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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-09-08 01:01:14 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-09-08 01:01:14 -0300
commite5fd91f1ef340da553f7a79da9540c3db711c937 (patch)
treeb11842027dc6641da63f4bcc524f8678263304a3 /arch/x86/kvm/emulate.c
parent2a9b0348e685a63d97486f6749622b61e9e3292f (diff)
Linux-libre 4.2-gnu
Diffstat (limited to 'arch/x86/kvm/emulate.c')
-rw-r--r--arch/x86/kvm/emulate.c303
1 files changed, 291 insertions, 12 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 630bcb0d7..e7a4fde5d 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -25,6 +25,7 @@
#include <linux/module.h>
#include <asm/kvm_emulate.h>
#include <linux/stringify.h>
+#include <asm/debugreg.h>
#include "x86.h"
#include "tss.h"
@@ -523,13 +524,9 @@ static void masked_increment(ulong *reg, ulong mask, int inc)
static inline void
register_address_increment(struct x86_emulate_ctxt *ctxt, int reg, int inc)
{
- ulong mask;
+ ulong *preg = reg_rmw(ctxt, reg);
- if (ctxt->ad_bytes == sizeof(unsigned long))
- mask = ~0UL;
- else
- mask = ad_mask(ctxt);
- masked_increment(reg_rmw(ctxt, reg), mask, inc);
+ assign_register(preg, *preg + inc, ctxt->ad_bytes);
}
static void rsp_increment(struct x86_emulate_ctxt *ctxt, int inc)
@@ -2262,6 +2259,260 @@ static int em_lseg(struct x86_emulate_ctxt *ctxt)
return rc;
}
+static int emulator_has_longmode(struct x86_emulate_ctxt *ctxt)
+{
+ u32 eax, ebx, ecx, edx;
+
+ eax = 0x80000001;
+ ecx = 0;
+ ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx);
+ return edx & bit(X86_FEATURE_LM);
+}
+
+#define GET_SMSTATE(type, smbase, offset) \
+ ({ \
+ type __val; \
+ int r = ctxt->ops->read_std(ctxt, smbase + offset, &__val, \
+ sizeof(__val), NULL); \
+ if (r != X86EMUL_CONTINUE) \
+ return X86EMUL_UNHANDLEABLE; \
+ __val; \
+ })
+
+static void rsm_set_desc_flags(struct desc_struct *desc, u32 flags)
+{
+ desc->g = (flags >> 23) & 1;
+ desc->d = (flags >> 22) & 1;
+ desc->l = (flags >> 21) & 1;
+ desc->avl = (flags >> 20) & 1;
+ desc->p = (flags >> 15) & 1;
+ desc->dpl = (flags >> 13) & 3;
+ desc->s = (flags >> 12) & 1;
+ desc->type = (flags >> 8) & 15;
+}
+
+static int rsm_load_seg_32(struct x86_emulate_ctxt *ctxt, u64 smbase, int n)
+{
+ struct desc_struct desc;
+ int offset;
+ u16 selector;
+
+ selector = GET_SMSTATE(u32, smbase, 0x7fa8 + n * 4);
+
+ if (n < 3)
+ offset = 0x7f84 + n * 12;
+ else
+ offset = 0x7f2c + (n - 3) * 12;
+
+ set_desc_base(&desc, GET_SMSTATE(u32, smbase, offset + 8));
+ set_desc_limit(&desc, GET_SMSTATE(u32, smbase, offset + 4));
+ rsm_set_desc_flags(&desc, GET_SMSTATE(u32, smbase, offset));
+ ctxt->ops->set_segment(ctxt, selector, &desc, 0, n);
+ return X86EMUL_CONTINUE;
+}
+
+static int rsm_load_seg_64(struct x86_emulate_ctxt *ctxt, u64 smbase, int n)
+{
+ struct desc_struct desc;
+ int offset;
+ u16 selector;
+ u32 base3;
+
+ offset = 0x7e00 + n * 16;
+
+ selector = GET_SMSTATE(u16, smbase, offset);
+ rsm_set_desc_flags(&desc, GET_SMSTATE(u16, smbase, offset + 2) << 8);
+ set_desc_limit(&desc, GET_SMSTATE(u32, smbase, offset + 4));
+ set_desc_base(&desc, GET_SMSTATE(u32, smbase, offset + 8));
+ base3 = GET_SMSTATE(u32, smbase, offset + 12);
+
+ ctxt->ops->set_segment(ctxt, selector, &desc, base3, n);
+ return X86EMUL_CONTINUE;
+}
+
+static int rsm_enter_protected_mode(struct x86_emulate_ctxt *ctxt,
+ u64 cr0, u64 cr4)
+{
+ int bad;
+
+ /*
+ * First enable PAE, long mode needs it before CR0.PG = 1 is set.
