xref: /freebsd/sys/amd64/vmm/intel/vmx_support.S (revision 193d9e768ba63fcfb187cfd17f461f7d41345048)
1/*-
2 * Copyright (c) 2011 NetApp, Inc.
3 * Copyright (c) 2013 Neel Natu <neel@freebsd.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 * $FreeBSD$
28 */
29
30#include <machine/asmacros.h>
31
32#include "vmx_assym.h"
33
34#ifdef SMP
35#define	LK	lock ;
36#else
37#define	LK
38#endif
39
40/* Be friendly to DTrace FBT's prologue/epilogue pattern matching */
41#define VENTER  push %rbp ; mov %rsp,%rbp
42#define VLEAVE  pop %rbp
43
44/*
45 * Assumes that %rdi holds a pointer to the 'vmxctx'.
46 *
47 * On "return" all registers are updated to reflect guest state. The two
48 * exceptions are %rip and %rsp. These registers are atomically switched
49 * by hardware from the guest area of the vmcs.
50 *
51 * We modify %rsp to point to the 'vmxctx' so we can use it to restore
52 * host context in case of an error with 'vmlaunch' or 'vmresume'.
53 */
54#define	VMX_GUEST_RESTORE						\
55	movq	%rdi,%rsp;						\
56	movq	VMXCTX_GUEST_CR2(%rdi),%rsi;				\
57	movq	%rsi,%cr2;						\
58	movq	VMXCTX_GUEST_RSI(%rdi),%rsi;				\
59	movq	VMXCTX_GUEST_RDX(%rdi),%rdx;				\
60	movq	VMXCTX_GUEST_RCX(%rdi),%rcx;				\
61	movq	VMXCTX_GUEST_R8(%rdi),%r8;				\
62	movq	VMXCTX_GUEST_R9(%rdi),%r9;				\
63	movq	VMXCTX_GUEST_RAX(%rdi),%rax;				\
64	movq	VMXCTX_GUEST_RBX(%rdi),%rbx;				\
65	movq	VMXCTX_GUEST_RBP(%rdi),%rbp;				\
66	movq	VMXCTX_GUEST_R10(%rdi),%r10;				\
67	movq	VMXCTX_GUEST_R11(%rdi),%r11;				\
68	movq	VMXCTX_GUEST_R12(%rdi),%r12;				\
69	movq	VMXCTX_GUEST_R13(%rdi),%r13;				\
70	movq	VMXCTX_GUEST_R14(%rdi),%r14;				\
71	movq	VMXCTX_GUEST_R15(%rdi),%r15;				\
72	movq	VMXCTX_GUEST_RDI(%rdi),%rdi; /* restore rdi the last */
73
74/*
75 * Save and restore the host context.
76 *
77 * Assumes that %rdi holds a pointer to the 'vmxctx'.
78 */
79#define	VMX_HOST_SAVE							\
80	movq    %r15, VMXCTX_HOST_R15(%rdi);				\
81	movq    %r14, VMXCTX_HOST_R14(%rdi);				\
82	movq    %r13, VMXCTX_HOST_R13(%rdi);				\
83	movq    %r12, VMXCTX_HOST_R12(%rdi);				\
84	movq    %rbp, VMXCTX_HOST_RBP(%rdi);				\
85	movq    %rsp, VMXCTX_HOST_RSP(%rdi);				\
86	movq    %rbx, VMXCTX_HOST_RBX(%rdi);				\
87
88#define	VMX_HOST_RESTORE						\
89	movq	VMXCTX_HOST_R15(%rdi), %r15;				\
90	movq	VMXCTX_HOST_R14(%rdi), %r14;				\
91	movq	VMXCTX_HOST_R13(%rdi), %r13;				\
92	movq	VMXCTX_HOST_R12(%rdi), %r12;				\
93	movq	VMXCTX_HOST_RBP(%rdi), %rbp;				\
94	movq	VMXCTX_HOST_RSP(%rdi), %rsp;				\
95	movq	VMXCTX_HOST_RBX(%rdi), %rbx;				\
96
97/*
98 * vmx_enter_guest(struct vmxctx *vmxctx, int launched)
99 * %rdi: pointer to the 'vmxctx'
100 * %rsi: pointer to the 'vmx'
101 * %edx: launch state of the VMCS
102 * Interrupts must be disabled on entry.
103 */
104ENTRY(vmx_enter_guest)
105	VENTER
106	/*
107	 * Save host state before doing anything else.
108	 */
109	VMX_HOST_SAVE
110
111	/*
112	 * Activate guest pmap on this cpu.
113	 */
114	movq	VMXCTX_PMAP(%rdi), %r11
115	movl	PCPU(CPUID), %eax
116	LK btsl	%eax, PM_ACTIVE(%r11)
117
118	/*
119	 * If 'vmx->eptgen[curcpu]' is not identical to 'pmap->pm_eptgen'
120	 * then we must invalidate all mappings associated with this EPTP.
