Re: [PATCH] target/i386: Add support save/load exception error_code

[Zhao Liu <zhao1.liu@intel.com>]

On Tue, Aug 19, 2025 at 10:58:34PM +0800, Wang Xin wrote:
> Date: Tue, 19 Aug 2025 22:58:34 +0800
> From: Wang Xin <wangxinxin.wang@huawei.com>
> Subject: [PATCH] target/i386: Add support save/load exception error_code
> X-Mailer: git-send-email 2.50.1.windows.1
> 
> From: WangXin <wangxinxin.wang@huawei.com>
> 
> 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>
> Signed-off-by: Tuo Xie <xietuo@huawei.com>

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>