All of lore.kernel.org
 help / color / mirror / Atom feed
From: Eric Blake <eblake@redhat.com>
To: Shivaprasad G Bhat <sbhat@linux.ibm.com>,
	david@gibson.dropbear.id.au, groug@kaod.org, qemu-ppc@nongnu.org,
	ehabkost@redhat.com, marcel.apfelbaum@gmail.com, mst@redhat.com,
	imammedo@redhat.com, xiaoguangrong.eric@gmail.com,
	peter.maydell@linaro.org, qemu-arm@nongnu.org,
	richard.henderson@linaro.org, pbonzini@redhat.com,
	stefanha@redhat.com, haozhong.zhang@intel.com,
	shameerali.kolothum.thodi@huawei.com, kwangwoo.lee@sk.com,
	armbru@redhat.com
Cc: qemu-devel@nongnu.org, aneesh.kumar@linux.ibm.com,
	linux-nvdimm@lists.01.org, kvm-ppc@vger.kernel.org,
	shivaprasadbhat@gmail.com, bharata@linux.vnet.ibm.com
Subject: Re: [PATCH v4 3/3] nvdimm: Enable sync-dax device property for nvdimm
Date: Mon, 3 May 2021 13:27:22 -0500	[thread overview]
Message-ID: <f035a4ce-c070-6bb9-5792-da0a2d9d0a99@redhat.com> (raw)
In-Reply-To: <161966813983.652.5749368609701495826.stgit@17be908f7c1c>

On 4/28/21 10:49 PM, Shivaprasad G Bhat wrote:
> The patch adds the 'sync-dax' property to the nvdimm device.
> 
> When the sync-dax is 'direct' indicates the backend is synchronous DAX
> capable and no explicit flush requests are required. When the mode is
> set to 'writeback' it indicates the backend is not synhronous DAX

synchronous

> capable and explicit flushes to Hypervisor are required.
> 
> On PPC where the flush requests from guest can be honoured by the qemu,

s/the qemu/qemu/

> the 'writeback' mode is supported and set as the default. The device
> tree property "hcall-flush-required" is added to the nvdimm node which
> makes the guest to issue H_SCM_FLUSH hcalls to request for flushes

s/to issue/issue/
s/request for/request/

> explicitly. This would be the default behaviour without sync-dax
> property set for the nvdimm device. For old pSeries machine, the
> default is 'unsafe'.
> 
> For non-PPC platforms, the mode is set to 'unsafe' as the default.
> 
> Signed-off-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
> ---

> +++ b/qapi/common.json
> @@ -197,3 +197,23 @@
>  { 'enum': 'GrabToggleKeys',
>    'data': [ 'ctrl-ctrl', 'alt-alt', 'shift-shift','meta-meta', 'scrolllock',
>              'ctrl-scrolllock' ] }
> +
> +##
> +# @NvdimmSyncModes:
> +#
> +# Indicates the mode of flush to be used to ensure persistence in case
> +# of power failures.
> +#
> +# @unsafe: This is to indicate, the data on the backend device not be
> +#          consistent in power failure scenarios.

s/This is to indicate, the/This indicates that/
s/device not/device might not/

> +# @direct: This is to indicate the backend device supports synchronous DAX
> +#          and no explicit flush requests from the guest is required.

This indicates the backend device supports synchronous DAX, and no
explicit flush requests from the guest are required.

> +# @writeback: To be used when the backend device doesn't support synchronous
> +#             DAX. The hypervisor issues flushes to the disk when requested
> +#             by the guest.
> +# Since: 6.0

6.1

> +#
> +##
> +{ 'enum': 'NvdimmSyncModes',
> +  'data': [ 'unsafe', 'writeback',
> +            { 'name': 'direct', 'if': 'defined(CONFIG_LIBPMEM)' } ] }
> 
> 

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org
_______________________________________________
Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org
To unsubscribe send an email to linux-nvdimm-leave@lists.01.org

