kvm: Implement virtqueues for virtio block device

This patch implements virtqueues for virtio block device. It doesn't handle the
I/O requests on the vring yet, though.

Signed-off-by: Pekka Enberg <penberg@kernel.org>

diff --git a/tools/kvm/blk-virtio.c b/tools/kvm/blk-virtio.c
index 580b45b88389ea4fd28c1fd8107cdac2c8691a37..9f98805761ca46d47150cc9ff55cc7de697e154e 100644 (file)
--- a/tools/kvm/blk-virtio.c
+++ b/tools/kvm/blk-virtio.c
@@ -1,5 +1,6 @@
 #include "kvm/blk-virtio.h"
 
+#include "kvm/virtio_ring.h"
 #include "kvm/virtio_blk.h"
 #include "kvm/virtio_pci.h"
 #include "kvm/ioport.h"
@@ -8,6 +9,15 @@
 
 #define VIRTIO_BLK_IRQ         14
 
+#define NUM_VIRT_QUEUES                1
+
+#define VIRTIO_BLK_QUEUE_SIZE  16
+
+struct virt_queue {
+       uint32_t                        pfn;
+       struct vring                    vring;
+};
+
 struct device {
        struct virtio_blk_config        blk_config;
        uint32_t                        host_features;
@@ -16,8 +26,9 @@ struct device {
        uint8_t                         status;
 
        /* virtio queue */
-       uint32_t                        queue_pfn;
        uint16_t                        queue_selector;
+
+       struct virt_queue               virt_queues[NUM_VIRT_QUEUES];
 };
 
 #define DISK_CYLINDERS 1024
@@ -66,10 +77,10 @@ static bool blk_virtio_in(struct kvm *self, uint16_t port, void *data, int size,
        case VIRTIO_PCI_GUEST_FEATURES:
                return false;
        case VIRTIO_PCI_QUEUE_PFN:
-               ioport__write32(data, 0x00);
+               ioport__write32(data, device.virt_queues[device.queue_selector].pfn);
                break;
        case VIRTIO_PCI_QUEUE_NUM:
-               ioport__write16(data, 0x10);
+               ioport__write16(data, VIRTIO_BLK_QUEUE_SIZE);
                break;
        case VIRTIO_PCI_QUEUE_SEL:
        case VIRTIO_PCI_QUEUE_NOTIFY:
@@ -101,15 +112,34 @@ static bool blk_virtio_out(struct kvm *self, uint16_t port, void *data, int size
        case VIRTIO_PCI_GUEST_FEATURES:
                device.guest_features   = ioport__read32(data);
                break;
-       case VIRTIO_PCI_QUEUE_PFN:
-               device.queue_pfn        = ioport__read32(data);
+       case VIRTIO_PCI_QUEUE_PFN: {
+               struct virt_queue *queue;
+               void *p;
+
+               queue                   = &device.virt_queues[device.queue_selector];
+
+               queue->pfn              = ioport__read32(data);
+
+               p                       = guest_flat_to_host(self, queue->pfn << 12);
+
+               vring_init(&queue->vring, VIRTIO_BLK_QUEUE_SIZE, p, 4096);
+
                break;
+       }
        case VIRTIO_PCI_QUEUE_SEL:
                device.queue_selector   = ioport__read16(data);
                break;
-       case VIRTIO_PCI_QUEUE_NOTIFY:
+       case VIRTIO_PCI_QUEUE_NOTIFY: {
+               struct virt_queue *queue;
+               uint16_t queue_index;
+
+               queue_index             = ioport__read16(data);
+
+               queue                   = &device.virt_queues[queue_index];
+
                kvm__irq_line(self, VIRTIO_BLK_IRQ, 1);
                break;
+       }
        case VIRTIO_PCI_STATUS:
                device.status           = ioport__read8(data);
                break;