Commit 9571c879 authored by James Hogan's avatar James Hogan Committed by Luis Henriques

MIPS: KVM: Fix ASID restoration logic

commit 002374f3 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: b680f70f ("KVM/MIPS32: Entry point for trampolining to...")
Signed-off-by: default avatarJames Hogan <james.hogan@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
[ luis: backported to 3.16:
  - file rename: locore.S -> kvm_locore.S ]
Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
parent a6248845
......@@ -159,9 +159,11 @@ 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:
......@@ -438,9 +440,11 @@ __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:
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment