A new version of the VMCI device will introduce two new major changes:
- support MMIO access to device registers
- support send/receive of datagrams using DMA transfers instead of
ioread8_rep/iowrite8_rep operations
This patch series updates the VMCI driver to support these new
features while maintaining backwards compatibility.
The DMA based datagram operations use a send and a receive buffer
allocated at module load time. The buffer contains a header
describing the layout of the buffer followed by either an SG list or
inline data. The header also contains a flag indicating whether the
buffer is currently owned by the driver or the device. Both for send
and receive, the driver will initialize the buffer, transfer ownership
to the device by writing the buffer address to a register, and then
wait for the ownership to be transferred back. The device will
generate an interrupt when this happens.
Jorgen Hansen (8):
VMCI: dma dg: whitespace formatting change for vmci register defines
VMCI: dma dg: add MMIO access to registers
VMCI: dma dg: detect DMA datagram capability
VMCI: dma dg: set OS page size
VMCI: dma dg: register dummy IRQ handlers for DMA datagrams
VMCI: dma dg: allocate send and receive buffers for DMA datagrams
VMCI: dma dg: add support for DMA datagrams sends
VMCI: dma dg: add support for DMA datagrams receive
drivers/misc/vmw_vmci/vmci_guest.c | 339 ++++++++++++++++++++++++-----
include/linux/vmw_vmci_defs.h | 84 ++++++-
2 files changed, 360 insertions(+), 63 deletions(-)
--
2.25.1
Detect the VMCI DMA datagram capability, and if present, ack it
to the device.
Reviewed-by: Vishnu Dasa <[email protected]>
Signed-off-by: Jorgen Hansen <[email protected]>
---
drivers/misc/vmw_vmci/vmci_guest.c | 11 +++++++++++
include/linux/vmw_vmci_defs.h | 1 +
2 files changed, 12 insertions(+)
diff --git a/drivers/misc/vmw_vmci/vmci_guest.c b/drivers/misc/vmw_vmci/vmci_guest.c
index d00430e5aba3..4bd5891ff910 100644
--- a/drivers/misc/vmw_vmci/vmci_guest.c
+++ b/drivers/misc/vmw_vmci/vmci_guest.c
@@ -565,6 +565,17 @@ static int vmci_guest_probe_device(struct pci_dev *pdev,
}
}
+ if (mmio_base != NULL) {
+ if (capabilities & VMCI_CAPS_DMA_DATAGRAM) {
+ caps_in_use |= VMCI_CAPS_DMA_DATAGRAM;
+ } else {
+ dev_err(&pdev->dev,
+ "Missing capability: VMCI_CAPS_DMA_DATAGRAM\n");
+ error = -ENXIO;
+ goto err_free_data_buffer;
+ }
+ }
+
dev_info(&pdev->dev, "Using capabilities 0x%x\n", caps_in_use);
/* Let the host know which capabilities we intend to use. */
diff --git a/include/linux/vmw_vmci_defs.h b/include/linux/vmw_vmci_defs.h
index 8fc00e2685cf..1ce2cffdc3ae 100644
--- a/include/linux/vmw_vmci_defs.h
+++ b/include/linux/vmw_vmci_defs.h
@@ -39,6 +39,7 @@
#define VMCI_CAPS_DATAGRAM BIT(2)
#define VMCI_CAPS_NOTIFICATIONS BIT(3)
#define VMCI_CAPS_PPN64 BIT(4)
+#define VMCI_CAPS_DMA_DATAGRAM BIT(5)
/* Interrupt Cause register bits. */
#define VMCI_ICR_DATAGRAM BIT(0)
--
2.25.1
Tell the device the page size used by the OS.
Reviewed-by: Vishnu Dasa <[email protected]>
Signed-off-by: Jorgen Hansen <[email protected]>
---
drivers/misc/vmw_vmci/vmci_guest.c | 9 +++++++++
include/linux/vmw_vmci_defs.h | 1 +
2 files changed, 10 insertions(+)
diff --git a/drivers/misc/vmw_vmci/vmci_guest.c b/drivers/misc/vmw_vmci/vmci_guest.c
index 4bd5891ff910..ec76661bde7e 100644
--- a/drivers/misc/vmw_vmci/vmci_guest.c
+++ b/drivers/misc/vmw_vmci/vmci_guest.c
@@ -581,6 +581,15 @@ static int vmci_guest_probe_device(struct pci_dev *pdev,
/* Let the host know which capabilities we intend to use. */
vmci_write_reg(vmci_dev, caps_in_use, VMCI_CAPS_ADDR);
+ if (caps_in_use & VMCI_CAPS_DMA_DATAGRAM) {
+ uint32_t page_shift;
+
+ /* Let the device know the size for pages passed down. */
+ vmci_write_reg(vmci_dev, PAGE_SHIFT, VMCI_GUEST_PAGE_SHIFT);
+ page_shift = vmci_read_reg(vmci_dev, VMCI_GUEST_PAGE_SHIFT);
+ dev_info(&pdev->dev, "Using page shift %d\n", page_shift);
+ }
+
/* Set up global device so that we can start sending datagrams */
spin_lock_irq(&vmci_dev_spinlock);
vmci_dev_g = vmci_dev;
diff --git a/include/linux/vmw_vmci_defs.h b/include/linux/vmw_vmci_defs.h
index 1ce2cffdc3ae..4167779469fd 100644
--- a/include/linux/vmw_vmci_defs.h
+++ b/include/linux/vmw_vmci_defs.h
@@ -21,6 +21,7 @@
#define VMCI_CAPS_ADDR 0x18
#define VMCI_RESULT_LOW_ADDR 0x1c
#define VMCI_RESULT_HIGH_ADDR 0x20
+#define VMCI_GUEST_PAGE_SHIFT 0x34
/* Max number of devices. */
#define VMCI_MAX_DEVICES 1
--
2.25.1
Update formatting of existing register defines in preparation for
adding additional register definitions for the VMCI device.
Reviewed-by: Vishnu Dasa <[email protected]>
Signed-off-by: Jorgen Hansen <[email protected]>
---
include/linux/vmw_vmci_defs.h | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)
diff --git a/include/linux/vmw_vmci_defs.h b/include/linux/vmw_vmci_defs.h
index e36cb114c188..9911ecfc18ba 100644
--- a/include/linux/vmw_vmci_defs.h
+++ b/include/linux/vmw_vmci_defs.h
@@ -12,15 +12,15 @@
#include <linux/bits.h>
/* Register offsets. */
-#define VMCI_STATUS_ADDR 0x00
-#define VMCI_CONTROL_ADDR 0x04
-#define VMCI_ICR_ADDR 0x08
-#define VMCI_IMR_ADDR 0x0c
-#define VMCI_DATA_OUT_ADDR 0x10
-#define VMCI_DATA_IN_ADDR 0x14
-#define VMCI_CAPS_ADDR 0x18
-#define VMCI_RESULT_LOW_ADDR 0x1c
-#define VMCI_RESULT_HIGH_ADDR 0x20
+#define VMCI_STATUS_ADDR 0x00
+#define VMCI_CONTROL_ADDR 0x04
+#define VMCI_ICR_ADDR 0x08
+#define VMCI_IMR_ADDR 0x0c
+#define VMCI_DATA_OUT_ADDR 0x10
+#define VMCI_DATA_IN_ADDR 0x14
+#define VMCI_CAPS_ADDR 0x18
+#define VMCI_RESULT_LOW_ADDR 0x1c
+#define VMCI_RESULT_HIGH_ADDR 0x20
/* Max number of devices. */
#define VMCI_MAX_DEVICES 1
--
2.25.1