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| author | James Hogan <james.hogan@imgtec.com> | 2016-11-28 18:39:24 +0000 |
|---|---|---|
| committer | James Hogan <james.hogan@imgtec.com> | 2017-02-03 15:21:05 +0000 |
| commit | a1ecc54d7ea629538116351a3ccc7d86bb9a3c69 (patch) | |
| tree | 3e012830ccb843c32c83eba923be93fbb86b883c /arch/mips/kvm | |
| parent | a98dd7410370634496aa500abf90ec6336b494ae (diff) | |
| download | linux-a1ecc54d7ea629538116351a3ccc7d86bb9a3c69.tar.gz | |
KVM: MIPS/T&E: Don't treat code fetch faults as MMIO
In order to make use of the CP0_BadInstr & CP0_BadInstrP registers we need to be a bit more careful not to treat code fetch faults as MMIO, lest we hit an UNPREDICTABLE register value when we try to emulate the MMIO load instruction but there was no valid instruction word available to the hardware. Add a kvm_is_ifetch_fault() helper to try to figure out whether a load fault was due to a code fetch, and prevent MMIO instruction emulation in that case. 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
Diffstat (limited to 'arch/mips/kvm')
| -rw-r--r-- | arch/mips/kvm/trap_emul.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/mips/kvm/trap_emul.c b/arch/mips/kvm/trap_emul.c index 653850c05b33..ccd56b3ce84b 100644 --- a/arch/mips/kvm/trap_emul.c +++ b/arch/mips/kvm/trap_emul.c @@ -178,6 +178,12 @@ static int kvm_trap_emul_handle_tlb_miss(struct kvm_vcpu *vcpu, bool store) } } else if (KVM_GUEST_KERNEL_MODE(vcpu) && (KSEGX(badvaddr) == CKSEG0 || KSEGX(badvaddr) == CKSEG1)) { + /* A code fetch fault doesn't count as an MMIO */ + if (!store && kvm_is_ifetch_fault(&vcpu->arch)) { + run->exit_reason = KVM_EXIT_INTERNAL_ERROR; + return RESUME_HOST; + } + /* * With EVA we may get a TLB exception instead of an address * error when the guest performs MMIO to KSeg1 addresses. @@ -255,6 +261,12 @@ static int kvm_trap_emul_handle_addr_err_ld(struct kvm_vcpu *vcpu) int ret = RESUME_GUEST; if (KSEGX(badvaddr) == CKSEG0 || KSEGX(badvaddr) == CKSEG1) { + /* A code fetch fault doesn't count as an MMIO */ + if (kvm_is_ifetch_fault(&vcpu->arch)) { + run->exit_reason = KVM_EXIT_INTERNAL_ERROR; + return RESUME_HOST; + } + kvm_debug("Emulate Load from MMIO space @ %#lx\n", badvaddr); er = kvm_mips_emulate_inst(cause, opc, run, vcpu); if (er == EMULATE_FAIL) { |