From 869be99c7579c857885643ba2aed87ced339c6a2 Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Wed, 13 Jun 2012 16:30:53 +0300 Subject: [PATCH] KVM: x86 emulator: make loading TR set the busy bit Guest software doesn't actually depend on it, but vmx will refuse us entry if we don't. Set the bit in both the cached segment and memory, just to be nice. Signed-off-by: Avi Kivity --- arch/x86/kvm/emulate.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 99e3df2..92a1add 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -1335,7 +1335,7 @@ static int write_segment_descriptor(struct x86_emulate_ctxt *ctxt, static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt, u16 selector, int seg) { - struct desc_struct seg_desc; + struct desc_struct seg_desc, old_desc; u8 dpl, rpl, cpl; unsigned err_vec = GP_VECTOR; u32 err_code = 0; @@ -1422,6 +1422,12 @@ static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt, case VCPU_SREG_TR: if (seg_desc.s || (seg_desc.type != 1 && seg_desc.type != 9)) goto exception; + old_desc = seg_desc; + seg_desc.type |= 2; /* busy */ + ret = ctxt->ops->cmpxchg_emulated(ctxt, desc_addr, &old_desc, &seg_desc, + sizeof(seg_desc), &ctxt->exception); + if (ret != X86EMUL_CONTINUE) + return ret; break; case VCPU_SREG_LDTR: if (seg_desc.s || seg_desc.type != 2) -- 2.7.4