| Message ID | 20200406121233.109889-3-mst@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | None | expand |
On Mon, 6 Apr 2020 at 14:12, Michael S. Tsirkin <mst@redhat.com> wrote: > > vhost is currently broken on the default ARM config. > Where did you get this idea? The report from the robot was using a randconfig build, and in general, AEABI is required to run anything on any modern ARM system . > The reason is that that uses apcs-gnu which is the ancient OABI that is been > deprecated for a long time. > > Given that virtio support on such ancient systems is not needed in the > first place, let's just add something along the lines of > > depends on !ARM || AEABI > > to the virtio Kconfig declaration, and add a comment that it has to do > with struct member alignment. > > Note: we can't make VHOST and VHOST_RING themselves have > a dependency since these are selected. Add a new symbol for that. > > Suggested-by: Ard Biesheuvel <ardb@kernel.org> > Siggested-by: Richard Earnshaw <Richard.Earnshaw@arm.com> typo ^^^ > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > --- > drivers/misc/mic/Kconfig | 2 +- > drivers/net/caif/Kconfig | 2 +- > drivers/vdpa/Kconfig | 2 +- > drivers/vhost/Kconfig | 17 +++++++++++++---- > 4 files changed, 16 insertions(+), 7 deletions(-) > > diff --git a/drivers/misc/mic/Kconfig b/drivers/misc/mic/Kconfig > index 8f201d019f5a..3bfe72c59864 100644 > --- a/drivers/misc/mic/Kconfig > +++ b/drivers/misc/mic/Kconfig > @@ -116,7 +116,7 @@ config MIC_COSM > > config VOP > tristate "VOP Driver" > - depends on VOP_BUS > + depends on VOP_BUS && VHOST_DPN > select VHOST_RING > select VIRTIO > help > diff --git a/drivers/net/caif/Kconfig b/drivers/net/caif/Kconfig > index 9db0570c5beb..661c25eb1c46 100644 > --- a/drivers/net/caif/Kconfig > +++ b/drivers/net/caif/Kconfig > @@ -50,7 +50,7 @@ config CAIF_HSI > > config CAIF_VIRTIO > tristate "CAIF virtio transport driver" > - depends on CAIF && HAS_DMA > + depends on CAIF && HAS_DMA && VHOST_DPN > select VHOST_RING > select VIRTIO > select GENERIC_ALLOCATOR > diff --git a/drivers/vdpa/Kconfig b/drivers/vdpa/Kconfig > index d0cb0e583a5d..aee28def466b 100644 > --- a/drivers/vdpa/Kconfig > +++ b/drivers/vdpa/Kconfig > @@ -14,7 +14,7 @@ if VDPA_MENU > > config VDPA_SIM > tristate "vDPA device simulator" > - depends on RUNTIME_TESTING_MENU && HAS_DMA > + depends on RUNTIME_TESTING_MENU && HAS_DMA && VHOST_DPN > select VDPA > select VHOST_RING > select VHOST_IOTLB > diff --git a/drivers/vhost/Kconfig b/drivers/vhost/Kconfig > index cb6b17323eb2..b3486e218f62 100644 > --- a/drivers/vhost/Kconfig > +++ b/drivers/vhost/Kconfig > @@ -12,6 +12,15 @@ config VHOST_RING > This option is selected by any driver which needs to access > the host side of a virtio ring. > > +config VHOST_DPN > + bool "VHOST dependencies" > + depends on !ARM || AEABI > + default y > + help > + Anything selecting VHOST or VHOST_RING must depend on VHOST_DPN. > + This excludes the deprecated ARM ABI since that forces a 4 byte > + alignment on all structs - incompatible with virtio spec requirements. > + > config VHOST > tristate > select VHOST_IOTLB > @@ -27,7 +36,7 @@ if VHOST_MENU > > config VHOST_NET > tristate "Host kernel accelerator for virtio net" > - depends on NET && EVENTFD && (TUN || !TUN) && (TAP || !TAP) > + depends on NET && EVENTFD && (TUN || !TUN) && (TAP || !TAP) && VHOST_DPN > select VHOST > ---help--- > This kernel module can be loaded in host kernel to accelerate > @@ -39,7 +48,7 @@ config VHOST_NET > > config VHOST_SCSI > tristate "VHOST_SCSI TCM fabric driver" > - depends on TARGET_CORE && EVENTFD > + depends on TARGET_CORE && EVENTFD && VHOST_DPN > select VHOST > default n > ---help--- > @@ -48,7 +57,7 @@ config VHOST_SCSI > > config VHOST_VSOCK > tristate "vhost virtio-vsock driver" > - depends on VSOCKETS && EVENTFD > + depends on VSOCKETS && EVENTFD && VHOST_DPN > select VHOST > select VIRTIO_VSOCKETS_COMMON > default n > @@ -62,7 +71,7 @@ config VHOST_VSOCK > > config VHOST_VDPA > tristate "Vhost driver for vDPA-based backend" > - depends on EVENTFD > + depends on EVENTFD && VHOST_DPN > select VHOST > select VDPA > help > -- > MST >
