c16312f4fa
POP [mem] defaults to the word size, and the only legal non-default size is 16 bits, e.g. a 32-bit POP will #UD in 64-bit mode and vice versa, no need to use __ASM_SIZE macro to force operating mode. Changes since v1: - Fix commit message. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Message-Id: <20200427205035.1594232-1-ubizjak@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
294 lines
6.9 KiB
ArmAsm
294 lines
6.9 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#include <linux/linkage.h>
|
|
#include <asm/asm.h>
|
|
#include <asm/bitsperlong.h>
|
|
#include <asm/kvm_vcpu_regs.h>
|
|
#include <asm/nospec-branch.h>
|
|
|
|
#define WORD_SIZE (BITS_PER_LONG / 8)
|
|
|
|
#define VCPU_RAX __VCPU_REGS_RAX * WORD_SIZE
|
|
#define VCPU_RCX __VCPU_REGS_RCX * WORD_SIZE
|
|
#define VCPU_RDX __VCPU_REGS_RDX * WORD_SIZE
|
|
#define VCPU_RBX __VCPU_REGS_RBX * WORD_SIZE
|
|
/* Intentionally omit RSP as it's context switched by hardware */
|
|
#define VCPU_RBP __VCPU_REGS_RBP * WORD_SIZE
|
|
#define VCPU_RSI __VCPU_REGS_RSI * WORD_SIZE
|
|
#define VCPU_RDI __VCPU_REGS_RDI * WORD_SIZE
|
|
|
|
#ifdef CONFIG_X86_64
|
|
#define VCPU_R8 __VCPU_REGS_R8 * WORD_SIZE
|
|
#define VCPU_R9 __VCPU_REGS_R9 * WORD_SIZE
|
|
#define VCPU_R10 __VCPU_REGS_R10 * WORD_SIZE
|
|
#define VCPU_R11 __VCPU_REGS_R11 * WORD_SIZE
|
|
#define VCPU_R12 __VCPU_REGS_R12 * WORD_SIZE
|
|
#define VCPU_R13 __VCPU_REGS_R13 * WORD_SIZE
|
|
#define VCPU_R14 __VCPU_REGS_R14 * WORD_SIZE
|
|
#define VCPU_R15 __VCPU_REGS_R15 * WORD_SIZE
|
|
#endif
|
|
|
|
.text
|
|
|
|
/**
|
|
* vmx_vmenter - VM-Enter the current loaded VMCS
|
|
*
|
|
* %RFLAGS.ZF: !VMCS.LAUNCHED, i.e. controls VMLAUNCH vs. VMRESUME
|
|
*
|
|
* Returns:
|
|
* %RFLAGS.CF is set on VM-Fail Invalid
|
|
* %RFLAGS.ZF is set on VM-Fail Valid
|
|
* %RFLAGS.{CF,ZF} are cleared on VM-Success, i.e. VM-Exit
|
|
*
|
|
* Note that VMRESUME/VMLAUNCH fall-through and return directly if
|
|
* they VM-Fail, whereas a successful VM-Enter + VM-Exit will jump
|
|
* to vmx_vmexit.
|
|
*/
|
|
SYM_FUNC_START(vmx_vmenter)
|
|
/* EFLAGS.ZF is set if VMCS.LAUNCHED == 0 */
|
|
je 2f
|
|
|
|
1: vmresume
|
|
ret
|
|
|
|
2: vmlaunch
|
|
ret
|
|
|
|
3: cmpb $0, kvm_rebooting
|
|
je 4f
|
|
ret
|
|
4: ud2
|
|
|
|
_ASM_EXTABLE(1b, 3b)
|
|
_ASM_EXTABLE(2b, 3b)
|
|
|
|
SYM_FUNC_END(vmx_vmenter)
|
|
|
|
/**
|
|
* vmx_vmexit - Handle a VMX VM-Exit
|
|
*
|
|
* Returns:
|
|
* %RFLAGS.{CF,ZF} are cleared on VM-Success, i.e. VM-Exit
|
|
*
|
|
* This is vmx_vmenter's partner in crime. On a VM-Exit, control will jump
|
|
* here after hardware loads the host's state, i.e. this is the destination
|
|
* referred to by VMCS.HOST_RIP.