121	 */
122	movq	PM_EPTGEN(%r11), %r10
123	cmpq	%r10, VMX_EPTGEN(%rsi, %rax, 8)
124	je	guest_restore
125
126	/* Refresh 'vmx->eptgen[curcpu]' */
127	movq	%r10, VMX_EPTGEN(%rsi, %rax, 8)
128
129	/* Setup the invept descriptor on the host stack */
130	mov	%rsp, %r11
131	movq	VMX_EPTP(%rsi), %rax
132	movq	%rax, -16(%r11)
133	movq	$0x0, -8(%r11)
134	mov	$0x1, %eax		/* Single context invalidate */
135	invept	-16(%r11), %rax
136	jbe	invept_error		/* Check invept instruction error */
137
138guest_restore:
139	cmpl	$0, %edx
140	je	do_launch
141
142	VMX_GUEST_RESTORE
143	vmresume
144	/*
145	 * In the common case 'vmresume' returns back to the host through
146	 * 'vmx_exit_guest' with %rsp pointing to 'vmxctx'.
147	 *
148	 * If there is an error we return VMX_VMRESUME_ERROR to the caller.
149	 */
150	movq	%rsp, %rdi		/* point %rdi back to 'vmxctx' */
151	movl	$VMX_VMRESUME_ERROR, %eax
152	jmp	decode_inst_error
153
154do_launch:
155	VMX_GUEST_RESTORE
156	vmlaunch
157	/*
158	 * In the common case 'vmlaunch' returns back to the host through
159	 * 'vmx_exit_guest' with %rsp pointing to 'vmxctx'.
160	 *
161	 * If there is an error we return VMX_VMLAUNCH_ERROR to the caller.
162	 */
163	movq	%rsp, %rdi		/* point %rdi back to 'vmxctx' */
164	movl	$VMX_VMLAUNCH_ERROR, %eax
165	jmp	decode_inst_error
166
167invept_error:
168	movl	$VMX_INVEPT_ERROR, %eax
169	jmp	decode_inst_error
170
171decode_inst_error:
172	movl	$VM_FAIL_VALID, %r11d
173	jz	inst_error
174	movl	$VM_FAIL_INVALID, %r11d
175inst_error:
176	movl	%r11d, VMXCTX_INST_FAIL_STATUS(%rdi)
177
178	/*
179	 * The return value is already populated in %eax so we cannot use
180	 * it as a scratch register beyond this point.
181	 */
182
183	/*
184	 * Deactivate guest pmap from this cpu.
185	 */
186	movq	VMXCTX_PMAP(%rdi), %r11
187	movl	PCPU(CPUID), %r10d
188	LK btrl	%r10d, PM_ACTIVE(%r11)
189
190	VMX_HOST_RESTORE
191	VLEAVE
192	ret
193
194/*
195 * Non-error VM-exit from the guest. Make this a label so it can
196 * be used by C code when setting up the VMCS.
197 * The VMCS-restored %rsp points to the struct vmxctx
198 */
199	ALIGN_TEXT
200	.globl	vmx_exit_guest
201vmx_exit_guest:
202	/*
203	 * Save guest state that is not automatically saved in the vmcs.
204	 */
205	movq	%rdi,VMXCTX_GUEST_RDI(%rsp)
206	movq	%rsi,VMXCTX_GUEST_RSI(%rsp)
207	movq	%rdx,VMXCTX_GUEST_RDX(%rsp)
208	movq	%rcx,VMXCTX_GUEST_RCX(%rsp)
209	movq	%r8,VMXCTX_GUEST_R8(%rsp)
210	movq	%r9,VMXCTX_GUEST_R9(%rsp)
211	movq	%rax,VMXCTX_GUEST_RAX(%rsp)
212	movq	%rbx,VMXCTX_GUEST_RBX(%rsp)
213	movq	%rbp,VMXCTX_GUEST_RBP(%rsp)
214	movq	%r10,VMXCTX_GUEST_R10(%rsp)
215	movq	%r11,VMXCTX_GUEST_R11(%rsp)
216	movq	%r12,VMXCTX_GUEST_R12(%rsp)
217	movq	%r13,VMXCTX_GUEST_R13(%rsp)
218	movq	%r14,VMXCTX_GUEST_R14(%rsp)
219	movq	%r15,VMXCTX_GUEST_R15(%rsp)
220
221	movq	%cr2,%rdi
222	movq	%rdi,VMXCTX_GUEST_CR2(%rsp)
223
224	movq	%rsp,%rdi
225
226	/*
227	 * Deactivate guest pmap from this cpu.
228	 */
229	movq	VMXCTX_PMAP(%rdi), %r11
230	movl	PCPU(CPUID), %r10d
231	LK btrl	%r10d, PM_ACTIVE(%r11)
232
233	VMX_HOST_RESTORE
234
235	/*
236	 * This will return to the caller of 'vmx_enter_guest()' with a return
237	 * value of VMX_GUEST_VMEXIT.
238	 */
239	movl	$VMX_GUEST_VMEXIT, %eax
240	VLEAVE
241	ret
242END(vmx_enter_guest)
243
244/*
245 * %rdi = interrupt handler entry point
246 *
247 * Calling sequence described in the "Instruction Set Reference" for the "INT"
248 * instruction in Intel SDM, Vol 2.
249 */
250ENTRY(vmx_call_isr)
251	VENTER
252	mov	%rsp, %r11			/* save %rsp */
253	and	$~0xf, %rsp			/* align on 16-byte boundary */
254	pushq	$KERNEL_SS			/* %ss */
255	pushq	%r11				/* %rsp */
256	pushfq					/* %rflags */
257	pushq	$KERNEL_CS			/* %cs */
258	cli					/* disable interrupts */
259	callq	*%rdi				/* push %rip and call isr */
260	VLEAVE
261	ret
262END(vmx_call_isr)
263