1 /******************************************************************************
2  * arch-x86/cpuid.h
3  *
4  * CPUID interface to Xen.
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to
8  * deal in the Software without restriction, including without limitation the
9  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
10  * sell copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
22  * DEALINGS IN THE SOFTWARE.
23  *
24  * Copyright (c) 2007 Citrix Systems, Inc.
25  *
26  * Authors:
27  *    Keir Fraser <keir@xen.org>
28  */
29 
30 #ifndef __XEN_PUBLIC_ARCH_X86_CPUID_H__
31 #define __XEN_PUBLIC_ARCH_X86_CPUID_H__
32 
33 /*
34  * For compatibility with other hypervisor interfaces, the Xen cpuid leaves
35  * can be found at the first otherwise unused 0x100 aligned boundary starting
36  * from 0x40000000.
37  *
38  * e.g If viridian extensions are enabled for an HVM domain, the Xen cpuid
39  * leaves will start at 0x40000100
40  */
41 
42 #define XEN_CPUID_FIRST_LEAF 0x40000000
43 #define XEN_CPUID_LEAF(i)    (XEN_CPUID_FIRST_LEAF + (i))
44 
45 /*
46  * Leaf 1 (0x40000x00)
47  * EAX: Largest Xen-information leaf. All leaves up to an including @EAX
48  *      are supported by the Xen host.
49  * EBX-EDX: "XenVMMXenVMM" signature, allowing positive identification
50  *      of a Xen host.
51  */
52 #define XEN_CPUID_SIGNATURE_EBX 0x566e6558 /* "XenV" */
53 #define XEN_CPUID_SIGNATURE_ECX 0x65584d4d /* "MMXe" */
54 #define XEN_CPUID_SIGNATURE_EDX 0x4d4d566e /* "nVMM" */
55 
56 /*
57  * Leaf 2 (0x40000x01)
58  * EAX[31:16]: Xen major version.
59  * EAX[15: 0]: Xen minor version.
60  * EBX-EDX: Reserved (currently all zeroes).
61  */
62 
63 /*
64  * Leaf 3 (0x40000x02)
65  * EAX: Number of hypercall transfer pages. This register is always guaranteed
66  *      to specify one hypercall page.
67  * EBX: Base address of Xen-specific MSRs.
68  * ECX: Features 1. Unused bits are set to zero.
69  * EDX: Features 2. Unused bits are set to zero.
70  */
71 
72 /* Does the host support MMU_PT_UPDATE_PRESERVE_AD for this guest? */
73 #define _XEN_CPUID_FEAT1_MMU_PT_UPDATE_PRESERVE_AD 0
74 #define XEN_CPUID_FEAT1_MMU_PT_UPDATE_PRESERVE_AD  (1u<<0)
75 
76 /*
77  * Leaf 4 (0x40000x03)
78  * Sub-leaf 0: EAX: bit 0: emulated tsc
79  *                  bit 1: host tsc is known to be reliable
80  *                  bit 2: RDTSCP instruction available
81  *             EBX: tsc_mode: 0=default (emulate if necessary), 1=emulate,
82  *                            2=no emulation, 3=no emulation + TSC_AUX support
83  *             ECX: guest tsc frequency in kHz
84  *             EDX: guest tsc incarnation (migration count)
85  * Sub-leaf 1: EAX: tsc offset low part
86  *             EBX: tsc offset high part
87  *             ECX: multiplicator for tsc->ns conversion
88  *             EDX: shift amount for tsc->ns conversion
89  * Sub-leaf 2: EAX: host tsc frequency in kHz
90  */
91 
92 /*
93  * Leaf 5 (0x40000x04)
94  * HVM-specific features
95  * Sub-leaf 0: EAX: Features
96  * Sub-leaf 0: EBX: vcpu id (iff EAX has XEN_HVM_CPUID_VCPU_ID_PRESENT flag)
97  */
98 #define XEN_HVM_CPUID_APIC_ACCESS_VIRT (1u << 0) /* Virtualized APIC registers */
99 #define XEN_HVM_CPUID_X2APIC_VIRT      (1u << 1) /* Virtualized x2APIC accesses */
100 /* Memory mapped from other domains has valid IOMMU entries */
101 #define XEN_HVM_CPUID_IOMMU_MAPPINGS   (1u << 2)
102 #define XEN_HVM_CPUID_VCPU_ID_PRESENT  (1u << 3) /* vcpu id is present in EBX */
103 
104 /*
105  * Leaf 6 (0x40000x05)
106  * PV-specific parameters
107  * Sub-leaf 0: EAX: max available sub-leaf
108  * Sub-leaf 0: EBX: bits 0-7: max machine address width
109  */
110 
111 /* Max. address width in bits taking memory hotplug into account. */
112 #define XEN_CPUID_MACHINE_ADDRESS_WIDTH_MASK (0xffu << 0)
113 
114 #define XEN_CPUID_MAX_NUM_LEAVES 5
115 
116 #endif /* __XEN_PUBLIC_ARCH_X86_CPUID_H__ */
117