The patch below does not apply to the 3.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 2b29a9fdcb92bfc6b6f4c412d71505869de61a56 Mon Sep 17 00:00:00 2001 From: Dominik Dingel <dingel@xxxxxxxxxxxxxxxxxx> Date: Fri, 26 Jul 2013 15:04:00 +0200 Subject: [PATCH] KVM: s390: move kvm_guest_enter,exit closer to sie 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> CC: stable@xxxxxxxxxxxxxxx Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index ba694d2..34c1c9a 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -702,14 +702,25 @@ static int __vcpu_run(struct kvm_vcpu *vcpu) return rc; 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 > 0) rc = 0; if (rc < 0) { @@ -721,10 +732,6 @@ static int __vcpu_run(struct kvm_vcpu *vcpu) 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 stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html