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Diffstat (limited to 'arch/x86/kvm/emulate.c')
-rw-r--r--arch/x86/kvm/emulate.c61
1 files changed, 32 insertions, 29 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 8079d141792a..abe74f779f9d 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1046,7 +1046,6 @@ static void fetch_register_operand(struct operand *op)
static void read_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data, int reg)
{
- ctxt->ops->get_fpu(ctxt);
switch (reg) {
case 0: asm("movdqa %%xmm0, %0" : "=m"(*data)); break;
case 1: asm("movdqa %%xmm1, %0" : "=m"(*data)); break;
@@ -1068,13 +1067,11 @@ static void read_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data, int reg)
#endif
default: BUG();
}
- ctxt->ops->put_fpu(ctxt);
}
static void write_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data,
int reg)
{
- ctxt->ops->get_fpu(ctxt);
switch (reg) {
case 0: asm("movdqa %0, %%xmm0" : : "m"(*data)); break;
case 1: asm("movdqa %0, %%xmm1" : : "m"(*data)); break;
@@ -1096,12 +1093,10 @@ static void write_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data,
#endif
default: BUG();
}
- ctxt->ops->put_fpu(ctxt);
}
static void read_mmx_reg(struct x86_emulate_ctxt *ctxt, u64 *data, int reg)
{
- ctxt->ops->get_fpu(ctxt);
switch (reg) {
case 0: asm("movq %%mm0, %0" : "=m"(*data)); break;
case 1: asm("movq %%mm1, %0" : "=m"(*data)); break;
@@ -1113,12 +1108,10 @@ static void read_mmx_reg(struct x86_emulate_ctxt *ctxt, u64 *data, int reg)
case 7: asm("movq %%mm7, %0" : "=m"(*data)); break;
default: BUG();
}
- ctxt->ops->put_fpu(ctxt);
}
static void write_mmx_reg(struct x86_emulate_ctxt *ctxt, u64 *data, int reg)
{
- ctxt->ops->get_fpu(ctxt);
switch (reg) {
case 0: asm("movq %0, %%mm0" : : "m"(*data)); break;
case 1: asm("movq %0, %%mm1" : : "m"(*data)); break;
@@ -1130,7 +1123,6 @@ static void write_mmx_reg(struct x86_emulate_ctxt *ctxt, u64 *data, int reg)
case 7: asm("movq %0, %%mm7" : : "m"(*data)); break;
default: BUG();
}
- ctxt->ops->put_fpu(ctxt);
}
static int em_fninit(struct x86_emulate_ctxt *ctxt)
@@ -1138,9 +1130,7 @@ static int em_fninit(struct x86_emulate_ctxt *ctxt)
if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM))
return emulate_nm(ctxt);
- ctxt->ops->get_fpu(ctxt);
asm volatile("fninit");
- ctxt->ops->put_fpu(ctxt);
return X86EMUL_CONTINUE;
}
@@ -1151,9 +1141,7 @@ static int em_fnstcw(struct x86_emulate_ctxt *ctxt)
if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM))
return emulate_nm(ctxt);
- ctxt->ops->get_fpu(ctxt);
asm volatile("fnstcw %0": "+m"(fcw));
- ctxt->ops->put_fpu(ctxt);
ctxt->dst.val = fcw;
@@ -1167,9 +1155,7 @@ static int em_fnstsw(struct x86_emulate_ctxt *ctxt)
if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM))
return emulate_nm(ctxt);
- ctxt->ops->get_fpu(ctxt);
asm volatile("fnstsw %0": "+m"(fsw));
- ctxt->ops->put_fpu(ctxt);
ctxt->dst.val = fsw;
@@ -4001,12 +3987,8 @@ static int em_fxsave(struct x86_emulate_ctxt *ctxt)
if (rc != X86EMUL_CONTINUE)
return rc;
- ctxt->ops->get_fpu(ctxt);
-
rc = asm_safe("fxsave %[fx]", , [fx] "+m"(fx_state));
- ctxt->ops->put_fpu(ctxt);
-
if (rc != X86EMUL_CONTINUE)
return rc;
@@ -4014,6 +3996,26 @@ static int em_fxsave(struct x86_emulate_ctxt *ctxt)
fxstate_size(ctxt));
}
+/*
+ * FXRSTOR might restore XMM registers not provided by the guest. Fill
+ * in the host registers (via FXSAVE) instead, so they won't be modified.
+ * (preemption has to stay disabled until FXRSTOR).
+ *
+ * Use noinline to keep the stack for other functions called by callers small.
+ */
+static noinline int fxregs_fixup(struct fxregs_state *fx_state,
+ const size_t used_size)
+{
+ struct fxregs_state fx_tmp;
+ int rc;
+
+ rc = asm_safe("fxsave %[fx]", , [fx] "+m"(fx_tmp));
+ memcpy((void *)fx_state + used_size, (void *)&fx_tmp + used_size,
+ __fxstate_size(16) - used_size);
+
+ return rc;
+}
+
static int em_fxrstor(struct x86_emulate_ctxt *ctxt)
{
struct fxregs_state fx_state;
@@ -4024,19 +4026,17 @@ static int em_fxrstor(struct x86_emulate_ctxt *ctxt)
if (rc != X86EMUL_CONTINUE)
return rc;
- ctxt->ops->get_fpu(ctxt);
-
size = fxstate_size(ctxt);
+ rc = segmented_read_std(ctxt, ctxt->memop.addr.mem, &fx_state, size);
+ if (rc != X86EMUL_CONTINUE)
+ return rc;
+
if (size < __fxstate_size(16)) {
- rc = asm_safe("fxsave %[fx]", , [fx] "+m"(fx_state));
+ rc = fxregs_fixup(&fx_state, size);
if (rc != X86EMUL_CONTINUE)
goto out;
}
- rc = segmented_read_std(ctxt, ctxt->memop.addr.mem, &fx_state, size);
- if (rc != X86EMUL_CONTINUE)
- goto out;
-
if (fx_state.mxcsr >> 16) {
rc = emulate_gp(ctxt, 0);
goto out;
@@ -4046,8 +4046,6 @@ static int em_fxrstor(struct x86_emulate_ctxt *ctxt)
rc = asm_safe("fxrstor %[fx]", : [fx] "m"(fx_state));
out:
- ctxt->ops->put_fpu(ctxt);
-
return rc;
}
@@ -5000,6 +4998,8 @@ int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len)
bool op_prefix = false;
bool has_seg_override = false;
struct opcode opcode;
+ u16 dummy;
+ struct desc_struct desc;
ctxt->memop.type = OP_NONE;
ctxt->memopp = NULL;
@@ -5018,6 +5018,11 @@ int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len)
switch (mode) {
case X86EMUL_MODE_REAL:
case X86EMUL_MODE_VM86:
+ def_op_bytes = def_ad_bytes = 2;
+ ctxt->ops->get_segment(ctxt, &dummy, &desc, NULL, VCPU_SREG_CS);
+ if (desc.d)
+ def_op_bytes = def_ad_bytes = 4;
+ break;
case X86EMUL_MODE_PROT16:
def_op_bytes = def_ad_bytes = 2;
break;
@@ -5290,9 +5295,7 @@ static int flush_pending_x87_faults(struct x86_emulate_ctxt *ctxt)
{
int rc;
- ctxt->ops->get_fpu(ctxt);
rc = asm_safe("fwait");
- ctxt->ops->put_fpu(ctxt);
if (unlikely(rc != X86EMUL_CONTINUE))
return emulate_exception(ctxt, MF_VECTOR, 0, false);
generated by cgit (git 2.34.1) at 2024-05-08 12:46:47 +0000