[PATCH/RFC 11/21] KVM: s390: SIGP SET PREFIX cleanup

Christian Borntraeger
2015-01-15T13:43:24Z

From: David Hildenbrand <dahi@linux.vnet.ibm.com>

This patch cleanes up the the SIGP SET PREFIX code.

A SIGP SET PREFIX irq may only be injected if the target vcpu is
stopped. Let's move the checking code into the injection code and
return -EBUSY if the target vcpu is not stopped.

Reviewed-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
arch/s390/kvm/interrupt.c | 3 +++
arch/s390/kvm/sigp.c | 30 +++++++++++-------------------
2 files changed, 14 insertions(+), 19 deletions(-)

diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index f753c0b..1ba9176 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -1026,6 +1026,9 @@ static int __inject_set_prefix(struct kvm_vcpu *vcpu, struct kvm_s390_irq *irq)
trace_kvm_s390_inject_vcpu(vcpu->vcpu_id, KVM_S390_SIGP_SET_PREFIX,
prefix->address, 0, 2);

+ if (!is_vcpu_stopped(vcpu))
+ return -EBUSY;
+
*prefix = irq->u.prefix;
set_bit(IRQ_PEND_SET_PREFIX, &li->pending_irqs);
return 0;
diff --git a/arch/s390/kvm/sigp.c b/arch/s390/kvm/sigp.c
index a251854..8ae4495 100644
--- a/arch/s390/kvm/sigp.c
+++ b/arch/s390/kvm/sigp.c
@@ -176,41 +176,33 @@ static int __sigp_set_arch(struct kvm_vcpu *vcpu, u32 parameter)
static int __sigp_set_prefix(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu,
u32 address, u64 *reg)
{
- struct kvm_s390_local_interrupt *li;
+ struct kvm_s390_irq irq = {
+ .type = KVM_S390_SIGP_SET_PREFIX,
+ .u.prefix.address = address & 0x7fffe000u,
+ };
int rc;

- li = &dst_vcpu->arch.local_int;
-
/*
* Make sure the new value is valid memory. We only need to check the
* first page, since address is 8k aligned and memory pieces are always
* at least 1MB aligned and have at least a size of 1MB.
*/
- address &= 0x7fffe000u;
- if (kvm_is_error_gpa(vcpu->kvm, address)) {
+ if (kvm_is_error_gpa(vcpu->kvm, irq.u.prefix.address)) {
*reg &= 0xffffffff00000000UL;
*reg |= SIGP_STATUS_INVALID_PARAMETER;
return SIGP_CC_STATUS_STORED;
}

- spin_lock(&li->lock);
- /* cpu must be in stopped state */
- if (!(atomic_read(li->cpuflags) & CPUSTAT_STOPPED)) {
+ rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
+ if (rc == -EBUSY) {
*reg &= 0xffffffff00000000UL;
*reg |= SIGP_STATUS_INCORRECT_STATE;
- rc = SIGP_CC_STATUS_STORED;
- goto out_li;
+ return SIGP_CC_STATUS_STORED;
+ } else if (rc == 0) {
+ VCPU_EVENT(vcpu, 4, "set prefix of cpu %02x to %x",
+ dst_vcpu->vcpu_id, irq.u.prefix.address);
}

- li->irq.prefix.address = address;
- set_bit(IRQ_PEND_SET_PREFIX, &li->pending_irqs);
- kvm_s390_vcpu_wakeup(dst_vcpu);
- rc = SIGP_CC_ORDER_CODE_ACCEPTED;
-
- VCPU_EVENT(vcpu, 4, "set prefix of cpu %02x to %x", dst_vcpu->vcpu_id,
- address);
-out_li:
- spin_unlock(&li->lock);
return rc;
}

--
1.9.3