Messages in this thread Patch in this message | | | Date | Tue, 27 Jan 2009 00:57:57 -0500 | Subject | Re: unified percpu stuff | From | Brian Gerst <> |
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On Mon, Jan 26, 2009 at 8:12 PM, Jeremy Fitzhardinge <jeremy@goop.org> wrote: > I'm really pleased to see the unified percpu stuff in the kernel, but > unfortunately its breaking Xen at the moment. > It looks like this is just a matter of initializing %gs properly in > xen_start_kernel. Is there any problem with me doing a load_gs_base(0) > somewhere early in xen_start_kernel (arch/x86/xen/enlighten.c)?
Some of the changes I did made the assumption that the percpu state is set up early in head_xx.S, which apparently is skipped for xen. Is there documentation anywhere for the xen bootstrap process?
Try this patch (untested):
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index bef941f..b90d061 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -1647,6 +1647,8 @@ asmlinkage void __init xen_start_kernel(void) have_vcpu_info_placement = 0; #endif
+ switch_to_new_gdt(); + xen_smp_init();
/* Get mfn list */ diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c index 7735e3d..00d9265 100644 --- a/arch/x86/xen/smp.c +++ b/arch/x86/xen/smp.c @@ -235,6 +235,8 @@ cpu_initialize_context(unsigned int cpu, struct task_struct *idle) ctxt->user_regs.ss = __KERNEL_DS; #ifdef CONFIG_X86_32 ctxt->user_regs.fs = __KERNEL_PERCPU; +#else + ctxt->gs_base_kernel = per_cpu_offset(cpu); #endif ctxt->user_regs.eip = (unsigned long)cpu_bringup_and_idle; ctxt->user_regs.eflags = 0x1000; /* IOPL_RING1 */ -- Brian Gerst
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