From: Cornelia Huck <cohuck@redhat.com>
To: Peter Xu <peterx@redhat.com>
Cc: Steven Price <steven.price@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Peter Collingbourne <pcc@google.com>,
kvmarm@lists.cs.columbia.edu, Marc Zyngier <maz@kernel.org>,
kvm@vger.kernel.org, Andy Lutomirski <luto@amacapital.net>,
linux-arm-kernel@lists.infradead.org,
Michael Roth <michael.roth@amd.com>,
Chao Peng <chao.p.peng@linux.intel.com>,
Will Deacon <will@kernel.org>,
Evgenii Stepanov <eugenis@google.com>,
Jean-Philippe Brucker <jean-philippe@linaro.org>,
Gavin Shan <gshan@redhat.com>, Eric Auger <eric.auger@redhat.com>,
"Dr. David Alan Gilbert" <dgilbert@redhat.com>
Subject: Re: [PATCH] KVM: arm64: permit MAP_SHARED mappings with MTE enabled
Date: Thu, 14 Jul 2022 15:30:54 +0200 [thread overview]
Message-ID: <87edynizxt.fsf@redhat.com> (raw)
In-Reply-To: <Ysg38XZSzPk8tYwK@xz-m1.local>
On Fri, Jul 08 2022, Peter Xu <peterx@redhat.com> wrote:
> On Fri, Jul 08, 2022 at 03:03:34PM +0200, Cornelia Huck wrote:
>> I was thinking about a new flag that implies "copy metadata"; not sure
>> how we would get the same atomicity with a separate ioctl. I've only
>> just started looking at userfaultfd, though, and I might be on a wrong
>> track... One thing I'd like to avoid is having something that is too
>> ARM-specific, I think there are other architecture features that might
>> have similar issues.
>
> Agreed, to propose such an interface we'd better make sure it'll be easily
> applicable to other similar memory protection mechanisms elsewhere.
There's storage keys on s390, although I believe they are considered
legacy by now. I dimly recall something in x86 land.
>
>>
>> Maybe someone more familiar with uffd and/or postcopy can chime in?
>
> Hanving UFFDIO_COPY provide a new flag sounds reasonable to me. I'm
> curious what's the maximum possible size of the tags and whether they can
> be embeded already into struct uffdio_copy somehow.
Each tag is four bits and covers 16 bytes (also see the defs in
arch/arm64/include/asm/mte-def.h).
WARNING: multiple messages have this Message-ID (diff)
From: Cornelia Huck <cohuck@redhat.com>
To: Peter Xu <peterx@redhat.com>
Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>,
kvm@vger.kernel.org, Catalin Marinas <catalin.marinas@arm.com>,
"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
Steven Price <steven.price@arm.com>,
Will Deacon <will@kernel.org>,
Evgenii Stepanov <eugenis@google.com>,
Michael Roth <michael.roth@amd.com>,
Marc Zyngier <maz@kernel.org>,
Chao Peng <chao.p.peng@linux.intel.com>,
Andy Lutomirski <luto@amacapital.net>,
Peter Collingbourne <pcc@google.com>,
kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] KVM: arm64: permit MAP_SHARED mappings with MTE enabled
Date: Thu, 14 Jul 2022 15:30:54 +0200 [thread overview]
Message-ID: <87edynizxt.fsf@redhat.com> (raw)
In-Reply-To: <Ysg38XZSzPk8tYwK@xz-m1.local>
On Fri, Jul 08 2022, Peter Xu <peterx@redhat.com> wrote:
> On Fri, Jul 08, 2022 at 03:03:34PM +0200, Cornelia Huck wrote:
>> I was thinking about a new flag that implies "copy metadata"; not sure
>> how we would get the same atomicity with a separate ioctl. I've only
>> just started looking at userfaultfd, though, and I might be on a wrong
>> track... One thing I'd like to avoid is having something that is too
>> ARM-specific, I think there are other architecture features that might
>> have similar issues.
>
> Agreed, to propose such an interface we'd better make sure it'll be easily
> applicable to other similar memory protection mechanisms elsewhere.
There's storage keys on s390, although I believe they are considered
legacy by now. I dimly recall something in x86 land.
>
>>
>> Maybe someone more familiar with uffd and/or postcopy can chime in?
>
> Hanving UFFDIO_COPY provide a new flag sounds reasonable to me. I'm
> curious what's the maximum possible size of the tags and whether they can
> be embeded already into struct uffdio_copy somehow.
Each tag is four bits and covers 16 bytes (also see the defs in
arch/arm64/include/asm/mte-def.h).
