diff options
| -rw-r--r-- | arch/x86/xen/enlighten.c | 4 | ||||
| -rw-r--r-- | arch/x86/xen/setup.c | 42 | ||||
| -rw-r--r-- | arch/x86/xen/smp.c | 1 | ||||
| -rw-r--r-- | arch/x86/xen/xen-asm_64.S | 129 | ||||
| -rw-r--r-- | arch/x86/xen/xen-ops.h | 3 |
5 files changed, 174 insertions, 5 deletions
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 48f1a7eca8b9..87d36044054d 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -1139,6 +1139,10 @@ static const struct pv_cpu_ops xen_cpu_ops __initdata = { .iret = xen_iret, .irq_enable_sysexit = xen_sysexit, +#ifdef CONFIG_X86_64 + .usergs_sysret32 = xen_sysret32, + .usergs_sysret64 = xen_sysret64, +#endif .load_tr_desc = paravirt_nop, .set_ldt = xen_set_ldt, diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c index bea3d4f779db..9d7a14402895 100644 --- a/arch/x86/xen/setup.c +++ b/arch/x86/xen/setup.c @@ -86,9 +86,11 @@ static void xen_idle(void) */ static void __init fiddle_vdso(void) { +#if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION) extern const char vdso32_default_start; u32 *mask = VDSO32_SYMBOL(&vdso32_default_start, NOTE_MASK); *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT; +#endif } static __cpuinit int register_callback(unsigned type, const void *func) @@ -106,15 +108,48 @@ void __cpuinit xen_enable_sysenter(void) { int cpu = smp_processor_id(); extern void xen_sysenter_target(void); + int ret; + +#ifdef CONFIG_X86_32 + if (!boot_cpu_has(X86_FEATURE_SEP)) { + return; + } +#else + if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL && + boot_cpu_data.x86_vendor != X86_VENDOR_CENTAUR) { + return; + } +#endif - if (!boot_cpu_has(X86_FEATURE_SEP) || - register_callback(CALLBACKTYPE_sysenter, - xen_sysenter_target) != 0) { + ret = register_callback(CALLBACKTYPE_sysenter, xen_sysenter_target); + if(ret != 0) { clear_cpu_cap(&cpu_data(cpu), X86_FEATURE_SEP); clear_cpu_cap(&boot_cpu_data, X86_FEATURE_SEP); } } +void __cpuinit xen_enable_syscall(void) +{ +#ifdef CONFIG_X86_64 + int cpu = smp_processor_id(); + int ret; + extern void xen_syscall_target(void); + extern void xen_syscall32_target(void); + + ret = register_callback(CALLBACKTYPE_syscall, xen_syscall_target); + if (ret != 0) { + printk("failed to set syscall: %d\n", ret); + clear_cpu_cap(&cpu_data(cpu), X86_FEATURE_SYSCALL); + clear_cpu_cap(&boot_cpu_data, X86_FEATURE_SYSCALL); + } else { + ret = register_callback(CALLBACKTYPE_syscall32, + xen_syscall32_target); + if (ret != 0) + printk("failed to set 32-bit syscall: %d\n", ret); + } +#endif /* CONFIG_X86_64 */ +} + void __init xen_arch_setup(void) { struct physdev_set_iopl set_iopl; @@ -131,6 +166,7 @@ void __init xen_arch_setup(void) BUG(); xen_enable_sysenter(); + xen_enable_syscall(); set_iopl.iopl = 1; rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl); diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c index 8310ca0ea375..f702199312a5 100644 --- a/arch/x86/xen/smp.c +++ b/arch/x86/xen/smp.c @@ -69,6 +69,7 @@ static __cpuinit void cpu_bringup_and_idle(void) preempt_disable(); xen_enable_sysenter(); + xen_enable_syscall(); cpu = smp_processor_id(); smp_store_cpu_info(cpu); diff --git a/arch/x86/xen/xen-asm_64.S b/arch/x86/xen/xen-asm_64.S index b147b495daef..4038cbfe3331 100644 --- a/arch/x86/xen/xen-asm_64.S +++ b/arch/x86/xen/xen-asm_64.S @@ -15,6 +15,8 @@ #include <asm/asm-offsets.h> #include <asm/processor-flags.h> +#include <asm/errno.h> +#include <asm/segment.h> #include <xen/interface/xen.h> @@ -138,9 +140,132 @@ ENTRY(xen_adjust_exception_frame) mov 8+8(%rsp),%r11 ret $16 +hypercall_iret = hypercall_page + __HYPERVISOR_iret * 32 +/* + Xen64 iret frame: + + ss + rsp + rflags + cs + rip <-- standard iret frame + + flags + + rcx } + r11 }<-- pushed by hypercall page +rsp -> rax } + */ ENTRY(xen_iret) pushq $0 - jmp hypercall_page + __HYPERVISOR_iret * 32 +1: jmp hypercall_iret +ENDPATCH(xen_iret) +RELOC(xen_iret, 1b+1) +/* + sysexit is not used for 64-bit processes, so it's + only ever used to return to 32-bit compat userspace. + */ ENTRY(xen_sysexit) - ud2a + pushq $__USER32_DS + pushq %rcx + pushq $X86_EFLAGS_IF + pushq $__USER32_CS + pushq %rdx + + pushq $VGCF_in_syscall +1: jmp hypercall_iret +ENDPATCH(xen_sysexit) +RELOC(xen_sysexit, 1b+1) + +ENTRY(xen_sysret64) + /* We're already on the usermode stack at this point, but still + with the kernel gs, so we can easily switch back */ + movq %rsp, %gs:pda_oldrsp + movq %gs:pda_kernelstack,%rsp + + pushq $__USER_DS + pushq %gs:pda_oldrsp + pushq %r11 + pushq $__USER_CS + pushq %rcx + + pushq $VGCF_in_syscall +1: jmp hypercall_iret +ENDPATCH(xen_sysret64) +RELOC(xen_sysret64, 1b+1) + +ENTRY(xen_sysret32) + /* We're already on the usermode stack at this point, but still + with the kernel gs, so we can easily switch back */ + movq %rsp, %gs:pda_oldrsp + movq %gs:pda_kernelstack, %rsp + + pushq $__USER32_DS + pushq %gs:pda_oldrsp + pushq %r11 + pushq $__USER32_CS + pushq %rcx + + pushq $VGCF_in_syscall +1: jmp hypercall_iret +ENDPATCH(xen_sysret32) +RELOC(xen_sysret32, 1b+1) + +/* + Xen handles syscall callbacks much like ordinary exceptions, + which means we have: + - kernel gs + - kernel rsp + - an iret-like stack frame on the stack (including rcx and r11): + ss + rsp + rflags + cs + rip + r11 + rsp-> rcx + + In all the entrypoints, we undo all that to make it look + like a CPU-generated syscall/sysenter and jump to the normal + entrypoint. + */ + +.macro undo_xen_syscall + mov 0*8(%rsp),%rcx + mov 1*8(%rsp),%r11 + mov 5*8(%rsp),%rsp +.endm + +/* Normal 64-bit system call target */ +ENTRY(xen_syscall_target) + undo_xen_syscall + jmp system_call_after_swapgs +ENDPROC(xen_syscall_target) + +#ifdef CONFIG_IA32_EMULATION + +/* 32-bit compat syscall target */ +ENTRY(xen_syscall32_target) + undo_xen_syscall + jmp ia32_cstar_target +ENDPROC(xen_syscall32_target) + +/* 32-bit compat sysenter target */ +ENTRY(xen_sysenter_target) + undo_xen_syscall + jmp ia32_sysenter_target +ENDPROC(xen_sysenter_target) + +#else /* !CONFIG_IA32_EMULATION */ + +ENTRY(xen_syscall32_target) +ENTRY(xen_sysenter_target) + lea 16(%rsp), %rsp /* strip %rcx,%r11 */ + mov $-ENOSYS, %rax + pushq $VGCF_in_syscall + jmp hypercall_iret +ENDPROC(xen_syscall32_target) +ENDPROC(xen_sysenter_target) + +#endif /* CONFIG_IA32_EMULATION */ diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h index c4800a2c5a41..dd3c23152a2e 100644 --- a/arch/x86/xen/xen-ops.h +++ b/arch/x86/xen/xen-ops.h @@ -26,6 +26,7 @@ char * __init xen_memory_setup(void); void __init xen_arch_setup(void); void __init xen_init_IRQ(void); void xen_enable_sysenter(void); +void xen_enable_syscall(void); void xen_vcpu_restore(void); void __init xen_build_dynamic_phys_to_machine(void); @@ -70,6 +71,8 @@ DECL_ASM(void, xen_restore_fl_direct, unsigned long); /* These are not functions, and cannot be called normally */ void xen_iret(void); void xen_sysexit(void); +void xen_sysret32(void); +void xen_sysret64(void); void xen_adjust_exception_frame(void); #endif /* XEN_OPS_H */ |
