This is a note to let you know that I've just added the patch titled

    KVM: s390: move kvm_guest_enter,exit closer to sie

to the 3.10-stable tree which can be found at:
    
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     kvm-s390-move-kvm_guest_enter-exit-closer-to-sie.patch
and it can be found in the queue-3.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.


>From 2b29a9fdcb92bfc6b6f4c412d71505869de61a56 Mon Sep 17 00:00:00 2001
From: Dominik Dingel <[email protected]>
Date: Fri, 26 Jul 2013 15:04:00 +0200
Subject: KVM: s390: move kvm_guest_enter,exit closer to sie

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;


Patches currently in stable-queue which might be from [email protected] 
are

queue-3.10/kvm-s390-move-kvm_guest_enter-exit-closer-to-sie.patch
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