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Diffstat (limited to 'arch/x86/kvm/emulate.c')
-rw-r--r--arch/x86/kvm/emulate.c112
1 files changed, 97 insertions, 15 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 0982507b962a..83756223f8aa 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -57,6 +57,7 @@
#define OpDS 23ull /* DS */
#define OpFS 24ull /* FS */
#define OpGS 25ull /* GS */
+#define OpMem8 26ull /* 8-bit zero extended memory operand */
#define OpBits 5 /* Width of operand field */
#define OpMask ((1ull << OpBits) - 1)
@@ -101,6 +102,7 @@
#define SrcAcc (OpAcc << SrcShift)
#define SrcImmU16 (OpImmU16 << SrcShift)
#define SrcDX (OpDX << SrcShift)
+#define SrcMem8 (OpMem8 << SrcShift)
#define SrcMask (OpMask << SrcShift)
#define BitOp (1<<11)
#define MemAbs (1<<12) /* Memory operand is absolute displacement */
@@ -858,8 +860,7 @@ static void write_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data,
}
static void decode_register_operand(struct x86_emulate_ctxt *ctxt,
- struct operand *op,
- int inhibit_bytereg)
+ struct operand *op)
{
unsigned reg = ctxt->modrm_reg;
int highbyte_regs = ctxt->rex_prefix == 0;
@@ -876,7 +877,7 @@ static void decode_register_operand(struct x86_emulate_ctxt *ctxt,
}
op->type = OP_REG;
- if ((ctxt->d & ByteOp) && !inhibit_bytereg) {
+ if (ctxt->d & ByteOp) {
op->addr.reg = decode_register(reg, ctxt->regs, highbyte_regs);
op->bytes = 1;
} else {
@@ -1151,6 +1152,22 @@ static int pio_in_emulated(struct x86_emulate_ctxt *ctxt,
return 1;
}
+static int read_interrupt_descriptor(struct x86_emulate_ctxt *ctxt,
+ u16 index, struct desc_struct *desc)
+{
+ struct desc_ptr dt;
+ ulong addr;
+
+ ctxt->ops->get_idt(ctxt, &dt);
+
+ if (dt.size < index * 8 + 7)
+ return emulate_gp(ctxt, index << 3 | 0x2);
+
+ addr = dt.address + index * 8;
+ return ctxt->ops->read_std(ctxt, addr, desc, sizeof *desc,
+ &ctxt->exception);
+}
+
static void get_descriptor_table_ptr(struct x86_emulate_ctxt *ctxt,
u16 selector, struct desc_ptr *dt)
{
@@ -1227,6 +1244,8 @@ static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt,
seg_desc.type = 3;
seg_desc.p = 1;
seg_desc.s = 1;
+ if (ctxt->mode == X86EMUL_MODE_VM86)
+ seg_desc.dpl = 3;
goto load;
}
@@ -1891,6 +1910,17 @@ setup_syscalls_segments(struct x86_emulate_ctxt *ctxt,
ss->p = 1;
}
+static bool vendor_intel(struct x86_emulate_ctxt *ctxt)
+{
+ u32 eax, ebx, ecx, edx;
+
+ eax = ecx = 0;
+ return ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx)
+ && ebx == X86EMUL_CPUID_VENDOR_GenuineIntel_ebx
+ && ecx == X86EMUL_CPUID_VENDOR_GenuineIntel_ecx
+ && edx == X86EMUL_CPUID_VENDOR_GenuineIntel_edx;
+}
+
static bool em_syscall_is_enabled(struct x86_emulate_ctxt *ctxt)
{
struct x86_emulate_ops *ops = ctxt->ops;
@@ -2007,6 +2037,14 @@ static int em_sysenter(struct x86_emulate_ctxt *ctxt)
if (ctxt->mode == X86EMUL_MODE_REAL)
return emulate_gp(ctxt, 0);
+ /*
+ * Not recognized on AMD in compat mode (but is recognized in legacy
+ * mode).
+ */
+ if ((ctxt->mode == X86EMUL_MODE_PROT32) && (efer & EFER_LMA)
+ && !vendor_intel(ctxt))
+ return emulate_ud(ctxt);
+
/* XXX sysenter/sysexit have not been tested in 64bit mode.
* Therefore, we inject an #UD.
*/
@@ -2306,6 +2344,8 @@ static int load_state_from_tss32(struct x86_emulate_ctxt *ctxt,
return emulate_gp(ctxt, 0);
ctxt->_eip = tss->eip;
ctxt->eflags = tss->eflags | 2;
+
+ /* General purpose registers */
ctxt->regs[VCPU_REGS_RAX] = tss->eax;
ctxt->regs[VCPU_REGS_RCX] = tss->ecx;
ctxt->regs[VCPU_REGS_RDX] = tss->edx;
@@ -2328,6 +2368,24 @@ static int load_state_from_tss32(struct x86_emulate_ctxt *ctxt,
set_segment_selector(ctxt, tss->gs, VCPU_SREG_GS);
/*
+ * If we're switching between Protected Mode and VM86, we need to make
+ * sure to update the mode before loading the segment descriptors so
+ * that the selectors are interpreted correctly.
