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| author | Ingo Molnar <mingo@elte.hu> | 2012-03-14 08:48:16 (GMT) |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2012-03-14 08:48:16 (GMT) |
| commit | c96a9876696d30783ad54399351a0bf3660db53f (patch) | |
| tree | 74daba0ed1fd2838e8eb527c4f7fe5262ee979bd /arch/x86/kvm/emulate.c | |
| parent | d1f42e314c9c50541c79a6edf2b4cab63fe02ee3 (diff) | |
| parent | fde7d9049e55ab85a390be7f415d74c9f62dd0f9 (diff) | |
| download | linux-fsl-qoriq-c96a9876696d30783ad54399351a0bf3660db53f.tar.xz | |
Merge tag 'v3.3-rc7' into x86/platform
Merge reason: Update to the almost-final v3.3 kernel.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kvm/emulate.c')
| -rw-r--r-- | arch/x86/kvm/emulate.c | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 05a562b..0982507 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -1891,6 +1891,51 @@ setup_syscalls_segments(struct x86_emulate_ctxt *ctxt, ss->p = 1; } +static bool em_syscall_is_enabled(struct x86_emulate_ctxt *ctxt) +{ + struct x86_emulate_ops *ops = ctxt->ops; + u32 eax, ebx, ecx, edx; + + /* + * syscall should always be enabled in longmode - so only become + * vendor specific (cpuid) if other modes are active... + */ + if (ctxt->mode == X86EMUL_MODE_PROT64) + return true; + + eax = 0x00000000; + ecx = 0x00000000; + if (ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx)) { + /* + * Intel ("GenuineIntel") + * remark: Intel CPUs only support "syscall" in 64bit + * longmode. Also an 64bit guest with a + * 32bit compat-app running will #UD !! While this + * behaviour can be fixed (by emulating) into AMD + * response - CPUs of AMD can't behave like Intel. + */ + if (ebx == X86EMUL_CPUID_VENDOR_GenuineIntel_ebx && + ecx == X86EMUL_CPUID_VENDOR_GenuineIntel_ecx && + edx == X86EMUL_CPUID_VENDOR_GenuineIntel_edx) + return false; + + /* AMD ("AuthenticAMD") */ + if (ebx == X86EMUL_CPUID_VENDOR_AuthenticAMD_ebx && + ecx == X86EMUL_CPUID_VENDOR_AuthenticAMD_ecx && + edx == X86EMUL_CPUID_VENDOR_AuthenticAMD_edx) + return true; + + /* AMD ("AMDisbetter!") */ + if (ebx == X86EMUL_CPUID_VENDOR_AMDisbetterI_ebx && + ecx == X86EMUL_CPUID_VENDOR_AMDisbetterI_ecx && + edx == X86EMUL_CPUID_VENDOR_AMDisbetterI_edx) + return true; + } + + /* default: (not Intel, not AMD), apply Intel's stricter rules... */ + return false; +} + static int em_syscall(struct x86_emulate_ctxt *ctxt) { struct x86_emulate_ops *ops = ctxt->ops; @@ -1904,9 +1949,15 @@ static int em_syscall(struct x86_emulate_ctxt *ctxt) ctxt->mode == X86EMUL_MODE_VM86) return emulate_ud(ctxt); + if (!(em_syscall_is_enabled(ctxt))) + return emulate_ud(ctxt); + ops->get_msr(ctxt, MSR_EFER, &efer); setup_syscalls_segments(ctxt, &cs, &ss); + if (!(efer & EFER_SCE)) + return emulate_ud(ctxt); + ops->get_msr(ctxt, MSR_STAR, &msr_data); msr_data >>= 32; cs_sel = (u16)(msr_data & 0xfffc); |