Commit a3704b91 authored by Andre Przywara's avatar Andre Przywara Committed by Will Deacon
Browse files

vfio: rework vfio_irq_set payload setting



struct vfio_irq_set from the kernel headers contains a variable sized
array to hold a payload. The vfio_irq_eventfd struct puts the "fd"
member right after this, hoping it to automatically fit in the payload slot.
But having a variable sized type not at the end of a struct is a GNU C
extension, so clang will refuse to compile this.

Solve this by somewhat doing the compiler's job and place the payload
manually at the end of the structure.
Reviewed-by: default avatarJean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: Andre Przywara's avatarAndre Przywara <andre.przywara@arm.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent 1ac5dce9
......@@ -9,11 +9,16 @@
#include <sys/time.h>
/* Wrapper around UAPI vfio_irq_set */
struct vfio_irq_eventfd {
union vfio_irq_eventfd {
struct vfio_irq_set irq;
int fd;
u8 buffer[sizeof(struct vfio_irq_set) + sizeof(int)];
};
static void set_vfio_irq_eventd_payload(union vfio_irq_eventfd *evfd, int fd)
{
memcpy(&evfd->irq.data, &fd, sizeof(fd));
}
#define msi_is_enabled(state) ((state) & VFIO_PCI_MSI_STATE_ENABLED)
#define msi_is_masked(state) ((state) & VFIO_PCI_MSI_STATE_MASKED)
#define msi_is_empty(state) ((state) & VFIO_PCI_MSI_STATE_EMPTY)
......@@ -38,7 +43,7 @@ static int vfio_pci_enable_msis(struct kvm *kvm, struct vfio_device *vdev,
int *eventfds;
struct vfio_pci_device *pdev = &vdev->pci;
struct vfio_pci_msi_common *msis = msix ? &pdev->msix : &pdev->msi;
struct vfio_irq_eventfd single = {
union vfio_irq_eventfd single = {
.irq = {
.argsz = sizeof(single),
.flags = VFIO_IRQ_SET_DATA_EVENTFD |
......@@ -117,7 +122,7 @@ static int vfio_pci_enable_msis(struct kvm *kvm, struct vfio_device *vdev,
continue;
single.irq.start = i;
single.fd = fd;
set_vfio_irq_eventd_payload(&single, fd);
ret = ioctl(vdev->fd, VFIO_DEVICE_SET_IRQS, &single);
if (ret < 0) {
......@@ -1021,8 +1026,8 @@ static int vfio_pci_enable_intx(struct kvm *kvm, struct vfio_device *vdev)
{
int ret;
int trigger_fd, unmask_fd;
struct vfio_irq_eventfd trigger;
struct vfio_irq_eventfd unmask;
union vfio_irq_eventfd trigger;
union vfio_irq_eventfd unmask;
struct vfio_pci_device *pdev = &vdev->pci;
int gsi = pdev->intx_gsi;
......@@ -1058,7 +1063,7 @@ static int vfio_pci_enable_intx(struct kvm *kvm, struct vfio_device *vdev)
.start = 0,
.count = 1,
};
trigger.fd = trigger_fd;
set_vfio_irq_eventd_payload(&trigger, trigger_fd);
ret = ioctl(vdev->fd, VFIO_DEVICE_SET_IRQS, &trigger);
if (ret < 0) {
......@@ -1073,7 +1078,7 @@ static int vfio_pci_enable_intx(struct kvm *kvm, struct vfio_device *vdev)
.start = 0,
.count = 1,
};
unmask.fd = unmask_fd;
set_vfio_irq_eventd_payload(&unmask, unmask_fd);
ret = ioctl(vdev->fd, VFIO_DEVICE_SET_IRQS, &unmask);
if (ret < 0) {
......
Supports Markdown
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment