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84d582d236
Recent discussion (http://marc.info/?l=xen-devel&m=149192184523741) established that commit72a9b18629("xen: Remove event channel notification through Xen PCI platform device") (and thus commitda72ff5bfc("partially revert "xen: Remove event channel notification through Xen PCI platform device"")) are unnecessary and, in fact, prevent HVM guests from booting on Xen releases prior to 4.0 Therefore we revert both of those commits. The summary of that discussion is below: Here is the brief summary of the current situation: Before the offending commit (72a9b18629): 1) INTx does not work because of the reset_watches path. 2) The reset_watches path is only taken if you have Xen > 4.0 3) The Linux Kernel by default will use vector inject if the hypervisor support. So even INTx does not work no body running the kernel with Xen > 4.0 would notice. Unless he explicitly disabled this feature either in the kernel or in Xen (and this can only be disabled by modifying the code, not user-supported way to do it). After the offending commit (+ partial revert): 1) INTx is no longer support for HVM (only for PV guests). 2) Any HVM guest The kernel will not boot on Xen < 4.0 which does not have vector injection support. Since the only other mode supported is INTx which. So based on this summary, I think before commit (72a9b18629) we were in much better position from a user point of view. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
64 lines
1.4 KiB
C
64 lines
1.4 KiB
C
#include <asm/smp.h>
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#include <xen/events.h>
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#include "xen-ops.h"
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#include "smp.h"
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static void __init xen_hvm_smp_prepare_boot_cpu(void)
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{
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BUG_ON(smp_processor_id() != 0);
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native_smp_prepare_boot_cpu();
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/*
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* Setup vcpu_info for boot CPU.
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*/
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xen_vcpu_setup(0);
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/*
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* The alternative logic (which patches the unlock/lock) runs before
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* the smp bootup up code is activated. Hence we need to set this up
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* the core kernel is being patched. Otherwise we will have only
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* modules patched but not core code.
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*/
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xen_init_spinlocks();
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}
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static void __init xen_hvm_smp_prepare_cpus(unsigned int max_cpus)
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{
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native_smp_prepare_cpus(max_cpus);
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WARN_ON(xen_smp_intr_init(0));
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xen_init_lock_cpu(0);
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}
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#ifdef CONFIG_HOTPLUG_CPU
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static void xen_hvm_cpu_die(unsigned int cpu)
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{
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if (common_cpu_die(cpu) == 0) {
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xen_smp_intr_free(cpu);
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xen_uninit_lock_cpu(cpu);
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xen_teardown_timer(cpu);
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}
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}
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#else
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static void xen_hvm_cpu_die(unsigned int cpu)
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{
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BUG();
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}
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#endif
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void __init xen_hvm_smp_init(void)
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{
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if (!xen_have_vector_callback)
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return;
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smp_ops.smp_prepare_cpus = xen_hvm_smp_prepare_cpus;
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smp_ops.smp_send_reschedule = xen_smp_send_reschedule;
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smp_ops.cpu_die = xen_hvm_cpu_die;
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smp_ops.send_call_func_ipi = xen_smp_send_call_function_ipi;
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smp_ops.send_call_func_single_ipi = xen_smp_send_call_function_single_ipi;
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smp_ops.smp_prepare_boot_cpu = xen_hvm_smp_prepare_boot_cpu;
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}
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