From: "Michael S. Tsirkin" <mst@redhat.com>
To: Laszlo Ersek <lersek@redhat.com>
Cc: Achin Gupta <achin.gupta@arm.com>,
gengdongjiu <gengdongjiu@huawei.com>,
ard.biesheuvel@linaro.org, edk2-devel@lists.01.org,
qemu-devel@nongnu.org, zhaoshenglong@huawei.com,
James Morse <james.morse@arm.com>,
Christoffer Dall <cdall@linaro.org>,
xiexiuqi@huawei.com, Marc Zyngier <marc.zyngier@arm.com>,
catalin.marinas@arm.com, will.deacon@arm.com,
christoffer.dall@linaro.org, rkrcmar@redhat.com,
suzuki.poulose@arm.com, andre.przywara@arm.com,
mark.rutland@arm.com, vladimir.murzin@arm.com,
linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org,
linux-kernel@vger.kernel.org, wangxiongfeng2@huawei.com,
wuquanming@huawei.com, huangshaoyu@huawei.com,
Leif.Lindholm@linaro.comnd@arm.com,
Igor Mammedov <imammedo@redhat.com>
Subject: Re: [Qemu-devel] [PATCH] kvm: pass the virtual SEI syndrome to guest OS
Date: Wed, 29 Mar 2017 15:51:44 +0300 [thread overview]
Message-ID: <20170329154539-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <2a427164-9b37-6711-3a56-906634ba7f12@redhat.com>
On Wed, Mar 29, 2017 at 01:58:29PM +0200, Laszlo Ersek wrote:
> (8) When QEMU gets SIGBUS from the kernel -- I hope that's going to come
> through a signalfd -- QEMU can format the CPER right into guest memory,
> and then inject whatever interrupt (or assert whatever GPIO line) is
> necessary for notifying the guest.
I think I see a race condition potential - what if guest accesses
CPER in guest memory while it's being written?
We can probably use another level of indirection to fix this:
allocate twice the space, add a pointer to where the valid
table is located and update that after writing CPER completely.
The pointer can be written atomically but also needs to
be read atomically, so I suspect it should be a single byte
as we don't know how are OSPMs implementing this.
--
MST
next prev parent reply other threads:[~2017-03-29 12:51 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <7055772d-2a20-6e0c-2bf8-204bc9ef52a5@arm.com>
[not found] ` <b912c293-4314-7c90-30a4-2f986feb1670@huawei.com>
[not found] ` <22fb583f-a33e-15f8-a059-fb112b27dd4f@arm.com>
[not found] ` <58CFF058.8020205@arm.com>
[not found] ` <76795e20-2f20-1e54-cfa5-7444f28b18ee@huawei.com>
[not found] ` <20170321113428.GC15920@cbox>
[not found] ` <58D17AF0.2010802@arm.com>
[not found] ` <20170321193933.GB31111@cbox>
[not found] ` <58DA3F68.6090901@arm.com>
[not found] ` <20170328112328.GA31156@cbox>
[not found] ` <20170328115413.GJ23682@e104320-lin>
[not found] ` <b1c6e747-2fa7-b7a1-60d5-4a9c480b9dc9@huawei.com>
[not found] ` <58DA67BA.8070404@arm.com>
2017-03-29 9:36 ` [Qemu-devel] [PATCH] kvm: pass the virtual SEI syndrome to guest OS gengdongjiu
2017-03-29 10:36 ` Achin Gupta
2017-03-29 11:58 ` Laszlo Ersek
2017-03-29 12:51 ` Michael S. Tsirkin [this message]
2017-03-29 13:36 ` Laszlo Ersek
2017-03-29 13:54 ` Michael S. Tsirkin
2017-03-29 13:56 ` Punit Agrawal
2017-04-06 12:35 ` gengdongjiu
2017-04-06 18:55 ` Laszlo Ersek
2017-04-07 2:52 ` gengdongjiu
2017-04-07 9:21 ` Laszlo Ersek
2017-04-21 13:27 ` gengdongjiu
2017-04-24 11:27 ` Laszlo Ersek
2017-03-29 14:36 ` gengdongjiu
2017-03-29 14:48 ` Christoffer Dall
2017-03-29 15:37 ` Laszlo Ersek
2017-03-29 17:44 ` Christoffer Dall
2017-03-30 1:22 ` gengdongjiu
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