|
|
*/
|
|
SYM_FUNC_START(vmx_vmexit)
|
|
#ifdef CONFIG_RETPOLINE
|
|
ALTERNATIVE "jmp .Lvmexit_skip_rsb", "", X86_FEATURE_RETPOLINE
|
|
/* Preserve guest's RAX, it's used to stuff the RSB. */
|
|
push %_ASM_AX
|
|
|
|
/* IMPORTANT: Stuff the RSB immediately after VM-Exit, before RET! */
|
|
FILL_RETURN_BUFFER %_ASM_AX, RSB_CLEAR_LOOPS, X86_FEATURE_RETPOLINE
|
|
|
|
/* Clear RFLAGS.CF and RFLAGS.ZF to preserve VM-Exit, i.e. !VM-Fail. */
|
|
or $1, %_ASM_AX
|
|
|
|
pop %_ASM_AX
|
|
.Lvmexit_skip_rsb:
|
|
#endif
|
|
ret
|
|
SYM_FUNC_END(vmx_vmexit)
|
|
|
|
/**
|
|
* __vmx_vcpu_run - Run a vCPU via a transition to VMX guest mode
|
|
* @vmx: struct vcpu_vmx * (forwarded to vmx_update_host_rsp)
|
|
* @regs: unsigned long * (to guest registers)
|
|
* @launched: %true if the VMCS has been launched
|
|
*
|
|
* Returns:
|
|
* 0 on VM-Exit, 1 on VM-Fail
|
|
*/
|
|
SYM_FUNC_START(__vmx_vcpu_run)
|
|
push %_ASM_BP
|
|
mov %_ASM_SP, %_ASM_BP
|
|
#ifdef CONFIG_X86_64
|
|
push %r15
|
|
push %r14
|
|
push %r13
|
|
push %r12
|
|
#else
|
|
push %edi
|
|
push %esi
|
|
#endif
|
|
push %_ASM_BX
|
|
|
|
/*
|
|
* Save @regs, _ASM_ARG2 may be modified by vmx_update_host_rsp() and
|
|
* @regs is needed after VM-Exit to save the guest's register values.
|
|
*/
|
|
push %_ASM_ARG2
|
|
|
|
/* Copy @launched to BL, _ASM_ARG3 is volatile. */
|
|
mov %_ASM_ARG3B, %bl
|
|
|
|
/* Adjust RSP to account for the CALL to vmx_vmenter(). */
|
|
lea -WORD_SIZE(%_ASM_SP), %_ASM_ARG2
|
|
call vmx_update_host_rsp
|
|
|
|
/* Load @regs to RAX. */
|
|
mov (%_ASM_SP), %_ASM_AX
|
|
|
|
/* Check if vmlaunch or vmresume is needed */
|
|
cmpb $0, %bl
|
|
|
|
/* Load guest registers. Don't clobber flags. */
|
|
mov VCPU_RCX(%_ASM_AX), %_ASM_CX
|
|
mov VCPU_RDX(%_ASM_AX), %_ASM_DX
|
|
mov VCPU_RBX(%_ASM_AX), %_ASM_BX
|
|
mov VCPU_RBP(%_ASM_AX), %_ASM_BP
|
|
mov VCPU_RSI(%_ASM_AX), %_ASM_SI
|
|
mov VCPU_RDI(%_ASM_AX), %_ASM_DI
|
|
#ifdef CONFIG_X86_64
|
|
mov VCPU_R8 (%_ASM_AX), %r8
|
|
mov VCPU_R9 (%_ASM_AX), %r9
|
|
mov VCPU_R10(%_ASM_AX), %r10
|
|
mov VCPU_R11(%_ASM_AX), %r11
|
|
mov VCPU_R12(%_ASM_AX), %r12
|
|
mov VCPU_R13(%_ASM_AX), %r13
|
|
mov VCPU_R14(%_ASM_AX), %r14
|
|
mov VCPU_R15(%_ASM_AX), %r15
|
|
#endif
|
|
/* Load guest RAX. This kills the @regs pointer! */
|
|
mov VCPU_RAX(%_ASM_AX), %_ASM_AX
|
|
|
|
/* Enter guest mode */
|
|
call vmx_vmenter
|
|
|
|
/* Jump on VM-Fail. */
|
|
jbe 2f
|
|
|
|
/* Temporarily save guest's RAX. */
|
|
push %_ASM_AX
|
|
|
|
/* Reload @regs to RAX. */
|
|
mov WORD_SIZE(%_ASM_SP), %_ASM_AX
|
|
|
|
/* Save all guest registers, including RAX from the stack */
|
|
pop VCPU_RAX(%_ASM_AX)
|
|
mov %_ASM_CX, VCPU_RCX(%_ASM_AX)
|
|
mov %_ASM_DX, VCPU_RDX(%_ASM_AX)
|
|
mov %_ASM_BX, VCPU_RBX(%_ASM_AX)
|
|
mov %_ASM_BP, VCPU_RBP(%_ASM_AX)
|
|
mov %_ASM_SI, VCPU_RSI(%_ASM_AX)
|
|
mov %_ASM_DI, VCPU_RDI(%_ASM_AX)
|
|
#ifdef CONFIG_X86_64
|
|
mov %r8, VCPU_R8 (%_ASM_AX)
|
|
mov %r9, VCPU_R9 (%_ASM_AX)
|
|
mov %r10, VCPU_R10(%_ASM_AX)
|
|
mov %r11, VCPU_R11(%_ASM_AX)
|
|
mov %r12, VCPU_R12(%_ASM_AX)
|
|
mov %r13, VCPU_R13(%_ASM_AX)
|
|
mov %r14, VCPU_R14(%_ASM_AX)
|
|
mov %r15, VCPU_R15(%_ASM_AX)
|
|
#endif
|
|
|
|
/* Clear RAX to indicate VM-Exit (as opposed to VM-Fail). */
|
|
xor %eax, %eax
|
|
|
|
/*
|
|
* Clear all general purpose registers except RSP and RAX to prevent
|
|
* speculative use of the guest's values, even those that are reloaded
|
|
* via the stack. In theory, an L1 cache miss when restoring registers
|
|
* could lead to speculative execution with the guest's values.
