Re: KVM on Via Nano (Isaiah) CPUs? <Virus checked>

[Avi Kivity <avi@redhat.com>]

Andreas Tanz wrote:
> i modded handle_exception as you said : 
>
> 2711         printk(KERN_ERR "vmx->handle_exception 0f : vcpu->arch.rmode.active: 0x%x\n",vcpu->arch.rmode.active);
> 2712         int debug_handle_rmode_exception = handle_rmode_exception(vcpu, intr_info & INTR_INFO_VECTOR_MASK, error_code);
> 2713         printk(KERN_ERR "vmx->handle_exception 10 : handle_rmode_exception(vcpu, intr_info & INTR_INFO_VECTOR_MASK, error_code) returned 0x%x\n", debug_handle_rmode_exception
> 2714         if (vcpu->arch.rmode.active &&  debug_handle_rmode_exception) {
>   

This bit is broken.  The original code:

    if (vcpu->arch.rmode.active &&
        handle_rmode_exception(vcpu, intr_info & INTR_INFO_VECTOR_MASK,
                                error_code)) {

Only executes handle_rmode_exception() if rmode.active is true.  Your 
code executes it unconditionally.

You can write it as

    if (vcpu->arch.rmode.active &&
        (retval = handle_rmode_exception(vcpu, intr_info & 
INTR_INFO_VECTOR_MASK,
                                error_code))) {


Please check for other cases as well.  As it happens, the guest crashed 
immediately after entering protected mode (so rmode.active became false, 
triggering the bug).

-- 
error compiling committee.c: too many arguments to function