[Virtio-fs] [PATCH v2 06/25] DAX: virtio: Add shared memory capability
Dr. David Alan Gilbert (git)
dgilbert at redhat.com
Wed Apr 14 15:51:18 UTC 2021
From: "Dr. David Alan Gilbert" <dgilbert at redhat.com>
Define a new capability type 'VIRTIO_PCI_CAP_SHARED_MEMORY_CFG'
and the data structure 'virtio_pci_cap64' to go with it.
They allow defining shared memory regions with sizes and offsets
of 2^32 and more.
Multiple instances of the capability are allowed and distinguished
by the 'id' field in the base capability.
Signed-off-by: Dr. David Alan Gilbert <dgilbert at redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha at redhat.com>
---
hw/virtio/virtio-pci.c | 20 ++++++++++++++++++++
hw/virtio/virtio-pci.h | 4 ++++
2 files changed, 24 insertions(+)
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index b321604d9b..493014fdf7 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -1138,6 +1138,26 @@ static int virtio_pci_add_mem_cap(VirtIOPCIProxy *proxy,
return offset;
}
+int virtio_pci_add_shm_cap(VirtIOPCIProxy *proxy,
+ uint8_t bar, uint64_t offset, uint64_t length,
+ uint8_t id)
+{
+ struct virtio_pci_cap64 cap = {
+ .cap.cap_len = sizeof cap,
+ .cap.cfg_type = VIRTIO_PCI_CAP_SHARED_MEMORY_CFG,
+ };
+ uint32_t mask32 = ~0;
+
+ cap.cap.bar = bar;
+ cap.cap.id = id;
+ cap.cap.length = cpu_to_le32(length & mask32);
+ cap.length_hi = cpu_to_le32((length >> 32) & mask32);
+ cap.cap.offset = cpu_to_le32(offset & mask32);
+ cap.offset_hi = cpu_to_le32((offset >> 32) & mask32);
+
+ return virtio_pci_add_mem_cap(proxy, &cap.cap);
+}
+
static uint64_t virtio_pci_common_read(void *opaque, hwaddr addr,
unsigned size)
{
diff --git a/hw/virtio/virtio-pci.h b/hw/virtio/virtio-pci.h
index 2446dcd9ae..5e5c4a4c6d 100644
--- a/hw/virtio/virtio-pci.h
+++ b/hw/virtio/virtio-pci.h
@@ -252,4 +252,8 @@ void virtio_pci_types_register(const VirtioPCIDeviceTypeInfo *t);
*/
unsigned virtio_pci_optimal_num_queues(unsigned fixed_queues);
+int virtio_pci_add_shm_cap(VirtIOPCIProxy *proxy,
+ uint8_t bar, uint64_t offset, uint64_t length,
+ uint8_t id);
+
#endif
--
2.31.1
More information about the Virtio-fs
mailing list