From: Yan Zhao <yan.y.zhao@intel.com>
To: Alex Williamson <alex.williamson@redhat.com>
Cc: "Zhengxiao.zx@Alibaba-inc.com" <Zhengxiao.zx@Alibaba-inc.com>,
"Tian, Kevin" <kevin.tian@intel.com>,
"Liu, Yi L" <yi.l.liu@intel.com>,
"cjia@nvidia.com" <cjia@nvidia.com>,
"eskultet@redhat.com" <eskultet@redhat.com>,
"Yang, Ziye" <ziye.yang@intel.com>,
"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>,
"cohuck@redhat.com" <cohuck@redhat.com>,
"shuangtai.tst@alibaba-inc.com" <shuangtai.tst@alibaba-inc.com>,
"dgilbert@redhat.com" <dgilbert@redhat.com>,
"Wang, Zhi A" <zhi.a.wang@intel.com>,
"mlevitsk@redhat.com" <mlevitsk@redhat.com>,
"pasic@linux.ibm.com" <pasic@linux.ibm.com>,
"aik@ozlabs.ru" <aik@ozlabs.ru>,
Kirti Wankhede <kwankhede@nvidia.com>,
"eauger@redhat.com" <eauger@redhat.com>,
"felipe@nutanix.com" <felipe@nutanix.com>,
"jonathan.davies@nutanix.com" <jonathan.davies@nutanix.com>,
"Liu, Changpeng" <changpeng.liu@intel.com>,
"Ken.Xue@amd.com" <Ken.Xue@amd.com>
Subject: Re: [PATCH v16 QEMU 08/16] vfio: Register SaveVMHandlers for VFIO device
Date: Wed, 6 May 2020 02:38:46 -0400 [thread overview]
Message-ID: <20200506063846.GB19334@joy-OptiPlex-7040> (raw)
In-Reply-To: <20200504223726.5d4bb9ce@x1.home>
On Tue, May 05, 2020 at 12:37:26PM +0800, Alex Williamson wrote:
> On Tue, 5 May 2020 04:49:10 +0530
> Kirti Wankhede <kwankhede@nvidia.com> wrote:
>
> > On 3/26/2020 2:32 AM, Alex Williamson wrote:
> > > On Wed, 25 Mar 2020 02:39:06 +0530
> > > Kirti Wankhede <kwankhede@nvidia.com> wrote:
> > >
> > >> Define flags to be used as delimeter in migration file stream.
> > >> Added .save_setup and .save_cleanup functions. Mapped & unmapped migration
> > >> region from these functions at source during saving or pre-copy phase.
> > >> Set VFIO device state depending on VM's state. During live migration, VM is
> > >> running when .save_setup is called, _SAVING | _RUNNING state is set for VFIO
> > >> device. During save-restore, VM is paused, _SAVING state is set for VFIO device.
