From 1aa366163b8b69f660cf94fd5062fa44859e4318 Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Wed, 27 Apr 2011 13:20:30 +0300 Subject: [PATCH] KVM: x86 emulator: consolidate segment accessors Instead of separate accessors for the segment selector and cached descriptor, use one accessor for both. This simplifies the code somewhat. Signed-off-by: Avi Kivity --- arch/x86/include/asm/kvm_emulate.h | 13 +-- arch/x86/kvm/emulate.c | 122 ++++++++++++++++------------- arch/x86/kvm/x86.c | 41 +++------- 3 files changed, 83 insertions(+), 93 deletions(-) diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h index 28114f581fa3..0049211959c0 100644 --- a/arch/x86/include/asm/kvm_emulate.h +++ b/arch/x86/include/asm/kvm_emulate.h @@ -164,15 +164,10 @@ struct x86_emulate_ops { int size, unsigned short port, const void *val, unsigned int count); - bool (*get_cached_descriptor)(struct x86_emulate_ctxt *ctxt, - struct desc_struct *desc, u32 *base3, - int seg); - void (*set_cached_descriptor)(struct x86_emulate_ctxt *ctxt, - struct desc_struct *desc, u32 base3, - int seg); - u16 (*get_segment_selector)(struct x86_emulate_ctxt *ctxt, int seg); - void (*set_segment_selector)(struct x86_emulate_ctxt *ctxt, - u16 sel, int seg); + bool (*get_segment)(struct x86_emulate_ctxt *ctxt, u16 *selector, + struct desc_struct *desc, u32 *base3, int seg); + void (*set_segment)(struct x86_emulate_ctxt *ctxt, u16 selector, + struct desc_struct *desc, u32 base3, int seg); unsigned long (*get_cached_segment_base)(struct x86_emulate_ctxt *ctxt, int seg); void (*get_gdt)(struct x86_emulate_ctxt *ctxt, struct desc_ptr *dt); diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 3624f202b440..59992484f5f3 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -553,6 +553,26 @@ static int emulate_nm(struct x86_emulate_ctxt *ctxt) return emulate_exception(ctxt, NM_VECTOR, 0, false); } +static u16 get_segment_selector(struct x86_emulate_ctxt *ctxt, unsigned seg) +{ + u16 selector; + struct desc_struct desc; + + ctxt->ops->get_segment(ctxt, &selector, &desc, NULL, seg); + return selector; +} + +static void set_segment_selector(struct x86_emulate_ctxt *ctxt, u16 selector, + unsigned seg) +{ + u16 dummy; + u32 base3; + struct desc_struct desc; + + ctxt->ops->get_segment(ctxt, &dummy, &desc, &base3, seg); + ctxt->ops->set_segment(ctxt, selector, &desc, base3, seg); +} + static int __linearize(struct x86_emulate_ctxt *ctxt, struct segmented_address addr, unsigned size, bool write, bool fetch, @@ -563,6 +583,7 @@ static int __linearize(struct x86_emulate_ctxt *ctxt, bool usable; ulong la; u32 lim; + u16 sel; unsigned cpl, rpl; la = seg_base(ctxt, ctxt->ops, addr.seg) + addr.ea; @@ -574,8 +595,8 @@ static int __linearize(struct x86_emulate_ctxt *ctxt, return emulate_gp(ctxt, 0); break; default: - usable = ctxt->ops->get_cached_descriptor(ctxt, &desc, NULL, - addr.seg); + usable = ctxt->ops->get_segment(ctxt, &sel, &desc, NULL, + addr.seg); if (!usable) goto bad; /* code segment or read-only data segment */ @@ -598,7 +619,7 @@ static int __linearize(struct x86_emulate_ctxt *ctxt, goto bad; } cpl = ctxt->ops->cpl(ctxt); - rpl = ctxt->ops->get_segment_selector(ctxt, addr.seg) & 3; + rpl = sel & 3; cpl = max(cpl, rpl); if (!(desc.type & 8)) { /* data segment */ @@ -1142,9 +1163,10 @@ static void get_descriptor_table_ptr(struct x86_emulate_ctxt *ctxt, { if (selector & 1 << 2) { struct desc_struct desc; + u16 sel; + memset (dt, 0, sizeof *dt); - if (!ops->get_cached_descriptor(ctxt, &desc, NULL, - VCPU_SREG_LDTR)) + if (!ops->get_segment(ctxt, &sel, &desc, NULL, VCPU_SREG_LDTR)) return; dt->size = desc_limit_scaled(&desc); /* what if limit > 65535? */ @@ -1305,8 +1327,7 @@ static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt, return ret; } load: - ops->set_segment_selector(ctxt, selector, seg); - ops->set_cached_descriptor(ctxt, &seg_desc, 0, seg); + ops->set_segment(ctxt, selector, &seg_desc, 0, seg); return X86EMUL_CONTINUE; exception: emulate_exception(ctxt, err_vec, err_code, true); @@ -1464,7 +1485,7 @@ static int emulate_push_sreg(struct x86_emulate_ctxt *ctxt, { struct decode_cache *c = &ctxt->decode; - c->src.val = ops->get_segment_selector(ctxt, seg); + c->src.val = get_segment_selector(ctxt, seg); return em_push(ctxt); } @@ -1552,7 +1573,7 @@ int emulate_int_real(struct x86_emulate_ctxt *ctxt, ctxt->eflags &= ~(EFLG_IF | EFLG_TF | EFLG_AC); - c->src.val = ops->get_segment_selector(ctxt, VCPU_SREG_CS); + c->src.val = get_segment_selector(ctxt, VCPU_SREG_CS); rc = em_push(ctxt); if (rc != X86EMUL_CONTINUE) return rc; @@ -1838,8 +1859,10 @@ setup_syscalls_segments(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops, struct desc_struct *cs, struct desc_struct *ss) { + u16 selector; + memset(cs, 0, sizeof(struct desc_struct)); - ops->get_cached_descriptor(ctxt, cs, NULL, VCPU_SREG_CS); + ops->get_segment(ctxt, &selector, cs, NULL, VCPU_SREG_CS); memset(ss, 0, sizeof(struct desc_struct)); cs->l = 0; /* will be adjusted later */ @@ -1888,10 +1911,8 @@ emulate_syscall(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) cs.d = 0; cs.l = 1; } - ops->set_cached_descriptor(ctxt, &cs, 0, VCPU_SREG_CS); - ops->set_segment_selector(ctxt, cs_sel, VCPU_SREG_CS); - ops->set_cached_descriptor(ctxt, &ss, 0, VCPU_SREG_SS); - ops->set_segment_selector(ctxt, ss_sel, VCPU_SREG_SS); + ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS); + ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS); c->regs[VCPU_REGS_RCX] = c->eip; if (efer & EFER_LMA) { @@ -1961,10 +1982,8 @@ emulate_sysenter(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) cs.l = 1; } - ops->set_cached_descriptor(ctxt, &cs, 0, VCPU_SREG_CS); - ops->set_segment_selector(ctxt, cs_sel, VCPU_SREG_CS); - ops->set_cached_descriptor(ctxt, &ss, 0, VCPU_SREG_SS); - ops->set_segment_selector(ctxt, ss_sel, VCPU_SREG_SS); + ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS); + ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS); ops->get_msr(ctxt, MSR_IA32_SYSENTER_EIP, &msr_data); c->eip = msr_data; @@ -2018,10 +2037,8 @@ emulate_sysexit(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) cs_sel |= SELECTOR_RPL_MASK; ss_sel |= SELECTOR_RPL_MASK; - ops->set_cached_descriptor(ctxt, &cs, 0, VCPU_SREG_CS); - ops->set_segment_selector(ctxt, cs_sel, VCPU_SREG_CS); - ops->set_cached_descriptor(ctxt, &ss, 0, VCPU_SREG_SS); - ops->set_segment_selector(ctxt, ss_sel, VCPU_SREG_SS); + ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS); + ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS); c->eip = c->regs[VCPU_REGS_RDX]; c->regs[VCPU_REGS_RSP] = c->regs[VCPU_REGS_RCX]; @@ -2048,11 +2065,11 @@ static bool emulator_io_port_access_allowed(struct x86_emulate_ctxt *ctxt, struct desc_struct tr_seg; u32 base3; int r; - u16 io_bitmap_ptr, perm, bit_idx = port & 0x7; + u16 tr, io_bitmap_ptr, perm, bit_idx = port & 0x7; unsigned mask = (1 << len) - 1; unsigned long base; - ops->get_cached_descriptor(ctxt, &tr_seg, &base3, VCPU_SREG_TR); + ops->get_segment(ctxt, &tr, &tr_seg, &base3, VCPU_SREG_TR); if (!tr_seg.p) return false; if (desc_limit_scaled(&tr_seg) < 103) @@ -2107,11 +2124,11 @@ static void save_state_to_tss16(struct x86_emulate_ctxt *ctxt, tss->si = c->regs[VCPU_REGS_RSI]; tss->di = c->regs[VCPU_REGS_RDI]; - tss->es = ops->get_segment_selector(ctxt, VCPU_SREG_ES); - tss->cs = ops->get_segment_selector(ctxt, VCPU_SREG_CS); - tss->ss = ops->get_segment_selector(ctxt, VCPU_SREG_SS); - tss->ds = ops->get_segment_selector(ctxt, VCPU_SREG_DS); - tss->ldt = ops->get_segment_selector(ctxt, VCPU_SREG_LDTR); + tss->es = get_segment_selector(ctxt, VCPU_SREG_ES); + tss->cs = get_segment_selector(ctxt, VCPU_SREG_CS); + tss->ss = get_segment_selector(ctxt, VCPU_SREG_SS); + tss->ds = get_segment_selector(ctxt, VCPU_SREG_DS); + tss->ldt = get_segment_selector(ctxt, VCPU_SREG_LDTR); } static int load_state_from_tss16(struct x86_emulate_ctxt *ctxt, @@ -2136,11 +2153,11 @@ static int load_state_from_tss16(struct x86_emulate_ctxt *ctxt, * SDM says that segment selectors are loaded before segment * descriptors */ - ops->set_segment_selector(ctxt, tss->ldt, VCPU_SREG_LDTR); - ops->set_segment_selector(ctxt, tss->es, VCPU_SREG_ES); - ops->set_segment_selector(ctxt, tss->cs, VCPU_SREG_CS); - ops->set_segment_selector(ctxt, tss->ss, VCPU_SREG_SS); - ops->set_segment_selector(ctxt, tss->ds, VCPU_SREG_DS); + set_segment_selector(ctxt, tss->ldt, VCPU_SREG_LDTR); + set_segment_selector(ctxt, tss->es, VCPU_SREG_ES); + set_segment_selector(ctxt, tss->cs, VCPU_SREG_CS); + set_segment_selector(ctxt, tss->ss, VCPU_SREG_SS); + set_segment_selector(ctxt, tss->ds, VCPU_SREG_DS); /* * Now load segment descriptors. If fault happenes at this stage @@ -2227,13 +2244,13 @@ static void save_state_to_tss32(struct x86_emulate_ctxt *ctxt, tss->esi = c->regs[VCPU_REGS_RSI]; tss->edi = c->regs[VCPU_REGS_RDI]; - tss->es = ops->get_segment_selector(ctxt, VCPU_SREG_ES); - tss->cs = ops->get_segment_selector(ctxt, VCPU_SREG_CS); - tss->ss = ops->get_segment_selector(ctxt, VCPU_SREG_SS); - tss->ds = ops->get_segment_selector(ctxt, VCPU_SREG_DS); - tss->fs = ops->get_segment_selector(ctxt, VCPU_SREG_FS); - tss->gs = ops->get_segment_selector(ctxt, VCPU_SREG_GS); - tss->ldt_selector = ops->get_segment_selector(ctxt, VCPU_SREG_LDTR); + tss->es = get_segment_selector(ctxt, VCPU_SREG_ES); + tss->cs = get_segment_selector(ctxt, VCPU_SREG_CS); + tss->ss = get_segment_selector(ctxt, VCPU_SREG_SS); + tss->ds = get_segment_selector(ctxt, VCPU_SREG_DS); + tss->fs = get_segment_selector(ctxt, VCPU_SREG_FS); + tss->gs = get_segment_selector(ctxt, VCPU_SREG_GS); + tss->ldt_selector = get_segment_selector(ctxt, VCPU_SREG_LDTR); } static int load_state_from_tss32(struct x86_emulate_ctxt *ctxt, @@ -2260,13 +2277,13 @@ static int load_state_from_tss32(struct x86_emulate_ctxt *ctxt, * SDM says that segment selectors are loaded before segment * descriptors */ - ops->set_segment_selector(ctxt, tss->ldt_selector, VCPU_SREG_LDTR); - ops->set_segment_selector(ctxt, tss->es, VCPU_SREG_ES); - ops->set_segment_selector(ctxt, tss->cs, VCPU_SREG_CS); - ops->set_segment_selector(ctxt, tss->ss, VCPU_SREG_SS); - ops->set_segment_selector(ctxt, tss->ds, VCPU_SREG_DS); - ops->set_segment_selector(ctxt, tss->fs, VCPU_SREG_FS); - ops->set_segment_selector(ctxt, tss->gs, VCPU_SREG_GS); + set_segment_selector(ctxt, tss->ldt_selector, VCPU_SREG_LDTR); + set_segment_selector(ctxt, tss->es, VCPU_SREG_ES); + set_segment_selector(ctxt, tss->cs, VCPU_SREG_CS); + set_segment_selector(ctxt, tss->ss, VCPU_SREG_SS); + set_segment_selector(ctxt, tss->ds, VCPU_SREG_DS); + set_segment_selector(ctxt, tss->fs, VCPU_SREG_FS); + set_segment_selector(ctxt, tss->gs, VCPU_SREG_GS); /* * Now load segment descriptors. If fault happenes at this stage @@ -2348,7 +2365,7 @@ static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt, { struct desc_struct curr_tss_desc, next_tss_desc; int ret; - u16 old_tss_sel = ops->get_segment_selector(ctxt, VCPU_SREG_TR); + u16 