Re: [PATCH v5 4/5] hyperv: Do not overlap the hvcall IO areas in get_vtl()

[Wei Liu <wei.liu@kernel.org>]

On Mon, Dec 30, 2024 at 10:09:40AM -0800, Roman Kisel wrote:
> The Top-Level Functional Specification for Hyper-V, Section 3.6 [1, 2],
> disallows overlapping of the input and output hypercall areas, and
> get_vtl(void) does overlap them.
> 
> Use the output hypercall page of the current vCPU for the hypercall.
> 
> [1] https://learn.microsoft.com/en-us/virtualization/hyper-v-on-windows/tlfs/hypercall-interface
> [2] https://github.com/MicrosoftDocs/Virtualization-Documentation/tree/main/tlfs
> 
> Fixes: 8387ce06d70b ("x86/hyperv: Set Virtual Trust Level in VMBus init message")
> Signed-off-by: Roman Kisel <romank@linux.microsoft.com>

You forgot to pick up Tianyu's Reviewed-by tag in the previous version.
In the future please make sure to collect all the tags you get from
previous review rounds.

Thanks,
Wei.

> ---
>  arch/x86/hyperv/hv_init.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
> index f82d1aefaa8a..173005e6a95d 100644
> --- a/arch/x86/hyperv/hv_init.c
> +++ b/arch/x86/hyperv/hv_init.c
> @@ -422,7 +422,7 @@ static u8 __init get_vtl(void)
>  
>  	local_irq_save(flags);
>  	input = *this_cpu_ptr(hyperv_pcpu_input_arg);
> -	output = (struct hv_output_get_vp_registers *)input;
> +	output = *this_cpu_ptr(hyperv_pcpu_output_arg);
>  
>  	memset(input, 0, struct_size(input, names, 1));
>  	input->partition_id = HV_PARTITION_ID_SELF;
> -- 
> 2.34.1
>