From: Alex Williamson <alex.williamson@redhat.com>
To: "Liu, Yi L" <yi.l.liu@intel.com>
Cc: jean-philippe@linaro.org, kevin.tian@intel.com,
ashok.raj@intel.com, kvm@vger.kernel.org, jun.j.tian@intel.com,
iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
yi.y.sun@intel.com, hao.wu@intel.com
Subject: Re: [PATCH v1 5/8] vfio/type1: Report 1st-level/stage-1 format to userspace
Date: Thu, 2 Apr 2020 13:20:12 -0600 [thread overview]
Message-ID: <20200402132012.390a7b54@w520.home> (raw)
In-Reply-To: <1584880325-10561-6-git-send-email-yi.l.liu@intel.com>
On Sun, 22 Mar 2020 05:32:02 -0700
"Liu, Yi L" <yi.l.liu@intel.com> wrote:
> From: Liu Yi L <yi.l.liu@intel.com>
>
> VFIO exposes IOMMU nesting translation (a.k.a dual stage translation)
> capability to userspace. Thus applications like QEMU could support
> vIOMMU with hardware's nesting translation capability for pass-through
> devices. Before setting up nesting translation for pass-through devices,
> QEMU and other applications need to learn the supported 1st-lvl/stage-1
> translation structure format like page table format.
>
> Take vSVA (virtual Shared Virtual Addressing) as an example, to support
> vSVA for pass-through devices, QEMU setup nesting translation for pass-
> through devices. The guest page table are configured to host as 1st-lvl/
> stage-1 page table. Therefore, guest format should be compatible with
> host side.
>
> This patch reports the supported 1st-lvl/stage-1 page table format on the
> current platform to userspace. QEMU and other alike applications should
> use this format info when trying to setup IOMMU nesting translation on
> host IOMMU.
>
> Cc: Kevin Tian <kevin.tian@intel.com>
> CC: Jacob Pan <jacob.jun.pan@linux.intel.com>
> Cc: Alex Williamson <alex.williamson@redhat.com>
> Cc: Eric Auger <eric.auger@redhat.com>
> Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>
> Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
> ---
> drivers/vfio/vfio_iommu_type1.c | 56 +++++++++++++++++++++++++++++++++++++++++
> include/uapi/linux/vfio.h | 1 +
> 2 files changed, 57 insertions(+)
>
> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
> index 9aa2a67..82a9e0b 100644
> --- a/drivers/vfio/vfio_iommu_type1.c
> +++ b/drivers/vfio/vfio_iommu_type1.c
> @@ -2234,11 +2234,66 @@ static int vfio_iommu_type1_pasid_free(struct vfio_iommu *iommu,
> return ret;
> }
>
> +static int vfio_iommu_get_stage1_format(struct vfio_iommu *iommu,
> + u32 *stage1_format)
> +{
> + struct vfio_domain *domain;
> + u32 format = 0, tmp_format = 0;
> + int ret;
> +
> + mutex_lock(&iommu->lock);
> + if (list_empty(&iommu->domain_list)) {
> + mutex_unlock(&iommu->lock);
> + return -EINVAL;
> + }
> +
> + list_for_each_entry(domain, &iommu->domain_list, next) {
> + if (iommu_domain_get_attr(domain->domain,
> + DOMAIN_ATTR_PASID_FORMAT, &format)) {
> + ret = -EINVAL;
> + format = 0;
> + goto out_unlock;
> + }
> + /*
> + * format is always non-zero (the first format is
> + * IOMMU_PASID_FORMAT_INTEL_VTD which is 1). For
> + * the reason of potential different backed IOMMU
> + * formats, here we expect to have identical formats
> + * in the domain list, no mixed formats support.
> + * return -EINVAL to fail the attempt of setup
> + * VFIO_TYPE1_NESTING_IOMMU if non-identical formats
> + * are detected.
> + */
> + if (tmp_format && tmp_format != format) {
> + ret = -EINVAL;
> + format = 0;
> + goto out_unlock;
> + }
> +
> + tmp_format = format;
> + }
> + ret = 0;
> +
> +out_unlock:
> + if (format)
> + *stage1_format = format;
> + mutex_unlock(&iommu->lock);
> + return ret;
> +}
> +
> static int vfio_iommu_info_add_nesting_cap(struct vfio_iommu *iommu,
> struct vfio_info_cap *caps)
> {
> struct vfio_info_cap_header *header;
> struct vfio_iommu_type1_info_cap_nesting *nesting_cap;
> + u32 formats = 0;
> + int ret;
> +
> + ret = vfio_iommu_get_stage1_format(iommu, &formats);
> + if (ret) {
> + pr_warn("Failed to get stage-1 format\n");
> + return ret;
Looks like this generates a warning and causes the iommu_get_info ioctl
to fail if the hardware doesn't support the pasid format attribute, or
the domain list is empty. This breaks users on existing hardware.
