KVM: s390: move kvm_guest_enter,exit closer to sie

commit 2b29a9fdcb92bfc6b6f4c412d71505869de61a56 upstream.

Any uaccess between guest_enter and guest_exit could trigger a page fault,
the page fault handler would handle it as a guest fault and translate a
user address as guest address.

Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
CC: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[hq: Backported to 3.4: adjust context]
Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index e00accf9523e60e24136bb2cae466a627906bb91..531de68f0b6830e28264934940321eb397083ff8 100644 (file)
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -525,13 +525,18 @@ static int __vcpu_run(struct kvm_vcpu *vcpu)
        if (!kvm_is_ucontrol(vcpu->kvm))
                kvm_s390_deliver_pending_interrupts(vcpu);
 
+       VCPU_EVENT(vcpu, 6, "entering sie flags %x",
+                  atomic_read(&vcpu->arch.sie_block->cpuflags));
+
        vcpu->arch.sie_block->icptcode = 0;
        local_irq_disable();
        kvm_guest_enter();
        local_irq_enable();
-       VCPU_EVENT(vcpu, 6, "entering sie flags %x",
-                  atomic_read(&vcpu->arch.sie_block->cpuflags));
        rc = sie64a(vcpu->arch.sie_block, vcpu->run->s.regs.gprs);
+       local_irq_disable();
+       kvm_guest_exit();
+       local_irq_enable();
+
        if (rc) {
                if (kvm_is_ucontrol(vcpu->kvm)) {
                        rc = SIE_INTERCEPT_UCONTROL;
@@ -543,9 +548,6 @@ static int __vcpu_run(struct kvm_vcpu *vcpu)
        }
        VCPU_EVENT(vcpu, 6, "exit sie icptcode %d",
                   vcpu->arch.sie_block->icptcode);
-       local_irq_disable();
-       kvm_guest_exit();
-       local_irq_enable();
 
        memcpy(&vcpu->run->s.regs.gprs[14], &vcpu->arch.sie_block->gg14, 16);
        return rc;