Re: [PATCH 1/3] x86/Hyper-V: Fix definition of struct hv_vp_assist_page

From: Vitaly Kuznetsov
Date: Fri Aug 09 2019 - 06:25:21 EST


lantianyu1986@xxxxxxxxx writes:

> From: Tianyu Lan <Tianyu.Lan@xxxxxxxxxxxxx>
>
> The struct hv_vp_assist_page was defined incorrectly.
> The "vtl_control" should be u64[3], "nested_enlightenments_control"
> should be a u64 and there is 7 reserved bytes following "enlighten_vmentry".
> This patch is to fix it.
>
> Signed-off-by: Tianyu Lan <Tianyu.Lan@xxxxxxxxxxxxx>
> ---
> arch/x86/include/asm/hyperv-tlfs.h | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
> index af78cd72b8f3..a79703c56ebe 100644
> --- a/arch/x86/include/asm/hyperv-tlfs.h
> +++ b/arch/x86/include/asm/hyperv-tlfs.h
> @@ -517,11 +517,11 @@ struct hv_timer_message_payload {
> /* Define virtual processor assist page structure. */
> struct hv_vp_assist_page {
> __u32 apic_assist;
> - __u32 reserved;
> - __u64 vtl_control[2];
> + __u32 reserved1;
> + __u64 vtl_control[3];
> __u64 nested_enlightenments_control[2];

In PATCH3 you define 'struct hv_nested_enlightenments_control' and it is
64bit long, not 128. We should change it here too as ...

> - __u32 enlighten_vmentry;

enlighten_vmentry filed will get a very different offset breaking
Enlightened VMCS.

> - __u32 padding;
> + __u8 enlighten_vmentry;
> + __u8 reserved2[7];
> __u64 current_nested_vmcs;
> } __packed;

--
Vitaly