From: "Baicar, Tyler" <tbaicar@codeaurora.org>
To: James Morse <james.morse@arm.com>
Cc: christoffer.dall@linaro.org, marc.zyngier@arm.com,
pbonzini@redhat.com, rkrcmar@redhat.com, linux@armlinux.org.uk,
catalin.marinas@arm.com, will.deacon@arm.com, rjw@rjwysocki.net,
lenb@kernel.org, matt@codeblueprint.co.uk,
robert.moore@intel.com, lv.zheng@intel.com, nkaje@codeaurora.org,
zjzhang@codeaurora.org, mark.rutland@arm.com,
akpm@linux-foundation.org, eun.taik.lee@samsung.com,
sandeepa.s.prabhu@gmail.com, labbott@redhat.com,
shijie.huang@arm.com, rruigrok@codeaurora.org,
paul.gortmaker@windriver.com, tn@semihalf.com, fu.wei@linaro.org,
rostedt@goodmis.org, bristot@redhat.com,
linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org,
linux-efi@vger.kernel.org, devel@acpica.org,
Suzuki.Poulose@arm.com, punit.agrawal@arm.com, astone@redhat.com,
harba@codeaurora.org, hanjun.guo@linaro.org,
john.garry@huawei.com, shiju.jose@huawei.com, joe@perches.com
Subject: Re: [PATCH V11 10/10] arm/arm64: KVM: add guest SEA support
Date: Mon, 6 Mar 2017 07:00:30 -0700 [thread overview]
Message-ID: <4b4bea7c-7591-8051-7be0-528581f29d10@codeaurora.org> (raw)
In-Reply-To: <58BD39B4.9050809@arm.com>
Hello James,
On 3/6/2017 3:28 AM, James Morse wrote:
> On 28/02/17 19:43, Baicar, Tyler wrote:
>> On 2/24/2017 3:42 AM, James Morse wrote:
>>> On 21/02/17 21:22, Tyler Baicar wrote:
>>>> Currently external aborts are unsupported by the guest abort
>>>> handling. Add handling for SEAs so that the host kernel reports
>>>> SEAs which occur in the guest kernel.
>>>> diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
>>>> index b2d57fc..403277b 100644
>>>> --- a/arch/arm64/mm/fault.c
>>>> +++ b/arch/arm64/mm/fault.c
>>>> @@ -602,6 +602,24 @@ static const char *fault_name(unsigned int esr)
>>>> }
>>>>
>>>> /*
>>>> + * Handle Synchronous External Aborts that occur in a guest kernel.
>>>> + */
>>>> +int handle_guest_sea(unsigned long addr, unsigned int esr)
>>>> +{
>>>> + if(IS_ENABLED(HAVE_ACPI_APEI_SEA)) {
>>>> + nmi_enter();
>>>> + ghes_notify_sea();
>>>> + nmi_exit();
>>> This nmi stuff was needed for synchronous aborts that may have interrupted
>>> APEI's interrupts-masked code. We want to avoid trying to take the same set of
>>> locks, hence taking the in_nmi() path through APEI. Here we know we interrupted
>>> a guest, so there is no risk that we have interrupted APEI on the host.
>>> ghes_notify_sea() can safely take the normal path.
>> Makes sense, I can remove the nmi_* calls here.
> Just occurs to me: if we do this we need to add the rcu_read_lock() in
> ghes_notify_sea() as its not protected by the rcu/nmi weirdness.
>
True, would you suggest leaving these nmi_* calls or adding the rcu_*
calls? And since that's only needed for this KVM case, shouldn't the
rcu_* calls just replace the nmi_* calls here (outside of ghes_notify_sea)?
Thanks,
Tyler
--
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project.
next prev parent reply other threads:[~2017-03-06 14:01 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-21 21:21 [PATCH V11 00/10] Add UEFI 2.6 and ACPI 6.1 updates for RAS on ARM64 Tyler Baicar
2017-02-21 21:21 ` [PATCH V11 01/10] acpi: apei: read ack upon ghes record consumption Tyler Baicar
2017-02-21 21:21 ` [PATCH V11 02/10] ras: acpi/apei: cper: generic error data entry v3 per ACPI 6.1 Tyler Baicar
2017-02-21 21:21 ` [PATCH V11 03/10] efi: parse ARM processor error Tyler Baicar
2017-02-21 21:21 ` [PATCH V11 04/10] arm64: exception: handle Synchronous External Abort Tyler Baicar
2017-02-21 21:21 ` [PATCH V11 05/10] acpi: apei: handle SEA notification type for ARMv8 Tyler Baicar
2017-03-01 7:42 ` Xie XiuQi
2017-03-01 19:22 ` Baicar, Tyler
2017-02-21 21:21 ` [PATCH V11 06/10] acpi: apei: panic OS with fatal error status block Tyler Baicar
2017-02-21 21:21 ` [PATCH V11 07/10] efi: print unrecognized CPER section Tyler Baicar
2017-02-21 21:21 ` [PATCH V11 08/10] ras: acpi / apei: generate trace event for " Tyler Baicar
2017-02-21 21:22 ` [PATCH V11 09/10] trace, ras: add ARM processor error trace event Tyler Baicar
2017-02-21 21:22 ` [PATCH V11 10/10] arm/arm64: KVM: add guest SEA support Tyler Baicar
2017-02-24 10:42 ` James Morse
2017-02-27 11:31 ` gengdongjiu
2017-02-28 19:43 ` Baicar, Tyler
2017-03-06 10:28 ` James Morse
2017-03-06 14:00 ` Baicar, Tyler [this message]
2017-02-25 7:15 ` Xiongfeng Wang
2017-02-27 13:58 ` James Morse
2017-02-28 6:25 ` Xiongfeng Wang
2017-02-28 13:21 ` James Morse
2017-03-01 2:31 ` Xiongfeng Wang
2017-03-02 9:39 ` Marc Zyngier
2017-03-06 3:38 ` Xiongfeng Wang
2017-03-06 1:28 ` gengdongjiu
2017-03-22 2:46 ` Xiongfeng Wang
2017-03-22 11:14 ` James Morse
2017-03-22 12:08 ` Xie XiuQi
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