[PATCH 3.14 19/46] [PATCH BACKPORT 3.10-3.15 4/4] MIPS: KVM: Propagate kseg0/mapped tlb fault errors

Greg Kroah-Hartman
2016-08-18T13:54:41Z

commit 9b731bcfdec4c159ad2e4312e25d69221709b96a upstream.

Propagate errors from kvm_mips_handle_kseg0_tlb_fault() and
kvm_mips_handle_mapped_seg_tlb_fault(), usually triggering an internal
error since they normally indicate the guest accessed bad physical
memory or the commpage in an unexpected way.

Fixes: 858dd5d45733 ("KVM/MIPS32: MMU/TLB operations for the Guest.")
Fixes: e685c689f3a8 ("KVM/MIPS32: Privileged instruction/target branch emulation.")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
[james.hogan@imgtec.com: Backport to v3.10.y - v3.15.y]
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/mips/kvm/kvm_mips_emul.c | 33 ++++++++++++++++++++++++---------
arch/mips/kvm/kvm_tlb.c | 14 ++++++++++----
2 files changed, 34 insertions(+), 13 deletions(-)

--- a/arch/mips/kvm/kvm_mips_emul.c
+++ b/arch/mips/kvm/kvm_mips_emul.c
@@ -972,8 +972,13 @@ kvm_mips_emulate_cache(uint32_t inst, ui
preempt_disable();
if (KVM_GUEST_KSEGX(va) == KVM_GUEST_KSEG0) {

- if (kvm_mips_host_tlb_lookup(vcpu, va) < 0) {
- kvm_mips_handle_kseg0_tlb_fault(va, vcpu);
+ if (kvm_mips_host_tlb_lookup(vcpu, va) < 0 &&
+ kvm_mips_handle_kseg0_tlb_fault(va, vcpu)) {
+ kvm_err("%s: handling mapped kseg0 tlb fault for %lx, vcpu: %p, ASID: %#lx\n",
+ __func__, va, vcpu, read_c0_entryhi());
+ er = EMULATE_FAIL;
+ preempt_enable();
+ goto done;
}
} else if ((KVM_GUEST_KSEGX(va) < KVM_GUEST_KSEG0) ||
KVM_GUEST_KSEGX(va) == KVM_GUEST_KSEG23) {
@@ -1006,11 +1011,16 @@ kvm_mips_emulate_cache(uint32_t inst, ui
run, vcpu);
preempt_enable();
goto dont_update_pc;
- } else {
- /* We fault an entry from the guest tlb to the shadow host TLB */
- kvm_mips_handle_mapped_seg_tlb_fault(vcpu, tlb,
- NULL,
- NULL);
+ }
+ /* We fault an entry from the guest tlb to the shadow host TLB */
+ if (kvm_mips_handle_mapped_seg_tlb_fault(vcpu, tlb,
+ NULL, NULL)) {
+ kvm_err("%s: handling mapped seg tlb fault for %lx, index: %u, vcpu: %p, ASID: %#lx\n",
+ __func__, va, index, vcpu,
+ read_c0_entryhi());
+ er = EMULATE_FAIL;
+ preempt_enable();
+ goto done;
}
}
} else {
@@ -1821,8 +1831,13 @@ kvm_mips_handle_tlbmiss(unsigned long ca
tlb->tlb_hi, tlb->tlb_lo0, tlb->tlb_lo1);
#endif
/* OK we have a Guest TLB entry, now inject it into the shadow host TLB */
- kvm_mips_handle_mapped_seg_tlb_fault(vcpu, tlb, NULL,
- NULL);
+ if (kvm_mips_handle_mapped_seg_tlb_fault(vcpu, tlb,
+ NULL, NULL)) {
+ kvm_err("%s: handling mapped seg tlb fault for %lx, index: %u, vcpu: %p, ASID: %#lx\n",
+ __func__, va, index, vcpu,
+ read_c0_entryhi());
+ er = EMULATE_FAIL;
+ }
}
}

--- a/arch/mips/kvm/kvm_tlb.c
+++ b/arch/mips/kvm/kvm_tlb.c
@@ -797,10 +797,16 @@ uint32_t kvm_get_inst(uint32_t *opc, str
local_irq_restore(flags);
return KVM_INVALID_INST;
}
- kvm_mips_handle_mapped_seg_tlb_fault(vcpu,
- &vcpu->arch.
- guest_tlb[index],
- NULL, NULL);
+ if (kvm_mips_handle_mapped_seg_tlb_fault(vcpu,
+ &vcpu->arch.guest_tlb[index],
+ NULL, NULL)) {
+ kvm_err("%s: handling mapped seg tlb fault failed for %p, index: %u, vcpu: %p, ASID: %#lx\n",
+ __func__, opc, index, vcpu,
+ read_c0_entryhi());
+ kvm_mips_dump_guest_tlbs(vcpu);
+ local_irq_restore(flags);
+ return KVM_INVALID_INST;
+ }
inst = *(opc);
}
local_irq_restore(flags);