On Fri, May 05, 2023 at 05:20:43PM +0200, Mickaël Salaün wrote:
> From: Madhavan T. Venkataraman <madve...@linux.microsoft.com>
>
> Each supported hypervisor in x86 implements a struct x86_hyper_init to
> define the init functions for the hypervisor. Define a new init_heki()
> entry point in struct x86_hyper_init. Hypervisors that support Heki
> must define this init_heki() function. Call init_heki() of the chosen
> hypervisor in init_hypervisor_platform().
>
> Create a heki_hypervisor structure that each hypervisor can fill
> with its data and functions. This will allow the Heki feature to work
> in a hypervisor agnostic way.
>
> Declare and initialize a "heki_hypervisor" structure for KVM so KVM can
> support Heki. Define the init_heki() function for KVM. In init_heki(),
> set the hypervisor field in the generic "heki" structure to the KVM
> "heki_hypervisor". After this point, generic Heki code can access the
> KVM Heki data and functions.
>
[...]
> +static void kvm_init_heki(void)
> +{
> + long err;
> +
> + if (!kvm_para_available())
> + /* Cannot make KVM hypercalls. */
> + return;
> +
> + err = kvm_hypercall3(KVM_HC_LOCK_MEM_PAGE_RANGES, -1, -1, -1);
Why not do a proper version check or capability check here? If the ABI
or supported features ever change then we have something to rely on?
Thanks,
Wei.
