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authorDominik Dingel <dingel@linux.vnet.ibm.com>2013-07-26 15:04:00 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2013-07-29 09:02:18 +0200
commit2b29a9fdcb92bfc6b6f4c412d71505869de61a56 (patch)
tree81e5b700617fbc5d9663eb01118b0ef944c237d4
parentMerge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/t... (diff)
downloadlinux-2b29a9fdcb92bfc6b6f4c412d71505869de61a56.tar.xz
linux-2b29a9fdcb92bfc6b6f4c412d71505869de61a56.zip
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@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> CC: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r--arch/s390/kvm/kvm-s390.c21
1 files changed, 14 insertions, 7 deletions
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index ba694d2ba51e..34c1c9a90be2 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;