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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2007 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <sys/asm_linkage.h>
#include <sys/hypervisor.h>
#include <sys/privregs.h>
#include <sys/segments.h>
#include <sys/traptrace.h>
#include <sys/trap.h>
#include <sys/psw.h>
#include <sys/x86_archext.h>
#include <sys/asm_misc.h>
#if !defined(__lint)
#include "assym.h"
#endif
#if defined(__lint)
void
xen_failsafe_callback(void)
{}
void
xen_callback(void)
{}
#else /* __lint */
/*
* The stack frame for events is exactly that of an x86 hardware
* interrupt.
*
* The stack frame for a failsafe callback is augmented with saved
* values for segment registers:
*
* i386
* %ds, %es, %fs, %gs, %eip, %cs, %eflags [, %oldesp, %oldss ]
*
* On amd64 the stack frame for events is exactly that of an hardware
* interrupt with the addition of rcx and r11.
*
* The stack frame for a failsafe callback is augmented with saved
* values for segment registers:
*
* amd64
* %rcx, %r11, %ds, %es, %fs, %gs, %rip, %cs, %rflags,
* [, %oldrsp, %oldss ]
*
* The hypervisor does this to allow the guest OS to handle returns
* to processes which have bad segment registers.
*
* [See comments in xen/arch/x86/[x86_64,x86_32]/entry.S]
*
* We will construct a fully fledged 'struct regs' and call trap
* with a #gp fault.
*/
#if defined(__amd64)
ENTRY(xen_failsafe_callback)
/*
* The saved values of rcx and r11 are on the top of the stack.
* pop them and let INTR_PUSH save them. We drop ds, es, fs and
* gs since the hypervisor will have already loaded these for us.
* If any were bad and faulted the hypervisor would have loaded
* them with the null selctor.
*/
XPV_TRAP_POP /* rcx, r11 */
/*
* XXPV
* If the current segregs are provided for us on the stack by
* the hypervisor then we should simply move them into their proper
* location in the regs struct?
*/
addq $_CONST(_MUL(4, CLONGSIZE)), %rsp
/*
* XXPV
* It would be nice to somehow figure out which selector caused
* #gp fault.
*/
pushq $0 /* dummy error */
pushq $T_GPFLT
INTR_PUSH
INTGATE_INIT_KERNEL_FLAGS
/*
* We're here because HYPERVISOR_IRET to userland failed due to a
* bad %cs value. Rewrite %cs, %ss and %rip on the stack so trap
* will know to handle this with kern_gpfault and kill the currently
* running process.
*/
movq $KCS_SEL, REGOFF_CS(%rsp)
movq $KDS_SEL, REGOFF_SS(%rsp)
leaq nopop_sys_rtt_syscall(%rip), %rdi
movq %rdi, REGOFF_RIP(%rsp)
TRACE_PTR(%rdi, %rbx, %ebx, %rcx, $TT_EVENT) /* Uses labels 8 and 9 */
TRACE_REGS(%rdi, %rsp, %rbx, %rcx) /* Uses label 9 */
TRACE_STAMP(%rdi) /* Clobbers %eax, %edx, uses 9 */
movq %rsp, %rbp
TRACE_STACK(%rdi)
movq %rbp, %rdi
ENABLE_INTR_FLAGS
movq %rbp, %rdi
xorl %esi, %esi
movl %gs:CPU_ID, %edx
call trap /* trap(rp, addr, cpuid) handles all trap */
jmp _sys_rtt
SET_SIZE(xen_failsafe_callback)
#elif defined(__i386)
ENTRY(xen_failsafe_callback)
/*
* drop ds, es, fs and gs
*/
addl $_CONST(_MUL(4, CLONGSIZE)), %esp /* see comment for 64-bit */
pushl $0 /* dummy error (see comment for 64-bit) */
pushl $T_GPFLT
INTR_PUSH
INTGATE_INIT_KERNEL_FLAGS /* (set kernel flag values) */
/*
* The fact were here is because HYPERVISOR_IRET to userland
* failed due to a bad %cs value. Rewrite %cs, %ss and %eip
* on the stack so trap will know to handle this with
* kern_gpfault and kill the currently running process.
*/
movl $KCS_SEL, REGOFF_CS(%esp)
movl $KDS_SEL, REGOFF_SS(%esp)
leal nopop_sys_rtt_syscall, %edi
movl %edi, REGOFF_EIP(%esp)
TRACE_PTR(%edi, %ebx, %ebx, %ecx, $TT_EVENT) /* Uses labels 8 and 9 */
TRACE_REGS(%edi, %esp, %ebx, %ecx) /* Uses label 9 */
TRACE_STAMP(%edi) /* Clobbers %eax, %edx, uses 9 */
movl %esp, %ebp
TRACE_STACK(%edi)
ENABLE_INTR_FLAGS
pushl %gs:CPU_ID
pushl $0
pushl %ebp
call trap /* trap(rp, addr, cpuid) handles all traps */
addl $12, %esp
jmp _sys_rtt
SET_SIZE(xen_failsafe_callback)
#endif /* __i386 */
#if defined(__amd64)
ENTRY(xen_callback)
XPV_TRAP_POP
pushq $0 /* dummy error */
pushq $T_AST
INTR_PUSH
INTGATE_INIT_KERNEL_FLAGS /* (set kernel flag values) */
TRACE_PTR(%rdi, %rbx, %ebx, %rcx, $TT_EVENT) /* Uses labels 8 and 9 */
TRACE_REGS(%rdi, %rsp, %rbx, %rcx) /* Uses label 9 */
TRACE_STAMP(%rdi) /* Clobbers %eax, %edx, uses 9 */
movq %rsp, %rbp
TRACE_STACK(%rdi)
movq %rdi, %rsi /* rsi = trap trace recode pointer */
movq %rbp, %rdi /* rdi = struct regs pointer */
call xen_callback_handler
jmp _sys_rtt_ints_disabled
/*NOTREACHED*/
SET_SIZE(xen_callback)
#elif defined(__i386)
ENTRY(xen_callback)
pushl $0 /* dummy error */
pushl $T_AST
INTR_PUSH
INTGATE_INIT_KERNEL_FLAGS /* (set kernel flag values) */
TRACE_PTR(%edi, %ebx, %ebx, %ecx, $TT_EVENT) /* Uses labels 8 and 9 */
TRACE_REGS(%edi, %esp, %ebx, %ecx) /* Uses label 9 */
TRACE_STAMP(%edi) /* Clobbers %eax, %edx, uses 9 */
movl %esp, %ebp
TRACE_STACK(%edi)
pushl %edi /* pass trap trace record pointer */
pushl %ebp /* pass struct regs pointer */
call xen_callback_handler
addl $8, %esp
jmp _sys_rtt_ints_disabled
/*NOTREACHED*/
SET_SIZE(xen_callback)
#endif /* __i386 */
#endif /* __lint */
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