Re: [PATCH V2] x86/sev-es: Fix SEV-ES #VC handler for string port IO

[Tom Lendacky]

On 1/10/21 1:11 AM, Hyunwook (Wooky) Baek wrote:
> Don't assume dest/source buffers are userspace addresses when manually
> copying data for string I/O or MOVS MMIO, as {get,put}_user() will fail
> if handed a kernel address and ultimately lead to a kernel panic.
>
> Signed-off-by: Hyunwook (Wooky) Baek <baekhw@xxxxxxxxxx>
> Acked-by: David Rientjes <rientjes@xxxxxxxxxx>
> ---
>
> This patch is tested by invoking INSB/OUTSB instructions in kernel space in a
> SEV-ES-enabled VM. Without the patch, the kernel crashed with the following
> message:
>    "SEV-ES: Unsupported exception in #VC instruction emulation - can't continue"
> With the patch, the instructions successfully read/wrote the string from/to
> the I/O port.

Shouldn't this have a Fixes: tag?

Thanks,
Tom

>   arch/x86/kernel/sev-es.c | 12 ++++++++++++
>   1 file changed, 12 insertions(+)