+ * Then enable protected mode. However, PCID cannot be enabled
+ * if EFER.LMA=0, so set it separately.
+ */
+ bad = ctxt->ops->set_cr(ctxt, 4, cr4 & ~X86_CR4_PCIDE);
+ if (bad)
+ return X86EMUL_UNHANDLEABLE;
+
+ bad = ctxt->ops->set_cr(ctxt, 0, cr0);
+ if (bad)
+ return X86EMUL_UNHANDLEABLE;
+
+ if (cr4 & X86_CR4_PCIDE) {
+ bad = ctxt->ops->set_cr(ctxt, 4, cr4);
+ if (bad)
+ return X86EMUL_UNHANDLEABLE;
+ }
+
+ return X86EMUL_CONTINUE;
+}
+
+static int rsm_load_state_32(struct x86_emulate_ctxt *ctxt, u64 smbase)
+{
+ struct desc_struct desc;
+ struct desc_ptr dt;
+ u16 selector;
+ u32 val, cr0, cr4;
+ int i;
+
+ cr0 = GET_SMSTATE(u32, smbase, 0x7ffc);
+ ctxt->ops->set_cr(ctxt, 3, GET_SMSTATE(u32, smbase, 0x7ff8));
+ ctxt->eflags = GET_SMSTATE(u32, smbase, 0x7ff4) | X86_EFLAGS_FIXED;
+ ctxt->_eip = GET_SMSTATE(u32, smbase, 0x7ff0);
+
+ for (i = 0; i < 8; i++)
+ *reg_write(ctxt, i) = GET_SMSTATE(u32, smbase, 0x7fd0 + i * 4);
+
+ val = GET_SMSTATE(u32, smbase, 0x7fcc);
+ ctxt->ops->set_dr(ctxt, 6, (val & DR6_VOLATILE) | DR6_FIXED_1);
+ val = GET_SMSTATE(u32, smbase, 0x7fc8);
+ ctxt->ops->set_dr(ctxt, 7, (val & DR7_VOLATILE) | DR7_FIXED_1);
+
+ selector = GET_SMSTATE(u32, smbase, 0x7fc4);
+ set_desc_base(&desc, GET_SMSTATE(u32, smbase, 0x7f64));
+ set_desc_limit(&desc, GET_SMSTATE(u32, smbase, 0x7f60));
+ rsm_set_desc_flags(&desc, GET_SMSTATE(u32, smbase, 0x7f5c));
+ ctxt->ops->set_segment(ctxt, selector, &desc, 0, VCPU_SREG_TR);
+
+ selector = GET_SMSTATE(u32, smbase, 0x7fc0);
+ set_desc_base(&desc, GET_SMSTATE(u32, smbase, 0x7f80));
+ set_desc_limit(&desc, GET_SMSTATE(u32, smbase, 0x7f7c));
+ rsm_set_desc_flags(&desc, GET_SMSTATE(u32, smbase, 0x7f78));
+ ctxt->ops->set_segment(ctxt, selector, &desc, 0, VCPU_SREG_LDTR);
+
+ dt.address = GET_SMSTATE(u32, smbase, 0x7f74);
+ dt.size = GET_SMSTATE(u32, smbase, 0x7f70);
+ ctxt->ops->set_gdt(ctxt, &dt);
+
+ dt.address = GET_SMSTATE(u32, smbase, 0x7f58);
+ dt.size = GET_SMSTATE(u32, smbase, 0x7f54);
+ ctxt->ops->set_idt(ctxt, &dt);
+