On Mon, Apr 6, 2020 at 2:12 PM Michael S. Tsirkin <mst@redhat.com> wrote: > > +config VHOST_DPN > + bool "VHOST dependencies" > + depends on !ARM || AEABI > + default y > + help > + Anything selecting VHOST or VHOST_RING must depend on VHOST_DPN. > + This excludes the deprecated ARM ABI since that forces a 4 byte > + alignment on all structs - incompatible with virtio spec requirements. > + This should not be a user-visible option, so just make this 'def_bool !ARM || AEABI' Arnd
On Mon, Apr 06, 2020 at 02:45:13PM +0200, Ard Biesheuvel wrote: > On Mon, 6 Apr 2020 at 14:12, Michael S. Tsirkin <mst@redhat.com> wrote: > > > > vhost is currently broken on the default ARM config. > > > > Where did you get this idea? The report from the robot was using a > randconfig build, and in general, AEABI is required to run anything on > any modern ARM system . Oh - I forgot it's randconfig. This part is wrong, sorry. I decided to just force 2-byte alignment instead (seems more robust) but I'll take this into account if we do decide to add this dependency. > > > The reason is that that uses apcs-gnu which is the ancient OABI that is been > > deprecated for a long time. > > > > Given that virtio support on such ancient systems is not needed in the > > first place, let's just add something along the lines of > > > > depends on !ARM || AEABI > > > > to the virtio Kconfig declaration, and add a comment that it has to do > > with struct member alignment. > > > > Note: we can't make VHOST and VHOST_RING themselves have > > a dependency since these are selected. Add a new symbol for that. > > > > Suggested-by: Ard Biesheuvel <ardb@kernel.org> > > Siggested-by: Richard Earnshaw <Richard.Earnshaw@arm.com> > > typo ^^^ Thanks! > > > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > > --- > > drivers/misc/mic/Kconfig | 2 +- > > drivers/net/caif/Kconfig | 2 +- > > drivers/vdpa/Kconfig | 2 +- > > drivers/vhost/Kconfig | 17 +++++++++++++---- > > 4 files changed, 16 insertions(+), 7 deletions(-) > > > > diff --git a/drivers/misc/mic/Kconfig b/drivers/misc/mic/Kconfig > > index 8f201d019f5a..3bfe72c59864 100644 > > --- a/drivers/misc/mic/Kconfig > > +++ b/drivers/misc/mic/Kconfig > > @@ -116,7 +116,7 @@ config MIC_COSM > > > > config VOP > > tristate "VOP Driver" > > - depends on VOP_BUS > > + depends on VOP_BUS && VHOST_DPN > > select VHOST_RING > > select VIRTIO > > help > > diff --git a/drivers/net/caif/Kconfig b/drivers/net/caif/Kconfig > > index 9db0570c5beb..661c25eb1c46 100644 > > --- a/drivers/net/caif/Kconfig > > +++ b/drivers/net/caif/Kconfig > > @@ -50,7 +50,7 @@ config CAIF_HSI > > > > config CAIF_VIRTIO > > tristate "CAIF virtio transport driver" > > - depends on CAIF && HAS_DMA > > + depends on CAIF && HAS_DMA && VHOST_DPN > > select VHOST_RING > > select VIRTIO > > select GENERIC_ALLOCATOR > > diff --git a/drivers/vdpa/Kconfig b/drivers/vdpa/Kconfig > > index d0cb0e583a5d..aee28def466b 100644 > > --- a/drivers/vdpa/Kconfig > > +++ b/drivers/vdpa/Kconfig > > @@ -14,7 +14,7 @@ if VDPA_MENU > > > > config VDPA_SIM > > tristate "vDPA device simulator" > > - depends on RUNTIME_TESTING_MENU && HAS_DMA > > + depends on RUNTIME_TESTING_MENU && HAS_DMA && VHOST_DPN > > select VDPA > > select VHOST_RING > > select VHOST_IOTLB > > diff --git a/drivers/vhost/Kconfig b/drivers/vhost/Kconfig > > index cb6b17323eb2..b3486e218f62 100644 > > --- a/drivers/vhost/Kconfig > > +++ b/drivers/vhost/Kconfig > > @@ -12,6 +12,15 @@ config VHOST_RING > > This option is selected by any driver which needs to access > > the host side of a virtio ring. > > > > +config VHOST_DPN > > + bool "VHOST dependencies" > > + depends on !ARM || AEABI > > + default y > > + help > > + Anything selecting VHOST or VHOST_RING must depend on VHOST_DPN. > > + This excludes the deprecated ARM ABI since that forces a 4 byte > > + alignment on all structs - incompatible with virtio spec requirements. > > + > > config VHOST > > tristate > > select VHOST_IOTLB > > @@ -27,7 +36,7 @@ if