From: Costin Lupu <costin.lupu@xxxxxxxxx>
Currently, the virtio base driver contains the implementation only for
virtio rings. The implementation was ported from Solo5 and adapted to
Unikraft APIs. Subsequent virtio drivers should depend on this base
driver.
This patch also introduces the plat/drivers/ directory which should
contain the drivers implementations which may be used by more than a
single platform.
Signed-off-by: Costin Lupu <costin.lupu@xxxxxxxxx>
Signed-off-by: Sharan Santhanam <sharan.santhanam@xxxxxxxxx>
---
include/uk/arch/atomic.h | 5 +
plat/Makefile.uk | 1 +
plat/common/include/pci/virtio/virtio_pci.h | 66 +++++++
plat/common/include/pci/virtio/virtio_ring.h | 276 +++++++++++++++++++++++++++
plat/drivers/virtio/virtio_ring.c | 169 ++++++++++++++++
plat/kvm/Config.uk | 8 +
plat/kvm/Makefile.uk | 8 +
7 files changed, 533 insertions(+)
create mode 100644 plat/common/include/pci/virtio/virtio_pci.h
create mode 100644 plat/common/include/pci/virtio/virtio_ring.h
create mode 100644 plat/drivers/virtio/virtio_ring.c
diff --git a/include/uk/arch/atomic.h b/include/uk/arch/atomic.h
index 331bd81..558067d 100644
--- a/include/uk/arch/atomic.h
+++ b/include/uk/arch/atomic.h
@@ -50,6 +50,11 @@ extern "C" {
#endif
/**
+ * Perform a atomic load operation.
+ */
+#define ukarch_load_n(src) \
+ __atomic_load_n(src, __ATOMIC_SEQ_CST)
+/**
* Writes *src into *dst, and returns the previous contents of *dst.
*/
#define ukarch_exchange(dst, src) \
diff --git a/plat/Makefile.uk b/plat/Makefile.uk
index 6ff632c..72155bd 100644
--- a/plat/Makefile.uk
+++ b/plat/Makefile.uk
@@ -1,5 +1,6 @@
UK_PLAT_BASE := $(CONFIG_UK_BASE)/plat
UK_PLAT_COMMON_BASE := $(UK_PLAT_BASE)/common
+UK_PLAT_DRIVERS_BASE:= $(UK_PLAT_BASE)/drivers
$(eval $(call _import_lib,$(UK_PLAT_BASE)/xen))
$(eval $(call _import_lib,$(UK_PLAT_BASE)/kvm))
diff --git a/plat/common/include/pci/virtio/virtio_pci.h
b/plat/common/include/pci/virtio/virtio_pci.h
new file mode 100644
index 0000000..6f9a6e1
--- /dev/null
+++ b/plat/common/include/pci/virtio/virtio_pci.h
@@ -0,0 +1,66 @@
+/* SPDX-License-Identifier: ISC */
+/*
+ * Authors: Dan Williams
+ * Costin Lupu <costin.lupu@xxxxxxxxx>
+ *
+ * Copyright (c) 2015, IBM
+ * Copyright (c) 2018, NEC Europe Ltd., NEC Corporation
+ *
+ * Permission to use, copy, modify, and/or distribute this software
+ * for any purpose with or without fee is hereby granted, provided
+ * that the above copyright notice and this permission notice appear
+ * in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
+ * AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
+ * OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
+ * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+/* Taken and adapted from solo5 virtio_pci.h */
+
+#ifndef __PLAT_CMN_PCI_VIRTIO_PCI_H__
+#define __PLAT_CMN_PCI_VIRTIO_PCI_H__
+
+/* virtio config space layout */
+/* TODO we currently support only the legacy interface */
+#define VIRTIO_PCI_HOST_FEATURES 0 /* 32-bit r/o */
+#define VIRTIO_PCI_GUEST_FEATURES 4 /* 32-bit r/w */
+#define VIRTIO_PCI_QUEUE_PFN 8 /* 32-bit r/w */
+#define VIRTIO_PCI_QUEUE_SIZE 12 /* 16-bit r/o */
+#define VIRTIO_PCI_QUEUE_SEL 14 /* 16-bit r/w */
+#define VIRTIO_PCI_QUEUE_NOTIFY 16 /* 16-bit r/w */
+
+/*
+ * Shift size used for writing physical queue address to QUEUE_PFN
+ */
+#define VIRTIO_PCI_QUEUE_ADDR_SHIFT 12
+
+
+/*
+ * The status register lets us tell the device where we are in
+ * initialization
+ */
+#define VIRTIO_PCI_STATUS 18 /* 8-bit r/w */
+#define VIRTIO_PCI_STATUS_ACK 0x1 /* we recognize device as virtio
*/
+#define VIRTIO_PCI_STATUS_DRIVER 0x2 /* we want to drive it */
+#define VIRTIO_PCI_STATUS_DRIVER_OK 0x4 /* initialization is complete */
+#define VIRTIO_PCI_STATUS_DEVICE_RESET 0x40 /* device needs reset */
+#define VIRTIO_PCI_STATUS_FAIL 0x80 /* tell device something's wrong
*/
+
+/*
+ * Reading the value will return the current contents of the interrupt
+ * status register and will also clear it. This is effectively a
+ * read-and-acknowledge.
