| Message ID | 20200807195526.426056-6-vgoyal@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | virtiofs: Add DAX support | expand |
On Fri, Aug 07, 2020 at 03:55:11PM -0400, Vivek Goyal wrote: > From: Sebastien Boeuf <sebastien.boeuf@intel.com> > > On MMIO a new set of registers is defined for finding SHM > regions. Add their definitions and use them to find the region. > > Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com> > Cc: kvm@vger.kernel.org > Cc: "Michael S. Tsirkin" <mst@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> > --- > drivers/virtio/virtio_mmio.c | 32 ++++++++++++++++++++++++++++++++ > include/uapi/linux/virtio_mmio.h | 11 +++++++++++ > 2 files changed, 43 insertions(+) > > diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c > index 627ac0487494..2697c492cf78 100644 > --- a/drivers/virtio/virtio_mmio.c > +++ b/drivers/virtio/virtio_mmio.c > @@ -498,6 +498,37 @@ static const char *vm_bus_name(struct virtio_device *vdev) > return vm_dev->pdev->name; > } > > +static bool vm_get_shm_region(struct virtio_device *vdev, > + struct virtio_shm_region *region, u8 id) > +{ > + struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); > + u64 len, addr; > + > + /* Select the region we're interested in */ > + writel(id, vm_dev->base + VIRTIO_MMIO_SHM_SEL); > + > + /* Read the region size */ > + len = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_LOW); > + len |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_HIGH) << 32; > + > + region->len = len; > + > + /* Check if region length is -1. If that's the case, the shared memory > + * region does not exist and there is no need to proceed further. > + */ > + if (len == ~(u64)0) { > + return false; > + } > + It might make sense to validate that addr/len do not overlap. Will be useful for PCI too. Can be a patch on top. > + /* Read the region base address */ > + addr = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_LOW); > + addr |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_HIGH) << 32; > + > + region->addr = addr; > + > + return true; > +} > + > static const struct virtio_config_ops virtio_mmio_config_ops = { > .get = vm_get, > .set = vm_set, > @@ -510,6 +541,7 @@ static const struct virtio_config_ops virtio_mmio_config_ops = { > .get_features = vm_get_features, > .finalize_features = vm_finalize_features, > .bus_name = vm_bus_name, > + .get_shm_region = vm_get_shm_region, > }; > > > diff --git a/include/uapi/linux/virtio_mmio.h b/include/uapi/linux/virtio_mmio.h > index c4b09689ab64..0650f91bea6c 100644 > --- a/include/uapi/linux/virtio_mmio.h > +++ b/include/uapi/linux/virtio_mmio.h > @@ -122,6 +122,17 @@ > #define VIRTIO_MMIO_QUEUE_USED_LOW 0x0a0 > #define VIRTIO_MMIO_QUEUE_USED_HIGH 0x0a4 > > +/* Shared memory region id */ > +#define VIRTIO_MMIO_SHM_SEL 0x0ac > + > +/* Shared memory region length, 64 bits in two halves */ > +#define VIRTIO_MMIO_SHM_LEN_LOW 0x0b0 > +#define VIRTIO_MMIO_SHM_LEN_HIGH 0x0b4 > + > +/* Shared memory region base address, 64 bits in two halves */ > +#define VIRTIO_MMIO_SHM_BASE_LOW 0x0b8 > +#define VIRTIO_MMIO_SHM_BASE_HIGH 0x0bc > + > /* Configuration atomicity value */ > #define VIRTIO_MMIO_CONFIG_GENERATION 0x0fc > > -- > 2.25.4 >
diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c index 627ac0487494..2697c492cf78 100644 --- a/drivers/virtio/virtio_mmio.c +++ b/drivers/virtio/virtio_mmio.c @@ -498,6 +498,37 @@ static const char *vm_bus_name(struct virtio_device *vdev) return vm_dev->pdev->name; } +static bool vm_get_shm_region(struct virtio_device *vdev, + struct virtio_shm_region *region, u8 id) +{ + struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); + u64 len, addr; + + /* Select the region we're interested in */ + writel(id, vm_dev->base + VIRTIO_MMIO_SHM_SEL); + + /* Read the region size */ + len = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_LOW); + len |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_HIGH) << 32; + + region->len = len; + + /* Check if region length is -1. If that's the case, the shared memory + * region does not exist and there is no need to proceed further. + */ + if (len == ~(u64)0) { + return false; + } + + /* Read the region base address */ + addr = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_LOW); + addr |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_HIGH) << 32; + + region->addr = addr; + + return true; +} + static const struct virtio_config_ops virtio_mmio_config_ops = { .get = vm_get, .set = vm_set, @@ -510,6 +541,7 @@ static const struct virtio_config_ops virtio_mmio_config_ops = { .get_features = vm_get_features, .finalize_features = vm_finalize_features, .bus_name = vm_bus_name, + .get_shm_region = vm_get_shm_region, }; diff --git a/include/uapi/linux/virtio_mmio.h b/include/uapi/linux/virtio_mmio.h index c4b09689ab64..0650f91bea6c 100644 --- a/include/uapi/linux/virtio_mmio.h +++ b/include/uapi/linux/virtio_mmio.h @@ -122,6 +122,17 @@ #define VIRTIO_MMIO_QUEUE_USED_LOW 0x0a0 #define VIRTIO_MMIO_QUEUE_USED_HIGH 0x0a4 +/* Shared memory region id */ +#define VIRTIO_MMIO_SHM_SEL 0x0ac + +/* Shared memory region length, 64 bits in two halves */ +#define VIRTIO_MMIO_SHM_LEN_LOW 0x0b0 +#define VIRTIO_MMIO_SHM_LEN_HIGH 0x0b4 + +/* Shared memory region base address, 64 bits in two halves */ +#define VIRTIO_MMIO_SHM_BASE_LOW 0x0b8 +#define VIRTIO_MMIO_SHM_BASE_HIGH 0x0bc + /* Configuration atomicity value */ #define VIRTIO_MMIO_CONFIG_GENERATION 0x0fc