[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <ZcDg1sP3EYZG-i_3@linux.dev>
Date: Mon, 5 Feb 2024 13:21:26 +0000
From: Oliver Upton <oliver.upton@...ux.dev>
To: Marc Zyngier <maz@...nel.org>
Cc: James Clark <james.clark@....com>, coresight@...ts.linaro.org,
linux-arm-kernel@...ts.infradead.org, kvmarm@...ts.linux.dev,
broonie@...nel.org, suzuki.poulose@....com, acme@...nel.org,
James Morse <james.morse@....com>,
Zenghui Yu <yuzenghui@...wei.com>,
Catalin Marinas <catalin.marinas@....com>,
Will Deacon <will@...nel.org>, Mike Leach <mike.leach@...aro.org>,
Leo Yan <leo.yan@...aro.org>,
Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
Anshuman Khandual <anshuman.khandual@....com>,
Rob Herring <robh@...nel.org>, Miguel Luis <miguel.luis@...cle.com>,
Jintack Lim <jintack.lim@...aro.org>,
Ard Biesheuvel <ardb@...nel.org>,
Mark Rutland <mark.rutland@....com>, Arnd Bergmann <arnd@...db.de>,
Vincent Donnefort <vdonnefort@...gle.com>,
Kristina Martsenko <kristina.martsenko@....com>,
Fuad Tabba <tabba@...gle.com>, Joey Gouly <joey.gouly@....com>,
Akihiko Odaki <akihiko.odaki@...nix.com>,
Jing Zhang <jingzhangos@...gle.com>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4 2/7] arm64: KVM: Use shared area to pass PMU event
state to hypervisor
On Mon, Feb 05, 2024 at 01:15:36PM +0000, Marc Zyngier wrote:
> On Mon, 05 Feb 2024 13:04:51 +0000,
> Oliver Upton <oliver.upton@...ux.dev> wrote:
> >
> > Unless someone has strong opinions about making this work in protected
> > mode, I am happy to see tracing support limited to the 'normal' nVHE
> > configuration. The protected feature as a whole is just baggage until
> > upstream support is completed.
>
> Limiting tracing to non-protected mode is a must IMO. Allowing tracing
> when pKVM is enabled is a sure way to expose secrets that should
> stay... secret. The only exception I can think of is when
> CONFIG_NVHE_EL2_DEBUG is enabled, at which point all bets are off.
Zero argument there :) I left off the "and PMU" part of what I was
saying, because that was a feature that semi-worked in protected mode
before VM/VCPU shadowing support landed.
--
Thanks,
Oliver
Powered by blists - more mailing lists