From: Julien Thierry <julien.thierry@arm.com>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: linux-arm-kernel@lists.infradead.org, mark.rutland@arm.com,
linux-arch@vger.kernel.org, daniel.thompson@linaro.org,
Arnd Bergmann <arnd@arndb.de>,
marc.zyngier@arm.com, will.deacon@arm.com,
linux-kernel@vger.kernel.org, stable@vger.kernel.org,
christoffer.dall@arm.com, james.morse@arm.com,
joel@joelfernandes.org
Subject: Re: [PATCH v8 01/26] arm64: Fix HCR.TGE status for NMI contexts
Date: Mon, 14 Jan 2019 16:12:39 +0000 [thread overview]
Message-ID: <229aade3-5bb3-aad4-bd9a-d6220db836c0@arm.com> (raw)
In-Reply-To: <20190114155634.GB84430@arrakis.emea.arm.com>
On 14/01/2019 15:56, Catalin Marinas wrote:
> On Tue, Jan 08, 2019 at 02:07:19PM +0000, Julien Thierry wrote:
>> When using VHE, the host needs to clear HCR_EL2.TGE bit in order
>> to interract with guest TLBs, switching from EL2&0 translation regime
>> to EL1&0.
>>
>> However, some non-maskable asynchronous event could happen while TGE is
>> cleared like SDEI. Because of this address translation operations
>> relying on EL2&0 translation regime could fail (tlb invalidation,
>> userspace access, ...).
>
> Why would an NMI context need to access user space? (just curious what
> breaks exactly without this patch; otherwise it looks fine)
If I remember correctly, the SDEI interrupt might perform cache
maintenance with EL2&0 translation regime, but James can probably give
more detail (or correct me if I'm wrong).
Otherwise, if we decide to use the pseudo NMI for profiling with perf, I
believe the perf interrupt can access user space (although I'm not
completely sure whether that might be to record profiling data in
buffers shared with user space or something else).
Thanks,
--
Julien Thierry
next prev parent reply other threads:[~2019-01-14 16:12 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-08 14:07 [PATCH v8 00/26] arm64: provide pseudo NMI with GICv3 Julien Thierry
2019-01-08 14:07 ` [PATCH v8 01/26] arm64: Fix HCR.TGE status for NMI contexts Julien Thierry
2019-01-14 15:56 ` Catalin Marinas
2019-01-14 16:12 ` Julien Thierry [this message]
2019-01-14 17:25 ` James Morse
2019-01-28 9:16 ` Marc Zyngier
2019-01-08 14:07 ` [PATCH v8 02/26] arm64: Remove unused daif related functions/macros Julien Thierry
2019-01-08 14:07 ` [PATCH v8 03/26] arm64: cpufeature: Set SYSREG_GIC_CPUIF as a boot system feature Julien Thierry
2019-01-08 14:07 ` [PATCH v8 04/26] arm64: cpufeature: Add cpufeature for IRQ priority masking Julien Thierry
2019-01-08 14:07 ` [PATCH v8 05/26] arm/arm64: gic-v3: Add PMR and RPR accessors Julien Thierry
2019-01-08 14:07 ` [PATCH v8 06/26] irqchip/gic-v3: Switch to PMR masking before calling IRQ handler Julien Thierry
2019-01-08 14:07 ` [PATCH v8 07/26] arm64: ptrace: Provide definitions for PMR values Julien Thierry
2019-01-14 16:12 ` Catalin Marinas
2019-01-08 14:07 ` [PATCH v8 08/26] arm64: Make PMR part of task context Julien Thierry
2019-01-18 16:10 ` Catalin Marinas
2019-01-08 14:07 ` [PATCH v8 09/26] arm64: Unmask PMR before going idle Julien Thierry
2019-01-18 16:23 ` Catalin Marinas
2019-01-18 17:17 ` Julien Thierry
2019-01-08 14:07 ` [PATCH v8 10/26] arm64: kvm: Unmask PMR before entering guest Julien Thierry
2019-01-18 16:25 ` Catalin Marinas
2019-01-08 14:07 ` [PATCH v8 11/26] efi: Let architectures decide the flags that should be saved/restored Julien Thierry
2019-01-18 16:26 ` Catalin Marinas
2019-01-08 14:07 ` [PATCH v8 12/26] arm64: irqflags: Use ICC_PMR_EL1 for interrupt masking Julien Thierry
2019-01-08 15:40 ` Dave Martin
2019-01-08 15:51 ` Marc Zyngier
2019-01-08 16:45 ` Dave Martin
2019-01-08 17:16 ` Marc Zyngier
2019-01-08 18:01 ` Dave Martin
2019-01-08 17:58 ` Julien Thierry
2019-01-08 18:37 ` Dave Martin
2019-01-18 16:09 ` Catalin Marinas
2019-01-18 16:57 ` Julien Thierry
2019-01-18 17:30 ` Catalin Marinas
2019-01-18 17:33 ` Catalin Marinas
2019-01-21 8:45 ` Julien Thierry
2019-01-18 16:35 ` Dave Martin
2019-01-18 17:27 ` Julien Thierry
2019-01-18 18:23 ` Dave Martin
2019-01-08 14:07 ` [PATCH v8 13/26] arm64: daifflags: Include PMR in daifflags restore operations Julien Thierry
2019-01-18 16:43 ` Catalin Marinas
2019-01-08 14:07 ` [PATCH v8 14/26] arm64: alternative: Allow alternative status checking per cpufeature Julien Thierry
2019-01-08 14:07 ` [PATCH v8 15/26] arm64: alternative: Apply alternatives early in boot process Julien Thierry
2019-01-08 14:51 ` Suzuki K Poulose
2019-01-08 15:20 ` Julien Thierry
2019-01-08 17:40 ` Suzuki K Poulose
2019-01-10 10:50 ` Julien Thierry
2019-01-08 14:07 ` [PATCH v8 16/26] irqchip/gic-v3: Factor group0 detection into functions Julien Thierry
2019-01-08 14:07 ` [PATCH v8 17/26] arm64: Switch to PMR masking when starting CPUs Julien Thierry
2019-01-08 14:07 ` [PATCH v8 18/26] arm64: gic-v3: Implement arch support for priority masking Julien Thierry
2019-01-08 14:07 ` [PATCH v8 19/26] irqchip/gic-v3: Detect if GIC can support pseudo-NMIs Julien Thierry
2019-01-08 14:07 ` [PATCH v8 20/26] irqchip/gic-v3: Handle pseudo-NMIs Julien Thierry
2019-01-08 14:07 ` [PATCH v8 21/26] irqchip/gic: Add functions to access irq priorities Julien Thierry
2019-01-08 14:07 ` [PATCH v8 22/26] irqchip/gic-v3: Allow interrupts to be set as pseudo-NMI Julien Thierry
2019-01-08 14:07 ` [PATCH v8 23/26] arm64: Handle serror in NMI context Julien Thierry
2019-01-08 14:07 ` [PATCH v8 24/26] arm64: Skip preemption when exiting an NMI Julien Thierry
2019-01-08 14:07 ` [PATCH v8 25/26] arm64: Skip irqflags tracing for NMI in IRQs disabled context Julien Thierry
2019-01-08 14:07 ` [PATCH v8 26/26] arm64: Enable the support of pseudo-NMIs Julien Thierry
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