+ for (i = 0; i < 6; i++) {
+ int r = rsm_load_seg_32(ctxt, smbase, i);
+ if (r != X86EMUL_CONTINUE)
+ return r;
+ }
+
+ cr4 = GET_SMSTATE(u32, smbase, 0x7f14);
+
+ ctxt->ops->set_smbase(ctxt, GET_SMSTATE(u32, smbase, 0x7ef8));
+
+ return rsm_enter_protected_mode(ctxt, cr0, cr4);
+}
+
+static int rsm_load_state_64(struct x86_emulate_ctxt *ctxt, u64 smbase)
+{
+ struct desc_struct desc;
+ struct desc_ptr dt;
+ u64 val, cr0, cr4;
+ u32 base3;
+ u16 selector;
+ int i;
+
+ for (i = 0; i < 16; i++)
+ *reg_write(ctxt, i) = GET_SMSTATE(u64, smbase, 0x7ff8 - i * 8);
+
+ ctxt->_eip = GET_SMSTATE(u64, smbase, 0x7f78);
+ ctxt->eflags = GET_SMSTATE(u32, smbase, 0x7f70) | X86_EFLAGS_FIXED;
+
+ val = GET_SMSTATE(u32, smbase, 0x7f68);
+ ctxt->ops->set_dr(ctxt, 6, (val & DR6_VOLATILE) | DR6_FIXED_1);
+ val = GET_SMSTATE(u32, smbase, 0x7f60);
+ ctxt->ops->set_dr(ctxt, 7, (val & DR7_VOLATILE) | DR7_FIXED_1);
+
+ cr0 = GET_SMSTATE(u64, smbase, 0x7f58);
+ ctxt->ops->set_cr(ctxt, 3, GET_SMSTATE(u64, smbase, 0x7f50));
+ cr4 = GET_SMSTATE(u64, smbase, 0x7f48);
+ ctxt->ops->set_smbase(ctxt, GET_SMSTATE(u32, smbase, 0x7f00));
+ val = GET_SMSTATE(u64, smbase, 0x7ed0);
+ ctxt->ops->set_msr(ctxt, MSR_EFER, val & ~EFER_LMA);
+
+ selector = GET_SMSTATE(u32, smbase, 0x7e90);
+ rsm_set_desc_flags(&desc, GET_SMSTATE(u32, smbase, 0x7e92) << 8);
+ set_desc_limit(&desc, GET_SMSTATE(u32, smbase, 0x7e94));
+ set_desc_base(&desc, GET_SMSTATE(u32, smbase, 0x7e98));
+ base3 = GET_SMSTATE(u32, smbase, 0x7e9c);
+ ctxt->ops->set_segment(ctxt, selector, &desc, base3, VCPU_SREG_TR);
+
+ dt.size = GET_SMSTATE(u32, smbase, 0x7e84);
+ dt.address = GET_SMSTATE(u64, smbase, 0x7e88);
+ ctxt->ops->set_idt(ctxt, &dt);
+
+ selector = GET_SMSTATE(u32, smbase, 0x7e70);
+ rsm_set_desc_flags(&desc, GET_SMSTATE(u32, smbase, 0x7e72) << 8);
+ set_desc_limit(&desc, GET_SMSTATE(u32, smbase, 0x7e74));
+ set_desc_base(&desc, GET_SMSTATE(u32, smbase, 0x7e78));
+ base3 = GET_SMSTATE(u32, smbase, 0x7e7c);
+ ctxt->ops->set_segment(ctxt, selector, &desc, base3, VCPU_SREG_LDTR);
