This patch adds an MMIO interface for each virtio-pci device, so that
they can be accessed without having to use an ioport. For each device, a
new memory BAR is added which corresponds to an area of MMIO space with
a shim trap handler. This handler simply translates the access into an
ioport access via kvm__emulate_io. Since guests can generate accesses
via either the ioport or MMIO regions, an ioeventfd is registered for
both.
Signed-off-by: Will Deacon <will.deacon@xxxxxxx>
---
tools/kvm/include/kvm/virtio-pci.h | 4 +-
tools/kvm/virtio/pci.c | 111 +++++++++++++++++++++++++------------
2 files changed, 78 insertions(+), 37 deletions(-)
diff --git a/tools/kvm/include/kvm/virtio-pci.h b/tools/kvm/include/kvm/virtio-pci.h
index 9b063924e5da..c795ce71fa88 100644
--- a/tools/kvm/include/kvm/virtio-pci.h
+++ b/tools/kvm/include/kvm/virtio-pci.h
@@ -22,8 +22,10 @@ struct virtio_pci {
struct pci_device_header pci_hdr;
struct device_header dev_hdr;
void *dev;
+ struct kvm *kvm;
- u16 base_addr;
+ u16 port_addr;
+ u32 mmio_addr;
u8 status;
u8 isr;
u32 features;
diff --git a/tools/kvm/virtio/pci.c b/tools/kvm/virtio/pci.c
index 77c933fd4ab2..e1b5be6b036e 100644
--- a/tools/kvm/virtio/pci.c
+++ b/tools/kvm/virtio/pci.c
@@ -24,7 +24,8 @@ static int virtio_pci__init_ioeventfd(struct kvm *kvm, struct virtio_device *vde
{
struct ioevent ioevent;
struct virtio_pci *vpci = vdev->virtio;
- int r;
+ int i, r, flags = IOEVENTFD_FLAG_PIO;
+ int fds[2];
vpci->ioeventfds[vq] = (struct virtio_pci_ioevent_param) {
.vdev = vdev,
@@ -32,32 +33,44 @@ static int virtio_pci__init_ioeventfd(struct kvm *kvm, struct virtio_device *vde
};
ioevent = (struct ioevent) {
- .io_addr = vpci->base_addr + VIRTIO_PCI_QUEUE_NOTIFY,
- .io_len = sizeof(u16),
.fn = virtio_pci__ioevent_callback,
.fn_ptr = &vpci->ioeventfds[vq],
.datamatch = vq,
.fn_kvm = kvm,
- .fd = eventfd(0, 0),
};
- if (vdev->use_vhost)
- /*
- * Vhost will poll the eventfd in host kernel side,
- * no need to poll in userspace.
- */
- r = ioeventfd__add_event(&ioevent, IOEVENTFD_FLAG_PIO);
- else
- /* Need to poll in userspace. */
- r = ioeventfd__add_event(&ioevent, IOEVENTFD_FLAG_PIO |
- IOEVENTFD_FLAG_USER_POLL);
+ /*
+ * Vhost will poll the eventfd in host kernel side, otherwise we
+ * need to poll in userspace.