> + }
>
> header = vfio_info_cap_add(caps, sizeof(*nesting_cap),
> VFIO_IOMMU_TYPE1_INFO_CAP_NESTING, 1);
> @@ -2254,6 +2309,7 @@ static int vfio_iommu_info_add_nesting_cap(struct vfio_iommu *iommu,
> /* nesting iommu type supports PASID requests (alloc/free) */
> nesting_cap->nesting_capabilities |= VFIO_IOMMU_PASID_REQS;
> }
> + nesting_cap->stage1_formats = formats;
>
> return 0;
> }
> diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
> index ed9881d..ebeaf3e 100644
> --- a/include/uapi/linux/vfio.h
> +++ b/include/uapi/linux/vfio.h
> @@ -763,6 +763,7 @@ struct vfio_iommu_type1_info_cap_nesting {
> struct vfio_info_cap_header header;
> #define VFIO_IOMMU_PASID_REQS (1 << 0)
> __u32 nesting_capabilities;
> + __u32 stage1_formats;
> };
>
> #define VFIO_IOMMU_GET_INFO _IO(VFIO_TYPE, VFIO_BASE + 12)
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
next prev parent reply other threads:[~2020-04-02 19:20 UTC|newest]
Thread overview: 110+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-22 12:31 [PATCH v1 0/8] vfio: expose virtual Shared Virtual Addressing to VMs Liu, Yi L
2020-03-22 12:31 ` [PATCH v1 1/8] vfio: Add VFIO_IOMMU_PASID_REQUEST(alloc/free) Liu, Yi L
2020-03-22 16:21 ` kbuild test robot
2020-03-30 8:32 ` Tian, Kevin
2020-03-30 14:36 ` Liu, Yi L
2020-03-31 5:40 ` Tian, Kevin
2020-03-31 13:22 ` Liu, Yi L
2020-04-01 5:43 ` Tian, Kevin
2020-04-01 5:48 ` Liu, Yi L
2020-03-31 7:53 ` Christoph Hellwig
2020-03-31 8:17 ` Liu, Yi L
2020-03-31 8:32 ` Liu, Yi L
2020-03-31 8:36 ` Liu, Yi L
2020-03-31 9:15 ` Christoph Hellwig
2020-04-02 13:52 ` Jean-Philippe Brucker
2020-04-03 11:56 ` Liu, Yi L
2020-04-03 12:39 ` Jean-Philippe Brucker
2020-04-03 12:44 ` Liu, Yi L
2020-04-02 17:50 ` Alex Williamson
2020-04-03 5:58 ` Tian, Kevin
2020-04-03 15:14 ` Alex Williamson
2020-04-07 4:42 ` Tian, Kevin
2020-04-07 15:14 ` Alex Williamson
2020-04-03 13:12 ` Liu, Yi L
2020-04-03 17:50 ` Alex Williamson
2020-04-07 4:52 ` Tian, Kevin
2020-04-08 0:52 ` Liu, Yi L
2020-03-22 12:31 ` [PATCH v1 2/8] vfio/type1: Add vfio_iommu_type1 parameter for quota tuning Liu, Yi L
2020-03-22 17:20 ` kbuild test robot
2020-03-30 8:40 ` Tian, Kevin
2020-03-30 8:52 ` Liu, Yi L
2020-03-30 9:19 ` Tian, Kevin
2020-03-30 9:26 ` Liu, Yi L
2020-03-30 11:44 ` Tian, Kevin
2020-04-02 17:58 ` Alex Williamson
2020-04-03 8:15 ` Liu, Yi L
2020-03-22 12:32 ` [PATCH v1 3/8] vfio/type1: Report PASID alloc/free support to userspace Liu, Yi L
2020-03-30 9:43 ` Tian, Kevin
2020-04-01 7:46 ` Liu, Yi L
2020-04-01 9:41 ` Auger Eric
2020-04-01 13:13 ` Liu, Yi L
2020-04-02 18:01 ` Alex Williamson
2020-04-03 8:17 ` Liu, Yi L
2020-04-03 17:28 ` Alex Williamson
2020-04-04 11:36 ` Liu, Yi L
2020-03-22 12:32 ` [PATCH v1 4/8] vfio: Check nesting iommu uAPI version Liu, Yi L
