This is a note to let you know that I've just added the patch titled
s390/kvm: Fix store status for ACRS/FPRS
to the 3.7-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:
s390-kvm-fix-store-status-for-acrs-fprs.patch
and it can be found in the queue-3.7 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 15bc8d8457875f495c59d933b05770ba88d1eacb Mon Sep 17 00:00:00 2001
From: Christian Borntraeger <[email protected]>
Date: Fri, 25 Jan 2013 15:34:15 +0100
Subject: s390/kvm: Fix store status for ACRS/FPRS
From: Christian Borntraeger <[email protected]>
commit 15bc8d8457875f495c59d933b05770ba88d1eacb upstream.
On store status we need to copy the current state of registers
into a save area. Currently we might save stale versions:
The sie state descriptor doesnt have fields for guest ACRS,FPRS,
those registers are simply stored in the host registers. The host
program must copy these away if needed. We do that in vcpu_put/load.
If we now do a store status in KVM code between vcpu_put/load, the
saved values are not up-to-date. Lets collect the ACRS/FPRS before
saving them.
This also fixes some strange problems with hotplug and virtio-ccw,
since the low level machine check handler (on hotplug a machine check
will happen) will revalidate all registers with the content of the
save area.
Signed-off-by: Christian Borntraeger <[email protected]>
Signed-off-by: Gleb Natapov <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
arch/s390/kvm/kvm-s390.c | 8 ++++++++
1 file changed, 8 insertions(+)
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -763,6 +763,14 @@ int kvm_s390_vcpu_store_status(struct kv
} else
prefix = 0;
+ /*
+ * The guest FPRS and ACRS are in the host FPRS/ACRS due to the lazy
+ * copying in vcpu load/put. Lets update our copies before we save
+ * it into the save area
+ */
+ save_fp_regs(&vcpu->arch.guest_fpregs);
+ save_access_regs(vcpu->run->s.regs.acrs);
+
if (__guestcopy(vcpu, addr + offsetof(struct save_area, fp_regs),
vcpu->arch.guest_fpregs.fprs, 128, prefix))
return -EFAULT;
Patches currently in stable-queue which might be from [email protected] are
queue-3.7/s390-kvm-fix-store-status-for-acrs-fprs.patch
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