From e919464b53ea29aed46ff10f7d6416268678bdb9 Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Wed, 13 Jun 2012 16:29:39 +0300 Subject: [PATCH] KVM: x86 emulator: make read_segment_descriptor() return the address Some operations want to modify the descriptor later on, so save the address for future use. Signed-off-by: Avi Kivity --- arch/x86/kvm/emulate.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 7b575ad..99e3df2 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -1296,7 +1296,8 @@ static void get_descriptor_table_ptr(struct x86_emulate_ctxt *ctxt, /* allowed just for 8 bytes segments */ static int read_segment_descriptor(struct x86_emulate_ctxt *ctxt, - u16 selector, struct desc_struct *desc) + u16 selector, struct desc_struct *desc, + ulong *desc_addr_p) { struct desc_ptr dt; u16 index = selector >> 3; @@ -1307,7 +1308,7 @@ static int read_segment_descriptor(struct x86_emulate_ctxt *ctxt, if (dt.size < index * 8 + 7) return emulate_gp(ctxt, selector & 0xfffc); - addr = dt.address + index * 8; + *desc_addr_p = addr = dt.address + index * 8; return ctxt->ops->read_std(ctxt, addr, desc, sizeof *desc, &ctxt->exception); } @@ -1339,6 +1340,7 @@ static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt, unsigned err_vec = GP_VECTOR; u32 err_code = 0; bool null_selector = !(selector & ~0x3); /* 0000-0003 are null */ + ulong desc_addr; int ret; memset(&seg_desc, 0, sizeof seg_desc); @@ -1374,7 +1376,7 @@ static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt, if (null_selector) /* for NULL selector skip all following checks */ goto load; - ret = read_segment_descriptor(ctxt, selector, &seg_desc); + ret = read_segment_descriptor(ctxt, selector, &seg_desc, &desc_addr); if (ret != X86EMUL_CONTINUE) return ret; @@ -2614,13 +2616,14 @@ static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt, ulong old_tss_base = ops->get_cached_segment_base(ctxt, VCPU_SREG_TR); u32 desc_limit; + ulong desc_addr; /* FIXME: old_tss_base == ~0 ? */ - ret = read_segment_descriptor(ctxt, tss_selector, &next_tss_desc); + ret = read_segment_descriptor(ctxt, tss_selector, &next_tss_desc, &desc_addr); if (ret != X86EMUL_CONTINUE) return ret; - ret = read_segment_descriptor(ctxt, old_tss_sel, &curr_tss_desc); + ret = read_segment_descriptor(ctxt, old_tss_sel, &curr_tss_desc, &desc_addr); if (ret != X86EMUL_CONTINUE) return ret; -- 2.7.4