+ */
+#define VIRTIO_PCI_ISR 19 /* 8-bit r/o */
+#define VIRTIO_PCI_ISR_HAS_INTR 0x1 /* interrupt is for this device */
+#define VIRTIO_PCI_ISR_CONFIG 0x2 /* config change bit */
+
+/* TODO Revisit when adding MSI support. */
+#define VIRTIO_PCI_CONFIG_OFF 20
+
+#endif /* __PLAT_CMN_PCI_VIRTIO_PCI_H__ */
diff --git a/plat/common/include/pci/virtio/virtio_ring.h
b/plat/common/include/pci/virtio/virtio_ring.h
new file mode 100644
index 0000000..82a006f
--- /dev/null
+++ b/plat/common/include/pci/virtio/virtio_ring.h
@@ -0,0 +1,276 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+/*
+ * Authors: Costin Lupu <costin.lupu@xxxxxxxxx>
+ *
+ * Copyright (c) 2018, NEC Europe Ltd., NEC Corporation. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the copyright holder nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * THIS HEADER MAY NOT BE EXTRACTED OR MODIFIED IN ANY WAY.
+ */
+/* An interface for efficient virtio implementation.
+ *
+ * This header is BSD licensed so anyone can use the definitions
+ * to implement compatible drivers/servers.
+ *
+ * Copyright 2007, 2009, IBM Corporation
+ * Copyright 2011, Red Hat, Inc
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of IBM nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL IBM OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifndef __PLAT_CMN_PCI_VIRTIO_RING_H__
+#define __PLAT_CMN_PCI_VIRTIO_RING_H__
+
+#include <uk/arch/limits.h>
+#include <uk/alloc.h>
+
+/*
+ * TODO In the future we may find that the Linux variant of virtio_ring.h
+ * (in include/uapi/linux/virtio_ring.h) may be more suitable for our needs.
+ */
+
+typedef __u16 __virtio_le16;
+typedef __u32 __virtio_le32;
+typedef __u64 __virtio_le64;
+
+#if __BYTE_ORDER__ != __ORDER_LITTLE_ENDIAN__
+#error "Please define conversion functions from host to little endian!"
+#endif
+
+/* This marks a buffer as continuing via the next field. */
+#define VIRTQ_DESC_F_NEXT 1
+/* This marks a buffer as write-only (otherwise read-only). */
+#define VIRTQ_DESC_F_WRITE 2
+/* This means the buffer contains a list of buffer descriptors. */
+#define VIRTQ_DESC_F_INDIRECT 4
+
+/*
+ * The device uses this in used->flags to advise the driver:
+ * don't kick me when you add a buffer. It's unreliable, so
+ * it's simply an optimization.
+ */
+#define VIRTQ_USED_F_NO_NOTIFY 1
+
+/*
+ * The driver uses this in avail->flags to advise the device:
+ * don't interrupt me when you consume a buffer. It's unreliable, so
+ * it's simply an optimization.
+ */
+#define VIRTQ_AVAIL_F_NO_INTERRUPT 1
+
+/* Support for indirect descriptors */
+#define VIRTIO_F_INDIRECT_DESC 28
+
+/* Support for avail_event and used_event fields */
+#define VIRTIO_F_EVENT_IDX 29
+
+/* Arbitrary descriptor layouts. */
+#define VIRTIO_F_ANY_LAYOUT 27
+
+
+/*
+ * Virtqueue descriptors: 16 bytes.
+ * These can chain together via "next".
