| Message ID | 20230621080204.420723-4-zhenzhong.duan@intel.com |
|---|---|
| State | New |
| Headers | show |
| Series | VFIO migration related refactor and bug fix | expand |
On 21/06/2023 11:02, Zhenzhong Duan wrote: > External email: Use caution opening links or attachments > > > This patch refactors vfio_migration_realize() and its dependend code > as follows: > > 1. It's redundant in vfio_migration_realize() to registers multiple blockers, > e.g: vIOMMU blocker can be refactored as per device blocker. > 2. Change vfio_block_giommu_migration() to be only a per device checker. > 3. Remove global vIOMMU blocker related stuff, e.g: > giommu_migration_blocker, vfio_unblock_giommu_migration(), > vfio_viommu_preset() and vfio_migration_finalize() > 4. Change vfio_migration_realize() and dependent vfio_block_*_migration() to > return bool type. > 5. Change to print "Migration disabled" only after adding blocker succeed. > 6. Add device name to errp so "info migrate" could be more informative. > > migrate_add_blocker() returns 0 when successfully adding the migration blocker. > However, the caller of vfio_migration_realize() considers that migration was > blocked when the latter returned an error. What matters for migration is that > the blocker is added in core migration, so this cleans up usability such that > user sees "Migrate disabled" when any of the vfio migration blockers are active. > > Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com> > --- > hw/vfio/common.c | 54 +++++------------------------------ > hw/vfio/migration.c | 37 +++++++++++------------- > hw/vfio/pci.c | 4 +-- > include/hw/vfio/vfio-common.h | 7 ++--- > 4 files changed, 29 insertions(+), 73 deletions(-) > > diff --git a/hw/vfio/common.c b/hw/vfio/common.c > index fa8fd949b1cf..cc5f4e805341 100644 > --- a/hw/vfio/common.c > +++ b/hw/vfio/common.c > @@ -362,8 +362,6 @@ bool vfio_mig_active(void) > } > > static Error *multiple_devices_migration_blocker; > -static Error *giommu_migration_blocker; > - > static unsigned int vfio_migratable_device_num(void) > { > VFIOGroup *group; > @@ -381,13 +379,13 @@ static unsigned int vfio_migratable_device_num(void) > return device_num; > } > > -int vfio_block_multiple_devices_migration(Error **errp) > +bool vfio_block_multiple_devices_migration(Error **errp) > { > int ret; > > if (multiple_devices_migration_blocker || > vfio_migratable_device_num() <= 1) { > - return 0; > + return true; > } > > error_setg(&multiple_devices_migration_blocker, > @@ -397,9 +395,11 @@ int vfio_block_multiple_devices_migration(Error **errp) > if (ret < 0) { > error_free(multiple_devices_migration_blocker); > multiple_devices_migration_blocker = NULL; > + } else { > + error_report("Migration disabled, not support multiple VFIO devices"); > } > > - return ret; > + return !ret; > } > > void vfio_unblock_multiple_devices_migration(void) > @@ -414,49 +414,9 @@ void vfio_unblock_multiple_devices_migration(void) > multiple_devices_migration_blocker = NULL; > } > > -static bool vfio_viommu_preset(void) > -{ > - VFIOAddressSpace *space; > - > - QLIST_FOREACH(space, &vfio_address_spaces, list) { > - if (space->as != &address_space_memory) { > - return true; > - } > - } > - > - return false; > -} > - > -int vfio_block_giommu_migration(Error **errp) > -{ > - int ret; > - > - if (giommu_migration_blocker || > - !vfio_viommu_preset()) { > - return 0; > - } > - > - error_setg(&giommu_migration_blocker, > - "Migration is currently not supported with vIOMMU enabled"); > - ret = migrate_add_blocker(giommu_migration_blocker, errp); > - if (ret < 0) { > - error_free(giommu_migration_blocker); > - giommu_migration_blocker = NULL; > - } > - > - return ret; > -} > - > -void vfio_migration_finalize(void) > +bool vfio_block_giommu_migration(VFIODevice *vbasedev) > { > - if (!giommu_migration_blocker || > - vfio_viommu_preset()) { > - return; > - } > - > - migrate_del_blocker(giommu_migration_blocker); > - error_free(giommu_migration_blocker); > - giommu_migration_blocker = NULL; > + return vbasedev->group->container->space->as != &address_space_memory; > } I guess vfio_block_giommu_migration can be moved to migration.c and made static? Although Joao's vIOMMU series will