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

    MIPS: KVM: Fix ASID restoration logic

to the 4.3-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:
     mips-kvm-fix-asid-restoration-logic.patch
and it can be found in the queue-4.3 subdirectory.

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


>From 002374f371bd02df864cce1fe85d90dc5b292837 Mon Sep 17 00:00:00 2001
From: James Hogan <[email protected]>
Date: Wed, 11 Nov 2015 14:21:18 +0000
Subject: MIPS: KVM: Fix ASID restoration logic

From: James Hogan <[email protected]>

commit 002374f371bd02df864cce1fe85d90dc5b292837 upstream.

ASID restoration on guest resume should determine the guest execution
mode based on the guest Status register rather than bit 30 of the guest
PC.

Fix the two places in locore.S that do this, loading the guest status
from the cop0 area. Note, this assembly is specific to the trap &
emulate implementation of KVM, so it doesn't need to check the
supervisor bit as that mode is not implemented in the guest.

Fixes: b680f70fc111 ("KVM/MIPS32: Entry point for trampolining to...")
Signed-off-by: James Hogan <[email protected]>
Cc: Ralf Baechle <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Cc: Gleb Natapov <[email protected]>
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Paolo Bonzini <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 arch/mips/kvm/locore.S |   16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

--- a/arch/mips/kvm/locore.S
+++ b/arch/mips/kvm/locore.S
@@ -165,9 +165,11 @@ FEXPORT(__kvm_mips_vcpu_run)
 
 FEXPORT(__kvm_mips_load_asid)
        /* Set the ASID for the Guest Kernel */
-       INT_SLL t0, t0, 1       /* with kseg0 @ 0x40000000, kernel */
-                               /* addresses shift to 0x80000000 */
-       bltz    t0, 1f          /* If kernel */
+       PTR_L   t0, VCPU_COP0(k1)
+       LONG_L  t0, COP0_STATUS(t0)
+       andi    t0, KSU_USER | ST0_ERL | ST0_EXL
+       xori    t0, KSU_USER
+       bnez    t0, 1f          /* If kernel */
         INT_ADDIU t1, k1, VCPU_GUEST_KERNEL_ASID  /* (BD)  */
        INT_ADDIU t1, k1, VCPU_GUEST_USER_ASID    /* else user */
 1:
@@ -482,9 +484,11 @@ __kvm_mips_return_to_guest:
        mtc0    t0, CP0_EPC
 
        /* Set the ASID for the Guest Kernel */
-       INT_SLL t0, t0, 1       /* with kseg0 @ 0x40000000, kernel */
-                               /* addresses shift to 0x80000000 */
-       bltz    t0, 1f          /* If kernel */
+       PTR_L   t0, VCPU_COP0(k1)
+       LONG_L  t0, COP0_STATUS(t0)
+       andi    t0, KSU_USER | ST0_ERL | ST0_EXL
+       xori    t0, KSU_USER
+       bnez    t0, 1f          /* If kernel */
         INT_ADDIU t1, k1, VCPU_GUEST_KERNEL_ASID  /* (BD)  */
        INT_ADDIU t1, k1, VCPU_GUEST_USER_ASID    /* else user */
 1:


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

queue-4.3/mips-kvm-fix-cache-immediate-offset-sign-extension.patch
queue-4.3/mips-kvm-fix-asid-restoration-logic.patch
queue-4.3/mips-cdmm-add-builtin_mips_cdmm_driver-macro.patch
queue-4.3/mips-kvm-uninit-vcpu-in-vcpu_create-error-path.patch
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