|
|
* Zeroing XORs are dirt cheap, i.e. the extra paranoia is essentially
|
|
* free. RSP and RAX are exempt as RSP is restored by hardware during
|
|
* VM-Exit and RAX is explicitly loaded with 0 or 1 to return VM-Fail.
|
|
*/
|
|
1: xor %ecx, %ecx
|
|
xor %edx, %edx
|
|
xor %ebx, %ebx
|
|
xor %ebp, %ebp
|
|
xor %esi, %esi
|
|
xor %edi, %edi
|
|
#ifdef CONFIG_X86_64
|
|
xor %r8d, %r8d
|
|
xor %r9d, %r9d
|
|
xor %r10d, %r10d
|
|
xor %r11d, %r11d
|
|
xor %r12d, %r12d
|
|
xor %r13d, %r13d
|
|
xor %r14d, %r14d
|
|
xor %r15d, %r15d
|
|
#endif
|
|
|
|
/* "POP" @regs. */
|
|
add $WORD_SIZE, %_ASM_SP
|
|
pop %_ASM_BX
|
|
|
|
#ifdef CONFIG_X86_64
|
|
pop %r12
|
|
pop %r13
|
|
pop %r14
|
|
pop %r15
|
|
#else
|
|
pop %esi
|
|
pop %edi
|
|
#endif
|
|
pop %_ASM_BP
|
|
ret
|
|
|
|
/* VM-Fail. Out-of-line to avoid a taken Jcc after VM-Exit. */
|
|
2: mov $1, %eax
|
|
jmp 1b
|
|
SYM_FUNC_END(__vmx_vcpu_run)
|
|
|
|
/**
|
|
* vmread_error_trampoline - Trampoline from inline asm to vmread_error()
|
|
* @field: VMCS field encoding that failed
|
|
* @fault: %true if the VMREAD faulted, %false if it failed
|
|
|
|
* Save and restore volatile registers across a call to vmread_error(). Note,
|
|
* all parameters are passed on the stack.
|
|
*/
|
|
SYM_FUNC_START(vmread_error_trampoline)
|
|
push %_ASM_BP
|
|
mov %_ASM_SP, %_ASM_BP
|
|
|
|
push %_ASM_AX
|
|
push %_ASM_CX
|
|
push %_ASM_DX
|
|
#ifdef CONFIG_X86_64
|
|
push %rdi
|
|
push %rsi
|
|
push %r8
|
|
push %r9
|
|
push %r10
|
|
push %r11
|
|
#endif
|
|
#ifdef CONFIG_X86_64
|
|
/* Load @field and @fault to arg1 and arg2 respectively. */
|
|
mov 3*WORD_SIZE(%rbp), %_ASM_ARG2
|
|
mov 2*WORD_SIZE(%rbp), %_ASM_ARG1
|
|
#else
|
|
/* Parameters are passed on the stack for 32-bit (see asmlinkage). */
|
|
push 3*WORD_SIZE(%ebp)
|
|
push 2*WORD_SIZE(%ebp)
|
|
#endif
|
|
|
|
call vmread_error
|
|
|
|
#ifndef CONFIG_X86_64
|
|
add $8, %esp
|
|
#endif
|
|
|
|
/* Zero out @fault, which will be popped into the result register. */
|
|
_ASM_MOV $0, 3*WORD_SIZE(%_ASM_BP)
|
|
|
|
#ifdef CONFIG_X86_64
|
|
pop %r11
|
|
pop %r10
|
|
pop %r9
|
|
pop %r8
|
|
pop %rsi
|
|
pop %rdi
|
|
#endif
|
|
pop %_ASM_DX
|
|
pop %_ASM_CX
|
|
pop %_ASM_AX
|
|
pop %_ASM_BP
|
|
|
|
ret
|
|
SYM_FUNC_END(vmread_error_trampoline)
|