vmx_support.S revision 264619
1100384Speter/*-
2100384Speter * Copyright (c) 2011 NetApp, Inc.
3100384Speter * Copyright (c) 2013 Neel Natu <neel@freebsd.org>
4100384Speter * All rights reserved.
5100384Speter *
6100384Speter * Redistribution and use in source and binary forms, with or without
7100384Speter * modification, are permitted provided that the following conditions
8100384Speter * are met:
9100384Speter * 1. Redistributions of source code must retain the above copyright
10100384Speter *    notice, this list of conditions and the following disclaimer.
11100384Speter * 2. Redistributions in binary form must reproduce the above copyright
12100384Speter *    notice, this list of conditions and the following disclaimer in the
13100384Speter *    documentation and/or other materials provided with the distribution.
14100384Speter *
15100384Speter * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
16100384Speter * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17100384Speter * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18100384Speter * ARE DISCLAIMED.  IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
19100384Speter * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20100384Speter * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21100384Speter * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22100384Speter * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23100384Speter * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24100384Speter * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25100384Speter * SUCH DAMAGE.
26100384Speter *
27116182Sobrien * $FreeBSD: stable/10/sys/amd64/vmm/intel/vmx_support.S 264619 2014-04-17 18:00:07Z jhb $
28116182Sobrien */
29116182Sobrien
30100384Speter#include <machine/asmacros.h>
31100384Speter
32#include "vmx_assym.s"
33
34#ifdef SMP
35#define	LK	lock ;
36#else
37#define	LK
38#endif
39
40/*
41 * Assumes that %rdi holds a pointer to the 'vmxctx'.
42 *
43 * On "return" all registers are updated to reflect guest state. The two
44 * exceptions are %rip and %rsp. These registers are atomically switched
45 * by hardware from the guest area of the vmcs.
46 *
47 * We modify %rsp to point to the 'vmxctx' so we can use it to restore
48 * host context in case of an error with 'vmlaunch' or 'vmresume'.
49 */
50#define	VMX_GUEST_RESTORE						\
51	movq	%rdi,%rsp;						\
52	movq	VMXCTX_GUEST_CR2(%rdi),%rsi;				\
53	movq	%rsi,%cr2;						\
54	movq	VMXCTX_GUEST_RSI(%rdi),%rsi;				\
55	movq	VMXCTX_GUEST_RDX(%rdi),%rdx;				\
56	movq	VMXCTX_GUEST_RCX(%rdi),%rcx;				\
57	movq	VMXCTX_GUEST_R8(%rdi),%r8;				\
58	movq	VMXCTX_GUEST_R9(%rdi),%r9;				\
59	movq	VMXCTX_GUEST_RAX(%rdi),%rax;				\
60	movq	VMXCTX_GUEST_RBX(%rdi),%rbx;				\
61	movq	VMXCTX_GUEST_RBP(%rdi),%rbp;				\
62	movq	VMXCTX_GUEST_R10(%rdi),%r10;				\
63	movq	VMXCTX_GUEST_R11(%rdi),%r11;				\
64	movq	VMXCTX_GUEST_R12(%rdi),%r12;				\
65	movq	VMXCTX_GUEST_R13(%rdi),%r13;				\
66	movq	VMXCTX_GUEST_R14(%rdi),%r14;				\
67	movq	VMXCTX_GUEST_R15(%rdi),%r15;				\
68	movq	VMXCTX_GUEST_RDI(%rdi),%rdi; /* restore rdi the last */
69
70/*
71 * Save and restore the host context.
72 *
73 * Assumes that %rdi holds a pointer to the 'vmxctx'.
74 */
75#define	VMX_HOST_SAVE(tmpreg)						\
76	movq	(%rsp), tmpreg;			/* return address */	\
77	movq    %r15, VMXCTX_HOST_R15(%rdi);				\
78	movq    %r14, VMXCTX_HOST_R14(%rdi);				\
79	movq    %r13, VMXCTX_HOST_R13(%rdi);				\
80	movq    %r12, VMXCTX_HOST_R12(%rdi);				\
81	movq    %rbp, VMXCTX_HOST_RBP(%rdi);				\
82	movq    %rsp, VMXCTX_HOST_RSP(%rdi);				\
83	movq    %rbx, VMXCTX_HOST_RBX(%rdi);				\
84	movq    tmpreg, VMXCTX_HOST_RIP(%rdi)
85
86#define	VMX_HOST_RESTORE(tmpreg)					\
87	movq	VMXCTX_HOST_R15(%rdi), %r15;				\
88	movq	VMXCTX_HOST_R14(%rdi), %r14;				\
89	movq	VMXCTX_HOST_R13(%rdi), %r13;				\
90	movq	VMXCTX_HOST_R12(%rdi), %r12;				\
91	movq	VMXCTX_HOST_RBP(%rdi), %rbp;				\
92	movq	VMXCTX_HOST_RSP(%rdi), %rsp;				\
93	movq	VMXCTX_HOST_RBX(%rdi), %rbx;				\
94	movq	VMXCTX_HOST_RIP(%rdi), tmpreg;				\
95	movq	tmpreg, (%rsp)			/* return address */
96
97/*
98 * vmx_enter_guest(struct vmxctx *vmxctx, int launched)
99 * %rdi: pointer to the 'vmxctx'
100 * %esi: launch state of the VMCS
101 * Interrupts must be disabled on entry.
102 */
103ENTRY(vmx_enter_guest)
104	/*
105	 * Save host state before doing anything else.
