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.
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);
}
--
Ben Hutchings
If you seem to know what you are doing, you'll be given more to do.
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