KVM: x86: drop error recovery in em_jmp_far and em_ret_far

[pandora-kernel.git] / arch / x86 / kvm / emulate.c

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 56047d2..73e065b 100644 (file)
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -539,12 +539,14 @@ static inline int assign_eip_far(struct x86_emulate_ctxt *ctxt, ulong dst,
        case 4:
                ctxt->_eip = (u32)dst;
                break;
+#ifdef CONFIG_X86_64
        case 8:
                if ((cs_l && is_noncanonical_address(dst)) ||
-                   (!cs_l && (dst & ~(u32)-1)))
+                   (!cs_l && (dst >> 32) != 0))
                        return emulate_gp(ctxt, 0);
                ctxt->_eip = dst;
                break;
+#endif
        default:
                WARN(1, "unsupported eip assignment size\n");
        }
@@ -1697,16 +1699,10 @@ static int em_iret(struct x86_emulate_ctxt *ctxt)
 static int em_jmp_far(struct x86_emulate_ctxt *ctxt)
 {
        int rc;
-       unsigned short sel, old_sel;
-       struct desc_struct old_desc, new_desc;
-       const struct x86_emulate_ops *ops = ctxt->ops;
+       unsigned short sel;
+       struct desc_struct new_desc;
        u8 cpl = ctxt->ops->cpl(ctxt);
 
-       /* Assignment of RIP may only fail in 64-bit mode */
-       if (ctxt->mode == X86EMUL_MODE_PROT64)
-               ops->get_segment(ctxt, &old_sel, &old_desc, NULL,
-                                VCPU_SREG_CS);
-
        memcpy(&sel, ctxt->src.valptr + ctxt->op_bytes, 2);
 
        rc = __load_segment_descriptor(ctxt, sel, VCPU_SREG_CS, cpl,
@@ -1715,12 +1711,10 @@ static int em_jmp_far(struct x86_emulate_ctxt *ctxt)
                return rc;
 
        rc = assign_eip_far(ctxt, ctxt->src.val, new_desc.l);
-       if (rc != X86EMUL_CONTINUE) {
-               WARN_ON(!ctxt->mode != X86EMUL_MODE_PROT64);
-               /* assigning eip failed; restore the old cs */
-               ops->set_segment(ctxt, old_sel, &old_desc, 0, VCPU_SREG_CS);
-               return rc;
-       }
+       /* Error handling is not implemented. */
+       if (rc != X86EMUL_CONTINUE)
+               return X86EMUL_UNHANDLEABLE;
+
        return rc;
 }
 
@@ -1874,14 +1868,8 @@ static int em_ret_far(struct x86_emulate_ctxt *ctxt)
 {
        int rc;
        unsigned long eip, cs;
-       u16 old_cs;
        int cpl = ctxt->ops->cpl(ctxt);
-       struct desc_struct old_desc, new_desc;
-       const struct x86_emulate_ops *ops = ctxt->ops;
-
-       if (ctxt->mode == X86EMUL_MODE_PROT64)
-               ops->get_segment(ctxt, &old_cs, &old_desc, NULL,
-                                VCPU_SREG_CS);
+       struct desc_struct new_desc;
 
        rc = emulate_pop(ctxt, &eip, ctxt->op_bytes);
        if (rc != X86EMUL_CONTINUE)
@@ -1897,10 +1885,10 @@ static int em_ret_far(struct x86_emulate_ctxt *ctxt)
        if (rc != X86EMUL_CONTINUE)
                return rc;
        rc = assign_eip_far(ctxt, eip, new_desc.l);
-       if (rc != X86EMUL_CONTINUE) {
-               WARN_ON(!ctxt->mode != X86EMUL_MODE_PROT64);
-               ops->set_segment(ctxt, old_cs, &old_desc, 0, VCPU_SREG_CS);
-       }
+       /* Error handling is not implemented. */
+       if (rc != X86EMUL_CONTINUE)
+               return X86EMUL_UNHANDLEABLE;
+
        return rc;
 }
 
@@ -1950,6 +1938,17 @@ 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;
@@ -2066,6 +2065,14 @@ 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_PROT64) && (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.
        */
@@ -2075,23 +2082,13 @@ static int em_sysenter(struct x86_emulate_ctxt *ctxt)
        setup_syscalls_segments(ctxt, &cs, &ss);
 
        ops->get_msr(ctxt, MSR_IA32_SYSENTER_CS, &msr_data);
-       switch (ctxt->mode) {
-       case X86EMUL_MODE_PROT32:
-               if ((msr_data & 0xfffc) == 0x0)
-                       return emulate_gp(ctxt, 0);
-               break;
-       case X86EMUL_MODE_PROT64:
-               if (msr_data == 0x0)
-                       return emulate_gp(ctxt, 0);
-               break;
-       }
+       if ((msr_data & 0xfffc) == 0x0)
+               return emulate_gp(ctxt, 0);
 
        ctxt->eflags &= ~(EFLG_VM | EFLG_IF | EFLG_RF);
-       cs_sel = (u16)msr_data;
-       cs_sel &= ~SELECTOR_RPL_MASK;
+       cs_sel = (u16)msr_data & ~SELECTOR_RPL_MASK;
        ss_sel = cs_sel + 8;
-       ss_sel &= ~SELECTOR_RPL_MASK;
-       if (ctxt->mode == X86EMUL_MODE_PROT64 || (efer & EFER_LMA)) {
+       if (efer & EFER_LMA) {
                cs.d = 0;
                cs.l = 1;
        }
@@ -2100,10 +2097,11 @@ static int em_sysenter(struct x86_emulate_ctxt *ctxt)
        ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS);
 
        ops->get_msr(ctxt, MSR_IA32_SYSENTER_EIP, &msr_data);
-       ctxt->_eip = msr_data;
+       ctxt->_eip = (efer & EFER_LMA) ? msr_data : (u32)msr_data;
 
        ops->get_msr(ctxt, MSR_IA32_SYSENTER_ESP, &msr_data);
-       ctxt->regs[VCPU_REGS_RSP] = msr_data;
+       ctxt->regs[VCPU_REGS_RSP] = (efer & EFER_LMA) ? msr_data :
+                                                       (u32)msr_data;
 
        return X86EMUL_CONTINUE;
 }
@@ -4002,7 +4000,8 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
                if (rc != X86EMUL_CONTINUE)
                        goto done;
        }
-       ctxt->dst.orig_val = ctxt->dst.val;
+       /* Copy full 64-bit value for CMPXCHG8B.  */
+       ctxt->dst.orig_val64 = ctxt->dst.val64;
 
 special_insn: