[RFC,22/37] KVM: s390: protvirt: Add SCLP handling

Commit Message

Janosch Frank Oct. 24, 2019, 11:40 a.m. UTC

From: Christian Borntraeger <[e-mail]>

Unmask the SCLP IRQ once we get the notification intercept on SCLP.

Signed-off-by: Christian Borntraeger <[e-mail]>
---
 arch/s390/kvm/intercept.c | 25 +++++++++++++++++++++++++
 arch/s390/kvm/kvm-s390.c  |  2 ++
 2 files changed, 27 insertions(+)

Patch

diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c
index a1df8a43c88b..510b1dee3320 100644
--- a/arch/s390/kvm/intercept.c
+++ b/arch/s390/kvm/intercept.c
@@ -460,11 +460,36 @@  static int handle_pv_spx(struct kvm_vcpu *vcpu)
 	return 0;
 }
 
+static int handle_pv_sclp(struct kvm_vcpu *vcpu)
+{
+	struct kvm_s390_float_interrupt *fi = &vcpu->kvm->arch.float_int;
+
+	spin_lock(&fi->lock);
+	/*
+	 * 2 cases:
+	 * a: an sccb answering interrupt was already pending or in flight.
+	 *    As the sccb value is not used we can simply set some more bits
+	 *    and make sure that we deliver something
+	 * b: an error sccb interrupt needs to be injected so we also inject
+	 *    something and let firmware do the right thing.
+	 * This makes sure, that both errors and real sccb returns will only
+	 * be delivered when we are unmasked.
+	 */
+	fi->srv_signal.ext_params |= 0x43000;
+	set_bit(IRQ_PEND_EXT_SERVICE, &fi->pending_irqs);
+	clear_bit(IRQ_PEND_EXT_SERVICE, &fi->masked_irqs);
+	spin_unlock(&fi->lock);
+	return 0;
+}
+
 static int handle_pv_not(struct kvm_vcpu *vcpu)
 {
 	if (vcpu->arch.sie_block->ipa == 0xb210)
 		return handle_pv_spx(vcpu);
 
+	if (vcpu->arch.sie_block->ipa == 0xb220)
+		return handle_pv_sclp(vcpu);
+
 	return handle_instruction(vcpu);
 }
 
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 6747cb6cf062..eddc9508c1b1 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -2189,6 +2189,8 @@  static int kvm_s390_handle_pv(struct kvm *kvm, struct kvm_pv_cmd *cmd)
 		if (!r)
 			r = kvm_s390_pv_create_vm(kvm);
 		kvm_s390_vcpu_unblock_all(kvm);
+		/* we need to block service interrupts from now on */
+		set_bit(IRQ_PEND_EXT_SERVICE,&kvm->arch.float_int.masked_irqs);
 		mutex_unlock(&kvm->lock);
 		break;
 	}