3.10-stable review patch. If anyone has any objections, please let me know.
------------------ From: Dominik Dingel <[email protected]> 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 <[email protected]> Signed-off-by: Christian Borntraeger <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- 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 @@ -622,14 +622,25 @@ static int __vcpu_run(struct kvm_vcpu *v kvm_s390_deliver_pending_interrupts(vcpu); vcpu->arch.sie_block->icptcode = 0; - preempt_disable(); - kvm_guest_enter(); - preempt_enable(); VCPU_EVENT(vcpu, 6, "entering sie flags %x", atomic_read(&vcpu->arch.sie_block->cpuflags)); trace_kvm_s390_sie_enter(vcpu, atomic_read(&vcpu->arch.sie_block->cpuflags)); + + /* + * As PF_VCPU will be used in fault handler, between guest_enter + * and guest_exit should be no uaccess. + */ + preempt_disable(); + kvm_guest_enter(); + preempt_enable(); rc = sie64a(vcpu->arch.sie_block, vcpu->run->s.regs.gprs); + kvm_guest_exit(); + + VCPU_EVENT(vcpu, 6, "exit sie icptcode %d", + vcpu->arch.sie_block->icptcode); + trace_kvm_s390_sie_exit(vcpu, vcpu->arch.sie_block->icptcode); + if (rc) { if (kvm_is_ucontrol(vcpu->kvm)) { rc = SIE_INTERCEPT_UCONTROL; @@ -639,10 +650,6 @@ static int __vcpu_run(struct kvm_vcpu *v rc = kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING); } } - VCPU_EVENT(vcpu, 6, "exit sie icptcode %d", - vcpu->arch.sie_block->icptcode); - trace_kvm_s390_sie_exit(vcpu, vcpu->arch.sie_block->icptcode); - kvm_guest_exit(); memcpy(&vcpu->run->s.regs.gprs[14], &vcpu->arch.sie_block->gg14, 16); return rc; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