_______________________________________________
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: Cornelia Huck <cohuck@redhat.com>
To: Peter Xu <peterx@redhat.com>
Cc: Steven Price <steven.price@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Peter Collingbourne <pcc@google.com>,
kvmarm@lists.cs.columbia.edu, Marc Zyngier <maz@kernel.org>,
kvm@vger.kernel.org, Andy Lutomirski <luto@amacapital.net>,
linux-arm-kernel@lists.infradead.org,
Michael Roth <michael.roth@amd.com>,
Chao Peng <chao.p.peng@linux.intel.com>,
Will Deacon <will@kernel.org>,
Evgenii Stepanov <eugenis@google.com>,
Jean-Philippe Brucker <jean-philippe@linaro.org>,
Gavin Shan <gshan@redhat.com>, Eric Auger <eric.auger@redhat.com>,
"Dr. David Alan Gilbert" <dgilbert@redhat.com>
Subject: Re: [PATCH] KVM: arm64: permit MAP_SHARED mappings with MTE enabled
Date: Thu, 14 Jul 2022 15:30:54 +0200 [thread overview]
Message-ID: <87edynizxt.fsf@redhat.com> (raw)
In-Reply-To: <Ysg38XZSzPk8tYwK@xz-m1.local>
On Fri, Jul 08 2022, Peter Xu <peterx@redhat.com> wrote:
> On Fri, Jul 08, 2022 at 03:03:34PM +0200, Cornelia Huck wrote:
>> I was thinking about a new flag that implies "copy metadata"; not sure
>> how we would get the same atomicity with a separate ioctl. I've only
>> just started looking at userfaultfd, though, and I might be on a wrong
>> track... One thing I'd like to avoid is having something that is too
>> ARM-specific, I think there are other architecture features that might
>> have similar issues.
>
> Agreed, to propose such an interface we'd better make sure it'll be easily
> applicable to other similar memory protection mechanisms elsewhere.
There's storage keys on s390, although I believe they are considered
legacy by now. I dimly recall something in x86 land.
>
>>
>> Maybe someone more familiar with uffd and/or postcopy can chime in?
>
> Hanving UFFDIO_COPY provide a new flag sounds reasonable to me. I'm
> curious what's the maximum possible size of the tags and whether they can
> be embeded already into struct uffdio_copy somehow.
Each tag is four bits and covers 16 bytes (also see the defs in
arch/arm64/include/asm/mte-def.h).
_______________________________________________
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:[~2022-07-14 13:31 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-23 23:49 [PATCH] KVM: arm64: permit MAP_SHARED mappings with MTE enabled Peter Collingbourne
2022-06-23 23:49 ` Peter Collingbourne
2022-06-23 23:49 ` Peter Collingbourne
2022-06-24 17:05 ` Catalin Marinas
2022-06-24 17:05 ` Catalin Marinas
2022-06-24 17:05 ` Catalin Marinas
2022-06-24 21:50 ` Peter Collingbourne
2022-06-24 21:50 ` Peter Collingbourne
2022-06-24 21:50 ` Peter Collingbourne
2022-06-27 11:43 ` Catalin Marinas
2022-06-27 11:43 ` Catalin Marinas
2022-06-27 11:43 ` Catalin Marinas
2022-06-27 18:16 ` Peter Collingbourne
2022-06-27 18:16 ` Peter Collingbourne
2022-06-27 18:16 ` Peter Collingbourne
2022-06-28 17:57 ` Catalin Marinas
2022-06-28 17:57 ` Catalin Marinas
2022-06-28 17:57 ` Catalin Marinas
2022-06-28 18:54 ` Peter Collingbourne
2022-06-28 18:54 ` Peter Collingbourne
2022-06-28 18:54 ` Peter Collingbourne
2022-06-29 19:15 ` Catalin Marinas
2022-06-29 19:15 ` Catalin Marinas
2022-06-29 19:15 ` Catalin Marinas
2022-06-30 17:24 ` Catalin Marinas
2022-06-30 17:24 ` Catalin Marinas
2022-06-30 17:24 ` Catalin Marinas
2022-06-25 8:14 ` Steven Price
2022-06-25 8:14 ` Steven Price
2022-06-25 8:14 ` Steven Price
2022-06-27 15:55 ` Cornelia Huck
2022-06-27 15:55 ` Cornelia Huck
2022-06-27 15:55 ` Cornelia Huck
2022-06-29 8:45 ` Catalin Marinas
2022-06-29 8:45 ` Catalin Marinas
2022-06-29 8:45 ` Catalin Marinas
2022-07-04 9:52 ` Steven Price
2022-07-04 9:52 ` Steven Price
2022-07-04 9:52 ` Steven Price
2022-07-04 12:19 ` Cornelia Huck
2022-07-04 12:19 ` Cornelia Huck
2022-07-04 12:19 ` Cornelia Huck
2022-07-04 15:00 ` Steven Price
2022-07-04 15:00 ` Steven Price
2022-07-04 15:00 ` Steven Price
2022-07-08 13:03 ` Cornelia Huck
2022-07-08 13:03 ` Cornelia Huck
2022-07-08 13:03 ` Cornelia Huck
2022-07-08 13:58 ` Peter Xu
2022-07-08 13:58 ` Peter Xu
2022-07-08 13:58 ` Peter Xu
2022-07-14 13:30 ` Cornelia Huck [this message]
2022-07-14 13:30 ` Cornelia Huck
2022-07-14 13:30 ` Cornelia Huck
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