| Message ID | 20150312093739.GA4655@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
"Michael S. Tsirkin" <mst@redhat.com> writes: > Subject: [PATCH] virtio_mmio: fix access width for mmio Just for the record: Applied. Thanks, Rusty. > Going over the virtio mmio code, I noticed that it doesn't correctly > access modern device config values using "natural" accessors: it uses > readb to get/set them byte by byte, while the virtio 1.0 spec explicitly states: > > 4.2.2.2 Driver Requirements: MMIO Device Register Layout > > ... > > The driver MUST only use 32 bit wide and aligned reads and writes to > access the control registers described in table 4.1. > For the device-specific configuration space, the driver MUST use > 8 bit wide accesses for 8 bit wide fields, 16 bit wide and aligned > accesses for 16 bit wide fields and 32 bit wide and aligned accesses for > 32 and 64 bit wide fields. > > Borrow code from virtio_pci_modern to do this correctly. > > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > > --- > > This is exactly the same as PATCH virtio_mmio: fix endian-ness for mmio > but with corrected subject and commit log, to make > it easier to apply. > > Note: untested: QEMU doesn't support virtio 1.0 for virtio-mmio, > but seems pretty obvious. Let's apply ASAP so we don't ship > incompliant drivers for virtio 1.0? > > drivers/virtio/virtio_mmio.c | 79 +++++++++++++++++++++++++++++++++++++++----- > 1 file changed, 71 insertions(+), 8 deletions(-) > > diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c > index cad5698..0375456 100644 > --- a/drivers/virtio/virtio_mmio.c > +++ b/drivers/virtio/virtio_mmio.c > @@ -156,22 +156,85 @@ static void vm_get(struct virtio_device *vdev, unsigned offset, > void *buf, unsigned len) > { > struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); > - u8 *ptr = buf; > - int i; > + void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG; > + u8 b; > + __le16 w; > + __le32 l; > > - for (i = 0; i < len; i++) > - ptr[i] = readb(vm_dev->base + VIRTIO_MMIO_CONFIG + offset + i); > + if (vm_dev->version == 1) { > + u8 *ptr = buf; > + int i; > + > + for (i = 0; i < len; i++) > + ptr[i] = readb(base + offset + i); > + return; > + } > + > + switch (len) { > + case 1: > + b = readb(base + offset); > + memcpy(buf, &b, sizeof b); > + break; > + case 2: > + w = cpu_to_le16(readw(base + offset)); > + memcpy(buf, &w, sizeof w); > + break; > + case 4: > + l = cpu_to_le32(readl(base + offset)); > + memcpy(buf, &l, sizeof l); > + break; > + case 8: > + l = cpu_to_le32(readl(base + offset)); > + memcpy(buf, &l, sizeof l); > + l = cpu_to_le32(ioread32(base + offset + sizeof l)); > + memcpy(buf + sizeof l, &l, sizeof l); > + break; > + default: > + BUG(); > + } > } > > static void vm_set(struct virtio_device *vdev, unsigned offset, > const void *buf, unsigned len) > { > struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); > - const u8 *ptr = buf; > - int i; > + void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG; > + u8 b; > + __le16 w; > + __le32 l; > > - for (i = 0; i < len; i++) > - writeb(ptr[i], vm_dev->base + VIRTIO_MMIO_CONFIG + offset + i); > + if (vm_dev->version == 1) { > + const u8 *ptr = buf; > + int i; > + > + for (i = 0; i < len; i++) > + writeb(ptr[i], base + offset + i); > + > + return; > + } > + > + switch (len) { > + case 1: > + memcpy(&b, buf, sizeof b); > + writeb(b, base + offset); > + break; > + case 2: > + memcpy(&w, buf, sizeof w); > + writew(le16_to_cpu(w), base + offset); > + break; > + case 4: > + memcpy(&l, buf, sizeof l); > + writel(le32_to_cpu(l), base + offset); > + break; > + case 8: > + memcpy(&l, buf, sizeof l); > + writel(le32_to_cpu(l), base + offset); > + memcpy(&l, buf + sizeof l, sizeof l); > + writel(le32_to_cpu(l), base + offset + sizeof l); > + break; > + default: > + BUG(); > + } > } > > static u8 vm_get_status(struct virtio_device *vdev) > -- > MST -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c index cad5698..0375456 100644 --- a/drivers/virtio/virtio_mmio.c +++ b/drivers/virtio/virtio_mmio.c @@ -156,22 +156,85 @@ static void vm_get(struct virtio_device *vdev, unsigned offset, void *buf, unsigned len) { struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); - u8 *ptr = buf; - int i; + void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG; + u8 b; + __le16 w; + __le32 l; - for (i = 0; i < len; i++) - ptr[i] = readb(vm_dev->base + VIRTIO_MMIO_CONFIG + offset + i); + if (vm_dev->version == 1) { + u8 *ptr = buf; + int i; + + for (i = 0; i < len; i++) + ptr[i] = readb(base + offset + i); + return; + } + + switch (len) { + case 1: + b = readb(base + offset); + memcpy(buf, &b, sizeof b); + break; + case 2: + w = cpu_to_le16(readw(base + offset)); + memcpy(buf, &w, sizeof w); + break; + case 4: + l = cpu_to_le32(readl(base + offset)); + memcpy(buf, &l, sizeof l); + break; + case 8: + l = cpu_to_le32(readl(base + offset)); + memcpy(buf, &l, sizeof l); + l = cpu_to_le32(ioread32(base + offset + sizeof l)); + memcpy(buf + sizeof l, &l, sizeof l); + break; + default: + BUG(); + } } static void vm_set(struct virtio_device *vdev, unsigned offset, const void *buf, unsigned len) { struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); - const u8 *ptr = buf; - int i; + void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG; + u8 b; + __le16 w; + __le32 l; - for (i = 0; i < len; i++) - writeb(ptr[i], vm_dev->base + VIRTIO_MMIO_CONFIG + offset + i); + if (vm_dev->version == 1) { + const u8 *ptr = buf; + int i; + + for (i = 0; i < len; i++) + writeb(ptr[i], base + offset + i); + + return; + } + + switch (len) { + case 1: + memcpy(&b, buf, sizeof b); + writeb(b, base + offset); + break; + case 2: + memcpy(&w, buf, sizeof w); + writew(le16_to_cpu(w), base + offset); + break; + case 4: + memcpy(&l, buf, sizeof l); + writel(le32_to_cpu(l), base + offset); + break; + case 8: + memcpy(&l, buf, sizeof l); + writel(le32_to_cpu(l), base + offset); + memcpy(&l, buf + sizeof l, sizeof l); + writel(le32_to_cpu(l), base + offset + sizeof l); + break; + default: + BUG(); + } } static u8 vm_get_status(struct virtio_device *vdev)
Subject: [PATCH] virtio_mmio: fix access width for mmio Going over the virtio mmio code, I noticed that it doesn't correctly access modern device config values using "natural" accessors: it uses readb to get/set them byte by byte, while the virtio 1.0 spec explicitly states: 4.2.2.2 Driver Requirements: MMIO Device Register Layout ... The driver MUST only use 32 bit wide and aligned reads and writes to access the control registers described in table 4.1. For the device-specific configuration space, the driver MUST use 8 bit wide accesses for 8 bit wide fields, 16 bit wide and aligned accesses for 16 bit wide fields and 32 bit wide and aligned accesses for 32 and 64 bit wide fields. Borrow code from virtio_pci_modern to do this correctly. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> --- This is exactly the same as PATCH virtio_mmio: fix endian-ness for mmio but with corrected subject and commit log, to make it easier to apply. Note: untested: QEMU doesn't support virtio 1.0 for virtio-mmio, but seems pretty obvious. Let's apply ASAP so we don't ship incompliant drivers for virtio 1.0? drivers/virtio/virtio_mmio.c | 79 +++++++++++++++++++++++++++++++++++++++----- 1 file changed, 71 insertions(+), 8 deletions(-)