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authorJan Kiszka <jan.kiszka@siemens.com>2007-11-19 10:21:45 +0100
committerAvi Kivity <avi@qumranet.com>2008-01-30 17:53:06 +0200
commit15b00f32d53f31fe194b17ca0384a37756b55be2 (patch)
tree2555b34389c6a4a3c24569201b6504794b566d5d
parent54f1585a8d0131bc3993902d4441f4049daed0d5 (diff)
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 <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
-rw-r--r--drivers/kvm/vmx.c3
1 files changed, 2 insertions, 1 deletions
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);
}