macro VIRTIO_PCI_CONFIG except in the unlikely event userspace
actually has a structure with a field named msix_enabled.
Get the msix_enabled by value instead, to make it useful
for userspace.
Signed-off-by: Michael S. Tsirkin <[email protected]>
---
drivers/virtio/virtio_pci.c | 8 ++++----
include/uapi/linux/virtio_pci.h | 2 +-
2 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
index a7ce730..1bb6ff3 100644
--- a/drivers/virtio/virtio_pci.c
+++ b/drivers/virtio/virtio_pci.c
@@ -132,8 +132,8 @@ static void vp_get(struct virtio_device *vdev, unsigned offset,
void *buf, unsigned len)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
- void __iomem *ioaddr = vp_dev->ioaddr +
- VIRTIO_PCI_CONFIG(vp_dev) + offset;
+ void __iomem *ioaddr = vp_dev->ioaddr + offset +
+ VIRTIO_PCI_CONFIG(vp_dev->msix_enabled);
u8 *ptr = buf;
int i;
@@ -147,8 +147,8 @@ static void vp_set(struct virtio_device *vdev, unsigned offset,
const void *buf, unsigned len)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
- void __iomem *ioaddr = vp_dev->ioaddr +
- VIRTIO_PCI_CONFIG(vp_dev) + offset;
+ void __iomem *ioaddr = vp_dev->ioaddr + offset +
+ VIRTIO_PCI_CONFIG(vp_dev->msix_enabled);
const u8 *ptr = buf;
int i;
diff --git a/include/uapi/linux/virtio_pci.h b/include/uapi/linux/virtio_pci.h
index ea66f3f..610c6c6 100644
--- a/include/uapi/linux/virtio_pci.h
+++ b/include/uapi/linux/virtio_pci.h
@@ -80,7 +80,7 @@
/* The remaining space is defined by each driver as the per-driver
* configuration space */
-#define VIRTIO_PCI_CONFIG(dev) ((dev)->msix_enabled ? 24 : 20)
+#define VIRTIO_PCI_CONFIG(msix_enabled) ((msix_enabled) ? 24 : 20)
/* Virtio ABI version, this must match exactly */
#define VIRTIO_PCI_ABI_VERSION 0
--
MST
"Michael S. Tsirkin" <[email protected]> writes:
> macro VIRTIO_PCI_CONFIG except in the unlikely event userspace
> actually has a structure with a field named msix_enabled.
> Get the msix_enabled by value instead, to make it useful
> for userspace.
>
> Signed-off-by: Michael S. Tsirkin <[email protected]>
Macro still isn't usable, because userspace can't know whether it's the
new or old.
We need to either remove it from UAPI, or rename it to
VIRTIO_PCI_CONFIG_OFF.
Cheers,
Rusty.
Rusty Russell <[email protected]> wrote:
> Macro still isn't usable, because userspace can't know whether it's the
> new or old.
>
> We need to either remove it from UAPI, or rename it to
> VIRTIO_PCI_CONFIG_OFF.
Surely, if userspace is using it as is, you can't remove it, rename it or
alter it?
David
David Howells <[email protected]> writes:
> Rusty Russell <[email protected]> wrote:
>
>> Macro still isn't usable, because userspace can't know whether it's the
>> new or old.
>>
>> We need to either remove it from UAPI, or rename it to
>> VIRTIO_PCI_CONFIG_OFF.
>
> Surely, if userspace is using it as is, you can't remove it, rename it or
> alter it?
The point of the patch is that it's unusable:
#define VIRTIO_PCI_CONFIG(dev) ((dev)->msix_enabled ? 24 : 20)
ie. it's accessing a member of the kernel's virtio_pci_dev structure.
In theory, userspace could have a structure with the same field and be
using it now, but that's unlikely (qemu certainly doesn't). No harm no
foul.
In theory it's actually a useful macro, so we could expose it to
userspace, but we'd need to have a new name so userspace can #ifdef for
older headers...
Hope that clarifies,
Rusty.
Rusty Russell <[email protected]> wrote:
> The point of the patch is that it's unusable:
>
> #define VIRTIO_PCI_CONFIG(dev) ((dev)->msix_enabled ? 24 : 20)
>
> ie. it's accessing a member of the kernel's virtio_pci_dev structure.
Ah, okay. In that case, zap it and see if anyone complains.
David