+ */
+struct virtq_desc {
+ /* Address (guest-physical). */
+ __virtio_le64 addr;
+ /* Length. */
+ __virtio_le32 len;
+ /* The flags as indicated above. */
+ __virtio_le16 flags;
+ /* We chain unused descriptors via this, too */
+ __virtio_le16 next;
+};
+
+struct virtq_avail {
+ __virtio_le16 flags;
+ __virtio_le16 idx;
+ __virtio_le16 ring[];
+ /* Only if VIRTIO_F_EVENT_IDX: __virtio_le16 used_event; */
+};
+
+/* __virtio_le32 is used here for ids for padding reasons. */
+struct virtq_used_elem {
+ /* Index of start of used descriptor chain. */
+ __virtio_le32 id;
+ /* Total length of the descriptor chain which was written to. */
+ __virtio_le32 len;
+};
+
+struct virtq_used {
+ __virtio_le16 flags;
+ __virtio_le16 idx;
+ struct virtq_used_elem ring[];
+ /* Only if VIRTIO_F_EVENT_IDX: __virtio_le16 avail_event; */
+};
+
+/*
+ * TODO We set the maximum buffer length as it was in Solo5. The value
+ * was chosen for keeping the 12 byte header and 1514 bytes for the
+ * network packet. Support should be added in order to allow drivers
+ * to configure their own buffer sizes (adopting the Linux variant of
+ * virtio_ring.h would help on that matter).
+ */
+#define MAX_BUFFER_LEN 1526
+
+/*
+ * Each one of these io_buffer's map to a descriptor.
+ * An array of io_buffer's of size virtq->num (same
+ * as virtq->desc) is allocated during init.
+ */
+struct io_buffer {
+ __u8 data[MAX_BUFFER_LEN];
+
+ /*
+ * Data length in bytes. It is written by the driver on
+ * a tx/write, or by the device on a rx/read on interrupt
+ * handling.
+ */
+ __u32 len;
+
+ /* Extra flags to be added to the corresponding descriptor. */
+ __u16 extra_flags;
+};
+
+struct virtq {
+ unsigned int num;
+
+ struct virtq_desc *desc;
+ struct virtq_avail *avail;
+ struct virtq_used *used;
+ struct io_buffer *bufs;
+
+ /* Keep track of available (free) descriptors */
+ __u16 num_avail;
+
+ /* Indexes in the descriptors array */
+ __u16 last_used;
+ __u16 next_avail;
+};
+
+/*
+ * Helper macros for accessing virtqueue fields
+ */
+
+#define VIRTQ_OFF_DESC(q) 0
+
+#define VIRTQ_OFF_AVAIL(q) ((q)->num * sizeof(struct virtq_desc))
+#define VIRTQ_OFF_AVAIL_RING(q) \
+ (VIRTQ_OFF_AVAIL(q) + sizeof(struct virtq_avail))
+
+#define VIRTQ_OFF_PADDING(q) \
+ (VIRTQ_OFF_AVAIL_RING(q) + (sizeof(__virtio_le16) * (q)->num))
+
+#define VIRTQ_OFF_USED(q) \
+ ((VIRTQ_OFF_PADDING(q) + __PAGE_SIZE - 1) & __PAGE_MASK)
+#define VIRTQ_OFF_USED_RING(q) \
+ (VIRTQ_OFF_USED(q) + sizeof(struct virtq_used))
+
+#define VIRTQ_SIZE(q) \
+ (VIRTQ_OFF_USED_RING(q) + (sizeof(struct virtq_used_elem) * (q)->num))
+
+static inline
+int virtq_need_event(__u16 event_idx, __u16 new_idx, __u16 old_idx)
+{
+ return (new_idx - event_idx - 1) < (new_idx - old_idx);
+}
+
+/* Get location of event indices (only with VIRTIO_F_EVENT_IDX) */
+static inline __virtio_le16 *virtq_used_event(struct virtq *vq)
+{
+ /*
+ * For backwards compatibility, used event index
+ * is at *end* of avail ring.
+ */
+ return &vq->avail->ring[vq->num];
+}
+
+static inline __virtio_le16 *virtq_avail_event(struct virtq *vq)
+{
+ /*
+ * For backwards compatibility, avail event index
+ * is at *end* of used ring.
+ */
+ return (__virtio_le16 *) &vq->used->ring[vq->num];
+}
+
+/*
+ * Create a descriptor chain starting at index head,
+ * using vq->bufs also starting at index head.
+ * @param vq Virtual queue
+ * @param head Starting descriptor index
+ * @param num Number of descriptors (and number of bufs).
