From: Richard Henderson <richard.henderson@linaro.org>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <maz@kernel.org>,
Steven Price <steven.price@arm.com>,
Peter Maydell <peter.maydell@linaro.org>,
Haibo Xu <haibo.xu@linaro.org>,
lkml - Kernel Mailing List <linux-kernel@vger.kernel.org>,
Juan Quintela <quintela@redhat.com>,
QEMU Developers <qemu-devel@nongnu.org>,
"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Will Deacon <will@kernel.org>,
kvmarm <kvmarm@lists.cs.columbia.edu>,
arm-mail-list <linux-arm-kernel@lists.infradead.org>,
Dave Martin <Dave.Martin@arm.com>
Subject: Re: [PATCH v5 0/2] MTE support for KVM guest
Date: Wed, 9 Dec 2020 14:13:05 -0600 [thread overview]
Message-ID: <6b9072fb-1232-e9fb-0b97-e69709980f99@linaro.org> (raw)
In-Reply-To: <20201209183920.GI13566@gaia>
On 12/9/20 12:39 PM, Catalin Marinas wrote:
>> I would have thought that the best way is to use TCO, so that we don't have to
>> have dual mappings (and however many MB of extra page tables that might imply).
>
> The problem appears when the VMM wants to use MTE itself (e.g. linked
> against an MTE-aware glibc), toggling TCO is no longer generic enough,
> especially when it comes to device emulation.
But we do know exactly when we're manipulating guest memory -- we have special
routines for that. So the special routines gain a toggle of TCO around the
exact guest memory manipulation, not a blanket disable of MTE across large
swaths of QEMU.
r~
WARNING: multiple messages have this Message-ID (diff)
From: Richard Henderson <richard.henderson@linaro.org>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: Peter Maydell <peter.maydell@linaro.org>,
Juan Quintela <quintela@redhat.com>,
QEMU Developers <qemu-devel@nongnu.org>,
Marc Zyngier <maz@kernel.org>,
lkml - Kernel Mailing List <linux-kernel@vger.kernel.org>,
Steven Price <steven.price@arm.com>,
arm-mail-list <linux-arm-kernel@lists.infradead.org>,
Haibo Xu <haibo.xu@linaro.org>,
Thomas Gleixner <tglx@linutronix.de>,
Will Deacon <will@kernel.org>,
kvmarm <kvmarm@lists.cs.columbia.edu>,
"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
Dave Martin <Dave.Martin@arm.com>
Subject: Re: [PATCH v5 0/2] MTE support for KVM guest
Date: Wed, 9 Dec 2020 14:13:05 -0600 [thread overview]
Message-ID: <6b9072fb-1232-e9fb-0b97-e69709980f99@linaro.org> (raw)
In-Reply-To: <20201209183920.GI13566@gaia>
On 12/9/20 12:39 PM, Catalin Marinas wrote:
>> I would have thought that the best way is to use TCO, so that we don't have to
>> have dual mappings (and however many MB of extra page tables that might imply).
>
> The problem appears when the VMM wants to use MTE itself (e.g. linked
> against an MTE-aware glibc), toggling TCO is no longer generic enough,
> especially when it comes to device emulation.
But we do know exactly when we're manipulating guest memory -- we have special
routines for that. So the special routines gain a toggle of TCO around the
exact guest memory manipulation, not a blanket disable of MTE across large
swaths of QEMU.
r~
WARNING: multiple messages have this Message-ID (diff)
From: Richard Henderson <richard.henderson@linaro.org>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: Juan Quintela <quintela@redhat.com>,
QEMU Developers <qemu-devel@nongnu.org>,
Marc Zyngier <maz@kernel.org>,
lkml - Kernel Mailing List <linux-kernel@vger.kernel.org>,
Steven Price <steven.price@arm.com>,
arm-mail-list <linux-arm-kernel@lists.infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Will Deacon <will@kernel.org>,
kvmarm <kvmarm@lists.cs.columbia.edu>,
"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
Dave Martin <Dave.Martin@arm.com>
Subject: Re: [PATCH v5 0/2] MTE support for KVM guest
Date: Wed, 9 Dec 2020 14:13:05 -0600 [thread overview]
Message-ID: <6b9072fb-1232-e9fb-0b97-e69709980f99@linaro.org> (raw)
In-Reply-To: <20201209183920.GI13566@gaia>
On 12/9/20 12:39 PM, Catalin Marinas wrote:
>> I would have thought that the best way is to use TCO, so that we don't have to
>> have dual mappings (and however many MB of extra page tables that might imply).
>
> The problem appears when the VMM wants to use MTE itself (e.g. linked
> against an MTE-aware glibc), toggling TCO is no longer generic enough,
> especially when it comes to device emulation.
