For now, qemu save/load CPU exception info(such as exception_nr and
has_error_code), while the exception error_code is ignored. This will
cause the dest hypervisor reinject a vCPU exception with error_code(0),
potentially causing a guest kernel panic.
For instance, if src VM stopped with an user-mode write #PF (error_code 6),
the dest hypervisor will reinject an #PF with error_code(0) when vCPU resume,
then guest kernel panic as:
BUG: unable to handle page fault for address: 00007f80319cb010
#PF: supervisor read access in user mode
#PF: error_code(0x0000) - not-present page
RIP: 0033:0x40115d
To fix it, support save/load exception error_code.
Signed-off-by: Xin Wang <wangxinxin.wang@huawei.com>
Link: https://lore.kernel.org/r/20250819145834.3998-1-wangxinxin.wang@huawei.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
27535e9cca