WARNING: multiple messages have this Message-ID (diff)
From: Eric Blake <eblake@redhat.com>
To: Shivaprasad G Bhat <sbhat@linux.ibm.com>,
	david@gibson.dropbear.id.au, groug@kaod.org, qemu-ppc@nongnu.org,
	ehabkost@redhat.com, marcel.apfelbaum@gmail.com, mst@redhat.com,
	imammedo@redhat.com, xiaoguangrong.eric@gmail.com,
	peter.maydell@linaro.org, qemu-arm@nongnu.org,
	richard.henderson@linaro.org, pbonzini@redhat.com,
	stefanha@redhat.com, haozhong.zhang@intel.com,
	shameerali.kolothum.thodi@huawei.com, kwangwoo.lee@sk.com,
	armbru@redhat.com
Cc: linux-nvdimm@lists.01.org, aneesh.kumar@linux.ibm.com,
	qemu-devel@nongnu.org, kvm-ppc@vger.kernel.org,
	shivaprasadbhat@gmail.com, bharata@linux.vnet.ibm.com
Subject: Re: [PATCH v4 3/3] nvdimm: Enable sync-dax device property for nvdimm
Date: Mon, 3 May 2021 13:27:22 -0500	[thread overview]
Message-ID: <f035a4ce-c070-6bb9-5792-da0a2d9d0a99@redhat.com> (raw)
In-Reply-To: <161966813983.652.5749368609701495826.stgit@17be908f7c1c>

On 4/28/21 10:49 PM, Shivaprasad G Bhat wrote:
> The patch adds the 'sync-dax' property to the nvdimm device.
> 
> When the sync-dax is 'direct' indicates the backend is synchronous DAX
> capable and no explicit flush requests are required. When the mode is
> set to 'writeback' it indicates the backend is not synhronous DAX

synchronous

> capable and explicit flushes to Hypervisor are required.
> 
> On PPC where the flush requests from guest can be honoured by the qemu,

s/the qemu/qemu/

> the 'writeback' mode is supported and set as the default. The device
> tree property "hcall-flush-required" is added to the nvdimm node which
> makes the guest to issue H_SCM_FLUSH hcalls to request for flushes

s/to issue/issue/
s/request for/request/

> explicitly. This would be the default behaviour without sync-dax
> property set for the nvdimm device. For old pSeries machine, the
> default is 'unsafe'.
> 
> For non-PPC platforms, the mode is set to 'unsafe' as the default.
> 
> Signed-off-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
> ---

> +++ b/qapi/common.json
> @@ -197,3 +197,23 @@
>  { 'enum': 'GrabToggleKeys',
>    'data': [ 'ctrl-ctrl', 'alt-alt', 'shift-shift','meta-meta', 'scrolllock',
>              'ctrl-scrolllock' ] }
> +
> +##
> +# @NvdimmSyncModes:
> +#
> +# Indicates the mode of flush to be used to ensure persistence in case
> +# of power failures.
> +#
> +# @unsafe: This is to indicate, the data on the backend device not be
> +#          consistent in power failure scenarios.

s/This is to indicate, the/This indicates that/
s/device not/device might not/

> +# @direct: This is to indicate the backend device supports synchronous DAX
> +#          and no explicit flush requests from the guest is required.

This indicates the backend device supports synchronous DAX, and no
explicit flush requests from the guest are required.

> +# @writeback: To be used when the backend device doesn't support synchronous
> +#             DAX. The hypervisor issues flushes to the disk when requested
> +#             by the guest.
> +# Since: 6.0

6.1

> +#
> +##
> +{ 'enum': 'NvdimmSyncModes',
> +  'data': [ 'unsafe', 'writeback',
> +            { 'name': 'direct', 'if': 'defined(CONFIG_LIBPMEM)' } ] }
> 
> 