VHOST_MENU > > > > config VHOST_NET > > tristate "Host kernel accelerator for virtio net" > > - depends on NET && EVENTFD && (TUN || !TUN) && (TAP || !TAP) > > + depends on NET && EVENTFD && (TUN || !TUN) && (TAP || !TAP) && VHOST_DPN > > select VHOST > > ---help--- > > This kernel module can be loaded in host kernel to accelerate > > @@ -39,7 +48,7 @@ config VHOST_NET > > > > config VHOST_SCSI > > tristate "VHOST_SCSI TCM fabric driver" > > - depends on TARGET_CORE && EVENTFD > > + depends on TARGET_CORE && EVENTFD && VHOST_DPN > > select VHOST > > default n > > ---help--- > > @@ -48,7 +57,7 @@ config VHOST_SCSI > > > > config VHOST_VSOCK > > tristate "vhost virtio-vsock driver" > > - depends on VSOCKETS && EVENTFD > > + depends on VSOCKETS && EVENTFD && VHOST_DPN > > select VHOST > > select VIRTIO_VSOCKETS_COMMON > > default n > > @@ -62,7 +71,7 @@ config VHOST_VSOCK > > > > config VHOST_VDPA > > tristate "Vhost driver for vDPA-based backend" > > - depends on EVENTFD > > + depends on EVENTFD && VHOST_DPN > > select VHOST > > select VDPA > > help > > -- > > MST > >
On Mon, Apr 06, 2020 at 02:50:32PM +0200, Arnd Bergmann wrote: > On Mon, Apr 6, 2020 at 2:12 PM Michael S. Tsirkin <mst@redhat.com> wrote: > > > > > +config VHOST_DPN > > + bool "VHOST dependencies" > > + depends on !ARM || AEABI > > + default y > > + help > > + Anything selecting VHOST or VHOST_RING must depend on VHOST_DPN. > > + This excludes the deprecated ARM ABI since that forces a 4 byte > > + alignment on all structs - incompatible with virtio spec requirements. > > + > > This should not be a user-visible option, so just make this 'def_bool > !ARM || AEABI' > > Arnd I like keeping some kind of hint around for when one tries to understand why is a specific symbol visible.
On Mon, Apr 6, 2020 at 3:02 PM Michael S. Tsirkin <mst@redhat.com> wrote: > > On Mon, Apr 06, 2020 at 02:50:32PM +0200, Arnd Bergmann wrote: > > On Mon, Apr 6, 2020 at 2:12 PM Michael S. Tsirkin <mst@redhat.com> wrote: > > > > > > > > +config VHOST_DPN > > > + bool "VHOST dependencies" > > > + depends on !ARM || AEABI > > > + default y > > > + help > > > + Anything selecting VHOST or VHOST_RING must depend on VHOST_DPN. > > > + This excludes the deprecated ARM ABI since that forces a 4 byte > > > + alignment on all structs - incompatible with virtio spec requirements. > > > + > > > > This should not be a user-visible option, so just make this 'def_bool > > !ARM || AEABI' > > > > I like keeping some kind of hint around for when one tries to understand > why is a specific symbol visible. I meant you should remove the "VHOST dependencies" prompt, not the help text, which is certainly useful here. You can also use the three lines bool depends on !ARM || AEABI default y in front of the help text, but those are equivalent to the one-line version I suggested. Arnd
On Mon, Apr 06, 2020 at 03:15:20PM +0200, Arnd Bergmann wrote: > On Mon, Apr 6, 2020 at 3:02 PM Michael S. Tsirkin <mst@redhat.com> wrote: > > > > On Mon, Apr 06, 2020 at 02:50:32PM +0200, Arnd Bergmann wrote: > > > On Mon, Apr 6, 2020 at 2:12 PM Michael S. Tsirkin <mst@redhat.com> wrote: > > > > > > > > > > > +config VHOST_DPN > > > > + bool "VHOST dependencies" > > > > + depends on !ARM || AEABI > > > > + default y > > > > + help > > > > + Anything selecting VHOST or VHOST_RING must depend on VHOST_DPN. > > > > + This excludes the deprecated ARM ABI since that forces a 4 byte > > > > + alignment on all structs - incompatible with virtio spec requirements. > > > > + > > > > > > This should not be a user-visible option, so just make this 'def_bool > > > !ARM || AEABI' > > > > > > > I like keeping some kind of hint around for when one tries to understand > > why is a specific symbol visible. > > I meant you should remove the "VHOST dependencies" prompt, not the > help text, which is certainly useful here. You can also use the three lines > > bool > depends on !ARM || AEABI > default y > > in front of the help text, but those are equivalent to the one-line version > I suggested. > > Arnd Oh right. Good point. Thanks!