> > >>
> > >> Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
> > >> Reviewed-by: Neo Jia <cjia@nvidia.com>
> > >> ---
> > >> hw/vfio/migration.c | 76 ++++++++++++++++++++++++++++++++++++++++++++++++++++
> > >> hw/vfio/trace-events | 2 ++
> > >> 2 files changed, 78 insertions(+)
> > >>
> > >> diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
> > >> index 22ded9d28cf3..033f76526e49 100644
> > >> --- a/hw/vfio/migration.c
> > >> +++ b/hw/vfio/migration.c
> > >> @@ -8,6 +8,7 @@
> > >> */
> > >>
> > >> #include "qemu/osdep.h"
> > >> +#include "qemu/main-loop.h"
> > >> #include <linux/vfio.h>
> > >>
> > >> #include "sysemu/runstate.h"
> > >> @@ -24,6 +25,17 @@
> > >> #include "pci.h"
> > >> #include "trace.h"
> > >>
> > >> +/*
> > >> + * Flags used as delimiter:
> > >> + * 0xffffffff => MSB 32-bit all 1s
> > >> + * 0xef10 => emulated (virtual) function IO
> > >> + * 0x0000 => 16-bits reserved for flags
> > >> + */
> > >> +#define VFIO_MIG_FLAG_END_OF_STATE (0xffffffffef100001ULL)
> > >> +#define VFIO_MIG_FLAG_DEV_CONFIG_STATE (0xffffffffef100002ULL)
> > >> +#define VFIO_MIG_FLAG_DEV_SETUP_STATE (0xffffffffef100003ULL)
> > >> +#define VFIO_MIG_FLAG_DEV_DATA_STATE (0xffffffffef100004ULL)
> > >> +
> > >> static void vfio_migration_region_exit(VFIODevice *vbasedev)
> > >> {
> > >> VFIOMigration *migration = vbasedev->migration;
> > >> @@ -126,6 +138,69 @@ static int vfio_migration_set_state(VFIODevice *vbasedev, uint32_t mask,
> > >> return 0;
> > >> }
> > >>
> > >> +/* ---------------------------------------------------------------------- */
> > >> +
> > >> +static int vfio_save_setup(QEMUFile *f, void *opaque)
> > >> +{
> > >> + VFIODevice *vbasedev = opaque;
> > >> + VFIOMigration *migration = vbasedev->migration;
> > >> + int ret;
> > >> +
> > >> + qemu_put_be64(f, VFIO_MIG_FLAG_DEV_SETUP_STATE);
> > >> +
> > >> + if (migration->region.mmaps) {
> > >> + qemu_mutex_lock_iothread();
> > >> + ret = vfio_region_mmap(&migration->region);
> > >> + qemu_mutex_unlock_iothread();
> > >> + if (ret) {
> > >> + error_report("%s: Failed to mmap VFIO migration region %d: %s",
> > >> + vbasedev->name, migration->region.index,
> > >> + strerror(-ret));
> > >> + return ret;
> > >> + }
> > >> + }
> > >> +
> > >> + ret = vfio_migration_set_state(vbasedev, ~0, VFIO_DEVICE_STATE_SAVING);
> > >> + if (ret) {
> > >> + error_report("%s: Failed to set state SAVING", vbasedev->name);
> > >> + return ret;
> > >> + }
> > >> +
> > >> + /*
> > >> + * Save migration region size. This is used to verify migration region size
> > >> + * is greater than or equal to migration region size at destination
> > >> + */
> > >> + qemu_put_be64(f, migration->region.size);
> > >
> > > Is this requirement supported by the uapi?
> >
> > Yes, on UAPI thread we discussed this:
> >
> > * For the user application, data is opaque. The user application
> > should write
> > * data in the same order as the data is received and the data should be of
> > * same transaction size at the source.
> >
> > data should be same transaction size, so migration region size should be
> > greater than or equal to the size at source when verifying at destination.
>
> We are that user application for which the data is opaque, therefore we
> should make no assumptions about how the vendor driver makes use of
> their region. If we get a transaction that exceeds the end of the
> region, I agree, that would be an error. But we have no business
> predicting that such a transaction might occur if the vendor driver
> indicates it can support the migration.
>
> > > The vendor driver operates
> > > within the migration region, but it has no requirement to use the full
> > > extent of the region. Shouldn't we instead insert the version string
> > > from versioning API Yan proposed? Is this were we might choose to use
> > > an interface via the vfio API rather than sysfs if we had one?
> > >
> >
> > VFIO API cannot be used by libvirt or management tool stack. We need
> > sysfs as Yan proposed to be used by libvirt or management tool stack.
>
> It's been a long time, but that doesn't seem like what I was asking.
