diff options
| -rw-r--r-- | arch/x86/kernel/entry_32.S | 18 | ||||
| -rw-r--r-- | arch/x86/xen/enlighten.c | 3 | ||||
| -rw-r--r-- | arch/x86/xen/setup.c | 21 | ||||
| -rw-r--r-- | arch/x86/xen/smp.c | 1 | ||||
| -rw-r--r-- | arch/x86/xen/xen-asm.S | 56 | ||||
| -rw-r--r-- | arch/x86/xen/xen-ops.h | 3 |
6 files changed, 99 insertions, 3 deletions
diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S index 568c6ccd7ae2..5d80d53eaff8 100644 --- a/arch/x86/kernel/entry_32.S +++ b/arch/x86/kernel/entry_32.S @@ -1017,6 +1017,13 @@ ENTRY(kernel_thread_helper) ENDPROC(kernel_thread_helper) #ifdef CONFIG_XEN +/* Xen doesn't set %esp to be precisely what the normal sysenter + entrypoint expects, so fix it up before using the normal path. */ +ENTRY(xen_sysenter_target) + RING0_INT_FRAME + addl $5*4, %esp /* remove xen-provided frame */ + jmp sysenter_past_esp + ENTRY(xen_hypervisor_callback) CFI_STARTPROC pushl $0 @@ -1036,8 +1043,17 @@ ENTRY(xen_hypervisor_callback) jae 1f call xen_iret_crit_fixup + jmp 2f + +1: cmpl $xen_sysexit_start_crit,%eax + jb 2f + cmpl $xen_sysexit_end_crit,%eax + jae 2f + + jmp xen_sysexit_crit_fixup -1: mov %esp, %eax +ENTRY(xen_do_upcall) +2: mov %esp, %eax call xen_evtchn_do_upcall jmp ret_from_intr CFI_ENDPROC diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 36f36e6b0874..943684566ebe 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -155,7 +155,6 @@ static void xen_cpuid(unsigned int *ax, unsigned int *bx, if (*ax == 1) maskedx = ~((1 << X86_FEATURE_APIC) | /* disable APIC */ (1 << X86_FEATURE_ACPI) | /* disable ACPI */ - (1 << X86_FEATURE_SEP) | /* disable SEP */ (1 << X86_FEATURE_ACC)); /* thermal monitoring */ asm(XEN_EMULATE_PREFIX "cpuid" @@ -994,7 +993,7 @@ static const struct pv_cpu_ops xen_cpu_ops __initdata = { .read_pmc = native_read_pmc, .iret = xen_iret, - .irq_enable_syscall_ret = NULL, /* never called */ + .irq_enable_syscall_ret = xen_sysexit, .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 2341492bf7a0..82517e4a752a 100644 --- a/arch/x86/xen/setup.c +++ b/arch/x86/xen/setup.c @@ -16,6 +16,7 @@ #include <asm/xen/hypervisor.h> #include <asm/xen/hypercall.h> +#include <xen/interface/callback.h> #include <xen/interface/physdev.h> #include <xen/features.h> @@ -68,6 +69,24 @@ static void __init fiddle_vdso(void) *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT; } +void xen_enable_sysenter(void) +{ + int cpu = smp_processor_id(); + extern void xen_sysenter_target(void); + /* Mask events on entry, even though they get enabled immediately */ + static struct callback_register sysenter = { + .type = CALLBACKTYPE_sysenter, + .address = { __KERNEL_CS, (unsigned long)xen_sysenter_target }, + .flags = CALLBACKF_mask_events, + }; + + if (!boot_cpu_has(X86_FEATURE_SEP) || + HYPERVISOR_callback_op(CALLBACKOP_register, &sysenter) != 0) { + clear_cpu_cap(&cpu_data(cpu), X86_FEATURE_SEP); + clear_cpu_cap(&boot_cpu_data, X86_FEATURE_SEP); + } +} + void __init xen_arch_setup(void) { struct physdev_set_iopl set_iopl; @@ -82,6 +101,8 @@ void __init