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From: Shuo A Liu <shuo.a.liu@intel.com>
To: Borislav Petkov <bp@alien8.de>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	linux-kernel@vger.kernel.org, x86@kernel.org,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"H . Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@redhat.com>,
	Sean Christopherson <sean.j.christopherson@intel.com>,
	Yu Wang <yu1.wang@intel.com>,
	Reinette Chatre <reinette.chatre@intel.com>,
	Yakui Zhao <yakui.zhao@intel.com>,
	Zhi Wang <zhi.a.wang@intel.com>,
	Dave Hansen <dave.hansen@intel.com>,
	Dan Williams <dan.j.williams@intel.com>,
	Fengwei Yin <fengwei.yin@intel.com>,
	Zhenyu Wang <zhenyuw@linux.intel.com>
Subject: Re: [PATCH v4 02/17] x86/acrn: Introduce acrn_{setup, remove}_intr_handler()
Date: Wed, 30 Sep 2020 11:02:44 +0800	[thread overview]
Message-ID: <20200930030244.GI1057@shuo-intel.sh.intel.com> (raw)
In-Reply-To: <20200929202604.GP21110@zn.tnic>

Hi Boris,

On Tue 29.Sep'20 at 22:26:54 +0200, Borislav Petkov wrote:
>On Tue, Sep 29, 2020 at 10:07:17PM +0200, Thomas Gleixner wrote:
>> That does not prevent that either and notifiers suck.
>
>Bah, atomic notifiers run functions which cannot block, not what is
>needed here, right.
>
>> The pointer is fine and if something removes the handler before all of
>> the muck is shutdown then the author can keep the pieces and mop up
>> the remains.
>
>Uhu, so what makes sure that the module is not removed while an IRQ is
>happening?

The precondition of the removing of the module is that there is no
User VM living (every opening of the dev file will hold a ref count of
the module). The interrupt only can occur with active User VMs. So if
a notification interrupt is happending, the module cannot be removed as
there is still User VM living.

Thanks
shuo

  reply	other threads:[~2020-09-30  3:02 UTC|newest]

Thread overview: 58+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-22 11:42 [PATCH v4 00/17] HSM driver for ACRN hypervisor shuo.a.liu
2020-09-22 11:42 ` [PATCH v4 01/17] docs: acrn: Introduce ACRN shuo.a.liu
2020-10-09  1:48   ` Randy Dunlap
2020-10-12  8:50     ` Shuo A Liu
2020-09-22 11:42 ` [PATCH v4 02/17] x86/acrn: Introduce acrn_{setup, remove}_intr_handler() shuo.a.liu
2020-09-27 10:49   ` Greg Kroah-Hartman
2020-09-28  3:28     ` Shuo A Liu
2020-09-29 18:01   ` Borislav Petkov
2020-09-29 20:07     ` Thomas Gleixner
2020-09-29 20:26       ` Borislav Petkov
2020-09-30  3:02         ` Shuo A Liu [this message]
2020-09-22 11:42 ` [PATCH v4 03/17] x86/acrn: Introduce an API to check if a VM is privileged shuo.a.liu
2020-09-30  8:09   ` Borislav Petkov
2020-10-12  8:40     ` Shuo A Liu
2020-09-22 11:42 ` [PATCH v4 04/17] x86/acrn: Introduce hypercall interfaces shuo.a.liu
2020-09-27 10:51   ` Greg Kroah-Hartman
2020-09-27 10:53     ` Greg Kroah-Hartman
2020-09-28  3:38       ` Shuo A Liu
2020-09-27 15:38     ` Dave Hansen
2020-09-30 11:16       ` Peter Zijlstra
2020-09-30 16:10         ` Segher Boessenkool
2020-09-30 17:13           ` Peter Zijlstra
2020-09-30 19:14             ` Nick Desaulniers
2020-09-30 19:42               ` Peter Zijlstra
2020-09-30 23:58                 ` Segher Boessenkool
2020-09-30 19:59               ` Arvind Sankar
2020-09-30 20:01                 ` Arvind Sankar
2020-10-01  0:08                 ` Segher Boessenkool
2020-09-30 23:25               ` Segher Boessenkool
2020-09-30 23:38                 ` Arvind Sankar
2020-10-01  0:11                   ` Segher Boessenkool
2020-10-12  8:44               ` Shuo A Liu
2020-10-12 16:49                 ` Arvind Sankar
2020-10-13  2:44                   ` Shuo A Liu
2020-09-30 10:54   ` Borislav Petkov
2020-10-12  8:49     ` Shuo A Liu
2020-09-22 11:42 ` [PATCH v4 05/17] virt: acrn: Introduce ACRN HSM basic driver shuo.a.liu
2020-09-22 11:43 ` [PATCH v4 08/17] virt: acrn: Introduce EPT mapping management shuo.a.liu
2020-09-22 11:43 ` [PATCH v4 10/17] virt: acrn: Introduce PCI configuration space PIO accesses combiner shuo.a.liu
2020-09-22 11:43 ` [PATCH v4 11/17] virt: acrn: Introduce interfaces for PCI device passthrough shuo.a.liu
2020-09-22 11:43 ` [PATCH v4 12/17] virt: acrn: Introduce interrupt injection interfaces shuo.a.liu
2020-09-22 11:43 ` [PATCH v4 14/17] virt: acrn: Introduce I/O ranges operation interfaces shuo.a.liu
2020-09-22 11:43 ` [PATCH v4 16/17] virt: acrn: Introduce irqfd shuo.a.liu
2020-09-22 11:43 ` [PATCH v4 17/17] virt: acrn: Introduce an interface for Service VM to control vCPU shuo.a.liu
2020-09-27 10:44   ` Greg Kroah-Hartman
2020-09-28  4:10     ` Shuo A Liu
2020-09-28  5:23       ` Greg Kroah-Hartman
2020-09-28  6:33         ` Shuo A Liu
2020-09-27  0:24 ` [PATCH v4 00/17] HSM driver for ACRN hypervisor Liu, Shuo A
2020-09-27  5:42   ` Greg Kroah-Hartman
     [not found] ` <20200922114311.38804-7-shuo.a.liu@intel.com>
2020-09-27 10:45   ` [PATCH v4 06/17] virt: acrn: Introduce VM management interfaces Greg Kroah-Hartman
2020-09-28  3:43     ` Shuo A Liu
2020-09-27 10:47   ` Greg Kroah-Hartman
2020-09-28  3:50     ` Shuo A Liu
2020-09-28  5:25       ` Greg Kroah-Hartman
2020-09-28  6:29         ` Shuo A Liu
2020-09-28 12:26           ` Greg Kroah-Hartman
2020-09-30  2:49             ` Shuo A Liu

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