probably change that back later in some way. > > static void vfio_set_migration_error(int err) > diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c > index 6b58dddb8859..7621074f156d 100644 > --- a/hw/vfio/migration.c > +++ b/hw/vfio/migration.c > @@ -632,42 +632,39 @@ int64_t vfio_mig_bytes_transferred(void) > return bytes_transferred; > } > > -int vfio_migration_realize(VFIODevice *vbasedev, Error **errp) > +/* Return true when either migration initialized or blocker registered */ > +bool vfio_migration_realize(VFIODevice *vbasedev, Error **errp) > { > - int ret = -ENOTSUP; > + int ret; > > - if (!vbasedev->enable_migration) { > + if (!vbasedev->enable_migration || vfio_migration_init(vbasedev)) { > + error_setg(&vbasedev->migration_blocker, > + "VFIO device %s doesn't support migration", vbasedev->name); > goto add_blocker; > } > > - ret = vfio_migration_init(vbasedev); > - if (ret) { > - goto add_blocker; > - } > - > - ret = vfio_block_multiple_devices_migration(errp); > - if (ret) { > - return ret; > + if (!vfio_block_multiple_devices_migration(errp)) { > + return false; > } > > - ret = vfio_block_giommu_migration(errp); > - if (ret) { > - return ret; > + if (vfio_block_giommu_migration(vbasedev)) { > + error_setg(&vbasedev->migration_blocker, > + "Migration is currently not supported on %s " > + "with vIOMMU enabled", vbasedev->name); > + goto add_blocker; > } > > - trace_vfio_migration_probe(vbasedev->name); > - return 0; > + return true; > > add_blocker: > - error_setg(&vbasedev->migration_blocker, > - "VFIO device doesn't support migration"); > - > ret = migrate_add_blocker(vbasedev->migration_blocker, errp); > if (ret < 0) { > error_free(vbasedev->migration_blocker); > vbasedev->migration_blocker = NULL; > + } else { > + error_report("%s: Migration disabled", vbasedev->name); When x-enable-migration=off, "Migration disabled" error will be printed, but this is the expected behavior, so we should not print it in this case. > } > - return ret; > + return !ret; > } > > void vfio_migration_exit(VFIODevice *vbasedev) > diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c > index 82c4cf4f7609..061ca96cbce2 100644 > --- a/hw/vfio/pci.c > +++ b/hw/vfio/pci.c > @@ -3209,7 +3209,8 @@ static void vfio_realize(PCIDevice *pdev, Error **errp) > if (!pdev->failover_pair_id) { > ret = vfio_migration_realize(vbasedev, errp); > if (ret) { > - error_report("%s: Migration disabled", vbasedev->name); > + trace_vfio_migration_probe(vbasedev->name); While we are here, let's rename trace_vfio_migration_probe() to trace_vfio_migration_realize() (I can do it too in my series). Thanks. > + } else { > goto out_deregister; > } > } > @@ -3250,7 +3251,6 @@ static void vfio_instance_finalize(Object *obj) > */ > vfio_put_device(vdev); > vfio_put_group(group); > - vfio_migration_finalize(); > } > > static void vfio_exitfn(PCIDevice *pdev) > diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h > index eed244f25f34..a2e2171b1f93 100644 > --- a/include/hw/vfio/vfio-common.h > +++ b/include/hw/vfio/vfio-common.h > @@ -220,9 +220,9 @@ typedef QLIST_HEAD(VFIOGroupList, VFIOGroup) VFIOGroupList; > extern VFIOGroupList vfio_group_list; > > bool vfio_mig_active(void); > -int vfio_block_multiple_devices_migration(Error **errp); > +bool vfio_block_multiple_devices_migration(Error **errp); > void vfio_unblock_multiple_devices_migration(void); > -int vfio_block_giommu_migration(Error **errp); > +bool vfio_block_giommu_migration(VFIODevice *vbasedev); > int64_t vfio_mig_bytes_transferred(void); > > #ifdef CONFIG_LINUX > @@ -246,8 +246,7 @@ int vfio_spapr_create_window(VFIOContainer *container, > int vfio_spapr_remove_window(VFIOContainer *container, > hwaddr offset_within_address_space); > > -int vfio_migration_realize(VFIODevice *vbasedev, Error **errp); > +bool vfio_migration_realize(VFIODevice *vbasedev, Error **errp); > void vfio_migration_exit(VFIODevice *vbasedev); > -void vfio_migration_finalize(void); > > #endif /* HW_VFIO_VFIO_COMMON_H */ > -- > 2.34.1 >
