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From: Christoffer Dall <christoffer.dall@arm.com>
To: Julien Thierry <julien.thierry@arm.com>
Cc: mark.rutland@arm.com, linux-arch@vger.kernel.org,
	daniel.thompson@linaro.org, Arnd Bergmann <arnd@arndb.de>,
	marc.zyngier@arm.com, catalin.marinas@arm.com,
	will.deacon@arm.com, linux-kernel@vger.kernel.org,
	stable@vger.kernel.org, James Morse <james.morse@arm.com>,
	joel@joelfernandes.org, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v9 01/26] arm64: Fix HCR.TGE status for NMI contexts
Date: Thu, 31 Jan 2019 09:19:00 +0100	[thread overview]
Message-ID: <20190131081900.GM13482@e113682-lin.lund.arm.com> (raw)
In-Reply-To: <847c54ef-ea41-eea5-8aff-72e0cea465f8@arm.com>

On Mon, Jan 28, 2019 at 03:42:42PM +0000, Julien Thierry wrote:
> Hi James,
> 
> On 28/01/2019 11:48, James Morse wrote:
> > Hi Julien,
> > 
> > On 21/01/2019 15:33, 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
> > 
> > (interact)
> > 
> > 
> >> 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, ...).
> >>
> >> Fix this by properly setting HCR_EL2.TGE when entering NMI context and
> >> clear it if necessary when returning to the interrupted context.
> > 
> > Yes please. This would not have been fun to debug!
> > 
> > Reviewed-by: James Morse <james.morse@arm.com>
> > 
> > 
> 
> Thanks.
> 
> > 
> > I was looking for why we need core code to do this, instead of updating the
> > arch's call sites. Your 'irqdesc: Add domain handlers for NMIs' patch (pointed
> > to from the cover letter) is the reason: core-code calls nmi_enter()/nmi_exit()
> > itself.
> > 
> 
> Yes, that's the main reason.
> 
I wondered the same thing, but I don't understand the explanation :(

Why can't we do a local_daif_mask() around the (very small) calls that
clear TGE instead?


Thanks,

    Christoffer

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  reply	other threads:[~2019-01-31  8:22 UTC|newest]

Thread overview: 82+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-21 15:33 [PATCH v9 00/26] arm64: provide pseudo NMI with GICv3 Julien Thierry
2019-01-21 15:33 ` [PATCH v9 01/26] arm64: Fix HCR.TGE status for NMI contexts Julien Thierry
2019-01-23 22:57   ` Sasha Levin
2019-01-28 11:48   ` James Morse
2019-01-28 15:42     ` Julien Thierry
2019-01-31  8:19       ` Christoffer Dall [this message]
2019-01-31  8:56         ` Julien Thierry
2019-01-31  9:27           ` Christoffer Dall
2019-01-31  9:40             ` Julien Thierry
2019-01-31  9:48               ` Christoffer Dall
2019-01-31  9:53               ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 02/26] arm64: Remove unused daif related functions/macros Julien Thierry
2019-01-28  9:21   ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 03/26] arm64: cpufeature: Set SYSREG_GIC_CPUIF as a boot system feature Julien Thierry
2019-01-28  9:22   ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 04/26] arm64: cpufeature: Add cpufeature for IRQ priority masking Julien Thierry
2019-01-28  9:24   ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 05/26] arm/arm64: gic-v3: Add PMR and RPR accessors Julien Thierry
2019-01-28  9:25   ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 06/26] irqchip/gic-v3: Switch to PMR masking before calling IRQ handler Julien Thierry
2019-01-28  9:30   ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 07/26] arm64: ptrace: Provide definitions for PMR values Julien Thierry
2019-01-28  9:37   ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 08/26] arm64: Make PMR part of task context Julien Thierry
2019-01-28  9:42   ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 09/26] arm64: Unmask PMR before going idle Julien Thierry
2019-01-22 15:23   ` Catalin Marinas
2019-01-22 20:18   ` Ard Biesheuvel
2019-01-23  8:56     ` Julien Thierry
2019-01-23  9:38       ` Ard Biesheuvel
2019-01-28  9:44   ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 10/26] arm64: kvm: Unmask PMR before entering guest Julien Thierry
2019-01-28  9:58   ` Marc Zyngier
2019-01-30 12:07   ` Christoffer Dall
2019-01-30 14:58     ` Julien Thierry
2019-01-21 15:33 ` [PATCH v9 11/26] efi: Let architectures decide the flags that should be saved/restored Julien Thierry
2019-01-21 15:42   ` Ard Biesheuvel
2019-01-23  9:04     ` Julien Thierry
2019-01-28 10:00   ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 12/26] arm64: irqflags: Use ICC_PMR_EL1 for interrupt masking Julien Thierry
2019-01-21 15:45   ` Ard Biesheuvel
2019-01-21 18:05     ` Julien Thierry
2019-01-22 15:21   ` Catalin Marinas
2019-01-23 10:44     ` Julien Thierry
2019-01-30 11:52       ` Julien Thierry
2019-01-21 15:33 ` [PATCH v9 13/26] arm64: daifflags: Include PMR in daifflags restore operations Julien Thierry
2019-01-28 10:37   ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 14/26] arm64: alternative: Allow alternative status checking per cpufeature Julien Thierry
2019-01-28 11:00   ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 15/26] arm64: alternative: Apply alternatives early in boot process Julien Thierry
2019-01-28 11:17   ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 16/26] irqchip/gic-v3: Factor group0 detection into functions Julien Thierry
2019-01-28 11:19   ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 17/26] arm64: Switch to PMR masking when starting CPUs Julien Thierry
2019-01-28 11:21   ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 18/26] arm64: gic-v3: Implement arch support for priority masking Julien Thierry
2019-01-28 11:23   ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 19/26] irqchip/gic-v3: Detect if GIC can support pseudo-NMIs Julien Thierry
2019-01-28 11:39   ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 20/26] irqchip/gic-v3: Handle pseudo-NMIs Julien Thierry
2019-01-28 11:59   ` Marc Zyngier
2019-01-29 11:33     ` Julien Thierry
2019-01-29 12:31       ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 21/26] irqchip/gic: Add functions to access irq priorities Julien Thierry
2019-01-28 12:04   ` Marc Zyngier
2019-01-29 11:36     ` Julien Thierry
2019-01-21 15:33 ` [PATCH v9 22/26] irqchip/gic-v3: Allow interrupts to be set as pseudo-NMI Julien Thierry
2019-01-26 10:19   ` liwei (GF)
2019-01-26 10:41     ` Marc Zyngier
2019-01-28  8:57     ` Julien Thierry
2019-01-28 13:59       ` liwei (GF)
2019-01-28 14:49         ` Julien Thierry
2019-01-28 12:08   ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 23/26] arm64: Handle serror in NMI context Julien Thierry
2019-01-28 12:26   ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 24/26] arm64: Skip preemption when exiting an NMI Julien Thierry
2019-01-28 12:34   ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 25/26] arm64: Skip irqflags tracing for NMI in IRQs disabled context Julien Thierry
2019-01-28 12:40   ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 26/26] arm64: Enable the support of pseudo-NMIs Julien Thierry
2019-01-28 12:47   ` Marc Zyngier
2019-01-30 13:46     ` Julien Thierry

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