[Xen-devel] [PATCH v10 10/12] x86/xen: Bypass intr mode setup in enlighten_pv system

[Dou Liyang <douly.fnst@xxxxxxxxxxxxxx>]

XEN PV overrides smp_prepare_cpus(). xen_pv_smp_prepare_cpus()
initializes interrupts in the XEN PV specific way and does not invoke
native_smp_prepare_cpus(). As a consequence, x86_init.intr_mode_init() is
not invoked either.

The invocation of x86_init.intr_mode_init() will be moved from
native_smp_prepare_cpus() in a follow up patch to solve the dump-capture
kernel hangs, if there is a notsc option in its command line.

That move would cause the invocation of x86_init.intr_mode_init() for XEN
PV platforms. To prevent that, override the default x86_init.intr_mode_init()
callback with a noop().

[Rewritten by Thomas Gleixner <tglx@xxxxxxxxxxxxx>]

Signed-off-by: Dou Liyang <douly.fnst@xxxxxxxxxxxxxx>
Acked-by: Juergen Gross <jgross@xxxxxxxx>
Cc: xen-devel@xxxxxxxxxxxxxxxxxxxx
Cc: boris.ostrovsky@xxxxxxxxxx
Cc: Juergen Gross <jgross@xxxxxxxx>
---
V10 --> V9:
 --Modify the changelog, suggested by Juergen
 arch/x86/xen/enlighten_pv.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index ae2a2e2..934dc7f 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -1232,6 +1232,7 @@ asmlinkage __visible void __init xen_start_kernel(void)
        x86_platform.get_nmi_reason = xen_get_nmi_reason;
 
        x86_init.resources.memory_setup = xen_memory_setup;
+       x86_init.irqs.intr_mode_init    = x86_init_noop;
        x86_init.oem.arch_setup = xen_arch_setup;
        x86_init.oem.banner = xen_banner;
 
-- 
2.5.5




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