+ *
+ * Need to get rflags to the vcpu struct immediately because it
+ * influences the CPL which is checked at least when loading the segment
+ * descriptors and when pushing an error code to the new kernel stack.
+ *
+ * TODO Introduce a separate ctxt->ops->set_cpl callback
+ */
+ if (ctxt->eflags & X86_EFLAGS_VM)
+ ctxt->mode = X86EMUL_MODE_VM86;
+ else
+ ctxt->mode = X86EMUL_MODE_PROT32;
+
+ ctxt->ops->set_rflags(ctxt, ctxt->eflags);
+
+ /*
* Now load segment descriptors. If fault happenes at this stage
* it is handled in a context of new task
*/
@@ -2401,7 +2459,7 @@ static int task_switch_32(struct x86_emulate_ctxt *ctxt,
}
static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt,
- u16 tss_selector, int reason,
+ u16 tss_selector, int idt_index, int reason,
bool has_error_code, u32 error_code)
{
struct x86_emulate_ops *ops = ctxt->ops;
@@ -2423,12 +2481,35 @@ static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt,
/* FIXME: check that next_tss_desc is tss */
- if (reason != TASK_SWITCH_IRET) {
- if ((tss_selector & 3) > next_tss_desc.dpl ||
- ops->cpl(ctxt) > next_tss_desc.dpl)
- return emulate_gp(ctxt, 0);
+ /*
+ * Check privileges. The three cases are task switch caused by...
+ *
+ * 1. jmp/call/int to task gate: Check against DPL of the task gate
+ * 2. Exception/IRQ/iret: No check is performed
+ * 3. jmp/call to TSS: Check agains DPL of the TSS
+ */
+ if (reason == TASK_SWITCH_GATE) {
+ if (idt_index != -1) {
+ /* Software interrupts */
+ struct desc_struct task_gate_desc;
+ int dpl;
+
+ ret = read_interrupt_descriptor(ctxt, idt_index,
+ &task_gate_desc);
+ if (ret != X86EMUL_CONTINUE)
+ return ret;
+
+ dpl = task_gate_desc.dpl;
+ if ((tss_selector & 3) > dpl || ops->cpl(ctxt) > dpl)
+ return emulate_gp(ctxt, (idt_index << 3) | 0x2);
+ }
+ } else if (reason != TASK_SWITCH_IRET) {
+ int dpl = next_tss_desc.dpl;
+ if ((tss_selector & 3) > dpl || ops->cpl(ctxt) > dpl)
+ return emulate_gp(ctxt, tss_selector);
}
+
desc_limit = desc_limit_scaled(&next_tss_desc);
if (!next_tss_desc.p ||
((desc_limit < 0x67 && (next_tss_desc.type & 8)) ||
@@ -2481,7 +2562,7 @@ static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt,
}
int emulator_task_switch(struct x86_emulate_ctxt *ctxt,
- u16 tss_selector, int reason,
+ u16 tss_selector, int idt_index, int reason,
bool has_error_code, u32 error_code)
{
int rc;
@@ -2489,7 +2570,7 @@ int emulator_task_switch(struct x86_emulate_ctxt *ctxt,
ctxt->_eip = ctxt->eip;
ctxt->dst.type = OP_NONE;
- rc = emulator_do_task_switch(ctxt, tss_selector, reason,
+ rc = emulator_do_task_switch(ctxt, tss_selector, idt_index, reason,
has_error_code, error_code);
if (rc == X86EMUL_CONTINUE)
@@ -3514,13 +3595,13 @@ static struct opcode twobyte_table[256] = {
I(DstMem | SrcReg | ModRM | BitOp | Lock, em_btr),
I(DstReg | SrcMemFAddr | ModRM | Src2FS, em_lseg),
I(DstReg | SrcMemFAddr | ModRM | Src2GS, em_lseg),
- D(ByteOp | DstReg | SrcMem | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
+ D(DstReg | SrcMem8 | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
/* 0xB8 - 0xBF */
N, N,
G(BitOp, group8),
I(DstMem | SrcReg | ModRM | BitOp | Lock | PageTable, em_btc),
I(DstReg | SrcMem | ModRM, em_bsf), I(DstReg | SrcMem | ModRM, em_bsr),
- D(ByteOp | DstReg | SrcMem | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
+ D(DstReg | SrcMem8 | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
/* 0xC0 - 0xCF */
D2bv(DstMem | SrcReg | ModRM | Lock),
N, D(DstMem | SrcReg | ModRM | Mov),
@@ -3602,9 +3683,7 @@ static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op,
switch (d) {
case OpReg:
- decode_register_operand(ctxt, op,
- op == &ctxt->dst &&
- ctxt->twobyte && (ctxt->b == 0xb6 || ctxt->b == 0xb7));
+ decode_register_operand(ctxt, op);
break;
case OpImmUByte:
rc = decode_imm(ctxt, op, 1, false);
@@ -3656,6 +3735,9 @@ static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op,
case OpImm:
rc = decode_imm(ctxt, op, imm_size(ctxt), true);
break;
+ case OpMem8:
+ ctxt->memop.bytes = 1;
+ goto mem_common;
case OpMem16:
ctxt->memop.bytes = 2;
goto mem_common;
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-26 02:21:50 +0100