+ * @return 0 on success, < 0 otherwise
+ */
+int virtq_add_descriptor_chain(struct virtq *vq,
+ __u16 head, __u16 num);
+
+/*
+ * Initializes a virtual queue
+ * @param vq Virtual queue
+ * @param pci_base Base in PCI configuration space
+ * @param queue_select Virtual queue selector
+ * @param a Memory allocator
+ * @return 0 on success, < 0 otherwise
+ */
+int virtq_rings_init(struct virtq *vq, __u16 pci_base,
+ __virtio_le16 queue_select, struct uk_alloc *a);
+
+/*
+ * Deinitializes a virtual queue
+ * @param vq Virtual queue
+ * @param pci_base Base in PCI configuration space
+ * @param queue_select Virtual queue selector
+ * @param a Memory allocator
+ */
+void virtq_rings_fini(struct virtq *vq, __u16 pci_base,
+ __virtio_le16 queue_select, struct uk_alloc *a);
+
+#endif /* __PLAT_CMN_PCI_VIRTIO_RING_H__ */
diff --git a/plat/drivers/virtio/virtio_ring.c
b/plat/drivers/virtio/virtio_ring.c
new file mode 100644
index 0000000..098c324
--- /dev/null
+++ b/plat/drivers/virtio/virtio_ring.c
@@ -0,0 +1,169 @@
+/* SPDX-License-Identifier: ISC */
+/*
+ * Authors: Dan Williams
+ * Martin Lucina
+ * Ricardo Koller
+ * Costin Lupu <costin.lupu@xxxxxxxxx>
+ *
+ * Copyright (c) 2015-2017 IBM
+ * Copyright (c) 2016-2017 Docker, Inc.
+ * Copyright (c) 2018, NEC Europe Ltd., NEC Corporation
+ *
+ * Permission to use, copy, modify, and/or distribute this software
+ * for any purpose with or without fee is hereby granted, provided
+ * that the above copyright notice and this permission notice appear
+ * in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
+ * AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
+ * OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
+ * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+/* Taken and adapted from solo5 virtio_ring.c */
+
+#include <string.h>
+#include <uk/print.h>
+#include <cpu.h>
+#include <pci/virtio/virtio_pci.h>
+#include <pci/virtio/virtio_ring.h>
+#include <uk/arch/atomic.h>
+
+#define VIRTQ_MAX_QUEUE_SIZE 32768
+
+
+/*
+ * Create a descriptor chain starting at index head, using vq->bufs
+ * also starting at index head.
+ * Make sure the vq-bufs are cleaned before using them again.
+ */
+int virtq_add_descriptor_chain(struct virtq *vq, __u16 head, __u16 num)
+{
+ struct virtq_desc *desc;
+ __u16 used_descs, mask, i;
+
+ UK_ASSERT(vq != NULL);
+
+ if (head >= vq->num)
+ return -EINVAL;
+
+ if (num == 0 || num > vq->num)
+ return -EINVAL;
+
+ if (vq->num_avail < num) {
+ uk_printd(DLVL_WARN, "virtq full! next_avail:%"__PRIu16"
last_used:%"__PRIu16"\n",
+ vq->next_avail, vq->last_used);
+ return -ENOMEM;
+ }
+
+ used_descs = num;
+ mask = vq->num - 1;
+
+ for (i = head; used_descs > 0; used_descs--) {
+ struct io_buffer *buf = &vq->bufs[i];
+ __u32 len = 0;
+
+ /*
+ * The first field of a "struct io_buffer" is the "data" field,
+ * so in the interrupt handler we can just cast this pointer
+ * back into a 'struct io_buffer'.
+ */
+ UK_ASSERT(buf->data == (__u8 *) buf);
+
+ len = ukarch_load_n(&buf->len);
+ UK_ASSERT(len <= MAX_BUFFER_LEN);
+
+ desc = &vq->desc[i];
+ desc->addr = (__u64) buf->data;
+ desc->len = len;
+ desc->flags = VIRTQ_DESC_F_NEXT | buf->extra_flags;
+
+ i = (i + 1) & mask;
+ desc->next = i;
+ }
+
+ /* The last descriptor in the chain does not have a next */
+ desc->next = 0;
+ desc->flags &= ~VIRTQ_DESC_F_NEXT;
