diff options
| -rw-r--r-- | arch/mips/kvm/emulate.c | 52 |
1 files changed, 46 insertions, 6 deletions
diff --git a/arch/mips/kvm/emulate.c b/arch/mips/kvm/emulate.c index 5f0354c80c8e..f0fa9e956056 100644 --- a/arch/mips/kvm/emulate.c +++ b/arch/mips/kvm/emulate.c @@ -161,9 +161,12 @@ unsigned long kvm_compute_return_epc(struct kvm_vcpu *vcpu, nextpc = epc; break; - case blez_op: /* not really i_format */ - case blezl_op: - /* rt field assumed to be zero */ + case blez_op: /* POP06 */ +#ifndef CONFIG_CPU_MIPSR6 + case blezl_op: /* removed in R6 */ +#endif + if (insn.i_format.rt != 0) + goto compact_branch; if ((long)arch->gprs[insn.i_format.rs] <= 0) epc = epc + 4 + (insn.i_format.simmediate << 2); else @@ -171,9 +174,12 @@ unsigned long kvm_compute_return_epc(struct kvm_vcpu *vcpu, nextpc = epc; break; - case bgtz_op: - case bgtzl_op: - /* rt field assumed to be zero */ + case bgtz_op: /* POP07 */ +#ifndef CONFIG_CPU_MIPSR6 + case bgtzl_op: /* removed in R6 */ +#endif + if (insn.i_format.rt != 0) + goto compact_branch; if ((long)arch->gprs[insn.i_format.rs] > 0) epc = epc + 4 + (insn.i_format.simmediate << 2); else @@ -185,6 +191,40 @@ unsigned long kvm_compute_return_epc(struct kvm_vcpu *vcpu, case cop1_op: kvm_err("%s: unsupported cop1_op\n", __func__); break; + +#ifdef CONFIG_CPU_MIPSR6 + /* R6 added the following compact branches with forbidden slots */ + case blezl_op: /* POP26 */ + case bgtzl_op: /* POP27 */ + /* only rt == 0 isn't compact branch */ + if (insn.i_format.rt != 0) + goto compact_branch; + break; + case pop10_op: + case pop30_op: + /* only rs == rt == 0 is reserved, rest are compact branches */ + if (insn.i_format.rs != 0 || insn.i_format.rt != 0) + goto compact_branch; + break; + case pop66_op: + case pop76_op: + /* only rs == 0 isn't compact branch */ + if (insn.i_format.rs != 0) + goto compact_branch; + break; +compact_branch: + /* + * If we've hit an exception on the forbidden slot, then + * the branch must not have been taken. + */ + epc += 8; + nextpc = epc; + break; +#else +compact_branch: + /* Compact branches not supported before R6 */ + break; +#endif } return nextpc; |