nested guest */
+ if (test_kvm_facility(vcpu->kvm, 82) &&
+ vcpu->arch.sie_block->fpf & FPF_BPBC)
+ set_thread_flag(TIF_ISOLATE_BP_GUEST);
+
local_irq_disable();
guest_enter_irqoff();
local_irq_enable();
@@ -840,6 +850,11 @@ static int do_vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
local_irq_disable();
guest_exit_irqoff();
local_irq_enable();
+
+ /* restore guest state for bp isolation override */
+ if (!guest_bp_isolation)
+ clear_thread_flag(TIF_ISOLATE_BP_GUEST);
+
vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
if (rc == -EINTR) {
--
2.14.3
