Re: [PATCH 5/7] x86/hyperv: Mark ACPI wakeup mailbox page as private
From: Thomas Gleixner
Date: Wed Aug 07 2024 - 13:09:12 EST
On Tue, Aug 06 2024 at 15:12, Yunhong Jiang wrote:
> The ACPI wakeup mailbox is accessed by the OS and the firmware, both are
> in the guest's context, instead of the hypervisor/VMM context. Mark the
> address private explicitly.
This lacks information why the realmode area must be reserved and
initialized, which is what the change is doing implicitely.
> Signed-off-by: Yunhong Jiang <yunhong.jiang@xxxxxxxxxxxxxxx>
>
> +/*
> + * The ACPI wakeup mailbox are accessed by the OS and the BIOS, both are in the
> + * guest's context, instead of the hypervisor/VMM context.
> + */
> +static bool hv_is_private_mmio_tdx(u64 addr)
> +{
> + if (wakeup_mailbox_addr && (addr >= wakeup_mailbox_addr &&
> + addr < (wakeup_mailbox_addr + PAGE_SIZE)))
> + return true;
> + return false;
> +}
static inline bool within_page(u64 addr, u64 start)
{
return addr >= start && addr < (start + PAGE_SIZE);
}
static bool hv_is_private_mmio_tdx(u64 addr)
{
return wakeup_mailbox_addr && within_page(addr, wakeup_mailbox_addr)
}
Hmm?
> +
> void __init hv_vtl_init_platform(void)
> {
> pr_info("Linux runs in Hyper-V Virtual Trust Level\n");
>
> - x86_platform.realmode_reserve = x86_init_noop;
> - x86_platform.realmode_init = x86_init_noop;
> + if (wakeup_mailbox_addr) {
Wants a comment vs. realmode here.
> + x86_platform.hyper.is_private_mmio = hv_is_private_mmio_tdx;
> + } else {
> + x86_platform.realmode_reserve = x86_init_noop;
> + x86_platform.realmode_init = x86_init_noop;
> + }
> x86_init.irqs.pre_vector_init = x86_init_noop;
> x86_init.timers.timer_init = x86_init_noop;
Thanks,
tglx