On Tue, 03 Sep 2013 03:56:06 +0100
Ben Hutchings <ben@xxxxxxxxxxxxxxx> wrote:
> 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@xxxxxxxxxxxxxxxxxx>
> Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> [bwh: Backported to 3.2: adjust context and add the rc variable]
> Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
> ---
> This is a blind backport, not even compile-tested, but I think it does
> logically the same thing as your fix and would apply to 3.0.y and 3.2.y.
> 3.4.y would need a different version again.
>
> Ben.
Reviewed-by: Dominik Dingel <dingel@xxxxxxxxxxxxxxxxxx>
Dominik
>
> arch/s390/kvm/kvm-s390.c | 21 ++++++++++++++-------
> 1 file changed, 14 insertions(+), 7 deletions(-)
>
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -469,6 +469,8 @@ int kvm_arch_vcpu_ioctl_set_mpstate(stru
>
> static void __vcpu_run(struct kvm_vcpu *vcpu)
> {
> + int rc;
> +
> memcpy(&vcpu->arch.sie_block->gg14, &vcpu->arch.guest_gprs[14], 16);
>
> if (need_resched())
> @@ -479,21 +481,24 @@ static void __vcpu_run(struct kvm_vcpu *
>
> 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));
> - if (sie64a(vcpu->arch.sie_block, vcpu->arch.guest_gprs)) {
> + rc = sie64a(vcpu->arch.sie_block, vcpu->arch.guest_gprs);
> + local_irq_disable();
> + kvm_guest_exit();
> + local_irq_enable();
> +
> + if (rc) {
> VCPU_EVENT(vcpu, 3, "%s", "fault in sie instruction");
> kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
> }
> VCPU_EVENT(vcpu, 6, "exit sie icptcode %d",
> vcpu->arch.sie_block->icptcode);
> - local_irq_disable();
> - kvm_guest_exit();
> - local_irq_enable();
>
> memcpy(&vcpu->arch.guest_gprs[14], &vcpu->arch.sie_block->gg14, 16);
> }
>
>
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