On 26/06/2023 10:34, Avihai Horon wrote: > > On 21/06/2023 11:02, Zhenzhong Duan wrote: >> External email: Use caution opening links or attachments >> >> >> This patch refactors vfio_migration_realize() and its dependend code >> as follows: >> >> 1. It's redundant in vfio_migration_realize() to registers multiple blockers, >> e.g: vIOMMU blocker can be refactored as per device blocker. >> 2. Change vfio_block_giommu_migration() to be only a per device checker. >> 3. Remove global vIOMMU blocker related stuff, e.g: >> giommu_migration_blocker, vfio_unblock_giommu_migration(), >> vfio_viommu_preset() and vfio_migration_finalize() >> 4. Change vfio_migration_realize() and dependent vfio_block_*_migration() to >> return bool type. >> 5. Change to print "Migration disabled" only after adding blocker succeed. >> 6. Add device name to errp so "info migrate" could be more informative. >> >> migrate_add_blocker() returns 0 when successfully adding the migration blocker. >> However, the caller of vfio_migration_realize() considers that migration was >> blocked when the latter returned an error. What matters for migration is that >> the blocker is added in core migration, so this cleans up usability such that >> user sees "Migrate disabled" when any of the vfio migration blockers are active. >> >> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com> >> --- >> hw/vfio/common.c | 54 +++++------------------------------ >> hw/vfio/migration.c | 37 +++++++++++------------- >> hw/vfio/pci.c | 4 +-- >> include/hw/vfio/vfio-common.h | 7 ++--- >> 4 files changed, 29 insertions(+), 73 deletions(-) >> >> diff --git a/hw/vfio/common.c b/hw/vfio/common.c >> index fa8fd949b1cf..cc5f4e805341 100644 >> --- a/hw/vfio/common.c >> +++ b/hw/vfio/common.c >> @@ -362,8 +362,6 @@ bool vfio_mig_active(void) >> } >> >> static Error *multiple_devices_migration_blocker; >> -static Error *giommu_migration_blocker; >> - >> static unsigned int vfio_migratable_device_num(void) >> { >> VFIOGroup *group; >> @@ -381,13 +379,13 @@ static unsigned int vfio_migratable_device_num(void) >> return device_num; >> } >> >> -int vfio_block_multiple_devices_migration(Error **errp) >> +bool vfio_block_multiple_devices_migration(Error **errp) >> { >> int ret; >> >> if (multiple_devices_migration_blocker || >> vfio_migratable_device_num() <= 1) { >> - return 0; >> + return true; >> } >> >> error_setg(&multiple_devices_migration_blocker, >> @@ -397,9 +395,11 @@ int vfio_block_multiple_devices_migration(Error **errp) >> if (ret < 0) { >> error_free(multiple_devices_migration_blocker); >> multiple_devices_migration_blocker = NULL; >> + } else { >> + error_report("Migration disabled, not support multiple VFIO devices"); >> } >> >> - return ret; >> + return !ret; >> } >> >> void vfio_unblock_multiple_devices_migration(void) >> @@ -414,49 +414,9 @@ void vfio_unblock_multiple_devices_migration(void) >> multiple_devices_migration_blocker = NULL; >> } >> >> -static bool vfio_viommu_preset(void) >> -{ >> - VFIOAddressSpace *space; >> - >> - QLIST_FOREACH(space, &vfio_address_spaces, list) { >> - if (space->as != &address_space_memory) { >> - return true; >> - } >> - } >> - >> - return false; >> -} >> - >> -int vfio_block_giommu_migration(Error **errp) >> -{ >> - int ret; >> - >> - if (giommu_migration_blocker || >> - !vfio_viommu_preset()) { >> - return 0; >> - } >> - >> - error_setg(&giommu_migration_blocker, >> - "Migration is currently not supported with vIOMMU enabled"); >> - ret = migrate_add_blocker(giommu_migration_blocker, errp); >> - if (ret < 0) { >> - error_free(giommu_migration_blocker); >> - giommu_migration_blocker = NULL; >> - } >> - >> - return ret; >> -} >> - >> -void vfio_migration_finalize(void) >> +bool vfio_block_giommu_migration(VFIODevice *vbasedev) >> { >> - if (!giommu_migration_blocker || >> - vfio_viommu_preset()) { >> - return; >> - } >> - >> - migrate_del_blocker(giommu_migration_blocker); >> - error_free(giommu_migration_blocker); >> - giommu_migration_blocker = NULL; >> + return vbasedev->group->container->space->as != &address_space_memory; >> } > > I guess vfio_block_giommu_migration can be moved to migration.c and made static? > Although Joao's vIOMMU series will probably change that back later in some way. > I guess it makes sense -- the thing that was tieing him was the global migration blocker, which is now consolidated into the main migration blocker. My vIOMMU series will relax this condition yes (still same per-device scope). And I will need to check the maximum IOVA in the vIOMMU. But it's new code I can adjust and Zhenzhong shouldn't worry about the vIOMMU future stuff but I don't expect to influence location, say if it gets moved into migration.c
