From 15b00f32d53f31fe194b17ca0384a37756b55be2 Mon Sep 17 00:00:00 2001 From: Jan Kiszka Date: Mon, 19 Nov 2007 10:21:45 +0100 Subject: [PATCH] KVM: VMX: Force seg.base == (seg.sel << 4) in real mode Ensure that segment.base == segment.selector << 4 when entering the real mode on Intel so that the CPU will not bark at us. This fixes some old protected mode demo from http://www.x86.org/articles/pmbasics/tspec_a1_doc.htm. Signed-off-by: Jan Kiszka Signed-off-by: Avi Kivity --- drivers/kvm/vmx.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c index 0c082faaa6db..b4c0bdce7b34 100644 --- a/drivers/kvm/vmx.c +++ b/drivers/kvm/vmx.c @@ -1165,7 +1165,8 @@ static void fix_rmode_seg(int seg, struct kvm_save_segment *save) save->base = vmcs_readl(sf->base); save->limit = vmcs_read32(sf->limit); save->ar = vmcs_read32(sf->ar_bytes); - vmcs_write16(sf->selector, vmcs_readl(sf->base) >> 4); + vmcs_write16(sf->selector, save->base >> 4); + vmcs_write32(sf->base, save->base & 0xfffff); vmcs_write32(sf->limit, 0xffff); vmcs_write32(sf->ar_bytes, 0xf3); } -- 2.39.2