+
+ dt.size = GET_SMSTATE(u32, smbase, 0x7e64);
+ dt.address = GET_SMSTATE(u64, smbase, 0x7e68);
+ ctxt->ops->set_gdt(ctxt, &dt);
+
+ for (i = 0; i < 6; i++) {
+ int r = rsm_load_seg_64(ctxt, smbase, i);
+ if (r != X86EMUL_CONTINUE)
+ return r;
+ }
+
+ return rsm_enter_protected_mode(ctxt, cr0, cr4);
+}
+
+static int em_rsm(struct x86_emulate_ctxt *ctxt)
+{
+ unsigned long cr0, cr4, efer;
+ u64 smbase;
+ int ret;
+
+ if ((ctxt->emul_flags & X86EMUL_SMM_MASK) == 0)
+ return emulate_ud(ctxt);
+
+ /*
+ * Get back to real mode, to prepare a safe state in which to load
+ * CR0/CR3/CR4/EFER. Also this will ensure that addresses passed
+ * to read_std/write_std are not virtual.
+ *
+ * CR4.PCIDE must be zero, because it is a 64-bit mode only feature.
+ */
+ cr0 = ctxt->ops->get_cr(ctxt, 0);
+ if (cr0 & X86_CR0_PE)
+ ctxt->ops->set_cr(ctxt, 0, cr0 & ~(X86_CR0_PG | X86_CR0_PE));
+ cr4 = ctxt->ops->get_cr(ctxt, 4);
+ if (cr4 & X86_CR4_PAE)
+ ctxt->ops->set_cr(ctxt, 4, cr4 & ~X86_CR4_PAE);
+ efer = 0;
+ ctxt->ops->set_msr(ctxt, MSR_EFER, efer);
+
+ smbase = ctxt->ops->get_smbase(ctxt);
+ if (emulator_has_longmode(ctxt))
+ ret = rsm_load_state_64(ctxt, smbase + 0x8000);
+ else
+ ret = rsm_load_state_32(ctxt, smbase + 0x8000);
+
+ if (ret != X86EMUL_CONTINUE) {
+ /* FIXME: should triple fault */
+ return X86EMUL_UNHANDLEABLE;
+ }
+
+ if ((ctxt->emul_flags & X86EMUL_SMM_INSIDE_NMI_MASK) == 0)
+ ctxt->ops->set_nmi_mask(ctxt, false);
+
+ ctxt->emul_flags &= ~X86EMUL_SMM_INSIDE_NMI_MASK;
+ ctxt->emul_flags &= ~X86EMUL_SMM_MASK;
+ return X86EMUL_CONTINUE;
+}
+
static void
setup_syscalls_segments(struct x86_emulate_ctxt *ctxt,
struct desc_struct *cs, struct desc_struct *ss)
@@ -2573,6 +2824,30 @@ static bool emulator_io_permited(struct x86_emulate_ctxt *ctxt,
return true;
}
+static void string_registers_quirk(struct x86_emulate_ctxt *ctxt)
+{
+ /*
+ * Intel CPUs mask the counter and pointers in quite strange
+ * manner when ECX is zero due to REP-string optimizations.