+
+ vq->num_avail -= num;
+ vq->avail->ring[vq->avail->idx & mask] = head;
+ /* The new entry must be set before announcing it. */
+ wmb();
+ /* avail->idx always increments and wraps naturally at 65536 */
+ vq->avail->idx++;
+ vq->next_avail += num;
+
+ return 0;
+}
+
+int virtq_rings_init(struct virtq *vq, __u16 pci_base,
+ __virtio_le16 queue_select, struct uk_alloc *a)
+{
+ __u8 *data = NULL;
+ __u16 vq_num;
+ __sz vq_size;
+
+ UK_ASSERT(vq != NULL);
+ UK_ASSERT(a != NULL);
+
+ /* read queue size */
+ outw(pci_base + VIRTIO_PCI_QUEUE_SEL, queue_select);
+ vq_num = inw(pci_base + VIRTIO_PCI_QUEUE_SIZE);
+
+ if (vq_num == 0) {
+ uk_printd(DLVL_ERR, "No such queue: pci_base=%"__PRIx16"
selector=%"__PRIx16"\n",
+ pci_base, queue_select);
+ return -EINVAL;
+ }
+
+ UK_ASSERT(vq_num <= VIRTQ_MAX_QUEUE_SIZE);
+
+ vq->last_used = vq->next_avail = 0;
+ vq->num = vq->num_avail = vq_num;
+
+ vq_size = VIRTQ_SIZE(vq);
+
+ /* allocate queue memory */
+ uk_posix_memalign_ifpages(a, (void **) &data, __PAGE_SIZE, vq_size);
+ if (!data)
+ return -ENOMEM;
+
+ memset(data, 0, vq_size);
+
+ vq->desc = (struct virtq_desc *) (data + VIRTQ_OFF_DESC(vq));
+ vq->avail = (struct virtq_avail *) (data + VIRTQ_OFF_AVAIL(vq));
+ vq->used = (struct virtq_used *) (data + VIRTQ_OFF_USED(vq));
+
+ /* set queue memory */
+ outw(pci_base + VIRTIO_PCI_QUEUE_SEL, queue_select);
+
+ /* TODO use physical address */
+ outl(pci_base + VIRTIO_PCI_QUEUE_PFN,
+ (__u64) data >> VIRTIO_PCI_QUEUE_ADDR_SHIFT);
+
+ return 0;
+}
+
+void virtq_rings_fini(struct virtq *vq, __u16 pci_base,
+ __virtio_le16 queue_select, struct uk_alloc *a)
+{
+ __u8 *data;
+
+ UK_ASSERT(vq != NULL);
+ UK_ASSERT(a != NULL);
+
+ /* reset queue memory */
+ outw(pci_base + VIRTIO_PCI_QUEUE_SEL, queue_select);
+ outl(pci_base + VIRTIO_PCI_QUEUE_PFN, 0);
+
+ /* free queue memory */
+ data = (__u8 *) vq->desc - VIRTQ_OFF_DESC(vq->num);
+ uk_free(a, data);
+
+ /* cleanup the queue */
+ memset(vq, 0, sizeof(*vq));
+}
diff --git a/plat/kvm/Config.uk b/plat/kvm/Config.uk
index 967a07b..118954d 100644
--- a/plat/kvm/Config.uk
+++ b/plat/kvm/Config.uk
@@ -17,4 +17,12 @@ config KVM_PCI
select LIBUKBUS
help
PCI bus driver for probing and operating PCI devices
+
+if (KVM_PCI)
+config KVM_PCI_VIRTIO
+ bool "Virtio Ring"
+ default n
+ help
+ Virtual queues to traverse host and guest transition
+endif
endif
diff --git a/plat/kvm/Makefile.uk b/plat/kvm/Makefile.uk
index c1e79a2..1ae1b08 100644
--- a/plat/kvm/Makefile.uk
+++ b/plat/kvm/Makefile.uk
@@ -8,6 +8,7 @@ $(eval $(call addplat_s,kvm,$(CONFIG_PLAT_KVM)))
##
$(eval $(call addplatlib,kvm,libkvmplat))
$(eval $(call addplatlib_s,kvm,libkvmpci,$(CONFIG_KVM_PCI)))
+$(eval $(call addplatlib_s,kvm,libkvmpcivirtio,$(CONFIG_KVM_PCI_VIRTIO)))
##
## Platform library definitions
@@ -46,3 +47,10 @@ LIBKVMPLAT_SRCS-y +=
$(UK_PLAT_COMMON_BASE)/memory.c|common
LIBKVMPCI_ASINCLUDES-$(CONFIG_ARCH_X86_64) +=
-I$(UK_PLAT_COMMON_BASE)/include
LIBKVMPCI_CINCLUDES-$(CONFIG_ARCH_X86_64) +=
-I$(UK_PLAT_COMMON_BASE)/include
LIBKVMPCI_SRCS-y +=
$(UK_PLAT_COMMON_BASE)/pci_bus.c|common
+
+##
+## Virtio library definitions
+##
+LIBKVMPCIVIRTIO_ASINCLUDES-y += -I$(UK_PLAT_COMMON_BASE)/include
+LIBKVMPCIVIRTIO_CINCLUDES-y += -I$(UK_PLAT_COMMON_BASE)/include
+LIBKVMPCIVIRTIO_SRCS-y += $(UK_PLAT_DRIVERS_BASE)/virtio/virtio_ring.c
