On 12/18/2024 12:54 PM, Roman Kisel wrote:
> Commit bc905fa8b633 ("hyperv: Switch from hyperv-tlfs.h to hyperv/hvhdk.h")
> changed the type of the output pointer to `struct hv_register_assoc` from
> `struct hv_get_vp_registers_output`. That leads to an incorrect computation,
> and leaves the system broken.
>
My bad! But, lets not use `struct hv_get_registers_output`. Instead, use
`struct hv_register_value`, since that is the more complete definition of a
register value. The output of the get_vp_registers hypercall is just an array
of these values.
Ideally we remove `struct hv_get_vp_registers_output` at some point, since
it serves the same role as `struct hv_register_value` but in a more limited
capacity.
Thanks
Nuno
> Use the correct pointer type for the output of the GetVpRegisters hypercall.
>
> Fixes: bc905fa8b633 ("hyperv: Switch from hyperv-tlfs.h to hyperv/hvhdk.h")
> Signed-off-by: Roman Kisel <rom...@linux.microsoft.com>
> ---
> arch/x86/hyperv/hv_init.c | 6 +++---
> include/hyperv/hvgdk_mini.h | 3 ---
> 2 files changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
> index 3cf2a227d666..c7185c6a290b 100644
> --- a/arch/x86/hyperv/hv_init.c
> +++ b/arch/x86/hyperv/hv_init.c
> @@ -416,13 +416,13 @@ static u8 __init get_vtl(void)
> {
> u64 control = HV_HYPERCALL_REP_COMP_1 | HVCALL_GET_VP_REGISTERS;
> struct hv_input_get_vp_registers *input;
> - struct hv_register_assoc *output;
> + struct hv_get_vp_registers_output *output;
> unsigned long flags;
> u64 ret;
>
> local_irq_save(flags);
> input = *this_cpu_ptr(hyperv_pcpu_input_arg);
> - output = (struct hv_register_assoc *)input;
> + output = (struct hv_get_vp_registers_output *)input;
>
> memset(input, 0, struct_size(input, names, 1));
> input->partition_id = HV_PARTITION_ID_SELF;
> @@ -432,7 +432,7 @@ static u8 __init get_vtl(void)
>
> ret = hv_do_hypercall(control, input, output);
> if (hv_result_success(ret)) {
> - ret = output->value.reg8 & HV_X64_VTL_MASK;
> + ret = output->as64.low & HV_X64_VTL_MASK;
> } else {
> pr_err("Failed to get VTL(error: %lld) exiting...\n", ret);
> BUG();
> diff --git a/include/hyperv/hvgdk_mini.h b/include/hyperv/hvgdk_mini.h
> index db3d1aaf7330..0b1a10828f33 100644
> --- a/include/hyperv/hvgdk_mini.h
> +++ b/include/hyperv/hvgdk_mini.h
> @@ -1107,7 +1107,6 @@ union hv_register_value {
> union hv_x64_pending_interruption_register pending_interruption;
> };
>
> -#if defined(CONFIG_ARM64)
> /* HvGetVpRegisters returns an array of these output elements */
> struct hv_get_vp_registers_output {
> union {
> @@ -1124,8 +1123,6 @@ struct hv_get_vp_registers_output {
> };
> };
>
> -#endif /* CONFIG_ARM64 */
> -
> struct hv_register_assoc {
> u32 name; /* enum hv_register_name */
> u32 reserved1;