But we do know exactly when we're manipulating guest memory -- we have special
routines for that. So the special routines gain a toggle of TCO around the
exact guest memory manipulation, not a blanket disable of MTE across large
swaths of QEMU.
r~
_______________________________________________
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: Richard Henderson <richard.henderson@linaro.org>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: Peter Maydell <peter.maydell@linaro.org>,
Juan Quintela <quintela@redhat.com>,
QEMU Developers <qemu-devel@nongnu.org>,
Marc Zyngier <maz@kernel.org>,
lkml - Kernel Mailing List <linux-kernel@vger.kernel.org>,
Steven Price <steven.price@arm.com>,
arm-mail-list <linux-arm-kernel@lists.infradead.org>,
Haibo Xu <haibo.xu@linaro.org>,
Thomas Gleixner <tglx@linutronix.de>,
Will Deacon <will@kernel.org>,
kvmarm <kvmarm@lists.cs.columbia.edu>,
"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
Dave Martin <Dave.Martin@arm.com>
Subject: Re: [PATCH v5 0/2] MTE support for KVM guest
Date: Wed, 9 Dec 2020 14:13:05 -0600 [thread overview]
Message-ID: <6b9072fb-1232-e9fb-0b97-e69709980f99@linaro.org> (raw)
In-Reply-To: <20201209183920.GI13566@gaia>
On 12/9/20 12:39 PM, Catalin Marinas wrote:
>> I would have thought that the best way is to use TCO, so that we don't have to
>> have dual mappings (and however many MB of extra page tables that might imply).
>
> The problem appears when the VMM wants to use MTE itself (e.g. linked
> against an MTE-aware glibc), toggling TCO is no longer generic enough,
> especially when it comes to device emulation.
But we do know exactly when we're manipulating guest memory -- we have special
routines for that. So the special routines gain a toggle of TCO around the
exact guest memory manipulation, not a blanket disable of MTE across large
swaths of QEMU.
r~
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-12-09 20:13 UTC|newest]
Thread overview: 152+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-19 15:38 [PATCH v5 0/2] MTE support for KVM guest Steven Price
2020-11-19 15:38 ` Steven Price
2020-11-19 15:38 ` Steven Price
2020-11-19 15:38 ` Steven Price
2020-11-19 15:39 ` [PATCH v5 1/2] arm64: kvm: Save/restore MTE registers Steven Price
2020-11-19 15:39 ` Steven Price
2020-11-19 15:39 ` Steven Price
2020-11-19 15:39 ` Steven Price
2020-11-19 15:39 ` [PATCH v5 2/2] arm64: kvm: Introduce MTE VCPU feature Steven Price
2020-11-19 15:39 ` Steven Price
2020-11-19 15:39 ` Steven Price
2020-11-19 15:39 ` Steven Price
2020-11-19 15:45 ` [PATCH v5 0/2] MTE support for KVM guest Peter Maydell
2020-11-19 15:45 ` Peter Maydell
2020-11-19 15:45 ` Peter Maydell
2020-11-19 15:45 ` Peter Maydell
2020-11-19 15:57 ` Steven Price
2020-11-19 15:57 ` Steven Price
2020-11-19 15:57 ` Steven Price
2020-11-19 15:57 ` Steven Price
2020-11-19 16:39 ` Peter Maydell
2020-11-19 16:39 ` Peter Maydell
2020-11-19 16:39 ` Peter Maydell
2020-11-19 16:39 ` Peter Maydell
2020-11-19 18:42 ` Andrew Jones
2020-11-19 18:42 ` Andrew Jones
2020-11-19 18:42 ` Andrew Jones
2020-11-19 18:42 ` Andrew Jones
2020-11-19 19:11 ` Marc Zyngier
2020-11-19 19:11 ` Marc Zyngier
2020-11-19 19:11 ` Marc Zyngier
2020-11-19 19:11 ` Marc Zyngier
2020-11-20 9:50 ` Steven Price
2020-11-20 9:50 ` Steven Price
2020-11-20 9:50 ` Steven Price
2020-11-20 9:50 ` Steven Price
2020-11-20 9:56 ` Marc Zyngier
2020-11-20 9:56 ` Marc Zyngier
2020-11-20 9:56 ` Marc Zyngier
2020-11-20 9:56 ` Marc Zyngier
2020-11-20 9:58 ` Steven Price
2020-11-20 9:58 ` Steven Price
2020-11-20 9:58 ` Steven Price
2020-11-20 9:58 ` Steven Price
2020-12-04 8:25 ` Haibo Xu
