KVM is not handling the case where EIP wraps around the 32-bit address
space (that is, outside long mode). This is needed both in vmx.c
and in emulate.c. SVM with NRIPS is okay, but it can still print
an error to dmesg due to integer overflow.
Reported-by: Nick Peterson <everdox@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
}
ctxt->eip = ctxt->_eip;
}
ctxt->eip = ctxt->_eip;
+ if (ctxt->mode != X86EMUL_MODE_PROT64)
+ ctxt->eip = (u32)ctxt->_eip;
done:
if (rc == X86EMUL_PROPAGATE_FAULT) {
done:
if (rc == X86EMUL_PROPAGATE_FAULT) {
if (!kvm_emulate_instruction(vcpu, EMULTYPE_SKIP))
return 0;
} else {
if (!kvm_emulate_instruction(vcpu, EMULTYPE_SKIP))
return 0;
} else {
- if (svm->next_rip - kvm_rip_read(vcpu) > MAX_INST_SIZE)
- pr_err("%s: ip 0x%lx next 0x%llx\n",
- __func__, kvm_rip_read(vcpu), svm->next_rip);
kvm_rip_write(vcpu, svm->next_rip);
}
svm_set_interrupt_shadow(vcpu, 0);
kvm_rip_write(vcpu, svm->next_rip);
}
svm_set_interrupt_shadow(vcpu, 0);
static int skip_emulated_instruction(struct kvm_vcpu *vcpu)
{
static int skip_emulated_instruction(struct kvm_vcpu *vcpu)
{
+ unsigned long rip, orig_rip;
/*
* Using VMCS.VM_EXIT_INSTRUCTION_LEN on EPT misconfig depends on
/*
* Using VMCS.VM_EXIT_INSTRUCTION_LEN on EPT misconfig depends on
*/
if (!static_cpu_has(X86_FEATURE_HYPERVISOR) ||
to_vmx(vcpu)->exit_reason != EXIT_REASON_EPT_MISCONFIG) {
*/
if (!static_cpu_has(X86_FEATURE_HYPERVISOR) ||
to_vmx(vcpu)->exit_reason != EXIT_REASON_EPT_MISCONFIG) {
- rip = kvm_rip_read(vcpu);
- rip += vmcs_read32(VM_EXIT_INSTRUCTION_LEN);
+ orig_rip = kvm_rip_read(vcpu);
+ rip = orig_rip + vmcs_read32(VM_EXIT_INSTRUCTION_LEN);
+#ifdef CONFIG_X86_64
+ /*
+ * We need to mask out the high 32 bits of RIP if not in 64-bit
+ * mode, but just finding out that we are in 64-bit mode is
+ * quite expensive. Only do it if there was a carry.
+ */
+ if (unlikely(((rip ^ orig_rip) >> 31) == 3) && !is_64_bit_mode(vcpu))
+ rip = (u32)rip;
+#endif
kvm_rip_write(vcpu, rip);
} else {
if (!kvm_emulate_instruction(vcpu, EMULTYPE_SKIP))
kvm_rip_write(vcpu, rip);
} else {
if (!kvm_emulate_instruction(vcpu, EMULTYPE_SKIP))