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[S390] kvm: fix address mode switching

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598841ca99 ([S390] use gmap address
spaces for kvm guest images) changed kvm to use a separate address
space for kvm guests. This address space was switched in __vcpu_run
In some cases (preemption, page fault) there is the possibility that
this address space switch is lost.
The typical symptom was a huge amount of validity intercepts or
random guest addressing exceptions.
Fix this by doing the switch in sie_loop and sie_exit and saving the
address space in the gmap structure itself. Also use the preempt
notifier.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
This commit is contained in:
Christian Borntraeger
2011-09-20 17:07:28 +02:00
committed by Heiko Carstens
parent 9d037a7776
commit 480e5926ce
5 changed files with 15 additions and 10 deletions
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4
arch/s390/kvm/kvm-s390.c
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@ -263,10 +263,12 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
vcpu->arch.guest_fpregs.fpc &= FPC_VALID_MASK;
restore_fp_regs(&vcpu->arch.guest_fpregs);
restore_access_regs(vcpu->arch.guest_acrs);
gmap_enable(vcpu->arch.gmap);
}
void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
{
gmap_disable(vcpu->arch.gmap);
save_fp_regs(&vcpu->arch.guest_fpregs);
save_access_regs(vcpu->arch.guest_acrs);
restore_fp_regs(&vcpu->arch.host_fpregs);
@ -461,7 +463,6 @@ static void __vcpu_run(struct kvm_vcpu *vcpu)
local_irq_disable();
kvm_guest_enter();
local_irq_enable();
gmap_enable(vcpu->arch.gmap);
VCPU_EVENT(vcpu, 6, "entering sie flags %x",
atomic_read(&vcpu->arch.sie_block->cpuflags));
if (sie64a(vcpu->arch.sie_block, vcpu->arch.guest_gprs)) {
@ -470,7 +471,6 @@ static void __vcpu_run(struct kvm_vcpu *vcpu)
}
VCPU_EVENT(vcpu, 6, "exit sie icptcode %d",
vcpu->arch.sie_block->icptcode);
gmap_disable(vcpu->arch.gmap);
local_irq_disable();
kvm_guest_exit();
local_irq_enable();