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

[Roman Kisel]

On 1/7/2025 11:36 PM, Wei Liu wrote:
> 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@xxxxxxxxxxxxxxxxxxx>
>
> 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.

Apologies, my bad! Will collect tags in the future.

> 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

--
Thank you,
Roman