diff --git a/drivers/misc/mic/Kconfig b/drivers/misc/mic/Kconfig index 8f201d019f5a..3bfe72c59864 100644 --- a/drivers/misc/mic/Kconfig +++ b/drivers/misc/mic/Kconfig @@ -116,7 +116,7 @@ config MIC_COSM config VOP tristate "VOP Driver" - depends on VOP_BUS + depends on VOP_BUS && VHOST_DPN select VHOST_RING select VIRTIO help diff --git a/drivers/net/caif/Kconfig b/drivers/net/caif/Kconfig index 9db0570c5beb..661c25eb1c46 100644 --- a/drivers/net/caif/Kconfig +++ b/drivers/net/caif/Kconfig @@ -50,7 +50,7 @@ config CAIF_HSI config CAIF_VIRTIO tristate "CAIF virtio transport driver" - depends on CAIF && HAS_DMA + depends on CAIF && HAS_DMA && VHOST_DPN select VHOST_RING select VIRTIO select GENERIC_ALLOCATOR diff --git a/drivers/vdpa/Kconfig b/drivers/vdpa/Kconfig index d0cb0e583a5d..aee28def466b 100644 --- a/drivers/vdpa/Kconfig +++ b/drivers/vdpa/Kconfig @@ -14,7 +14,7 @@ if VDPA_MENU config VDPA_SIM tristate "vDPA device simulator" - depends on RUNTIME_TESTING_MENU && HAS_DMA + depends on RUNTIME_TESTING_MENU && HAS_DMA && VHOST_DPN select VDPA select VHOST_RING select VHOST_IOTLB diff --git a/drivers/vhost/Kconfig b/drivers/vhost/Kconfig index cb6b17323eb2..b3486e218f62 100644 --- a/drivers/vhost/Kconfig +++ b/drivers/vhost/Kconfig @@ -12,6 +12,15 @@ config VHOST_RING This option is selected by any driver which needs to access the host side of a virtio ring. +config VHOST_DPN + bool "VHOST dependencies" + depends on !ARM || AEABI + default y + help + Anything selecting VHOST or VHOST_RING must depend on VHOST_DPN. + This excludes the deprecated ARM ABI since that forces a 4 byte + alignment on all structs - incompatible with virtio spec requirements. + config VHOST tristate select VHOST_IOTLB @@ -27,7 +36,7 @@ if VHOST_MENU config VHOST_NET tristate "Host kernel accelerator for virtio net" - depends on NET && EVENTFD && (TUN || !TUN) && (TAP || !TAP) + depends on NET && EVENTFD && (TUN || !TUN) && (TAP || !TAP) && VHOST_DPN select VHOST ---help--- This kernel module can be loaded in host kernel to accelerate @@ -39,7 +48,7 @@ config VHOST_NET config VHOST_SCSI tristate "VHOST_SCSI TCM fabric driver" - depends on TARGET_CORE && EVENTFD + depends on TARGET_CORE && EVENTFD && VHOST_DPN select VHOST default n ---help--- @@ -48,7 +57,7 @@ config VHOST_SCSI config VHOST_VSOCK tristate "vhost virtio-vsock driver" - depends on VSOCKETS && EVENTFD + depends on VSOCKETS && EVENTFD && VHOST_DPN select VHOST select VIRTIO_VSOCKETS_COMMON default n @@ -62,7 +71,7 @@ config VHOST_VSOCK config VHOST_VDPA tristate "Vhost driver for vDPA-based backend" - depends on EVENTFD + depends on EVENTFD && VHOST_DPN select VHOST select VDPA help
vhost is currently broken on the default ARM config. The reason is that that uses apcs-gnu which is the ancient OABI that is been deprecated for a long time. Given that virtio support on such ancient systems is not needed in the first place, let's just add something along the lines of depends on !ARM || AEABI to the virtio Kconfig declaration, and add a comment that it has to do with struct member alignment. Note: we can't make VHOST and VHOST_RING themselves have a dependency since these are selected. Add a new symbol for that. Suggested-by: Ard Biesheuvel <ardb@kernel.org> Siggested-by: Richard Earnshaw <Richard.Earnshaw@arm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> --- drivers/misc/mic/Kconfig | 2 +- drivers/net/caif/Kconfig | 2 +- drivers/vdpa/Kconfig | 2 +- drivers/vhost/Kconfig | 17 +++++++++++++---- 4 files changed, 16 insertions(+), 7 deletions(-)