xen_arch_setup(void) HYPERVISOR_set_callbacks(__KERNEL_CS, (unsigned long)xen_hypervisor_callback, __KERNEL_CS, (unsigned long)xen_failsafe_callback); + xen_enable_sysenter(); + set_iopl.iopl = 1; rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl); if (rc != 0) diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c index e340ff92f6b6..d61e4f8b07c7 100644 --- a/arch/x86/xen/smp.c +++ b/arch/x86/xen/smp.c @@ -72,6 +72,7 @@ static __cpuinit void cpu_bringup_and_idle(void) int cpu = smp_processor_id(); cpu_init(); + xen_enable_sysenter(); preempt_disable(); per_cpu(cpu_state, cpu) = CPU_ONLINE; diff --git a/arch/x86/xen/xen-asm.S b/arch/x86/xen/xen-asm.S index 99223cc323be..1ac08082a4b4 100644 --- a/arch/x86/xen/xen-asm.S +++ b/arch/x86/xen/xen-asm.S @@ -280,6 +280,62 @@ ENTRY(xen_iret_crit_fixup) 2: ret +ENTRY(xen_sysexit) + /* Store vcpu_info pointer for easy access. Do it this + way to avoid having to reload %fs */ +#ifdef CONFIG_SMP + GET_THREAD_INFO(%eax) + movl TI_cpu(%eax),%eax + movl __per_cpu_offset(,%eax,4),%eax + mov per_cpu__xen_vcpu(%eax),%eax +#else + movl per_cpu__xen_vcpu, %eax +#endif + + /* We can't actually use sysexit in a pv guest, + so fake it up with iret */ + pushl $__USER_DS /* user stack segment */ + pushl %ecx /* user esp */ + pushl PT_EFLAGS+2*4(%esp) /* user eflags */ + pushl $__USER_CS /* user code segment */ + pushl %edx /* user eip */ + +xen_sysexit_start_crit: + /* Unmask events... */ + movb $0, XEN_vcpu_info_mask(%eax) + /* ...and test for pending. + There's a preempt window here, but it doesn't + matter because we're within the critical section. */ + testb $0xff, XEN_vcpu_info_pending(%eax) + + /* If there's something pending, mask events again so we + can directly inject it back into the kernel. */ + jnz 1f + + movl PT_EAX+5*4(%esp),%eax +2: iret +1: movb $1, XEN_vcpu_info_mask(%eax) +xen_sysexit_end_crit: + addl $5*4, %esp /* remove iret frame */ + /* no need to re-save regs, but need to restore kernel %fs */ + mov $__KERNEL_PERCPU, %eax + mov %eax, %fs + jmp xen_do_upcall +.section __ex_table,"a" + .align 4 + .long 2b,iret_exc +.previous + + .globl xen_sysexit_start_crit, xen_sysexit_end_crit +/* + sysexit fixup is easy, since the old frame is still sitting there + on the stack. We just need to remove the new recursive + interrupt and return. + */ +ENTRY(xen_sysexit_crit_fixup) + addl $PT_OLDESP+5*4, %esp /* remove frame+iret */ + jmp xen_do_upcall + /* Force an event check by making a hypercall, but preserve regs before making the call. diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h index 956a491ea998..01d4ff2ce404 100644 --- a/arch/x86/xen/xen-ops.h +++ b/arch/x86/xen/xen-ops.h @@ -19,6 +19,7 @@ extern struct shared_info *HYPERVISOR_shared_info; 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_setup_timer(int cpu); void xen_setup_cpu_clockevents(void); @@ -64,4 +65,6 @@ DECL_ASM(unsigned long, xen_save_fl_direct, void); DECL_ASM(void, xen_restore_fl_direct, unsigned long); void xen_iret(void); +void xen_sysexit(void); + #endif /* XEN_OPS_H */ |