Re: [PATCH v6 1/5] hyperv: Define struct hv_output_get_vp_registers

Nuno Das Neves
2025-01-08T23:25:26Z

On 1/8/2025 2:21 PM, Roman Kisel wrote:
> There is no definition of the output structure for the
> GetVpRegisters hypercall. Hence, using the hypercall
> is not possible when the output value has some structure
> to it. Even getting a datum of a primitive type reads
> as ad-hoc without that definition.
>
> Define struct hv_output_get_vp_registers to enable using
> the GetVpRegisters hypercall. Make provisions for all
> supported architectures. No functional changes.
>
> Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
> ---
> include/hyperv/hvgdk_mini.h | 41 +++++++++++++++++++++++++++++++++++++
> 1 file changed, 41 insertions(+)
>
> diff --git a/include/hyperv/hvgdk_mini.h b/include/hyperv/hvgdk_mini.h
> index db3d1aaf7330..4fffca9e16df 100644
> --- a/include/hyperv/hvgdk_mini.h
> +++ b/include/hyperv/hvgdk_mini.h
> @@ -1068,6 +1068,35 @@ union hv_dispatch_suspend_register {
> } __packed;
> };
>
> +union hv_arm64_pending_interruption_register {
> + u64 as_uint64;
> + struct {
> + u64 interruption_pending : 1;
> + u64 interruption_type: 1;
> + u64 reserved : 30;
> + u64 error_code : 32;
> + } __packed;
> +};
> +
> +union hv_arm64_interrupt_state_register {
> + u64 as_uint64;
> + struct {
> + u64 interrupt_shadow : 1;
> + u64 reserved : 63;
> + } __packed;
> +};
> +
> +union hv_arm64_pending_synthetic_exception_event {
> + u64 as_uint64[2];
> + struct {
> + u8 event_pending : 1;
> + u8 event_type : 3;
> + u8 reserved : 4;
> + u8 rsvd[3];
> + u64 context;
> + } __packed;
> +};
> +

You've omitted the exception_type field.
This is how it should be:

union hv_arm64_pending_synthetic_exception_event {
u64 as_uint64[2];
struct {
u8 event_pending : 1;
u8 event_type : 3;
u8 reserved : 4;
u8 rsvd[3];
u32 exception_type;
u64 context;
} __packed;
};

> union hv_x64_interrupt_state_register {
> u64 as_uint64;
> struct {
> @@ -1103,8 +1132,20 @@ union hv_register_value {
> union hv_explicit_suspend_register explicit_suspend;
> union hv_intercept_suspend_register intercept_suspend;
> union hv_dispatch_suspend_register dispatch_suspend;
> +#ifdef CONFIG_ARM64
> + union hv_arm64_interrupt_state_register interrupt_state;
> + union hv_arm64_pending_interruption_register pending_interruption;
> +#endif
> +#ifdef CONFIG_X86
> union hv_x64_interrupt_state_register interrupt_state;
> union hv_x64_pending_interruption_register pending_interruption;
> +#endif
> + union hv_arm64_pending_synthetic_exception_event pending_synthetic_exception_event;
> +};
> +
> +/* NOTE: Linux helper struct - NOT from Hyper-V code. */
> +struct hv_output_get_vp_registers {
> + DECLARE_FLEX_ARRAY(union hv_register_value, values);
> };
>
> #if defined(CONFIG_ARM64)