[3.19.y-ckt stable] Patch "KVM: PPC: Fix emulation of H_SET_DABR/X on POWER8" has been added to the 3.19.y-ckt tree

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    KVM: PPC: Fix emulation of H_SET_DABR/X on POWER8

to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue

This patch is scheduled to be released in version 3.19.8-ckt15.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.19.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

---8<------------------------------------------------------------

>From c5d0118490913313b87414af7e67de8a7c8f8430 Mon Sep 17 00:00:00 2001
From: Thomas Huth <thuth at redhat.com>
Date: Fri, 20 Nov 2015 09:11:45 +0100
Subject: KVM: PPC: Fix emulation of H_SET_DABR/X on POWER8

commit 760a7364f27d974d100118d88190e574626e18a6 upstream.

In the old DABR register, the BT (Breakpoint Translation) bit
is bit number 61. In the new DAWRX register, the WT (Watchpoint
Translation) bit is bit number 59. So to move the DABR-BT bit
into the position of the DAWRX-WT bit, it has to be shifted by
two, not only by one. This fixes hardware watchpoints in gdb of
older guests that only use the H_SET_DABR/X interface instead
of the new H_SET_MODE interface.

Signed-off-by: Thomas Huth <thuth at redhat.com>
Reviewed-by: Laurent Vivier <lvivier at redhat.com>
Reviewed-by: David Gibson <david at gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus at samba.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 arch/powerpc/kvm/book3s_hv_rmhandlers.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 10554df..aa3016c 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -1874,7 +1874,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)

 	/* Emulate H_SET_DABR/X on P8 for the sake of compat mode guests */
 2:	rlwimi	r5, r4, 5, DAWRX_DR | DAWRX_DW
-	rlwimi	r5, r4, 1, DAWRX_WT
+	rlwimi	r5, r4, 2, DAWRX_WT
 	clrrdi	r4, r4, 3
 	std	r4, VCPU_DAWR(r3)
 	std	r5, VCPU_DAWRX(r3)
--
1.9.1