+ */
+#ifdef CONFIG_X86_64
+ if (ctxt->ad_bytes != 4 || !vendor_intel(ctxt))
+ return;
+
+ *reg_write(ctxt, VCPU_REGS_RCX) = 0;
+
+ switch (ctxt->b) {
+ case 0xa4: /* movsb */
+ case 0xa5: /* movsd/w */
+ *reg_rmw(ctxt, VCPU_REGS_RSI) &= (u32)-1;
+ /* fall through */
+ case 0xaa: /* stosb */
+ case 0xab: /* stosd/w */
+ *reg_rmw(ctxt, VCPU_REGS_RDI) &= (u32)-1;
+ }
+#endif
+}
+
static void save_state_to_tss16(struct x86_emulate_ctxt *ctxt,
struct tss_segment_16 *tss)
{
@@ -2849,7 +3124,7 @@ 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;
+ ulong desc_addr, dr7;
/* FIXME: old_tss_base == ~0 ? */
@@ -2934,6 +3209,9 @@ static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt,
ret = em_push(ctxt);
}
+ ops->get_dr(ctxt, 7, &dr7);
+ ops->set_dr(ctxt, 7, dr7 & ~(DR_LOCAL_ENABLE_MASK | DR_LOCAL_SLOWDOWN));
+
return ret;
}
@@ -3840,7 +4118,7 @@ static const struct opcode group5[] = {
F(DstMem | SrcNone | Lock, em_inc),
F(DstMem | SrcNone | Lock, em_dec),
I(SrcMem | NearBranch, em_call_near_abs),
- I(SrcMemFAddr | ImplicitOps | Stack, em_call_far),
+ I(SrcMemFAddr | ImplicitOps, em_call_far),
I(SrcMem | NearBranch, em_jmp_abs),
I(SrcMemFAddr | ImplicitOps, em_jmp_far),
I(SrcMem | Stack, em_push), D(Undefined),
@@ -4173,7 +4451,7 @@ static const struct opcode twobyte_table[256] = {
F(DstMem | SrcReg | Src2CL | ModRM, em_shld), N, N,
/* 0xA8 - 0xAF */
I(Stack | Src2GS, em_push_sreg), I(Stack | Src2GS, em_pop_sreg),
- DI(ImplicitOps, rsm),
+ II(No64 | EmulateOnUD | ImplicitOps, em_rsm, rsm),
F(DstMem | SrcReg | ModRM | BitOp | Lock | PageTable, em_bts),
F(DstMem | SrcReg | Src2ImmByte | ModRM, em_shrd),
F(DstMem | SrcReg | Src2CL | ModRM, em_shrd),
@@ -4871,7 +5149,7 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
fetch_possible_mmx_operand(ctxt, &ctxt->dst);
}
- if (unlikely(ctxt->guest_mode) && (ctxt->d & Intercept)) {
+ if (unlikely(ctxt->emul_flags & X86EMUL_GUEST_MASK) && ctxt->intercept) {
rc = emulator_check_intercept(ctxt, ctxt->intercept,
X86_ICPT_PRE_EXCEPT);
if (rc != X86EMUL_CONTINUE)
@@ -4900,7 +5178,7 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
goto done;
}
- if (unlikely(ctxt->guest_mode) && (ctxt->d & Intercept)) {
+ if (unlikely(ctxt->emul_flags & X86EMUL_GUEST_MASK) && (ctxt->d & Intercept)) {
rc = emulator_check_intercept(ctxt, ctxt->intercept,
X86_ICPT_POST_EXCEPT);
if (rc != X86EMUL_CONTINUE)
@@ -4910,6 +5188,7 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
if (ctxt->rep_prefix && (ctxt->d & String)) {
/* All REP prefixes have the same first termination condition */
if (address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) == 0) {
+ string_registers_quirk(ctxt);
ctxt->eip = ctxt->_eip;
ctxt->eflags &= ~X86_EFLAGS_RF;
goto done;
@@ -4953,7 +5232,7 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
special_insn:
- if (unlikely(ctxt->guest_mode) && (ctxt->d & Intercept)) {
+ if (unlikely(ctxt->emul_flags & X86EMUL_GUEST_MASK) && (ctxt->d & Intercept)) {
rc = emulator_check_intercept(ctxt, ctxt->intercept,
X86_ICPT_POST_MEMACCESS);
if (rc != X86EMUL_CONTINUE)