[PATCH v2] x86/Hyper-V: Expand definition of struct hv_vp_assist_page

[PATCH v2] x86/Hyper-V: Expand definition of struct hv_vp_assist_page

[Saurabh Sengar]

The struct hv_vp_assist_page has 24 bytes which is defined as u64[3],
expand that to expose vtl_entry_reason, vtl_ret_x64rax and vtl_ret_x64rcx
field. vtl_entry_reason is updated by hypervisor for the entry reason as
to why the VTL was entered on the virtual processor.
Guest updates the vtl_ret_* fields to provide the register values to
restore on VTL return. The specific register values that are restored
which will be updated on vtl_ret_x64rax and vtl_ret_x64rcx.
Also added the missing fields for synthetic_time_unhalted_timer_expired,
virtualization_fault_information and intercept_message.

Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
---
[v2]: Corrected vtl_entry_reson size from u8 to u32

 arch/x86/include/asm/hyperv-tlfs.h | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
index 3089ec3..6d9368e 100644
--- a/arch/x86/include/asm/hyperv-tlfs.h
+++ b/arch/x86/include/asm/hyperv-tlfs.h
@@ -374,11 +374,20 @@ struct hv_nested_enlightenments_control {
 struct hv_vp_assist_page {
 	__u32 apic_assist;
 	__u32 reserved1;
-	__u64 vtl_control[3];
+	__u32 vtl_entry_reason;
+	__u32 vtl_reserved;
+	__u64 vtl_ret_x64rax;
+	__u64 vtl_ret_x64rcx;
 	struct hv_nested_enlightenments_control nested_control;
 	__u8 enlighten_vmentry;
 	__u8 reserved2[7];
 	__u64 current_nested_vmcs;
+	__u8 synthetic_time_unhalted_timer_expired;
+	__u8 reserved3[7];
+	__u8 virtualization_fault_information[40];
+	__u8 reserved4[8];
+	__u8 intercept_message[256];
+	__u8 vtl_ret_actions[256];
 } __packed;
 
 struct hv_enlightened_vmcs {
-- 
1.8.3.1

Re: [PATCH v2] x86/Hyper-V: Expand definition of struct hv_vp_assist_page

[Anirudh Rayabharam]

On Fri, Nov 04, 2022 at 11:38:43AM -0700, Saurabh Sengar wrote:
> The struct hv_vp_assist_page has 24 bytes which is defined as u64[3],
> expand that to expose vtl_entry_reason, vtl_ret_x64rax and vtl_ret_x64rcx
> field. vtl_entry_reason is updated by hypervisor for the entry reason as
> to why the VTL was entered on the virtual processor.
> Guest updates the vtl_ret_* fields to provide the register values to
> restore on VTL return. The specific register values that are restored
> which will be updated on vtl_ret_x64rax and vtl_ret_x64rcx.
> Also added the missing fields for synthetic_time_unhalted_timer_expired,
> virtualization_fault_information and intercept_message.
> 
> Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
> ---
> [v2]: Corrected vtl_entry_reson size from u8 to u32
> 
>  arch/x86/include/asm/hyperv-tlfs.h | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
> index 3089ec3..6d9368e 100644
> --- a/arch/x86/include/asm/hyperv-tlfs.h
> +++ b/arch/x86/include/asm/hyperv-tlfs.h
> @@ -374,11 +374,20 @@ struct hv_nested_enlightenments_control {
>  struct hv_vp_assist_page {
>  	__u32 apic_assist;
>  	__u32 reserved1;
> -	__u64 vtl_control[3];
> +	__u32 vtl_entry_reason;
> +	__u32 vtl_reserved;
> +	__u64 vtl_ret_x64rax;
> +	__u64 vtl_ret_x64rcx;
>  	struct hv_nested_enlightenments_control nested_control;
>  	__u8 enlighten_vmentry;
>  	__u8 reserved2[7];
>  	__u64 current_nested_vmcs;
> +	__u8 synthetic_time_unhalted_timer_expired;
> +	__u8 reserved3[7];
> +	__u8 virtualization_fault_information[40];
> +	__u8 reserved4[8];
> +	__u8 intercept_message[256];
> +	__u8 vtl_ret_actions[256];
>  } __packed;
>  
>  struct hv_enlightened_vmcs {
> -- 
> 1.8.3.1

Reviewed-by: <anrayabh@linux.microsoft.com>

Re: [PATCH v2] x86/Hyper-V: Expand definition of struct hv_vp_assist_page

[Wei Liu]

On Mon, Nov 07, 2022 at 04:03:07PM +0530, Anirudh Rayabharam wrote:
> On Fri, Nov 04, 2022 at 11:38:43AM -0700, Saurabh Sengar wrote:
> > The struct hv_vp_assist_page has 24 bytes which is defined as u64[3],
> > expand that to expose vtl_entry_reason, vtl_ret_x64rax and vtl_ret_x64rcx
> > field. vtl_entry_reason is updated by hypervisor for the entry reason as
> > to why the VTL was entered on the virtual processor.
> > Guest updates the vtl_ret_* fields to provide the register values to
> > restore on VTL return. The specific register values that are restored
> > which will be updated on vtl_ret_x64rax and vtl_ret_x64rcx.
> > Also added the missing fields for synthetic_time_unhalted_timer_expired,
> > virtualization_fault_information and intercept_message.

I did a bit of stylistic changes to the commit message and queued this
up to hyperv-next. Thanks.