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org



WARNING: multiple messages have this Message-ID (diff)
From: Eric Blake <eblake@redhat.com>
To: Shivaprasad G Bhat <sbhat@linux.ibm.com>,
	david@gibson.dropbear.id.au, groug@kaod.org, qemu-ppc@nongnu.org,
	ehabkost@redhat.com, marcel.apfelbaum@gmail.com, mst@redhat.com,
	imammedo@redhat.com, xiaoguangrong.eric@gmail.com,
	peter.maydell@linaro.org, qemu-arm@nongnu.org,
	richard.henderson@linaro.org, pbonzini@redhat.com,
	stefanha@redhat.com, haozhong.zhang@intel.com,
	shameerali.kolothum.thodi@huawei.com, kwangwoo.lee@sk.com,
	armbru@redhat.com
Cc: qemu-devel@nongnu.org, aneesh.kumar@linux.ibm.com,
	linux-nvdimm@lists.01.org, kvm-ppc@vger.kernel.org,
	shivaprasadbhat@gmail.com, bharata@linux.vnet.ibm.com
Subject: Re: [PATCH v4 3/3] nvdimm: Enable sync-dax device property for nvdimm
Date: Mon, 03 May 2021 18:27:22 +0000	[thread overview]
Message-ID: <f035a4ce-c070-6bb9-5792-da0a2d9d0a99@redhat.com> (raw)
In-Reply-To: <161966813983.652.5749368609701495826.stgit@17be908f7c1c>

On 4/28/21 10:49 PM, Shivaprasad G Bhat wrote:
> The patch adds the 'sync-dax' property to the nvdimm device.
> 
> When the sync-dax is 'direct' indicates the backend is synchronous DAX
> capable and no explicit flush requests are required. When the mode is
> set to 'writeback' it indicates the backend is not synhronous DAX

synchronous

> capable and explicit flushes to Hypervisor are required.
> 
> On PPC where the flush requests from guest can be honoured by the qemu,

s/the qemu/qemu/

> the 'writeback' mode is supported and set as the default. The device
> tree property "hcall-flush-required" is added to the nvdimm node which
> makes the guest to issue H_SCM_FLUSH hcalls to request for flushes

s/to issue/issue/
s/request for/request/

> explicitly. This would be the default behaviour without sync-dax
> property set for the nvdimm device. For old pSeries machine, the
> default is 'unsafe'.
> 
> For non-PPC platforms, the mode is set to 'unsafe' as the default.
> 
> Signed-off-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
> ---

> +++ b/qapi/common.json
> @@ -197,3 +197,23 @@
>  { 'enum': 'GrabToggleKeys',
>    'data': [ 'ctrl-ctrl', 'alt-alt', 'shift-shift','meta-meta', 'scrolllock',
>              'ctrl-scrolllock' ] }
> +
> +##
> +# @NvdimmSyncModes:
> +#
> +# Indicates the mode of flush to be used to ensure persistence in case
> +# of power failures.
> +#
> +# @unsafe: This is to indicate, the data on the backend device not be
> +#          consistent in power failure scenarios.

s/This is to indicate, the/This indicates that/
s/device not/device might not/

> +# @direct: This is to indicate the backend device supports synchronous DAX
> +#          and no explicit flush requests from the guest is required.

This indicates the backend device supports synchronous DAX, and no
explicit flush requests from the guest are required.

> +# @writeback: To be used when the backend device doesn't support synchronous
> +#             DAX. The hypervisor issues flushes to the disk when requested
> +#             by the guest.
> +# Since: 6.0

6.1

> +#
> +##
> +{ 'enum': 'NvdimmSyncModes',
> +  'data': [ 'unsafe', 'writeback',
> +            { 'name': 'direct', 'if': 'defined(CONFIG_LIBPMEM)' } ] }
> 
> 

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org

  reply	other threads:[~2021-05-03 18:27 UTC|newest]

