This patch implements basic MSI-X support for virtio-rng.
The device uses the virtio preferred method of working with MSI-X by
creating one vector for configuration and one vector for each vq in the
device.
Signed-off-by: Sasha Levin <levinsasha928@xxxxxxxxx>
---
tools/kvm/include/kvm/pci.h | 16 +++++++++++++
tools/kvm/virtio/rng.c | 53 ++++++++++++++++++++++++++++++++++++++----
2 files changed, 64 insertions(+), 5 deletions(-)
diff --git a/tools/kvm/include/kvm/pci.h b/tools/kvm/include/kvm/pci.h
index a7532e3..27fa349 100644
--- a/tools/kvm/include/kvm/pci.h
+++ b/tools/kvm/include/kvm/pci.h
@@ -24,6 +24,21 @@ struct pci_config_address {
unsigned enable_bit : 1; /* 31 */
};
+struct msix_table {
+ u32 low;
+ u32 high;
+ u32 data;
+ u32 ctrl;
+};
+
+struct msix_cap {
+ u8 cap;
+ u8 next;
+ u16 table_size;
+ u32 table_offset;
+ struct msix_table table[3 * PCI_MSIX_ENTRY_SIZE];
+};
+
struct pci_device_header {
u16 vendor_id;
u16 device_id;
@@ -47,6 +62,7 @@ struct pci_device_header {
u8 irq_pin;
u8 min_gnt;
u8 max_lat;
+ struct msix_cap msix;
};
void pci__init(void);
diff --git a/tools/kvm/virtio/rng.c b/tools/kvm/virtio/rng.c
index 1a7f569..6841623 100644
--- a/tools/kvm/virtio/rng.c
+++ b/tools/kvm/virtio/rng.c
@@ -39,6 +39,8 @@ struct rng_dev {
u8 isr;
u16 config_vector;
int fd;
+ u32 vq_vector[NUM_VIRT_QUEUES];
+ u32 msix_io_block;
/* virtio queue */
u16 queue_selector;
@@ -81,6 +83,9 @@ static bool virtio_rng_pci_io_in(struct ioport *ioport, struct kvm *kvm, u16 por
case VIRTIO_MSI_CONFIG_VECTOR:
ioport__write16(data, rdev->config_vector);
break;
+ case VIRTIO_MSI_QUEUE_VECTOR:
+ ioport__write16(data, rdev->vq_vector[rdev->queue_selector]);
+ break;
default:
ret = false;
break;
@@ -109,10 +114,10 @@ static void virtio_rng_do_io(struct kvm *kvm, void *param)
struct virt_queue *vq = job->vq;
struct rng_dev *rdev = job->rdev;
- while (virt_queue__available(vq)) {
+ while (virt_queue__available(vq))
virtio_rng_do_io_request(kvm, rdev, vq);
- virt_queue__trigger_irq(vq, rdev->pci_hdr.irq_line, &rdev->isr, kvm);
- }
+
+ kvm__irq_line(kvm, rdev->pci_hdr.irq_line, VIRTIO_IRQ_HIGH);
}
static bool virtio_rng_pci_io_out(struct ioport *ioport, struct kvm *kvm, u16 port, void *data, int size, u32 count)
@@ -125,7 +130,6 @@ static bool virtio_rng_pci_io_out(struct ioport *ioport, struct kvm *kvm, u16 po
offset = port - rdev->base_addr;
switch (offset) {
- case VIRTIO_MSI_QUEUE_VECTOR:
case VIRTIO_PCI_GUEST_FEATURES:
break;
case VIRTIO_PCI_QUEUE_PFN: {
@@ -163,8 +167,21 @@ static bool virtio_rng_pci_io_out(struct ioport *ioport, struct kvm *kvm, u16 po
rdev->status = ioport__read8(data);
break;
case VIRTIO_MSI_CONFIG_VECTOR:
- rdev->config_vector = VIRTIO_MSI_NO_VECTOR;
+ rdev->config_vector = ioport__read16(data);
break;
+ case VIRTIO_MSI_QUEUE_VECTOR:
+ {
+ u32 gsi;
+ u32 vec;
+
+ vec = rdev->vq_vector[rdev->queue_selector] = ioport__read16(data);
+
+ gsi = irq__add_msix_route(rdev->pci_hdr.msix.table[vec].low,
+ rdev->pci_hdr.msix.table[vec].high,
+ rdev->pci_hdr.msix.table[vec].data);
+ rdev->pci_hdr.irq_line = gsi;
+ break;
+ }
default:
ret = false;
break;
@@ -185,6 +202,16 @@ static void ioevent_callback(struct kvm *kvm, void *param)
thread_pool__do_job(&job->job_id);
}
+static void callback_mmio(u64 addr, u8 *data, u32 len, u8 is_write, void *ptr)
+{
+ struct rng_dev *rdev = ptr;
+ void *table = &rdev->pci_hdr.msix.table;
+ if (is_write)
+ memcpy(table + addr - rdev->msix_io_block, data, len);
+ else
+ memcpy(data, table + addr - rdev->msix_io_block, len);
+}
+
void virtio_rng__init(struct kvm *kvm)
{
u8 pin, line, dev, i;
@@ -196,7 +223,10 @@ void virtio_rng__init(struct kvm *kvm)
if (rdev == NULL)
return;
+ rdev->msix_io_block = pci_get_io_space_block();
+
rdev_base_addr = ioport__register(IOPORT_EMPTY, &virtio_rng_io_ops, IOPORT_SIZE, rdev);
+ kvm__register_mmio(kvm, rdev->msix_io_block, 0x100, callback_mmio, rdev);
rdev->pci_hdr = (struct pci_device_header) {
.vendor_id = PCI_VENDOR_ID_REDHAT_QUMRANET,
@@ -207,8 +237,21 @@ void virtio_rng__init(struct kvm *kvm)
.subsys_vendor_id = PCI_SUBSYSTEM_VENDOR_ID_REDHAT_QUMRANET,
.subsys_id = VIRTIO_ID_RNG,
.bar[0] = rdev_base_addr | PCI_BASE_ADDRESS_SPACE_IO,
+ .bar[1] = rdev->msix_io_block |
+ PCI_BASE_ADDRESS_SPACE_MEMORY |
+ PCI_BASE_ADDRESS_MEM_TYPE_64,
+ /* bar[2] is the continuation of bar[1] for 64bit addressing */
+ .bar[2] = 0,
+ .status = PCI_STATUS_CAP_LIST,
+ .capabilities = (void *)&rdev->pci_hdr.msix - (void *)&rdev->pci_hdr,
};
+ rdev->pci_hdr.msix.cap = PCI_CAP_ID_MSIX;
+ rdev->pci_hdr.msix.next = 0;
+ rdev->pci_hdr.msix.table_size = (NUM_VIRT_QUEUES + 1) | PCI_MSIX_FLAGS_ENABLE;
+ rdev->pci_hdr.msix.table_offset = 1; /* Use BAR 1 */
+
+ rdev->config_vector = 0;
rdev->base_addr = rdev_base_addr;
rdev->fd = open("/dev/urandom", O_RDONLY);
if (rdev->fd < 0)
--
1.7.6
--
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