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65501a745d
This adds the core of the QEMU VFIO-based PCI device assignment driver.
To make use of this driver, enable CONFIG_VFIO, CONFIG_VFIO_IOMMU_TYPE1,
and CONFIG_VFIO_PCI in your host Linux kernel config. Load the vfio-pci
module. To assign device 0000:05:00.0 to a guest, do the following:
for dev in $(ls /sys/bus/pci/devices/0000:05:00.0/iommu_group/devices); do
vendor=$(cat /sys/bus/pci/devices/$dev/vendor)
device=$(cat /sys/bus/pci/devices/$dev/device)
if [ -e /sys/bus/pci/devices/$dev/driver ]; then
echo $dev > /sys/bus/pci/devices/$dev/driver/unbind
fi
echo $vendor $device > /sys/bus/pci/drivers/vfio-pci/new_id
done
See Documentation/vfio.txt in the Linux kernel tree for further
description of IOMMU groups and VFIO.
Then launch qemu including the option:
-device vfio-pci,host=0000:05:00.0
Legacy PCI interrupts (INTx) currently makes use of a kludge where we
trap BAR accesses and assume the access is in response to an interrupt,
therefore de-asserting and unmasking the interrupt. It's not quite as
targetted as using the EOI for this, but it's self contained and seems
to work across all architectures. The side-effect is a significant
performance slow-down for device in INTx mode. Some devices, like
graphics cards, don't really use their interrupt, so this can be turned
off with the x-intx=off option, which disables INTx alltogether. This
should be considered an experimental option until we refine this code.
Both MSI and MSI-X are supported and avoid these issues.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
115 lines
3.2 KiB
C
115 lines
3.2 KiB
C
/*
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* vfio based device assignment support
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*
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* Copyright Red Hat, Inc. 2012
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*
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* Authors:
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* Alex Williamson <alex.williamson@redhat.com>
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*
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* This work is licensed under the terms of the GNU GPL, version 2. See
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* the COPYING file in the top-level directory.
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*/
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#ifndef HW_VFIO_PCI_INT_H
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#define HW_VFIO_PCI_INT_H
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#include "qemu-common.h"
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#include "qemu-queue.h"
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#include "pci.h"
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#include "event_notifier.h"
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typedef struct VFIOBAR {
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off_t fd_offset; /* offset of BAR within device fd */
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int fd; /* device fd, allows us to pass VFIOBAR as opaque data */
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MemoryRegion mem; /* slow, read/write access */
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MemoryRegion mmap_mem; /* direct mapped access */
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void *mmap;
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size_t size;
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uint32_t flags; /* VFIO region flags (rd/wr/mmap) */
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uint8_t nr; /* cache the BAR number for debug */
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} VFIOBAR;
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typedef struct VFIOINTx {
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bool pending; /* interrupt pending */
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bool kvm_accel; /* set when QEMU bypass through KVM enabled */
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uint8_t pin; /* which pin to pull for qemu_set_irq */
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EventNotifier interrupt; /* eventfd triggered on interrupt */
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EventNotifier unmask; /* eventfd for unmask on QEMU bypass */
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PCIINTxRoute route; /* routing info for QEMU bypass */
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bool disabled;
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char *intx;
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} VFIOINTx;
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struct VFIODevice;
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typedef struct VFIOMSIVector {
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EventNotifier interrupt; /* eventfd triggered on interrupt */
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struct VFIODevice *vdev; /* back pointer to device */
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int virq; /* KVM irqchip route for QEMU bypass */
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bool use;
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} VFIOMSIVector;
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enum {
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VFIO_INT_NONE = 0,
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VFIO_INT_INTx = 1,
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VFIO_INT_MSI = 2,
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VFIO_INT_MSIX = 3,
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};
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struct VFIOGroup;
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typedef struct VFIOContainer {
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int fd; /* /dev/vfio/vfio, empowered by the attached groups */
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struct {
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/* enable abstraction to support various iommu backends */
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union {
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MemoryListener listener; /* Used by type1 iommu */
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};
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void (*release)(struct VFIOContainer *);
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} iommu_data;
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QLIST_HEAD(, VFIOGroup) group_list;
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QLIST_ENTRY(VFIOContainer) next;
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} VFIOContainer;
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/* Cache of MSI-X setup plus extra mmap and memory region for split BAR map */
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typedef struct VFIOMSIXInfo {
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uint8_t table_bar;
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uint8_t pba_bar;
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uint16_t entries;
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uint32_t table_offset;
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uint32_t pba_offset;
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MemoryRegion mmap_mem;
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void *mmap;
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} VFIOMSIXInfo;
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typedef struct VFIODevice {
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PCIDevice pdev;
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int fd;
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VFIOINTx intx;
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unsigned int config_size;
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off_t config_offset; /* Offset of config space region within device fd */
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unsigned int rom_size;
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off_t rom_offset; /* Offset of ROM region within device fd */
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int msi_cap_size;
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VFIOMSIVector *msi_vectors;
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VFIOMSIXInfo *msix;
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int nr_vectors; /* Number of MSI/MSIX vectors currently in use */
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int interrupt; /* Current interrupt type */
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VFIOBAR bars[PCI_NUM_REGIONS - 1]; /* No ROM */
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PCIHostDeviceAddress host;
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QLIST_ENTRY(VFIODevice) next;
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struct VFIOGroup *group;
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bool reset_works;
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} VFIODevice;
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typedef struct VFIOGroup {
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int fd;
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int groupid;
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VFIOContainer *container;
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QLIST_HEAD(, VFIODevice) device_list;
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QLIST_ENTRY(VFIOGroup) next;
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QLIST_ENTRY(VFIOGroup) container_next;
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} VFIOGroup;
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#endif /* HW_VFIO_PCI_INT_H */
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