old_tss_sel = get_segment_selector(ctxt, VCPU_SREG_TR); ulong old_tss_base = ops->get_cached_segment_base(ctxt, VCPU_SREG_TR); u32 desc_limit; @@ -2411,8 +2428,7 @@ static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt, } ops->set_cr(ctxt, 0, ops->get_cr(ctxt, 0) | X86_CR0_TS); - ops->set_cached_descriptor(ctxt, &next_tss_desc, 0, VCPU_SREG_TR); - ops->set_segment_selector(ctxt, tss_selector, VCPU_SREG_TR); + ops->set_segment(ctxt, tss_selector, &next_tss_desc, 0, VCPU_SREG_TR); if (has_error_code) { struct decode_cache *c = &ctxt->decode; @@ -2503,7 +2519,7 @@ static int em_call_far(struct x86_emulate_ctxt *ctxt) ulong old_eip; int rc; - old_cs = ctxt->ops->get_segment_selector(ctxt, VCPU_SREG_CS); + old_cs = get_segment_selector(ctxt, VCPU_SREG_CS); old_eip = c->eip; memcpy(&sel, c->src.valptr + c->op_bytes, 2); @@ -3881,7 +3897,7 @@ special_insn: rc = emulate_ud(ctxt); goto done; } - c->dst.val = ops->get_segment_selector(ctxt, c->modrm_reg); + c->dst.val = get_segment_selector(ctxt, c->modrm_reg); break; case 0x8d: /* lea r16/r32, m */ c->dst.val = c->src.addr.mem.ea; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 22bc69ccf3ef..77c9d8673dc4 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4304,13 +4304,14 @@ static unsigned long emulator_get_cached_segment_base( return get_segment_base(emul_to_vcpu(ctxt), seg); } -static bool emulator_get_cached_descriptor(struct x86_emulate_ctxt *ctxt, - struct desc_struct *desc, u32 *base3, - int seg) +static bool emulator_get_segment(struct x86_emulate_ctxt *ctxt, u16 *selector, + struct desc_struct *desc, u32 *base3, + int seg) { struct kvm_segment var; kvm_get_segment(emul_to_vcpu(ctxt), &var, seg); + *selector = var.selector; if (var.unusable) return false; @@ -4335,16 +4336,14 @@ static bool emulator_get_cached_descriptor(struct x86_emulate_ctxt *ctxt, return true; } -static void emulator_set_cached_descriptor(struct x86_emulate_ctxt *ctxt, - struct desc_struct *desc, u32 base3, - int seg) +static void emulator_set_segment(struct x86_emulate_ctxt *ctxt, u16 selector, + struct desc_struct *desc, u32 base3, + int seg) { struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt); struct kvm_segment var; - /* needed to preserve selector */ - kvm_get_segment(vcpu, &var, seg); - + var.selector = selector; var.base = get_desc_base(desc); #ifdef CONFIG_X86_64 var.base |= ((u64)base3) << 32; @@ -4368,24 +4367,6 @@ static void emulator_set_cached_descriptor(struct x86_emulate_ctxt *ctxt, return; } -static u16 emulator_get_segment_selector(struct x86_emulate_ctxt *ctxt, int seg) -{ - struct kvm_segment kvm_seg; - - kvm_get_segment(emul_to_vcpu(ctxt), &kvm_seg, seg); - return kvm_seg.selector; -} - -static void emulator_set_segment_selector(struct x86_emulate_ctxt *ctxt, - u16 sel, int seg) -{ - struct kvm_segment kvm_seg; - - kvm_get_segment(emul_to_vcpu(ctxt), &kvm_seg, seg); - kvm_seg.selector = sel; - kvm_set_segment(emul_to_vcpu(ctxt), &kvm_seg, seg); -} - static int emulator_get_msr(struct x86_emulate_ctxt *ctxt, u32 msr_index, u64 *pdata) { @@ -4436,10 +4417,8 @@ static struct x86_emulate_ops emulate_ops = { .invlpg = emulator_invlpg, .pio_in_emulated = emulator_pio_in_emulated, .pio_out_emulated = emulator_pio_out_emulated, - .get_cached_descriptor = emulator_get_cached_descriptor, - .set_cached_descriptor = emulator_set_cached_descriptor, - .get_segment_selector = emulator_get_segment_selector, - .set_segment_selector = emulator_set_segment_selector, + .get_segment = emulator_get_segment, + .set_segment = emulator_set_segment, .get_cached_segment_base = emulator_get_cached_segment_base, .get_gdt = emulator_get_gdt, .get_idt = emulator_get_idt,