* [PATCH] virtio: kconfig: memory devices are PCI only
@ 2024-09-06 7:37 Paolo Bonzini
2024-09-06 7:40 ` David Hildenbrand
0 siblings, 1 reply; 5+ messages in thread
From: Paolo Bonzini @ 2024-09-06 7:37 UTC (permalink / raw)
To: qemu-devel; +Cc: David Hildenbrand, Michael Tokarev
Virtio memory devices rely on PCI BARs to expose the contents of memory.
Because of this they cannot be used 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.
Without this patch it is possible to create a configuration with
CONFIG_VIRTIO_PCI=n and CONFIG_VIRTIO_MEM=y, but that causes a
compilation 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 | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/hw/virtio/Kconfig b/hw/virtio/Kconfig
index aa63ff7fd41..7c554d230d8 100644
--- a/hw/virtio/Kconfig
+++ b/hw/virtio/Kconfig
@@ -37,6 +37,7 @@ config VIRTIO_CRYPTO
config VIRTIO_MD
bool
+ depends on VIRTIO_PCI
select MEM_DEVICE
config VIRTIO_PMEM_SUPPORTED
@@ -45,7 +46,7 @@ config VIRTIO_PMEM_SUPPORTED
config VIRTIO_PMEM
bool
default y
- depends on VIRTIO
+ depends on VIRTIO_PCI
depends on VIRTIO_PMEM_SUPPORTED
select VIRTIO_MD
@@ -55,7 +56,7 @@ config VIRTIO_MEM_SUPPORTED
config VIRTIO_MEM
bool
default y
- depends on VIRTIO
+ depends on VIRTIO_PCI
depends on LINUX
depends on VIRTIO_MEM_SUPPORTED
select VIRTIO_MD
--
2.46.0
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH] virtio: kconfig: memory devices are PCI only
2024-09-06 7:37 [PATCH] virtio: kconfig: memory devices are PCI only Paolo Bonzini
@ 2024-09-06 7:40 ` David Hildenbrand
2024-09-06 7:42 ` David Hildenbrand
2024-09-06 8:18 ` Paolo Bonzini
0 siblings, 2 replies; 5+ messages in thread
From: David Hildenbrand @ 2024-09-06 7:40 UTC (permalink / raw)
To: Paolo Bonzini, qemu-devel; +Cc: Michael Tokarev
On 06.09.24 09:37, Paolo Bonzini wrote:
> Virtio memory devices rely on PCI BARs to expose the contents of memory.
> Because of this they cannot be used with virtio-mmio or virtio-ccw. In fact
Guess what I am working on at this very the moment ;)
> 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.
>
> Without this patch it is possible to create a configuration with
> CONFIG_VIRTIO_PCI=n and CONFIG_VIRTIO_MEM=y, but that causes a
> compilation failure.
Right.
>
> 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 | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/hw/virtio/Kconfig b/hw/virtio/Kconfig
> index aa63ff7fd41..7c554d230d8 100644
> --- a/hw/virtio/Kconfig
> +++ b/hw/virtio/Kconfig
> @@ -37,6 +37,7 @@ config VIRTIO_CRYPTO
>
> config VIRTIO_MD
> bool
> + depends on VIRTIO_PCI
> select MEM_DEVICE
>
> config VIRTIO_PMEM_SUPPORTED
> @@ -45,7 +46,7 @@ config VIRTIO_PMEM_SUPPORTED
> config VIRTIO_PMEM
> bool
> default y
> - depends on VIRTIO
> + depends on VIRTIO_PCI
depends on VIRTIO_MD ?
> depends on VIRTIO_PMEM_SUPPORTED
> select VIRTIO_MD
>
> @@ -55,7 +56,7 @@ config VIRTIO_MEM_SUPPORTED
> config VIRTIO_MEM
> bool
> default y
> - depends on VIRTIO
> + depends on VIRTIO_PCI
Same here.
With CCW support, I can unlock VIRTIO_MD and VIRTIO_MEM_SUPPORTED and it
should fly.
--
Cheers,
David / dhildenb
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] virtio: kconfig: memory devices are PCI only
2024-09-06 7:40 ` David Hildenbrand
@ 2024-09-06 7:42 ` David Hildenbrand
2024-09-06 8:18 ` Paolo Bonzini
1 sibling, 0 replies; 5+ messages in thread
From: David Hildenbrand @ 2024-09-06 7:42 UTC (permalink / raw)
To: Paolo Bonzini, qemu-devel; +Cc: Michael Tokarev
>> 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 | 5 +++--
>> 1 file changed, 3 insertions(+), 2 deletions(-)
>>
>> diff --git a/hw/virtio/Kconfig b/hw/virtio/Kconfig
>> index aa63ff7fd41..7c554d230d8 100644
>> --- a/hw/virtio/Kconfig
>> +++ b/hw/virtio/Kconfig
>> @@ -37,6 +37,7 @@ config VIRTIO_CRYPTO
>>
>> config VIRTIO_MD
>> bool
>> + depends on VIRTIO_PCI
>> select MEM_DEVICE
>>
>> config VIRTIO_PMEM_SUPPORTED
>> @@ -45,7 +46,7 @@ config VIRTIO_PMEM_SUPPORTED
>> config VIRTIO_PMEM
>> bool
>> default y
>> - depends on VIRTIO
>> + depends on VIRTIO_PCI
>
> depends on VIRTIO_MD ?