> The sysfs version checking is used to select a target that is likely to
> succeed, but the migration stream is still generated by a user and the
> vendor driver is still ultimately responsible for validating that
> stream. I would hope that a vendor migration stream therefore starts
> with information similar to that found in the sysfs interface, allowing
> the receiving vendor driver to validate the source device and vendor
> software version, such that we can fail an incoming migration that the
> vendor driver deems incompatible. Ideally the vendor driver might also
> include consistency and sequence checking throughout the stream to
> prevent a malicious user from exploiting the internal operation of the
> vendor driver. Thanks,
>
maybe we can add a rw field migration_version in
struct vfio_device_migration_info besides sysfs interface ?
when reading it in src, it gets the same string as that from sysfs;
when writing it in target, it returns success or not to check
compatibility and fails the migration early in setup phase.
Thanks
Yan.
next prev parent reply other threads:[~2020-05-06 6:49 UTC|newest]
Thread overview: 74+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-24 21:08 [PATCH v16 QEMU 00/16] Add migration support for VFIO devices Kirti Wankhede
2020-03-24 21:08 ` [PATCH v16 QEMU 01/16] vfio: KABI for migration interface - Kernel header placeholder Kirti Wankhede
2020-03-24 21:09 ` [PATCH v16 QEMU 02/16] vfio: Add function to unmap VFIO region Kirti Wankhede
2020-03-24 21:09 ` [PATCH v16 QEMU 03/16] vfio: Add vfio_get_object callback to VFIODeviceOps Kirti Wankhede
2020-03-24 21:09 ` [PATCH v16 QEMU 04/16] vfio: Add save and load functions for VFIO PCI devices Kirti Wankhede
2020-03-25 19:56 ` Alex Williamson
2020-03-26 17:29 ` Dr. David Alan Gilbert
2020-03-26 17:38 ` Alex Williamson
2020-05-04 23:18 ` Kirti Wankhede
2020-05-05 4:37 ` Alex Williamson
2020-05-06 6:11 ` Yan Zhao
2020-05-06 19:48 ` Kirti Wankhede
2020-05-06 20:03 ` Alex Williamson
2020-05-07 5:40 ` Kirti Wankhede
2020-05-07 18:14 ` Alex Williamson
2020-03-26 17:46 ` Dr. David Alan Gilbert
2020-05-04 23:19 ` Kirti Wankhede
2020-04-07 4:10 ` Longpeng (Mike, Cloud Infrastructure Service Product Dept.)
2020-05-04 23:21 ` Kirti Wankhede
2020-03-24 21:09 ` [PATCH v16 QEMU 05/16] vfio: Add migration region initialization and finalize function Kirti Wankhede
2020-03-26 17:52 ` Dr. David Alan Gilbert
2020-05-04 23:19 ` Kirti Wankhede
2020-05-19 19:32 ` Dr. David Alan Gilbert
2020-03-24 21:09 ` [PATCH v16 QEMU 06/16] vfio: Add VM state change handler to know state of VM Kirti Wankhede
2020-03-24 21:09 ` [PATCH v16 QEMU 07/16] vfio: Add migration state change notifier Kirti Wankhede
2020-04-01 11:27 ` Dr. David Alan Gilbert
2020-05-04 23:20 ` Kirti Wankhede
2020-03-24 21:09 ` [PATCH v16 QEMU 08/16] vfio: Register SaveVMHandlers for VFIO device Kirti Wankhede
2020-03-25 21:02 ` Alex Williamson
