From c678acb180c75c45d75e1ca7dee6e19cba55ce33 Mon Sep 17 00:00:00 2001 From: Keir Fraser Date: Thu, 4 Oct 2007 09:40:31 +0100 Subject: [PATCH] This patch ensures xen vmm has exclusive access of vt-d hw by zapping vt-d "DMAR" ACPI table signature after xen has finished using it. Signed-off-by: Allen Kay --- xen/arch/x86/hvm/vmx/vtd/dmar.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/xen/arch/x86/hvm/vmx/vtd/dmar.c b/xen/arch/x86/hvm/vmx/vtd/dmar.c index 44ca487bdb..7103994ff6 100644 --- a/xen/arch/x86/hvm/vmx/vtd/dmar.c +++ b/xen/arch/x86/hvm/vmx/vtd/dmar.c @@ -483,6 +483,10 @@ acpi_parse_dmar(unsigned long phys_addr, unsigned long size) entry_header = ((void *)entry_header + entry_header->length); } + + /* Zap APCI DMAR signature to prevent dom0 using vt-d HW. */ + dmar->header.signature[0] = '\0'; + return ret; } -- 2.30.2