2020-12-04 8:25 ` Haibo Xu
2020-12-04 8:25 ` Haibo Xu
2020-12-04 8:25 ` Haibo Xu
2020-12-07 14:48 ` Steven Price
2020-12-07 14:48 ` Steven Price
2020-12-07 14:48 ` Steven Price
2020-12-07 14:48 ` Steven Price
2020-12-07 15:27 ` Peter Maydell
2020-12-07 15:27 ` Peter Maydell
2020-12-07 15:27 ` Peter Maydell
2020-12-07 15:27 ` Peter Maydell
2020-12-07 15:45 ` Steven Price
2020-12-07 15:45 ` Steven Price
2020-12-07 15:45 ` Steven Price
2020-12-07 15:45 ` Steven Price
2020-12-07 16:05 ` Marc Zyngier
2020-12-07 16:05 ` Marc Zyngier
2020-12-07 16:05 ` Marc Zyngier
2020-12-07 16:05 ` Marc Zyngier
2020-12-07 16:34 ` Catalin Marinas
2020-12-07 16:34 ` Catalin Marinas
2020-12-07 16:34 ` Catalin Marinas
2020-12-07 16:34 ` Catalin Marinas
2020-12-07 19:03 ` Marc Zyngier
2020-12-07 19:03 ` Marc Zyngier
2020-12-07 19:03 ` Marc Zyngier
2020-12-07 19:03 ` Marc Zyngier
2020-12-08 17:21 ` Catalin Marinas
2020-12-08 17:21 ` Catalin Marinas
2020-12-08 17:21 ` Catalin Marinas
2020-12-08 17:21 ` Catalin Marinas
2020-12-08 18:21 ` Marc Zyngier
2020-12-08 18:21 ` Marc Zyngier
2020-12-08 18:21 ` Marc Zyngier
2020-12-08 18:21 ` Marc Zyngier
2020-12-09 12:44 ` Catalin Marinas
2020-12-09 12:44 ` Catalin Marinas
2020-12-09 12:44 ` Catalin Marinas
2020-12-09 12:44 ` Catalin Marinas
2020-12-09 13:25 ` Marc Zyngier
2020-12-09 13:25 ` Marc Zyngier
2020-12-09 13:25 ` Marc Zyngier
2020-12-09 13:25 ` Marc Zyngier
2020-12-09 15:27 ` Catalin Marinas
2020-12-09 15:27 ` Catalin Marinas
2020-12-09 15:27 ` Catalin Marinas
2020-12-09 15:27 ` Catalin Marinas
2020-12-09 18:27 ` Richard Henderson
2020-12-09 18:27 ` Richard Henderson
2020-12-09 18:27 ` Richard Henderson
2020-12-09 18:27 ` Richard Henderson
2020-12-09 18:39 ` Catalin Marinas
2020-12-09 18:39 ` Catalin Marinas
2020-12-09 18:39 ` Catalin Marinas
2020-12-09 18:39 ` Catalin Marinas
2020-12-09 20:13 ` Richard Henderson [this message]
2020-12-09 20:13 ` Richard Henderson
2020-12-09 20:13 ` Richard Henderson
2020-12-09 20:13 ` Richard Henderson
2020-12-09 20:20 ` Peter Maydell
2020-12-09 20:20 ` Peter Maydell
2020-12-09 20:20 ` Peter Maydell
2020-12-09 20:20 ` Peter Maydell
2020-12-07 16:44 ` Dr. David Alan Gilbert
2020-12-07 16:44 ` Dr. David Alan Gilbert
2020-12-07 16:44 ` Dr. David Alan Gilbert
2020-12-07 16:44 ` Dr. David Alan Gilbert
2020-12-07 17:10 ` Peter Maydell
2020-12-07 17:10 ` Peter Maydell
2020-12-07 17:10 ` Peter Maydell
2020-12-07 17:10 ` Peter Maydell
2020-12-07 17:44 ` Dr. David Alan Gilbert
2020-12-07 17:44 ` Dr. David Alan Gilbert
2020-12-07 17:44 ` Dr. David Alan Gilbert
2020-12-07 17:44 ` Dr. David Alan Gilbert
2020-12-08 10:05 ` Haibo Xu
2020-12-08 10:05 ` Haibo Xu
2020-12-08 10:05 ` Haibo Xu
2020-12-08 10:05 ` Haibo Xu
2020-12-08 9:51 ` Haibo Xu
2020-12-08 9:51 ` Haibo Xu
2020-12-08 9:51 ` Haibo Xu
2020-12-08 9:51 ` Haibo Xu
2020-12-08 10:01 ` Marc Zyngier
2020-12-08 10:01 ` Marc Zyngier
2020-12-08 10:01 ` Marc Zyngier
2020-12-08 10:01 ` Marc Zyngier
2020-12-08 10:10 ` Haibo Xu
2020-12-08 10:10 ` Haibo Xu
2020-12-08 10:10 ` Haibo Xu
2020-12-08 10:10 ` Haibo Xu
2020-12-16 7:31 ` Haibo Xu
2020-12-16 7:31 ` Haibo Xu
2020-12-16 7:31 ` Haibo Xu
2020-12-16 7:31 ` Haibo Xu
2020-12-16 10:22 ` Steven Price
2020-12-16 10:22 ` Steven Price
2020-12-16 10:22 ` Steven Price
2020-12-16 10:22 ` Steven Price
2020-12-17 1:47 ` Haibo Xu
2020-12-17 1:47 ` Haibo Xu
2020-12-17 1:47 ` Haibo Xu
2020-12-17 1:47 ` Haibo Xu
2020-11-23 12:16 ` Dr. David Alan Gilbert
2020-11-23 12:16 ` Dr. David Alan Gilbert
2020-11-23 12:16 ` Dr. David Alan Gilbert
2020-11-23 12:16 ` Dr. David Alan Gilbert
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