106	 */
107	VMX_HOST_SAVE(%r10)
108
109	/*
110	 * Activate guest pmap on this cpu.
111	 */
112	movq	VMXCTX_PMAP(%rdi), %r11
113	movl	PCPU(CPUID), %eax
114	LK btsl	%eax, PM_ACTIVE(%r11)
115
116	/*
117	 * If 'vmxctx->eptgen[curcpu]' is not identical to 'pmap->pm_eptgen'
118	 * then we must invalidate all mappings associated with this EPTP.
119	 */
120	movq	PM_EPTGEN(%r11), %r10
121	cmpq	%r10, VMXCTX_EPTGEN(%rdi, %rax, 8)
122	je	guest_restore
123
124	/* Refresh 'vmxctx->eptgen[curcpu]' */
125	movq	%r10, VMXCTX_EPTGEN(%rdi, %rax, 8)
126
127	/* Setup the invept descriptor on the host stack */
128	mov	%rsp, %r11
129	movq	VMXCTX_EPTP(%rdi), %rax
130	movq	%rax, -16(%r11)
131	movq	$0x0, -8(%r11)
132	mov	$0x1, %eax		/* Single context invalidate */
133	invept	-16(%r11), %rax
134	jbe	invept_error		/* Check invept instruction error */
135
136guest_restore:
137	cmpl	$0, %esi
138	je	do_launch
139
140	VMX_GUEST_RESTORE
141	vmresume
142	/*
143	 * In the common case 'vmresume' returns back to the host through
144	 * 'vmx_exit_guest' with %rsp pointing to 'vmxctx'.
145	 *
146	 * If there is an error we return VMX_VMRESUME_ERROR to the caller.
147	 */
148	movq	%rsp, %rdi		/* point %rdi back to 'vmxctx' */
149	movl	$VMX_VMRESUME_ERROR, %eax
150	jmp	decode_inst_error
151
152do_launch:
153	VMX_GUEST_RESTORE
154	vmlaunch
155	/*
156	 * In the common case 'vmlaunch' returns back to the host through
157	 * 'vmx_exit_guest' with %rsp pointing to 'vmxctx'.
158	 *
159	 * If there is an error we return VMX_VMLAUNCH_ERROR to the caller.
160	 */
161	movq	%rsp, %rdi		/* point %rdi back to 'vmxctx' */
162	movl	$VMX_VMLAUNCH_ERROR, %eax
163	jmp	decode_inst_error
164
165invept_error:
166	movl	$VMX_INVEPT_ERROR, %eax
167	jmp	decode_inst_error
168
169decode_inst_error:
170	movl	$VM_FAIL_VALID, %r11d
171	jz	inst_error
172	movl	$VM_FAIL_INVALID, %r11d
173inst_error:
174	movl	%r11d, VMXCTX_INST_FAIL_STATUS(%rdi)
175
176	/*
177	 * The return value is already populated in %eax so we cannot use
178	 * it as a scratch register beyond this point.
179	 */
180
181	/*
182	 * Deactivate guest pmap from this cpu.
183	 */
184	movq	VMXCTX_PMAP(%rdi), %r11
185	movl	PCPU(CPUID), %r10d
186	LK btrl	%r10d, PM_ACTIVE(%r11)
187
188	VMX_HOST_RESTORE(%r10)
189	ret
190END(vmx_enter_guest)
191
192/*
193 * void vmx_exit_guest(void)
194 * %rsp points to the struct vmxctx
195 */
196ENTRY(vmx_exit_guest)
197	/*
198	 * Save guest state that is not automatically saved in the vmcs.
199	 */
200	movq	%rdi,VMXCTX_GUEST_RDI(%rsp)
201	movq	%rsi,VMXCTX_GUEST_RSI(%rsp)
202	movq	%rdx,VMXCTX_GUEST_RDX(%rsp)
203	movq	%rcx,VMXCTX_GUEST_RCX(%rsp)
204	movq	%r8,VMXCTX_GUEST_R8(%rsp)
205	movq	%r9,VMXCTX_GUEST_R9(%rsp)
206	movq	%rax,VMXCTX_GUEST_RAX(%rsp)
207	movq	%rbx,VMXCTX_GUEST_RBX(%rsp)
208	movq	%rbp,VMXCTX_GUEST_RBP(%rsp)
209	movq	%r10,VMXCTX_GUEST_R10(%rsp)
210	movq	%r11,VMXCTX_GUEST_R11(%rsp)
211	movq	%r12,VMXCTX_GUEST_R12(%rsp)
212	movq	%r13,VMXCTX_GUEST_R13(%rsp)
213	movq	%r14,VMXCTX_GUEST_R14(%rsp)
214	movq	%r15,VMXCTX_GUEST_R15(%rsp)
215
216	movq	%cr2,%rdi
217	movq	%rdi,VMXCTX_GUEST_CR2(%rsp)
218
219	movq	%rsp,%rdi
220
221	/*
222	 * Deactivate guest pmap from this cpu.
223	 */
224	movq	VMXCTX_PMAP(%rdi), %r11
225	movl	PCPU(CPUID), %r10d
226	LK btrl	%r10d, PM_ACTIVE(%r11)
227
228	VMX_HOST_RESTORE(%r10)
229
230	/*
231	 * This will return to the caller of 'vmx_enter_guest()' with a return
232	 * value of VMX_GUEST_VMEXIT.
233	 */
234	movl	$VMX_GUEST_VMEXIT, %eax
235	ret
236END(vmx_exit_guest)
237