From: Marc Zyngier <maz@kernel.org>
To: Mingwei Zhang <mizhang@google.com>,
Oliver Upton <oliver.upton@linux.dev>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
linux-kernel@vger.kernel.org, Will Deacon <will@kernel.org>,
kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] KVM: arm64: Cleanup the __get_fault_info() to take out the code that validates HPFAR
Date: Tue, 27 Sep 2022 06:18:03 -0400 [thread overview]
Message-ID: <86zgel6rz8.wl-maz@kernel.org> (raw)
In-Reply-To: <YzKGqLzjv0I/gkMi@google.com>
On Tue, 27 Sep 2022 01:14:16 -0400,
Oliver Upton <oliver.upton@linux.dev> wrote:
>
> Hi Mingwei,
>
> On Tue, Sep 27, 2022 at 12:27:15AM +0000, Mingwei Zhang wrote:
> > Cleanup __get_fault_info() to take out the code that checks HPFAR. The
> > conditions in __get_fault_info() that checks if HPFAR contains a valid IPA
> > is slightly messy in that several conditions are written within one IF
> > statement acrossing multiple lines and are connected with different logical
> > operators. Among them, some conditions come from ARM Spec, while others
> ^~~~~~~~
>
> Call it the ARM ARM or Arm ARM, depending on what stylization you
> subscribe to :)
>
> > come from CPU erratum. This makes the code hard to read and
> > difficult to extend.
>
> I'd recommend you avoid alluding to future changes unless they're posted
> on the mailing list.
Honestly, I'd refrain from such changes *unless* they enable something
else. The current code is well understood by people hacking on it, and
although I don't mind revamping it, it has to be for a good reason.
I'd be much more receptive to such a change if it was a prefix to
something that actually made a significant change.
Thanks,
M.
--
Without deviation from the norm, progress is not possible.
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
WARNING: multiple messages have this Message-ID (diff)
From: Marc Zyngier <maz@kernel.org>
To: Mingwei Zhang <mizhang@google.com>,
Oliver Upton <oliver.upton@linux.dev>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>, James Morse <james.morse@arm.com>,
Alexandru Elisei <alexandru.elisei@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] KVM: arm64: Cleanup the __get_fault_info() to take out the code that validates HPFAR
Date: Tue, 27 Sep 2022 06:18:03 -0400 [thread overview]
Message-ID: <86zgel6rz8.wl-maz@kernel.org> (raw)
In-Reply-To: <YzKGqLzjv0I/gkMi@google.com>
On Tue, 27 Sep 2022 01:14:16 -0400,
Oliver Upton <oliver.upton@linux.dev> wrote:
>
> Hi Mingwei,
>
> On Tue, Sep 27, 2022 at 12:27:15AM +0000, Mingwei Zhang wrote:
> > Cleanup __get_fault_info() to take out the code that checks HPFAR. The
> > conditions in __get_fault_info() that checks if HPFAR contains a valid IPA
> > is slightly messy in that several conditions are written within one IF
> > statement acrossing multiple lines and are connected with different logical
> > operators. Among them, some conditions come from ARM Spec, while others
> ^~~~~~~~
>
> Call it the ARM ARM or Arm ARM, depending on what stylization you
> subscribe to :)
>
> > come from CPU erratum. This makes the code hard to read and
> > difficult to extend.
>
> I'd recommend you avoid alluding to future changes unless they're posted
> on the mailing list.
Honestly, I'd refrain from such changes *unless* they enable something
else. The current code is well understood by people hacking on it, and
although I don't mind revamping it, it has to be for a good reason.
I'd be much more receptive to such a change if it was a prefix to
something that actually made a significant change.
Thanks,
M.
--
Without deviation from the norm, progress is not possible.
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
WARNING: multiple messages have this Message-ID (diff)
From: Marc Zyngier <maz@kernel.org>
To: Mingwei Zhang <mizhang@google.com>,
Oliver Upton <oliver.upton@linux.dev>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>, James Morse <james.morse@arm.com>,
Alexandru Elisei <alexandru.elisei@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] KVM: arm64: Cleanup the __get_fault_info() to take out the code that validates HPFAR
Date: Tue, 27 Sep 2022 06:18:03 -0400 [thread overview]
Message-ID: <86zgel6rz8.wl-maz@kernel.org> (raw)
In-Reply-To: <YzKGqLzjv0I/gkMi@google.com>
On Tue, 27 Sep 2022 01:14:16 -0400,
Oliver Upton <oliver.upton@linux.dev> wrote:
>
> Hi Mingwei,
>
> On Tue, Sep 27, 2022 at 12:27:15AM +0000, Mingwei Zhang wrote:
> > Cleanup __get_fault_info() to take out the code that checks HPFAR. The
> > conditions in __get_fault_info() that checks if HPFAR contains a valid IPA
> > is slightly messy in that several conditions are written within one IF
> > statement acrossing multiple lines and are connected with different logical
> > operators. Among them, some conditions come from ARM Spec, while others
> ^~~~~~~~
>
> Call it the ARM ARM or Arm ARM, depending on what stylization you
> subscribe to :)
>
> > come from CPU erratum. This makes the code hard to read and
> > difficult to extend.
>
> I'd recommend you avoid alluding to future changes unless they're posted
> on the mailing list.
Honestly, I'd refrain from such changes *unless* they enable something
else. The current code is well understood by people hacking on it, and
although I don't mind revamping it, it has to be for a good reason.
I'd be much more receptive to such a change if it was a prefix to
something that actually made a significant change.
Thanks,
M.
--
Without deviation from the norm, progress is not possible.
next prev parent reply other threads:[~2022-09-27 10:18 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-27 0:27 [PATCH] KVM: arm64: Cleanup the __get_fault_info() to take out the code that validates HPFAR Mingwei Zhang
2022-09-27 0:27 ` Mingwei Zhang
2022-09-27 0:27 ` Mingwei Zhang
2022-09-27 5:14 ` Oliver Upton
2022-09-27 5:14 ` Oliver Upton
2022-09-27 5:14 ` Oliver Upton
2022-09-27 10:18 ` Marc Zyngier [this message]
2022-09-27 10:18 ` Marc Zyngier
2022-09-27 10:18 ` Marc Zyngier
2022-09-27 17:48 ` Mingwei Zhang
2022-09-27 17:48 ` Mingwei Zhang
2022-09-27 17:48 ` Mingwei Zhang
2022-09-28 10:40 ` Marc Zyngier
2022-09-28 10:40 ` Marc Zyngier
2022-09-28 10:40 ` Marc Zyngier
2022-09-27 7:01 ` Reiji Watanabe
2022-09-27 7:01 ` Reiji Watanabe
2022-09-27 7:01 ` Reiji Watanabe
2022-09-27 17:38 ` Mingwei Zhang
2022-09-27 17:38 ` Mingwei Zhang
2022-09-27 17:38 ` Mingwei Zhang
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