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From: Pavel Machek <pavel@suse.cz>
To: Eduardo Habkost <ehabkost@redhat.com>
Cc: Avi Kivity <avi@redhat.com>, Ingo Molnar <mingo@elte.hu>,
	"Eric W. Biederman" <ebiederm@xmission.com>,
	Simon Horman <horms@verge.net.au>, Andrew Morton <akpm@osdl.org>,
	Vivek Goyal <vgoyal@redhat.com>, Haren Myneni <hbabu@us.ibm.com>,
	Andrey Borzenkov <arvidjaar@mail.ru>,
	mingo@redhat.com, "Rafael J. Wysocki" <rjw@sisk.pl>,
	kexec@lists.infradead.org, kvm@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 09/15] x86: Emergency virtualization disable function
Date: Wed, 5 Nov 2008 23:27:32 +0100	[thread overview]
Message-ID: <20081105222731.GA14202@elf.ucw.cz> (raw)
In-Reply-To: <1225915018-6548-10-git-send-email-ehabkost@redhat.com>

On Wed 2008-11-05 17:56:52, Eduardo Habkost wrote:
> This patch adds an interface to set a function that can be used to
> disable virtualization extensions on the CPU on emergency cases, such
> as on kdump or emergency reboot.
> 
> The function will be set by code that enables virtualization extensions
> on the CPUs (i.e. KVM), and should do the very least to disable virt
> extensions on the CPU where it is being called.
> 
> The functions that set the function pointer uses RCU synchronization,
> just in case the crash NMI is triggered while KVM is unloading.
> 
> We can't just use the same notifiers used at reboot time (that are used
> by non-crash-dump kexec), because at crash time some CPUs may have IRQs
> disabled, so we can't use IPIs. The crash shutdown code use NMIs to tell
> the other CPUs to be halted, so the notifier call will be hooked into
> the CPU halting code that is on the crash shutdown NMI handler.
> 
> [v2: drop 'unsigned int cpu' arg from function]
> [v3: make emergency_virt_disable() non-static]
> [v4: add a config option for it: CPU_VIRT_EXTENSIONS]
> [v5: add has_virt_extensions() function]
> [v6: don't define the registering functions if CPU_VIRT_EXTENSIONS is
>  not enabled]
> [v7: use EXPORT_SYMBOL_GPL]
> 

> --- /dev/null
> +++ b/arch/x86/kernel/virtext.c
> @@ -0,0 +1,89 @@
> +/* Core CPU virtualization extensions handling
> + *
> + * This should carry the code for handling CPU virtualization extensions
> + * that needs to live in the kernel core.
> + *
> + * Author: Eduardo Habkost <ehabkost@redhat.com>
> + *
> + * Copyright (C) 2008, Red Hat Inc.
> + */

GPL?

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

  reply	other threads:[~2008-11-05 22:26 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-11-05 19:56 [PATCH 00/15] x86: disable virt on kdump and emergency_restart (v2) Eduardo Habkost
2008-11-05 19:56 ` [PATCH 01/15] x86 kdump: Extract kdump-specific code from crash_nmi_callback() Eduardo Habkost
2008-11-05 19:56 ` [PATCH 02/15] x86 kdump: Move crashing_cpu assignment to nmi_shootdown_cpus() Eduardo Habkost
2008-11-05 19:56 ` [PATCH 03/15] x86 kdump: Create kdump_nmi_shootdown_cpus() Eduardo Habkost
2008-11-05 19:56 ` [PATCH 04/15] x86 kdump: Make kdump_nmi_callback() a function ptr on crash_nmi_callback() Eduardo Habkost
2008-11-05 19:56 ` [PATCH 05/15] x86 kdump: Make nmi_shootdown_cpus() non-static Eduardo Habkost
2008-11-05 19:56 ` [PATCH 06/15] x86: Move nmi_shootdown_cpus() to reboot.c Eduardo Habkost
2008-11-05 19:56 ` [PATCH 07/15] x86: Make nmi_shootdown_cpus() available on !SMP and !X86_LOCAL_APIC Eduardo Habkost
2008-11-05 19:56 ` [PATCH 08/15] x86: Disable IRQs before doing anything on nmi_shootdown_cpus() Eduardo Habkost
2008-11-05 19:56 ` [PATCH 09/15] x86: Emergency virtualization disable function Eduardo Habkost
2008-11-05 22:27   ` Pavel Machek [this message]
2008-11-06 15:34     ` Eduardo Habkost
2008-11-06 18:11       ` Pavel Machek
2008-11-05 19:56 ` [PATCH 10/15] kdump: Hook emergency_virt_disable() on crash shutdown code Eduardo Habkost
2008-11-05 19:56 ` [PATCH 11/15] x86: disable virtualization on all CPUs if needed, on emergency_restart Eduardo Habkost
2008-11-05 19:56 ` [PATCH 12/15] kvm: svm: no-parameters version of svm_hardware_disable() Eduardo Habkost
2008-11-05 19:56 ` [PATCH 13/15] kvm: svm: register virt_disable function on hardware_setup Eduardo Habkost
2008-11-05 19:56 ` [PATCH 14/15] kvm: vmx: crash_hardware_disable function Eduardo Habkost
2008-11-05 19:56 ` [PATCH 15/15] Revert "x86: default to reboot via ACPI" Eduardo Habkost
2008-11-06  7:14   ` Ingo Molnar
2008-11-06 12:40     ` Eduardo Habkost
2008-11-06 14:30       ` Ingo Molnar
2008-11-06 15:06         ` Ingo Molnar
2008-11-06 15:41           ` Eric W. Biederman
2008-11-06 15:52             ` Avi Kivity
2008-11-06 15:53           ` Andrey Borzenkov
2008-11-06 19:50             ` Len Brown
2008-11-06 21:50               ` Matthew Garrett
2008-11-06 22:17                 ` Len Brown
2008-11-06 23:24                   ` Matthew Garrett
2008-11-07  1:01                   ` Zhao Yakui
2008-11-07  0:59                     ` Matthew Garrett
2008-11-09 10:11                       ` Avi Kivity
2008-11-09 10:24                         ` Matthew Garrett

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