>-----Original Message----- >From: Avihai Horon <avihaih@nvidia.com> >Sent: Monday, June 26, 2023 5:35 PM >To: Duan, Zhenzhong <zhenzhong.duan@intel.com>; qemu- >devel@nongnu.org >Cc: alex.williamson@redhat.com; clg@redhat.com; Martins, Joao ><joao.m.martins@oracle.com>; Peng, Chao P <chao.p.peng@intel.com> >Subject: Re: [PATCH v3 3/3] vfio/migration: vfio/migration: Refactor and fix >print of "Migration disabled" > > >On 21/06/2023 11:02, Zhenzhong Duan wrote: >> External email: Use caution opening links or attachments >> >> >> This patch refactors vfio_migration_realize() and its dependend code >> as follows: >> >> 1. It's redundant in vfio_migration_realize() to registers multiple blockers, >> e.g: vIOMMU blocker can be refactored as per device blocker. >> 2. Change vfio_block_giommu_migration() to be only a per device checker. >> 3. Remove global vIOMMU blocker related stuff, e.g: >> giommu_migration_blocker, vfio_unblock_giommu_migration(), >> vfio_viommu_preset() and vfio_migration_finalize() 4. Change >> vfio_migration_realize() and dependent vfio_block_*_migration() to >> return bool type. >> 5. Change to print "Migration disabled" only after adding blocker succeed. >> 6. Add device name to errp so "info migrate" could be more informative. >> >> migrate_add_blocker() returns 0 when successfully adding the migration >blocker. >> However, the caller of vfio_migration_realize() considers that >> migration was blocked when the latter returned an error. What matters >> for migration is that the blocker is added in core migration, so this >> cleans up usability such that user sees "Migrate disabled" when any of the >vfio migration blockers are active. >> >> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com> >> --- >> hw/vfio/common.c | 54 +++++------------------------------ >> hw/vfio/migration.c | 37 +++++++++++------------- >> hw/vfio/pci.c | 4 +-- >> include/hw/vfio/vfio-common.h | 7 ++--- >> 4 files changed, 29 insertions(+), 73 deletions(-) >> >> diff --git a/hw/vfio/common.c b/hw/vfio/common.c index >> fa8fd949b1cf..cc5f4e805341 100644 >> --- a/hw/vfio/common.c >> +++ b/hw/vfio/common.c >> @@ -362,8 +362,6 @@ bool vfio_mig_active(void) >> } >> >> static Error *multiple_devices_migration_blocker; >> -static Error *giommu_migration_blocker; >> - >> static unsigned int vfio_migratable_device_num(void) >> { >> VFIOGroup *group; >> @@ -381,13 +379,13 @@ static unsigned int >vfio_migratable_device_num(void) >> return device_num; >> } >> >> -int vfio_block_multiple_devices_migration(Error **errp) >> +bool vfio_block_multiple_devices_migration(Error **errp) >> { >> int ret; >> >> if (multiple_devices_migration_blocker || >> vfio_migratable_device_num() <= 1) { >> - return 0; >> + return true; >> } >> >> error_setg(&multiple_devices_migration_blocker, >> @@ -397,9 +395,11 @@ int vfio_block_multiple_devices_migration(Error >**errp) >> if (ret < 0) { >> error_free(multiple_devices_migration_blocker); >> multiple_devices_migration_blocker = NULL; >> + } else { >> + error_report("Migration disabled, not support multiple VFIO >> + devices"); >> } >> >> - return ret; >> + return !ret; >> } >> >> void vfio_unblock_multiple_devices_migration(void) >> @@ -414,49 +414,9 @@ void vfio_unblock_multiple_devices_migration(void) >> multiple_devices_migration_blocker = NULL; >> } >> >> -static bool vfio_viommu_preset(void) >> -{ >> - VFIOAddressSpace *space; >> - >> - QLIST_FOREACH(space, &vfio_address_spaces, list) { >> - if (space->as != &address_space_memory) { >> - return true; >> - } >> - } >> - >> - return false; >> -} >> - >> -int vfio_block_giommu_migration(Error **errp) -{ >> - int ret; >> - >> - if (giommu_migration_blocker || >> - !vfio_viommu_preset()) { >> - return 0; >> - } >> - >> - error_setg(&giommu_migration_blocker, >> - "Migration is currently not supported with vIOMMU enabled"); >> - ret = migrate_add_blocker(giommu_migration_blocker, errp); >> - if (ret < 0) { >> - error_free(giommu_migration_blocker); >> - giommu_migration_blocker = NULL; >> - } >> - >> - return ret; >> -} >> - >> -void vfio_migration_finalize(void) >> +bool vfio_block_giommu_migration(VFIODevice *vbasedev) >> { >> - if (!giommu_migration_blocker || >> - vfio_viommu_preset()) { >> - return; >> - } >> - >> - migrate_del_blocker(giommu_migration_blocker); >> - error_free(giommu_migration_blocker); >> - giommu_migration_blocker = NULL; >> + return vbasedev->group->container->space->as != >> + &address_space_memory; >> } > >I guess vfio_block_giommu_migration can be moved to migration.c and made >static? >Although Joao's vIOMMU series will probably change that back later in some >way. Good idea, will do. > >> >> static void vfio_set_migration_error(int err) >> diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c >> index 6b58dddb8859..7621074f156d 100644 >> --- a/hw/vfio/migration.c >> +++ b/hw/vfio/migration.c >> @@ -632,42 +632,39 @@ int64_t vfio_mig_bytes_transferred(void) >> return bytes_transferred; >> } >> >> -int vfio_migration_realize(VFIODevice *vbasedev, Error **errp) >> +/* Return true when either migration initialized or blocker registered */ >> +bool vfio_migration_realize(VFIODevice *vbasedev, Error **errp) >> { >> - int ret = -ENOTSUP; >> + int ret; >> >> - if (!vbasedev->enable_migration) { >> + if (!vbasedev->enable_migration || vfio_migration_init(vbasedev)) { >> + error_setg(&vbasedev->migration_blocker, >> + "VFIO device %s doesn't support migration", vbasedev->name); >> goto add_blocker; >> } >> >> - ret = vfio_migration_init(vbasedev); >> - if (ret) { >> - goto add_blocker; >> - } >> - >> - ret = vfio_block_multiple_devices_migration(errp); >> - if (ret) { >> - return ret; >> + if (!vfio_block_multiple_devices_migration(errp)) { >> + return false; >> } >> >> - ret = vfio_block_giommu_migration(errp); >> - if (ret) { >> - return ret; >> + if (vfio_block_giommu_migration(vbasedev)) { >> + error_setg(&vbasedev->migration_blocker, >> + "Migration is currently not supported on %s " >> + "with vIOMMU enabled", vbasedev->name); >> + goto add_blocker; >> } >> >> - trace_vfio_migration_probe(vbasedev->name); >> - return 0; >> + return true; >> >> add_blocker: >> - error_setg(&vbasedev->migration_blocker, >> - "VFIO device doesn't support migration"); >> - >> ret = migrate_add_blocker(vbasedev->migration_blocker, errp); >> if (ret < 0) { >> error_free(vbasedev->migration_blocker); >> vbasedev->migration_blocker = NULL; >> + } else { >> + error_report("%s: Migration disabled", vbasedev->name); > >When x-enable-migration=off, "Migration disabled" error will be printed, >but this is the expected behavior, so we should not print it in this case. Make sense, will do. > >> } >> - return ret; >> + return !ret; >> } >> >> void vfio_migration_exit(VFIODevice *vbasedev) >> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c >> index 82c4cf4f7609..061ca96cbce2 100644 >> --- a/hw/vfio/pci.c >> +++ b/hw/vfio/pci.c >> @@ -3209,7 +3209,8 @@ static void vfio_realize(PCIDevice *pdev, Error >**errp) >> if (!pdev->failover_pair_id) { >> ret = vfio_migration_realize(vbasedev, errp); >> if (ret) { >> - error_report("%s: Migration disabled", vbasedev->name); >> + trace_vfio_migration_probe(vbasedev->name); > >While we are here, let's rename trace_vfio_migration_probe() to >trace_vfio_migration_realize() (I can do it too in my series). Good finding, will do. Thanks Zhenzhong
>-----Original Message----- >From: Joao Martins <joao.m.martins@oracle.com> >Sent: Monday, June 26, 2023 6:19 PM >To: Avihai Horon <avihaih@nvidia.com>; Duan, Zhenzhong ><zhenzhong.duan@intel.com> >Cc: alex.williamson@redhat.com; clg@redhat.com; Peng, Chao P ><chao.p.peng@intel.com>; qemu-devel@nongnu.org >Subject: Re: [PATCH v3 3/3] vfio/migration: vfio/migration: Refactor and fix >print of "Migration disabled" > > > >On 26/06/2023 10:34, Avihai Horon wrote: >> >> On 21/06/2023 11:02, Zhenzhong Duan wrote: ... >>> -void vfio_migration_finalize(void) >>> +bool vfio_block_giommu_migration(VFIODevice *vbasedev) >>> { >>> - if (!giommu_migration_blocker || >>> - vfio_viommu_preset()) { >>> - return; >>> - } >>> - >>> - migrate_del_blocker(giommu_migration_blocker); >>> - error_free(giommu_migration_blocker); >>> - giommu_migration_blocker = NULL; >>> + return vbasedev->group->container->space->as != >>> +&address_space_memory; >>> } >> >> I guess vfio_block_giommu_migration can be moved to migration.c and >made static? >> Although Joao's vIOMMU series will probably change that back later in some >way. >> >I guess it makes sense -- the thing that was tieing him was the global migration >blocker, which is now consolidated into the main migration blocker. > >My vIOMMU series will relax this condition yes (still same per-device scope). >And I will need to check the maximum IOVA in the vIOMMU. But it's new code >I can adjust and Zhenzhong shouldn't worry about the vIOMMU future stuff A bit confused, you agreed to move vfio_block_giommu_migration into migration.c >but I don't expect to influence location, say if it gets moved into migration.c and final decision is no move for influencing location reason? Do I misunderstand? Thanks Zhenzhong
On 27/06/2023 03:55, Duan, Zhenzhong wrote: >> I guess it makes sense -- the thing that was tieing him was the global migration >> blocker, which is now consolidated into the main migration blocker. >> >> My vIOMMU series will relax this condition yes (still same per-device scope). >> And I will need to check the maximum IOVA in the vIOMMU. But it's new code >> I can adjust and Zhenzhong shouldn't worry about the vIOMMU future stuff > A bit confused, you agreed to move vfio_block_giommu_migration into migration.c > >> but I don't expect to influence location, say if it gets moved into migration.c > and final decision is no move for influencing location reason? Do I misunderstand? Sorry for the confusion. The thing is that I will need 'similar code' to test if a vIOMMU is enabled or not. The reason being that dirty tracking will need this to understand what to track meaning to decide whether we track the whole address space or just the linear map[0]. And all that code is in common, not migration.c and where I use it will have to look at all address spaces (because dirty tracking is started for all devices, so there's no vbasedev to look at). Eventually after the vIOMMU stuff, the migration blocker condition will look more or less like this: return (!vfio_viommu_preset(vbasedev) || (vfio_viommu_preset(vbasedev) && !vfio_viommu_get_max_iova(&max))) Whereby vfio_viommu_preset(vbasedev) is what you currently call vfio_block_giommu_migration(vbasedev) in current patch. So perhaps I would say to leave it in common.c and rename it to vfio_viommu_preset(vbasedev) with a comment on top for /* Block migration with a vIOMMU */ Then when the time comes I can introduce in my vIOMMU series a vfio_viommu_possible() [or some other name] when starting dirty tracking which looks all VFIOAddressSpaces and reuses your vfio_viommu_preset(vbasedev). This should cover current and future needs, without going to great extents beyond the purpose of this patch? [0] https://lore.kernel.org/qemu-devel/20230622214845.3980-13-joao.m.martins@oracle.com/#iZ31hw:vfio:common.c
>-----Original Message----- >From: Joao Martins <joao.m.martins@oracle.com> >Sent: Tuesday, June 27, 2023 6:57 PM >To: Duan, Zhenzhong <zhenzhong.duan@intel.com>; Avihai Horon ><avihaih@nvidia.com> >Cc: alex.williamson@redhat.com; clg@redhat.com; Peng, Chao P ><chao.p.peng@intel.com>; qemu-devel@nongnu.org >Subject: Re: [PATCH v3 3/3] vfio/migration: vfio/migration: Refactor and fix >print of "Migration disabled" > >On 27/06/2023 03:55, Duan, Zhenzhong wrote: >>> I guess it makes sense -- the thing that was tieing him was the >>> global migration blocker, which is now consolidated into the main >migration blocker. >>> >>> My vIOMMU series will relax this condition yes (still same per-device scope). >>> And I will need to check the maximum IOVA in the vIOMMU. But it's new >>> code I can adjust and Zhenzhong shouldn't worry about the vIOMMU >>> future stuff >> A bit confused, you agreed to move vfio_block_giommu_migration into >> migration.c >> >>> but I don't expect to influence location, say if it gets moved into >>> migration.c >> and final decision is no move for influencing location reason? Do I >misunderstand? > >Sorry for the confusion. > >The thing is that I will need 'similar code' to test if a vIOMMU is enabled or not. >The reason being that dirty tracking will need this to understand what to track >meaning to decide whether we track the whole address space or just the >linear map[0]. And all that code is in common, not migration.c and where I >use it will have to look at all address spaces (because dirty tracking is started >for all devices, so there's no vbasedev to look at). > >Eventually after the vIOMMU stuff, the migration blocker condition will look >more or less like this: > > return (!vfio_viommu_preset(vbasedev) || > (vfio_viommu_preset(vbasedev) && > !vfio_viommu_get_max_iova(&max))) > >Whereby vfio_viommu_preset(vbasedev) is what you currently call >vfio_block_giommu_migration(vbasedev) in current patch. So perhaps I would >say to leave it in common.c and rename it to vfio_viommu_preset(vbasedev) >with a comment on top for /* Block migration with a vIOMMU */ > >Then when the time comes I can introduce in my vIOMMU series a >vfio_viommu_possible() [or some other name] when starting dirty tracking >which looks all VFIOAddressSpaces and reuses your >vfio_viommu_preset(vbasedev). This should cover current and future needs, >without going to great extents beyond the purpose of this patch? Thanks for detailed explanation, clear, I'll update based on above suggestions. Zhenzhong
diff --git a/hw/vfio/common.c b/hw/vfio/common.c index fa8fd949b1cf..cc5f4e805341 100644 --- a/hw/vfio/common.c +++ b/hw/vfio/common.c @@ -362,8 +362,6 @@ bool vfio_mig_active(void) } static Error *multiple_devices_migration_blocker; -static Error *giommu_migration_blocker; - static unsigned int vfio_migratable_device_num(void) { VFIOGroup *group; @@ -381,13 +379,13 @@ static unsigned int vfio_migratable_device_num(void) return device_num; } -int vfio_block_multiple_devices_migration(Error **errp) +bool vfio_block_multiple_devices_migration(Error **errp) { int ret; if (multiple_devices_migration_blocker || vfio_migratable_device_num() <= 1) { - return 0; + return true; } error_setg(&multiple_devices_migration_blocker, @@ -397,9 +395,11 @@ int vfio_block_multiple_devices_migration(Error **errp) if (ret < 0) { error_free(multiple_devices_migration_blocker); multiple_devices_migration_blocker = NULL; + } else { + error_report("Migration disabled, not support multiple VFIO devices"); } - return ret; + return !ret; } void vfio_unblock_multiple_devices_migration(void) @@ -414,49 +414,9 @@ void vfio_unblock_multiple_devices_migration(void) multiple_devices_migration_blocker = NULL; } -static bool vfio_viommu_preset(void) -{ - VFIOAddressSpace *space; - - QLIST_FOREACH(space, &vfio_address_spaces, list) { - if (space->as != &address_space_memory) { - return true; - } - } - - return false; -} - -int vfio_block_giommu_migration(Error **errp) -{ - int ret; - - if (giommu_migration_blocker || - !vfio_viommu_preset()) { - return 0; - } - - error_setg(&giommu_migration_blocker, - "Migration is currently not supported with vIOMMU enabled"); - ret = migrate_add_blocker(giommu_migration_blocker, errp); - if (ret < 0) { - error_free(giommu_migration_blocker); - giommu_migration_blocker = NULL; - } - - return ret; -} - -void vfio_migration_finalize(void) +bool vfio_block_giommu_migration(VFIODevice *vbasedev) { - if (!giommu_migration_blocker || - vfio_viommu_preset()) { - return; - } - - migrate_del_blocker(giommu_migration_blocker); - error_free(giommu_migration_blocker); - giommu_migration_blocker = NULL; + return vbasedev->group->container->space->as != &address_space_memory; } static void vfio_set_migration_error(int err) diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c index 6b58dddb8859..7621074f156d 100644 --- a/hw/vfio/migration.c +++ b/hw/vfio/migration.c @@ -632,42 +632,39 @@ int64_t vfio_mig_bytes_transferred(void) return bytes_transferred; } -int vfio_migration_realize(VFIODevice *vbasedev, Error **errp) +/* Return true when either migration initialized or blocker registered */ +bool vfio_migration_realize(VFIODevice *vbasedev, Error **errp) { - int ret = -ENOTSUP; + int ret; - if (!vbasedev->enable_migration) { + if (!vbasedev->enable_migration || vfio_migration_init(vbasedev)) { + error_setg(&vbasedev->migration_blocker, + "VFIO device %s doesn't support migration", vbasedev->name); goto add_blocker; } - ret = vfio_migration_init(vbasedev); - if (ret) { - goto add_blocker; - } - - ret = vfio_block_multiple_devices_migration(errp); - if (ret) { - return ret; + if (!vfio_block_multiple_devices_migration(errp)) { + return false; } - ret = vfio_block_giommu_migration(errp); - if (ret) { - return ret; + if (vfio_block_giommu_migration(vbasedev)) { + error_setg(&vbasedev->migration_blocker, + "Migration is currently not supported on %s " + "with vIOMMU enabled", vbasedev->name); + goto add_blocker; } - trace_vfio_migration_probe(vbasedev->name); - return 0; + return true; add_blocker: - error_setg(&vbasedev->migration_blocker, - "VFIO device doesn't support migration"); - ret = migrate_add_blocker(vbasedev->migration_blocker, errp); if (ret < 0) { error_free(vbasedev->migration_blocker); vbasedev->migration_blocker = NULL; + } else { + error_report("%s: Migration disabled", vbasedev->name); } - return ret; + return !ret; } void vfio_migration_exit(VFIODevice *vbasedev) diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c index 82c4cf4f7609..061ca96cbce2 100644 --- a/hw/vfio/pci.c +++ b/hw/vfio/pci.c @@ -3209,7 +3209,8 @@ static void vfio_realize(PCIDevice *pdev, Error **errp) if (!pdev->failover_pair_id) { ret = vfio_migration_realize(vbasedev, errp); if (ret) { - error_report("%s: Migration disabled", vbasedev->name); + trace_vfio_migration_probe(vbasedev->name); + } else { goto out_deregister; } } @@ -3250,7 +3251,6 @@ static void vfio_instance_finalize(Object *obj) */ vfio_put_device(vdev); vfio_put_group(group); - vfio_migration_finalize(); } static void vfio_exitfn(PCIDevice *pdev) diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h index eed244f25f34..a2e2171b1f93 100644 --- a/include/hw/vfio/vfio-common.h +++ b/include/hw/vfio/vfio-common.h @@ -220,9 +220,9 @@ typedef QLIST_HEAD(VFIOGroupList, VFIOGroup) VFIOGroupList; extern VFIOGroupList vfio_group_list; bool vfio_mig_active(void); -int vfio_block_multiple_devices_migration(Error **errp); +bool vfio_block_multiple_devices_migration(Error **errp); void vfio_unblock_multiple_devices_migration(void); -int vfio_block_giommu_migration(Error **errp); +bool vfio_block_giommu_migration(VFIODevice *vbasedev); int64_t vfio_mig_bytes_transferred(void); #ifdef CONFIG_LINUX @@ -246,8 +246,7 @@ int vfio_spapr_create_window(VFIOContainer *container, int vfio_spapr_remove_window(VFIOContainer *container, hwaddr offset_within_address_space); -int vfio_migration_realize(VFIODevice *vbasedev, Error **errp); +bool vfio_migration_realize(VFIODevice *vbasedev, Error **errp); void vfio_migration_exit(VFIODevice *vbasedev); -void vfio_migration_finalize(void); #endif /* HW_VFIO_VFIO_COMMON_H */
This patch refactors vfio_migration_realize() and its dependend code as follows: 1. It's redundant in vfio_migration_realize() to registers multiple blockers, e.g: vIOMMU blocker can be refactored as per device blocker. 2. Change vfio_block_giommu_migration() to be only a per device checker. 3. Remove global vIOMMU blocker related stuff, e.g: giommu_migration_blocker, vfio_unblock_giommu_migration(), vfio_viommu_preset() and vfio_migration_finalize() 4. Change vfio_migration_realize() and dependent vfio_block_*_migration() to return bool type. 5. Change to print "Migration disabled" only after adding blocker succeed. 6. Add device name to errp so "info migrate" could be more informative. migrate_add_blocker() returns 0 when successfully adding the migration blocker. However, the caller of vfio_migration_realize() considers that migration was blocked when the latter returned an error. What matters for migration is that the blocker is added in core migration, so this cleans up usability such that user sees "Migrate disabled" when any of the vfio migration blockers are active. Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com> --- hw/vfio/common.c | 54 +++++------------------------------ hw/vfio/migration.c | 37 +++++++++++------------- hw/vfio/pci.c | 4 +-- include/hw/vfio/vfio-common.h | 7 ++--- 4 files changed, 29 insertions(+), 73 deletions(-)