2020-03-22 18:30 ` kbuild test robot
2020-03-22 12:32 ` [PATCH v1 5/8] vfio/type1: Report 1st-level/stage-1 format to userspace Liu, Yi L
2020-03-22 16:44 ` kbuild test robot
2020-03-30 11:48 ` Tian, Kevin
2020-04-01 7:38 ` Liu, Yi L
2020-04-01 7:56 ` Tian, Kevin
2020-04-01 8:06 ` Liu, Yi L
2020-04-01 8:08 ` Tian, Kevin
2020-04-01 8:09 ` Liu, Yi L
2020-04-01 8:51 ` Auger Eric
2020-04-01 12:51 ` Liu, Yi L
2020-04-01 13:01 ` Auger Eric
2020-04-03 8:23 ` Jean-Philippe Brucker
2020-04-07 9:43 ` Liu, Yi L
2020-04-08 1:02 ` Liu, Yi L
2020-04-08 10:27 ` Auger Eric
2020-04-09 8:14 ` Jean-Philippe Brucker
2020-04-09 9:01 ` Auger Eric
2020-04-09 12:47 ` Liu, Yi L
2020-04-10 3:28 ` Auger Eric
2020-04-10 3:48 ` Liu, Yi L
2020-04-10 12:30 ` Liu, Yi L
2020-04-02 19:20 ` Alex Williamson [this message]
2020-04-03 11:59 ` Liu, Yi L
2020-03-22 12:32 ` [PATCH v1 6/8] vfio/type1: Bind guest page tables to host Liu, Yi L
2020-03-22 18:10 ` kbuild test robot
2020-03-30 12:46 ` Tian, Kevin
2020-04-01 9:13 ` Liu, Yi L
2020-04-02 2:12 ` Tian, Kevin
2020-04-02 8:05 ` Liu, Yi L
2020-04-03 8:34 ` Jean-Philippe Brucker
2020-04-07 10:33 ` Liu, Yi L
2020-04-09 8:28 ` Jean-Philippe Brucker
2020-04-09 9:15 ` Liu, Yi L
2020-04-09 9:38 ` Jean-Philippe Brucker
2020-04-02 19:57 ` Alex Williamson
2020-04-03 13:30 ` Liu, Yi L
2020-04-03 18:11 ` Alex Williamson
2020-04-04 10:28 ` Liu, Yi L
2020-04-11 5:52 ` Liu, Yi L
2020-03-22 12:32 ` [PATCH v1 7/8] vfio/type1: Add VFIO_IOMMU_CACHE_INVALIDATE Liu, Yi L
2020-03-30 12:58 ` Tian, Kevin
2020-04-01 7:49 ` Liu, Yi L
2020-03-31 7:56 ` Christoph Hellwig
2020-03-31 10:48 ` Liu, Yi L
2020-04-02 20:24 ` Alex Williamson
2020-04-03 6:39 ` Tian, Kevin
2020-04-03 15:31 ` Jacob Pan
2020-04-03 15:34 ` Alex Williamson
2020-04-08 2:28 ` Liu, Yi L
2020-04-16 10:40 ` Liu, Yi L
2020-04-16 12:09 ` Tian, Kevin
2020-04-16 12:42 ` Auger Eric
2020-04-16 13:28 ` Tian, Kevin
2020-04-16 15:12 ` Auger Eric
2020-04-16 14:40 ` Alex Williamson
2020-04-16 14:48 ` Alex Williamson
2020-04-17 6:03 ` Liu, Yi L
2020-03-22 12:32 ` [PATCH v1 8/8] vfio/type1: Add vSVA support for IOMMU-backed mdevs Liu, Yi L
2020-03-30 13:18 ` Tian, Kevin
2020-04-01 7:51 ` Liu, Yi L
2020-04-02 20:33 ` Alex Williamson
2020-04-03 13:39 ` Liu, Yi L
2020-03-26 12:56 ` [PATCH v1 0/8] vfio: expose virtual Shared Virtual Addressing to VMs Liu, Yi L
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=20200402132012.390a7b54@w520.home \
--to=alex.williamson@redhat.com \
--cc=ashok.raj@intel.com \
--cc=hao.wu@intel.com \
--cc=iommu@lists.linux-foundation.org \
--cc=jean-philippe@linaro.org \
--cc=jun.j.tian@intel.com \
--cc=kevin.tian@intel.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=yi.l.liu@intel.com \
--cc=yi.y.sun@intel.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).