+ */
+ if (!vdev->use_vhost)
+ flags |= IOEVENTFD_FLAG_USER_POLL;
+
+ /* ioport */
+ ioevent.io_addr = vpci->port_addr + VIRTIO_PCI_QUEUE_NOTIFY;
+ ioevent.io_len = sizeof(u16);
+ ioevent.fd = fds[0] = eventfd(0, 0);
+ r = ioeventfd__add_event(&ioevent, flags);
if (r)
return r;
- if (vdev->ops->notify_vq_eventfd)
- vdev->ops->notify_vq_eventfd(kvm, vpci->dev, vq, ioevent.fd);
+ /* mmio */
+ ioevent.io_addr = vpci->mmio_addr + VIRTIO_PCI_QUEUE_NOTIFY;
+ ioevent.io_len = sizeof(u32);
+ ioevent.fd = fds[1] = eventfd(0, 0);
+ r = ioeventfd__add_event(&ioevent, flags);
+ if (r)
+ goto free_ioport_evt;
+ if (vdev->ops->notify_vq_eventfd)
+ for (i = 0; i < 2; ++i)
+ vdev->ops->notify_vq_eventfd(kvm, vpci->dev, vq,
+ fds[i]);
return 0;
+
+free_ioport_evt:
+ ioeventfd__del_event(vpci->port_addr + VIRTIO_PCI_QUEUE_NOTIFY, vq);
+ return r;
}
static inline bool virtio_pci__msix_enabled(struct virtio_pci *vpci)
@@ -105,7 +118,7 @@ static bool virtio_pci__io_in(struct ioport *ioport, struct kvm *kvm, u16 port,
vdev = ioport->priv;
vpci = vdev->virtio;
- offset = port - vpci->base_addr;
+ offset = port - vpci->port_addr;
switch (offset) {
case VIRTIO_PCI_HOST_FEATURES:
@@ -188,7 +201,7 @@ static bool virtio_pci__io_out(struct ioport *ioport, struct kvm *kvm, u16 port,
vdev = ioport->priv;
vpci = vdev->virtio;
- offset = port - vpci->base_addr;
+ offset = port - vpci->port_addr;
switch (offset) {
case VIRTIO_PCI_GUEST_FEATURES:
@@ -227,7 +240,8 @@ static struct ioport_operations virtio_pci__io_ops = {
.io_out = virtio_pci__io_out,
};
-static void virtio_pci__mmio_callback(u64 addr, u8 *data, u32 len, u8 is_write, void *ptr)
+static void virtio_pci__msix_mmio_callback(u64 addr, u8 *data, u32 len,
+ u8 is_write, void *ptr)
{
struct virtio_pci *vpci = ptr;
void *table;
@@ -307,6 +321,16 @@ int virtio_pci__signal_config(struct kvm *kvm, struct virtio_device *vdev)
return 0;
}
+static void virtio_pci__io_mmio_callback(u64 addr, u8 *data, u32 len,
+ u8 is_write, void *ptr)
+{
+ struct virtio_pci *vpci = ptr;
+ int direction = is_write ? KVM_EXIT_IO_OUT : KVM_EXIT_IO_IN;
+ u16 port = vpci->port_addr + (addr & (IOPORT_SIZE - 1));
+
+ kvm__emulate_io(vpci->kvm, port, data, direction, len, 1);
+}
+
int virtio_pci__init(struct kvm *kvm, void *dev, struct virtio_device *vdev,
int device_id, int subsys_id, int class)
{
@@ -314,19 +338,26 @@ int virtio_pci__init(struct kvm *kvm, void *dev, struct virtio_device *vdev,
u8 pin, line;
int r;
+ vpci->kvm = kvm;
vpci->dev = dev;
- vpci->msix_io_block = pci_get_io_space_block(PCI_IO_SIZE * 2);
r = ioport__register(kvm, IOPORT_EMPTY, &virtio_pci__io_ops, IOPORT_SIZE, vdev);
if (r < 0)
return r;
+ vpci->port_addr = (u16)r;
- vpci->base_addr = (u16)r;
- r = kvm__register_mmio(kvm, vpci->msix_io_block, PCI_IO_SIZE * 2, false,
- virtio_pci__mmio_callback, vpci);
+ vpci->mmio_addr = pci_get_io_space_block(IOPORT_SIZE);
+ r = kvm__register_mmio(kvm, vpci->mmio_addr, IOPORT_SIZE, false,
+ virtio_pci__io_mmio_callback, vpci);
if (r < 0)
goto free_ioport;
+ vpci->msix_io_block = pci_get_io_space_block(PCI_IO_SIZE * 2);