(of course, removing the "select VIRTIO_MD")
--
Cheers,
David / dhildenb
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] virtio: kconfig: memory devices are PCI only
2024-09-06 7:40 ` David Hildenbrand
2024-09-06 7:42 ` David Hildenbrand
@ 2024-09-06 8:18 ` Paolo Bonzini
2024-09-06 9:22 ` David Hildenbrand
1 sibling, 1 reply; 5+ messages in thread
From: Paolo Bonzini @ 2024-09-06 8:18 UTC (permalink / raw)
To: David Hildenbrand; +Cc: qemu-devel, Michael Tokarev
On Fri, Sep 6, 2024 at 9:40 AM David Hildenbrand <david@redhat.com> wrote:
> On 06.09.24 09:37, Paolo Bonzini wrote:
> > Virtio memory devices rely on PCI BARs to expose the contents of memory.
> > Because of this they cannot be used with virtio-mmio or virtio-ccw. In fact
>
> Guess what I am working on at this very the moment ;)
Ok, then hardcoding VIRTIO_PCI is not nice.
> > @@ -45,7 +46,7 @@ config VIRTIO_PMEM_SUPPORTED
> > config VIRTIO_PMEM
> > bool
> > default y
> > - depends on VIRTIO
> > + depends on VIRTIO_PCI
>
> depends on VIRTIO_MD ?
No, because VIRTIO_MD is "default n" (and anyway you don't want to
enable it by hand in the --without-default-devices case).
But something like this could be a good alternative if you plan to
support virtio-ccw as well:
diff --git a/hw/virtio/Kconfig b/hw/virtio/Kconfig
index aa63ff7fd41..253e7d3f90a 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
@@ -35,8 +36,14 @@ 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
config VIRTIO_PMEM_SUPPORTED
@@ -46,6 +51,7 @@ config VIRTIO_PMEM
bool
default y
depends on VIRTIO
+ depends on VIRTIO_MD_SUPPORTED
depends on VIRTIO_PMEM_SUPPORTED
select VIRTIO_MD
@@ -57,6 +63,7 @@ config VIRTIO_MEM
default y
depends on VIRTIO
depends on LINUX
+ depends on VIRTIO_MD_SUPPORTED
depends on VIRTIO_MEM_SUPPORTED
select VIRTIO_MD
and then you just need to select VIRTIO_MD_SUPPORTED from VIRTIO_CCW.
In the case of PCI there is some board support code as well, which is
why VIRTIO_{MEM,PMEM}_SUPPORTED is selected from "config PC", but
perhaps in the s390 code you can select those three from VIRTIO_CCW as
well.
If this looks good I'll send it as v2.
Thanks,
Paolo
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH] virtio: kconfig: memory devices are PCI only
2024-09-06 8:18 ` Paolo Bonzini
@ 2024-09-06 9:22 ` David Hildenbrand
0 siblings, 0 replies; 5+ messages in thread
From: David Hildenbrand @ 2024-09-06 9:22 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: qemu-devel, Michael Tokarev
On 06.09.24 10:18, Paolo Bonzini wrote:
> On Fri, Sep 6, 2024 at 9:40 AM David Hildenbrand <david@redhat.com> wrote:
>> On 06.09.24 09:37, Paolo Bonzini wrote:
>>> Virtio memory devices rely on PCI BARs to expose the contents of memory.
>>> Because of this they cannot be used with virtio-mmio or virtio-ccw. In fact
>>
>> Guess what I am working on at this very the moment ;)
>
> Ok, then hardcoding VIRTIO_PCI is not nice.
>
>>> @@ -45,7 +46,7 @@ config VIRTIO_PMEM_SUPPORTED
>>> config VIRTIO_PMEM
>>> bool
>>> default y
>>> - depends on VIRTIO
>>> + depends on VIRTIO_PCI
>>
>> depends on VIRTIO_MD ?
>
> No, because VIRTIO_MD is "default n" (and anyway you don't want to
> enable it by hand in the --without-default-devices case).
Right, that's what I originally tried to achieve.
>
> But something like this could be a good alternative if you plan to
> support virtio-ccw as well:
>
> diff --git a/hw/virtio/Kconfig b/hw/virtio/Kconfig
> index aa63ff7fd41..253e7d3f90a 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
> @@ -35,8 +36,14 @@ 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
>
> config VIRTIO_PMEM_SUPPORTED
> @@ -46,6 +51,7 @@ config VIRTIO_PMEM
> bool
> default y
> depends on VIRTIO
> + depends on VIRTIO_MD_SUPPORTED
> depends on VIRTIO_PMEM_SUPPORTED
> select VIRTIO_MD
>
> @@ -57,6 +63,7 @@ config VIRTIO_MEM
> default y
> depends on VIRTIO
> depends on LINUX
> + depends on VIRTIO_MD_SUPPORTED
> depends on VIRTIO_MEM_SUPPORTED
> select VIRTIO_MD
>
>
> and then you just need to select VIRTIO_MD_SUPPORTED from VIRTIO_CCW.
Sounds good.
> In the case of PCI there is some board support code as well, which is
> why VIRTIO_{MEM,PMEM}_SUPPORTED is selected from "config PC", but
> perhaps in the s390 code you can select those three from VIRTIO_CCW as
> well.
Yes, only VIRTIO_MEM_SUPPORTED for now.
>
> If this looks good I'll send it as v2.
Thanks!
--
Cheers,
David / dhildenb
^ permalink raw reply [flat|nested] 5+ messages in thread
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2024-09-06 7:37 [PATCH] virtio: kconfig: memory devices are PCI only Paolo Bonzini
2024-09-06 7:40 ` David Hildenbrand
2024-09-06 7:42 ` David Hildenbrand
2024-09-06 8:18 ` Paolo Bonzini
2024-09-06 9:22 ` David Hildenbrand
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