From 59115e2e25f42924181055ed7cc1d123af7598b7 Mon Sep 17 00:00:00 2001 From: Naman Jain Date: Thu, 16 Jan 2025 06:12:24 +0000 Subject: [PATCH] x86/hyperv/vtl: Stop kernel from probing VTL0 low memory For Linux, running in Hyper-V VTL (Virtual Trust Level), kernel in VTL2 tries to access VTL0 low memory in probe_roms. This memory is not described in the e820 map. Initialize probe_roms call to no-ops during boot for VTL2 kernel to avoid this. The issue got identified in OpenVMM which detects invalid accesses initiated from kernel running in VTL2. Co-developed-by: Saurabh Sengar Signed-off-by: Saurabh Sengar Signed-off-by: Naman Jain Tested-by: Roman Kisel Reviewed-by: Roman Kisel Link: https://lore.kernel.org/r/20250116061224.1701-1-namjain@linux.microsoft.com Signed-off-by: Wei Liu Message-ID: <20250116061224.1701-1-namjain@linux.microsoft.com> --- arch/x86/hyperv/hv_vtl.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/hyperv/hv_vtl.c b/arch/x86/hyperv/hv_vtl.c index 4e1b1e3b5658..3f4e20d7b724 100644 --- a/arch/x86/hyperv/hv_vtl.c +++ b/arch/x86/hyperv/hv_vtl.c @@ -30,6 +30,7 @@ void __init hv_vtl_init_platform(void) x86_platform.realmode_init = x86_init_noop; x86_init.irqs.pre_vector_init = x86_init_noop; x86_init.timers.timer_init = x86_init_noop; + x86_init.resources.probe_roms = x86_init_noop; /* Avoid searching for BIOS MP tables */ x86_init.mpparse.find_mptable = x86_init_noop;