+ r = kvm__register_mmio(kvm, vpci->msix_io_block, PCI_IO_SIZE * 2, false,
+ virtio_pci__msix_mmio_callback, vpci);
+ if (r < 0)
+ goto free_mmio;
+
vpci->pci_hdr = (struct pci_device_header) {
.vendor_id = cpu_to_le16(PCI_VENDOR_ID_REDHAT_QUMRANET),
.device_id = cpu_to_le16(device_id),
@@ -337,14 +368,17 @@ int virtio_pci__init(struct kvm *kvm, void *dev, struct virtio_device *vdev,
.class[2] = (class >> 16) & 0xff,
.subsys_vendor_id = cpu_to_le16(PCI_SUBSYSTEM_VENDOR_ID_REDHAT_QUMRANET),
.subsys_id = cpu_to_le16(subsys_id),
- .bar[0] = cpu_to_le32(vpci->base_addr
+ .bar[0] = cpu_to_le32(vpci->mmio_addr
+ | PCI_BASE_ADDRESS_SPACE_MEMORY),
+ .bar[1] = cpu_to_le32(vpci->port_addr
| PCI_BASE_ADDRESS_SPACE_IO),
- .bar[1] = cpu_to_le32(vpci->msix_io_block
+ .bar[2] = cpu_to_le32(vpci->msix_io_block
| PCI_BASE_ADDRESS_SPACE_MEMORY),
.status = cpu_to_le16(PCI_STATUS_CAP_LIST),
.capabilities = (void *)&vpci->pci_hdr.msix - (void *)&vpci->pci_hdr,
.bar_size[0] = IOPORT_SIZE,
- .bar_size[1] = PCI_IO_SIZE * 2,
+ .bar_size[1] = IOPORT_SIZE,
+ .bar_size[2] = PCI_IO_SIZE * 2,
};
vpci->dev_hdr = (struct device_header) {
@@ -367,14 +401,14 @@ int virtio_pci__init(struct kvm *kvm, void *dev, struct virtio_device *vdev,
*/
vpci->pci_hdr.msix.ctrl = cpu_to_le16(VIRTIO_PCI_MAX_VQ + VIRTIO_PCI_MAX_CONFIG - 1);
- /* Both table and PBA are mapped to the same BAR (1) */
- vpci->pci_hdr.msix.table_offset = cpu_to_le32(1);
- vpci->pci_hdr.msix.pba_offset = cpu_to_le32(1 | PCI_IO_SIZE);
+ /* Both table and PBA are mapped to the same BAR (2) */
+ vpci->pci_hdr.msix.table_offset = cpu_to_le32(2);
+ vpci->pci_hdr.msix.pba_offset = cpu_to_le32(2 | PCI_IO_SIZE);
vpci->config_vector = 0;
r = irq__register_device(subsys_id, &pin, &line);
if (r < 0)
- goto free_mmio;
+ goto free_msix_mmio;
if (kvm__supports_extension(kvm, KVM_CAP_SIGNAL_MSI))
vpci->features |= VIRTIO_PCI_F_SIGNAL_MSI;
@@ -383,14 +417,16 @@ int virtio_pci__init(struct kvm *kvm, void *dev, struct virtio_device *vdev,
vpci->pci_hdr.irq_line = line;
r = device__register(&vpci->dev_hdr);
if (r < 0)
- goto free_ioport;
+ goto free_msix_mmio;
return 0;
-free_mmio:
+free_msix_mmio:
kvm__deregister_mmio(kvm, vpci->msix_io_block);
+free_mmio:
+ kvm__deregister_mmio(kvm, vpci->mmio_addr);
free_ioport:
- ioport__unregister(kvm, vpci->base_addr);
+ ioport__unregister(kvm, vpci->port_addr);
return r;
}
@@ -399,11 +435,14 @@ int virtio_pci__exit(struct kvm *kvm, struct virtio_device *vdev)
struct virtio_pci *vpci = vdev->virtio;
int i;
+ kvm__deregister_mmio(kvm, vpci->mmio_addr);
kvm__deregister_mmio(kvm, vpci->msix_io_block);
- ioport__unregister(kvm, vpci->base_addr);
+ ioport__unregister(kvm, vpci->port_addr);
- for (i = 0; i < VIRTIO_PCI_MAX_VQ; i++)
- ioeventfd__del_event(vpci->base_addr + VIRTIO_PCI_QUEUE_NOTIFY, i);
+ for (i = 0; i < VIRTIO_PCI_MAX_VQ; i++) {
+ ioeventfd__del_event(vpci->port_addr + VIRTIO_PCI_QUEUE_NOTIFY, i);
+ ioeventfd__del_event(vpci->mmio_addr + VIRTIO_PCI_QUEUE_NOTIFY, i);
+ }
return 0;
}
--
1.8.2.2
--
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