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 <avi@redhat.com>
diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h
index 28114f5..00492119 100644
--- a/arch/x86/include/asm/kvm_emulate.h
+++ b/arch/x86/include/asm/kvm_emulate.h
@@ -164,15 +164,10 @@
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 3624f20..59992484 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -553,6 +553,26 @@
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 @@
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 @@
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 @@
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 @@
{
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 @@
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 @@
{
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
* 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 @@
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 @@
* 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 @@
{
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 @@
}
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 @@
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 @@
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 22bc69c..77c9d86 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4304,13 +4304,14 @@
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 @@
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 @@
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 @@
.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,