2020-05-04 23:19 ` Kirti Wankhede
2020-05-05 4:37 ` Alex Williamson
2020-05-06 6:38 ` Yan Zhao [this message]
2020-05-06 9:58 ` Cornelia Huck
2020-05-06 16:53 ` Dr. David Alan Gilbert
2020-05-06 19:30 ` Kirti Wankhede
2020-05-07 6:37 ` Cornelia Huck
2020-05-07 20:29 ` Alex Williamson
2020-04-01 17:36 ` Dr. David Alan Gilbert
2020-05-04 23:20 ` Kirti Wankhede
2020-03-24 21:09 ` [PATCH v16 QEMU 09/16] vfio: Add save state functions to SaveVMHandlers Kirti Wankhede
2020-03-25 22:03 ` Alex Williamson
2020-05-04 23:18 ` Kirti Wankhede
2020-05-05 4:37 ` Alex Williamson
2020-05-11 9:53 ` Kirti Wankhede
2020-05-11 15:59 ` Alex Williamson
2020-05-12 2:06 ` Yan Zhao
2020-05-09 5:31 ` Yan Zhao
2020-05-11 10:22 ` Kirti Wankhede
2020-05-12 0:50 ` Yan Zhao
2020-03-24 21:09 ` [PATCH v16 QEMU 10/16] vfio: Add load " Kirti Wankhede
2020-03-25 22:36 ` Alex Williamson
2020-04-01 18:58 ` Dr. David Alan Gilbert
2020-05-04 23:20 ` Kirti Wankhede
2020-03-24 21:09 ` [PATCH v16 QEMU 11/16] iommu: add callback to get address limit IOMMU supports Kirti Wankhede
2020-03-24 21:09 ` [PATCH v16 QEMU 12/16] memory: Set DIRTY_MEMORY_MIGRATION when IOMMU is enabled Kirti Wankhede
2020-04-01 19:00 ` Dr. David Alan Gilbert
2020-04-01 19:42 ` Alex Williamson
2020-03-24 21:09 ` [PATCH v16 QEMU 13/16] vfio: Add function to start and stop dirty pages tracking Kirti Wankhede
2020-03-26 19:10 ` Alex Williamson
2020-05-04 23:20 ` Kirti Wankhede
2020-04-01 19:03 ` Dr. David Alan Gilbert
2020-05-04 23:21 ` Kirti Wankhede
2020-03-24 21:09 ` [PATCH v16 QEMU 14/16] vfio: Add vfio_listener_log_sync to mark dirty pages Kirti Wankhede
2020-03-25 2:19 ` Yan Zhao
2020-03-26 19:46 ` Alex Williamson
2020-04-01 19:08 ` Dr. David Alan Gilbert
2020-04-01 5:50 ` Yan Zhao
2020-04-03 20:11 ` Kirti Wankhede
2020-03-24 21:09 ` [PATCH v16 QEMU 15/16] vfio: Add ioctl to get dirty pages bitmap during dma unmap Kirti Wankhede
2020-03-24 21:09 ` [PATCH v16 QEMU 16/16] vfio: Make vfio-pci device migration capable Kirti Wankhede
2020-03-24 23:36 ` [PATCH v16 QEMU 00/16] Add migration support for VFIO devices no-reply
2020-03-31 18:34 ` Alex Williamson
2020-04-01 6:41 ` Yan Zhao
2020-04-01 18:34 ` Alex Williamson
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=20200506063846.GB19334@joy-OptiPlex-7040 \
--to=yan.y.zhao@intel.com \
--cc=Ken.Xue@amd.com \
--cc=Zhengxiao.zx@Alibaba-inc.com \
--cc=aik@ozlabs.ru \
--cc=alex.williamson@redhat.com \
--cc=changpeng.liu@intel.com \
--cc=cjia@nvidia.com \
--cc=cohuck@redhat.com \
--cc=dgilbert@redhat.com \
--cc=eauger@redhat.com \
--cc=eskultet@redhat.com \
--cc=felipe@nutanix.com \
--cc=jonathan.davies@nutanix.com \
--cc=kevin.tian@intel.com \
--cc=kwankhede@nvidia.com \
--cc=mlevitsk@redhat.com \
--cc=pasic@linux.ibm.com \
--cc=qemu-devel@nongnu.org \
--cc=shuangtai.tst@alibaba-inc.com \
--cc=yi.l.liu@intel.com \
--cc=zhi.a.wang@intel.com \
--cc=ziye.yang@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).