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/*
* entry.S: VMX architecture-specific entry/exit handling.
* Copyright (c) 2004, Intel Corporation.
* Copyright (c) 2008, Citrix Systems, Inc.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; If not, see <http://www.gnu.org/licenses/>.
*/
.file "vmx/entry.S"
#include <asm/asm_defns.h>
#include <asm/page.h>
#define VMRESUME .byte 0x0f,0x01,0xc3
#define VMLAUNCH .byte 0x0f,0x01,0xc2
ENTRY(vmx_asm_vmexit_handler)
SAVE_ALL
mov %cr2,%rax
GET_CURRENT(bx)
movb $1,VCPU_vmx_launched(%rbx)
mov %rax,VCPU_hvm_guest_cr2(%rbx)
/* SPEC_CTRL_ENTRY_FROM_VMX Req: b=curr %rsp=regs/cpuinfo, Clob: acd */
ALTERNATIVE "", DO_OVERWRITE_RSB, X86_FEATURE_SC_RSB_HVM
.macro restore_spec_ctrl
mov $MSR_SPEC_CTRL, %ecx
movzbl CPUINFO_xen_spec_ctrl(%rsp), %eax
xor %edx, %edx
wrmsr
.endm
ALTERNATIVE "", restore_spec_ctrl, X86_FEATURE_SC_MSR_HVM
/* WARNING! `ret`, `call *`, `jmp *` not safe before this point. */
/* Hardware clears MSR_DEBUGCTL on VMExit. Reinstate it if debugging Xen. */
.macro restore_lbr
mov $IA32_DEBUGCTLMSR_LBR, %eax
mov $MSR_IA32_DEBUGCTLMSR, %ecx
xor %edx, %edx
wrmsr
.endm
ALTERNATIVE "", restore_lbr, X86_FEATURE_XEN_LBR
mov %rsp,%rdi
call vmx_vmexit_handler
.Lvmx_do_vmentry:
call vmx_intr_assist
call nvmx_switch_guest
ASSERT_NOT_IN_ATOMIC
mov VCPU_processor(%rbx),%eax
lea irq_stat+IRQSTAT_softirq_pending(%rip),%rdx
xor %ecx,%ecx
shl $IRQSTAT_shift,%eax
cli
cmp %ecx,(%rdx,%rax,1)
jnz .Lvmx_process_softirqs
cmp %cl,VCPU_vmx_emulate(%rbx)
jne .Lvmx_goto_emulator
cmp %cl,VCPU_vmx_realmode(%rbx)
UNLIKELY_START(ne, realmode)
cmp %cx,VCPU_vm86_seg_mask(%rbx)
jnz .Lvmx_goto_emulator
mov %rsp,%rdi
call vmx_enter_realmode
UNLIKELY_END(realmode)
mov %rsp,%rdi
call vmx_vmenter_helper
test %al, %al
jz .Lvmx_vmentry_restart
mov VCPU_arch_msrs(%rbx), %rax
mov VCPUMSR_spec_ctrl_raw(%rax), %eax
/* WARNING! `ret`, `call *`, `jmp *` not safe beyond this point. */
/* SPEC_CTRL_EXIT_TO_VMX Req: %rsp=regs/cpuinfo Clob: */
ALTERNATIVE "", __stringify(verw CPUINFO_verw_sel(%rsp)), X86_FEATURE_SC_VERW_HVM
mov VCPU_hvm_guest_cr2(%rbx),%rax
pop %r15
pop %r14
pop %r13
pop %r12
pop %rbp
mov %rax,%cr2
cmpb $0,VCPU_vmx_launched(%rbx)
pop %rbx
pop %r11
pop %r10
pop %r9
pop %r8
pop %rax
pop %rcx
pop %rdx
pop %rsi
pop %rdi
je .Lvmx_launch
/*.Lvmx_resume:*/
VMRESUME
jmp .Lvmx_vmentry_fail
.Lvmx_launch:
VMLAUNCH
.Lvmx_vmentry_fail:
sti
SAVE_ALL
/*
* SPEC_CTRL_ENTRY notes
*
* If we end up here, no guest code has executed. The MSR lists have
* not been processed, so we still have Xen's choice of MSR_SPEC_CTRL
* in context, and the RSB is unchanged.
*/
call vmx_vmentry_failure
jmp .Lvmx_process_softirqs
ENTRY(vmx_asm_do_vmentry)
GET_CURRENT(bx)
jmp .Lvmx_do_vmentry
.Lvmx_vmentry_restart:
sti
jmp .Lvmx_do_vmentry
.Lvmx_goto_emulator:
sti
mov %rsp,%rdi
call vmx_realmode
jmp .Lvmx_do_vmentry
.Lvmx_process_softirqs:
sti
call do_softirq
jmp .Lvmx_do_vmentry
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