Thread overview: 57+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-29  3:48 [PATCH v4 0/3] nvdimm: Enable sync-dax property for nvdimm Shivaprasad G Bhat
2021-04-29  3:48 ` Shivaprasad G Bhat
2021-04-29  3:48 ` Shivaprasad G Bhat
2021-04-29  3:48 ` [PATCH v4 1/3] spapr: nvdimm: Forward declare and move the definitions Shivaprasad G Bhat
2021-04-29  3:48   ` Shivaprasad G Bhat
2021-04-29  3:48   ` Shivaprasad G Bhat
2021-05-03 18:23   ` Eric Blake
2021-05-03 18:23     ` Eric Blake
2021-05-03 18:23     ` Eric Blake
2021-05-04  1:21     ` David Gibson
2021-05-04  1:21       ` David Gibson
2021-05-04  1:21       ` David Gibson
2021-04-29  3:48 ` [PATCH v4 2/3] spapr: nvdimm: Implement H_SCM_FLUSH hcall Shivaprasad G Bhat
2021-04-29  3:48   ` Shivaprasad G Bhat
2021-04-29  3:48   ` Shivaprasad G Bhat
2021-04-29  3:49 ` [PATCH v4 3/3] nvdimm: Enable sync-dax device property for nvdimm Shivaprasad G Bhat
2021-04-29  3:49   ` Shivaprasad G Bhat
2021-04-29  3:49   ` Shivaprasad G Bhat
2021-05-03 18:27   ` Eric Blake [this message]
2021-05-03 18:27     ` Eric Blake
2021-05-03 18:27     ` Eric Blake
2021-04-29 15:55 ` [PATCH v4 0/3] nvdimm: Enable sync-dax " Stefan Hajnoczi
2021-04-29 15:55   ` Stefan Hajnoczi
2021-04-29 15:55   ` Stefan Hajnoczi
2021-04-29 16:32   ` Aneesh Kumar K.V
2021-04-29 16:44     ` Aneesh Kumar K.V
2021-04-29 16:32     ` Aneesh Kumar K.V
2021-04-30  4:27     ` David Gibson
2021-04-30  4:27       ` David Gibson
2021-04-30  4:27       ` David Gibson
2021-04-30 15:08       ` Stefan Hajnoczi
2021-04-30 15:08         ` Stefan Hajnoczi
2021-04-30 15:08         ` Stefan Hajnoczi
2021-04-30 19:14 ` Dan Williams
2021-04-30 19:14   ` Dan Williams
2021-04-30 19:14   ` Dan Williams
2021-05-01 13:55   ` Aneesh Kumar K.V
2021-05-01 13:56     ` Aneesh Kumar K.V
2021-05-01 13:55     ` Aneesh Kumar K.V
2021-05-03 14:05   ` Shivaprasad G Bhat
2021-05-03 14:17     ` Shivaprasad G Bhat
2021-05-03 14:05     ` Shivaprasad G Bhat
2021-05-03 19:41     ` Dan Williams
2021-05-03 19:41       ` Dan Williams
2021-05-03 19:41       ` Dan Williams
2021-05-04  4:59       ` Aneesh Kumar K.V
2021-05-04  4:59         ` Aneesh Kumar K.V
2021-05-04  4:59         ` Aneesh Kumar K.V
2021-05-04  5:43         ` Pankaj Gupta
2021-05-04  5:43           ` Pankaj Gupta
2021-05-04  5:43           ` Pankaj Gupta
2021-05-04  9:02           ` Aneesh Kumar K.V
2021-05-04  9:14             ` Aneesh Kumar K.V
2021-05-04  9:02             ` Aneesh Kumar K.V
2021-05-05  0:12             ` Dan Williams
2021-05-05  0:12               ` Dan Williams
2021-05-05  0:12               ` Dan Williams

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=f035a4ce-c070-6bb9-5792-da0a2d9d0a99@redhat.com \
    --to=eblake@redhat.com \
    --cc=aneesh.kumar@linux.ibm.com \
    --cc=armbru@redhat.com \
    --cc=bharata@linux.vnet.ibm.com \
    --cc=david@gibson.dropbear.id.au \
    --cc=ehabkost@redhat.com \
    --cc=groug@kaod.org \
    --cc=haozhong.zhang@intel.com \
    --cc=imammedo@redhat.com \
    --cc=kvm-ppc@vger.kernel.org \
    --cc=kwangwoo.lee@sk.com \
    --cc=linux-nvdimm@lists.01.org \
    --cc=marcel.apfelbaum@gmail.com \
    --cc=mst@redhat.com \
    --cc=pbonzini@redhat.com \
    --cc=peter.maydell@linaro.org \
    --cc=qemu-arm@nongnu.org \
    --cc=qemu-devel@nongnu.org \
    --cc=qemu-ppc@nongnu.org \
    --cc=richard.henderson@linaro.org \
    --cc=sbhat@linux.ibm.com \
    --cc=shameerali.kolothum.thodi@huawei.com \
    --cc=shivaprasadbhat@gmail.com \
    --cc=stefanha@redhat.com \
    --cc=xiaoguangrong.eric@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.