The VTL2 TDX guest may have no sub-1M memory available, but it needs to invoke trampoline_start64 to wake up the APs through the wakeup mailbox mechanism. Set realmode_limit to 4G for the VTL2 TDX guest, so that reserve_real_mode allocae memory under 4G. Signed-off-by: Yunhong Jiang <yunhong.jiang@xxxxxxxxxxxxxxx> --- arch/x86/hyperv/hv_vtl.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/arch/x86/hyperv/hv_vtl.c b/arch/x86/hyperv/hv_vtl.c index e5aa2688cdd0..5829aac74f80 100644 --- a/arch/x86/hyperv/hv_vtl.c +++ b/arch/x86/hyperv/hv_vtl.c @@ -40,11 +40,15 @@ void __init hv_vtl_init_platform(void) { pr_info("Linux runs in Hyper-V Virtual Trust Level\n"); - if (hv_isolation_type_tdx()) + if (hv_isolation_type_tdx()) { x86_platform.hyper.is_private_mmio = hv_is_private_mmio_tdx; - x86_platform.realmode_reserve = x86_init_noop; - x86_platform.realmode_init = x86_init_noop; - real_mode_header = &hv_vtl_real_mode_header; + x86_init.resources.realmode_limit = SZ_4G; + x86_init.resources.reserve_bios = 0; + } else { + x86_platform.realmode_reserve = x86_init_noop; + x86_platform.realmode_init = x86_init_noop; + real_mode_header = &hv_vtl_real_mode_header; + } x86_init.irqs.pre_vector_init = x86_init_noop; x86_init.timers.timer_init = x86_init_noop; -- 2.25.1