| Message ID | 20240906101658.514470-1-pbonzini@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] virtio: kconfig: memory devices are PCI only | expand |
On 06.09.24 12:16, Paolo Bonzini wrote: > Virtio memory devices rely on PCI BARs to expose the contents of memory. > Because of this they cannot be used (yet) with virtio-mmio or virtio-ccw. > In fact the code that is common to virtio-mem and virtio-pmem, which > is in hw/virtio/virtio-md-pci.c, is only included if CONFIG_VIRTIO_PCI > is set. Reproduce the same condition in the Kconfig file, only allowing > VIRTIO_MEM and VIRTIO_PMEM to be defined if the transport supports it. > > Without this patch it is possible to create a configuration with > CONFIG_VIRTIO_PCI=n and CONFIG_VIRTIO_MEM=y, but that causes a > linking failure. > > Cc: David Hildenbrand <david@redhat.com> > Reported-by: Michael Tokarev <mjt@tls.msk.ru> > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > --- Reviewed-by: David Hildenbrand <david@redhat.com> Thanks!
On 06.09.24 12:16, Paolo Bonzini wrote: > Virtio memory devices rely on PCI BARs to expose the contents of memory. > Because of this they cannot be used (yet) with virtio-mmio or virtio-ccw. > In fact the code that is common to virtio-mem and virtio-pmem, which > is in hw/virtio/virtio-md-pci.c, is only included if CONFIG_VIRTIO_PCI > is set. Reproduce the same condition in the Kconfig file, only allowing > VIRTIO_MEM and VIRTIO_PMEM to be defined if the transport supports it. > > Without this patch it is possible to create a configuration with > CONFIG_VIRTIO_PCI=n and CONFIG_VIRTIO_MEM=y, but that causes a > linking failure. I'll queue this to https://github.com/davidhildenbrand/qemu.git mem-next and drop it if someone beats me to up-streaming it :)
> Virtio memory devices rely on PCI BARs to expose the contents of memory. > Because of this they cannot be used (yet) with virtio-mmio or virtio-ccw. > In fact the code that is common to virtio-mem and virtio-pmem, which > is in hw/virtio/virtio-md-pci.c, is only included if CONFIG_VIRTIO_PCI > is set. Reproduce the same condition in the Kconfig file, only allowing > VIRTIO_MEM and VIRTIO_PMEM to be defined if the transport supports it. > > Without this patch it is possible to create a configuration with > CONFIG_VIRTIO_PCI=n and CONFIG_VIRTIO_MEM=y, but that causes a > linking failure. Just curious what is required to make virtio-mem & virtio-pmem compatible with virtio-mmio? Maybe late but still: Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com> Thanks, Pankaj > > Cc: David Hildenbrand <david@redhat.com> > Reported-by: Michael Tokarev <mjt@tls.msk.ru> > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > --- > hw/virtio/Kconfig | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/hw/virtio/Kconfig b/hw/virtio/Kconfig > index aa63ff7fd41..0afec2ae929 100644 > --- a/hw/virtio/Kconfig > +++ b/hw/virtio/Kconfig > @@ -16,6 +16,7 @@ config VIRTIO_PCI > default y if PCI_DEVICES > depends on PCI > select VIRTIO > + select VIRTIO_MD_SUPPORTED > > config VIRTIO_MMIO > bool > @@ -35,10 +36,17 @@ config VIRTIO_CRYPTO > default y > depends on VIRTIO > > +# not all virtio transports support memory devices; if none does, > +# no need to include the code > +config VIRTIO_MD_SUPPORTED > + bool > + > config VIRTIO_MD > bool > + depends on VIRTIO_MD_SUPPORTED > select MEM_DEVICE > > +# selected by the board if it has the required support code > config VIRTIO_PMEM_SUPPORTED > bool > > @@ -46,9 +54,11 @@ config VIRTIO_PMEM > bool > default y > depends on VIRTIO > + depends on VIRTIO_MD_SUPPORTED > depends on VIRTIO_PMEM_SUPPORTED > select VIRTIO_MD > > +# selected by the board if it has the required support code > config VIRTIO_MEM_SUPPORTED > bool > > @@ -57,6 +67,7 @@ config VIRTIO_MEM > default y > depends on VIRTIO > depends on LINUX > + depends on VIRTIO_MD_SUPPORTED > depends on VIRTIO_MEM_SUPPORTED > select VIRTIO_MD > > -- > 2.46.0 > >
