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MIPS: KVM: Fix ASID restoration logic

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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: b680f70fc1 ("KVM/MIPS32: Entry point for trampolining to...")
Signed-off-by: James 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
Cc: <stable@vger.kernel.org> # 3.10.x-
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
James Hogan 2015-11-11 14:21:18 +00:00 committed by Paolo Bonzini
parent 8005c49d9a
commit 002374f371
1 changed files with 10 additions and 6 deletions
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16
arch/mips/kvm/locore.S
View file

@ -157,9 +157,11 @@ 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 */
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@ -474,9 +476,11 @@ __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 */
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