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From: Dave Young <dyoung@redhat.com>
To: Matthew Garrett <mjg59@google.com>
Cc: linux-efi <linux-efi@vger.kernel.org>,
	Ard Biesheuvel <ard.biesheuvel@linaro.org>,
	kexec@lists.infradead.org,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	bhsharma@redhat.com
Subject: Re: [PATCH] do not clean dummy variable in kexec path
Date: Tue, 6 Aug 2019 10:44:13 +0800	[thread overview]
Message-ID: <20190806024413.GB6956@dhcp-128-65.nay.redhat.com> (raw)
In-Reply-To: <CACdnJusRUnhmOLdowqbGoM9Z-tWsKrhZ8sFfQUUmjyKmRVN+vw@mail.gmail.com>

On 08/05/19 at 10:09am, Matthew Garrett wrote:
> On Mon, Aug 5, 2019 at 1:36 AM Dave Young <dyoung@redhat.com> wrote:
> >
> > kexec reboot fails randomly in UEFI based kvm guest.  The firmware
> > just reset while calling efi_delete_dummy_variable();  Unfortunately
> > I don't know how to debug the firmware, it is also possible a potential
> > problem on real hardware as well although nobody reproduced it.
> >
> > The intention of efi_delete_dummy_variable is to trigger garbage collection
> > when entering virtual mode.  But SetVirtualAddressMap can only run once
> > for each physical reboot, thus kexec_enter_virtual_mode is not necessarily
> > a good place to clean dummy object.
> 
> I agree that this isn't necessarily the best place to do this in the
> kexec case, but given we control the firmware, figuring out what's
> actually breaking seems like a good plan.

I'm more than glad to get the root cause, if you can help on debugging I
would like to share the efi var file etc.

But it is indeed a problem cause weird reset on end user part, but even if we can
not find the root cause (in firmware..)  I think we still need avoid it
with such workaround.

Thanks
Dave

      reply	other threads:[~2019-08-06  2:44 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-05  8:35 Dave Young
2019-08-05 15:55 ` Ard Biesheuvel
2019-08-06  2:41   ` Dave Young
2019-08-08  7:49   ` Dave Young
2019-08-05 17:09 ` Matthew Garrett
2019-08-06  2:44   ` Dave Young [this message]

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