On 25.09.24 09:39, Pankaj Gupta wrote: >> Virtio memory devices rely on PCI BARs to expose the contents of memory. >> Because of this they cannot be used (yet) with virtio-mmio or virtio-ccw. >> In fact the code that is common to virtio-mem and virtio-pmem, which >> is in hw/virtio/virtio-md-pci.c, is only included if CONFIG_VIRTIO_PCI >> is set. Reproduce the same condition in the Kconfig file, only allowing >> VIRTIO_MEM and VIRTIO_PMEM to be defined if the transport supports it. >> >> Without this patch it is possible to create a configuration with >> CONFIG_VIRTIO_PCI=n and CONFIG_VIRTIO_MEM=y, but that causes a >> linking failure. > > Just curious what is required to make virtio-mem & virtio-pmem compatible with > virtio-mmio? I assume not that much: primarily implementing the virtio-md-mmio abstraction, and the virtio-mem-mmio/virtio-pmem-mmio proxy devices. Then, it needs to be wired up in the machine hotplug code. I posted the virtio-ccw variant a couple of days ago [1]. > > Maybe late but still: > Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com> I already sent a merge request that includes this change. If I have to resend it, I'll include that. Thanks! [1] https://lkml.kernel.org/r/20240910175809.2135596-1-david@redhat.com
diff --git a/hw/virtio/Kconfig b/hw/virtio/Kconfig index aa63ff7fd41..0afec2ae929 100644 --- a/hw/virtio/Kconfig +++ b/hw/virtio/Kconfig @@ -16,6 +16,7 @@ config VIRTIO_PCI default y if PCI_DEVICES depends on PCI select VIRTIO + select VIRTIO_MD_SUPPORTED config VIRTIO_MMIO bool @@ -35,10 +36,17 @@ config VIRTIO_CRYPTO default y depends on VIRTIO +# not all virtio transports support memory devices; if none does, +# no need to include the code +config VIRTIO_MD_SUPPORTED + bool + config VIRTIO_MD bool + depends on VIRTIO_MD_SUPPORTED select MEM_DEVICE +# selected by the board if it has the required support code config VIRTIO_PMEM_SUPPORTED bool @@ -46,9 +54,11 @@ config VIRTIO_PMEM bool default y depends on VIRTIO + depends on VIRTIO_MD_SUPPORTED depends on VIRTIO_PMEM_SUPPORTED select VIRTIO_MD +# selected by the board if it has the required support code config VIRTIO_MEM_SUPPORTED bool @@ -57,6 +67,7 @@ config VIRTIO_MEM default y depends on VIRTIO depends on LINUX + depends on VIRTIO_MD_SUPPORTED depends on VIRTIO_MEM_SUPPORTED select VIRTIO_MD
Virtio memory devices rely on PCI BARs to expose the contents of memory. Because of this they cannot be used (yet) with virtio-mmio or virtio-ccw. In fact the code that is common to virtio-mem and virtio-pmem, which is in hw/virtio/virtio-md-pci.c, is only included if CONFIG_VIRTIO_PCI is set. Reproduce the same condition in the Kconfig file, only allowing VIRTIO_MEM and VIRTIO_PMEM to be defined if the transport supports it. Without this patch it is possible to create a configuration with CONFIG_VIRTIO_PCI=n and CONFIG_VIRTIO_MEM=y, but that causes a linking failure. Cc: David Hildenbrand <david@redhat.com> Reported-by: Michael Tokarev <mjt@tls.msk.ru> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- hw/virtio/Kconfig | 11 +++++++++++ 1 file changed, 11 insertions(+)