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Commit a463650c authored by Will Deacon's avatar Will Deacon
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kvm tools: pci: add MMIO interface to virtio-pci devices 



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: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarPekka Enberg <penberg@kernel.org>
parent c7575d17
Hide whitespace changes
Inline Side-by-side
include/kvm/virtio-pci.h
View file @ a463650c
......@@ -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;
......
virtio/pci.c
View file @ a463650c
......@@ -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;
}
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