linux/drivers/xen
Viresh Kumar f8941e6c4c xen: privcmd: Add support for irqfd
Xen provides support for injecting interrupts to the guests via the
HYPERVISOR_dm_op() hypercall. The same is used by the Virtio based
device backend implementations, in an inefficient manner currently.

Generally, the Virtio backends are implemented to work with the Eventfd
based mechanism. In order to make such backends work with Xen, another
software layer needs to poll the Eventfds and raise an interrupt to the
guest using the Xen based mechanism. This results in an extra context
switch.

This is not a new problem in Linux though. It is present with other
hypervisors like KVM, etc. as well. The generic solution implemented in
the kernel for them is to provide an IOCTL call to pass the interrupt
details and eventfd, which lets the kernel take care of polling the
eventfd and raising of the interrupt, instead of handling this in user
space (which involves an extra context switch).

This patch adds support to inject a specific interrupt to guest using
the eventfd mechanism, by preventing the extra context switch.

Inspired by existing implementations for KVM, etc..

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/8e724ac1f50c2bc1eb8da9b3ff6166f1372570aa.1692697321.git.viresh.kumar@linaro.org
Signed-off-by: Juergen Gross <jgross@suse.com>
2023-08-22 12:12:50 +02:00
..
events xen/evtchn: Introduce new IOCTL to bind static evtchn 2023-07-26 08:42:34 +02:00
xen-pciback xen-pciback: Remove unused function declarations 2023-08-21 09:53:22 +02:00
xenbus xen/xenbus: Avoid a lockdep warning when adding a watch 2023-08-22 08:04:59 +02:00
xenfs xen: remove unnecessary (void*) conversions 2023-03-16 12:04:00 +01:00
acpi.c
arm-device.c
balloon.c xen: simplify sysctl registration for balloon 2023-04-13 11:49:20 -07:00
biomerge.c
cpu_hotplug.c
dbgp.c
efi.c efi: Apply allowlist to EFI configuration tables when running under Xen 2023-01-23 11:33:24 +01:00
evtchn.c xen/evtchn: Introduce new IOCTL to bind static evtchn 2023-07-26 08:42:34 +02:00
features.c x86/xen: Remove undefined behavior in setup_features() 2022-06-21 16:36:11 +02:00
gntalloc.c mm: replace vma->vm_flags direct modifications with modifier calls 2023-02-09 16:51:39 -08:00
gntdev-common.h xen/gntdev: Accommodate VMA splitting 2022-10-06 10:40:21 +02:00
gntdev-dmabuf.c xen/gntdev: Prepare to dynamic dma-buf locking specification 2022-10-18 01:21:47 +03:00
gntdev-dmabuf.h
gntdev.c mm: replace vma->vm_flags direct modifications with modifier calls 2023-02-09 16:51:39 -08:00
grant-dma-iommu.c xen/grant-dma-iommu: Implement a dummy probe_device() callback 2023-02-13 07:22:08 +01:00
grant-dma-ops.c xen/virtio: Fix NULL deref when a bridge of PCI root bus has no parent 2023-07-04 08:18:21 +02:00
grant-table.c xen: Fix one kernel-doc comment 2023-08-21 15:58:57 +02:00
Kconfig xen: privcmd: Add support for irqfd 2023-08-22 12:12:50 +02:00
Makefile xen/grant-dma-iommu: Introduce stub IOMMU driver 2022-06-06 16:07:30 +02:00
manage.c xen/manage: Use orderly_reboot() to reboot 2022-08-01 07:42:22 +02:00
mcelog.c
mem-reservation.c x86/xen: remove 32-bit pv leftovers 2021-11-02 08:03:43 -05:00
pci.c xen/pci: Make use of the helper macro LIST_HEAD() 2022-02-10 11:10:23 +01:00
pcpu.c ACPI: processor: Fix evaluating _PDC method when running as Xen dom0 2023-03-22 19:36:31 +01:00
platform-pci.c xen: Allow platform PCI interrupt to be shared 2023-02-13 06:53:20 +01:00
privcmd-buf.c mm: replace vma->vm_flags direct modifications with modifier calls 2023-02-09 16:51:39 -08:00
privcmd.c xen: privcmd: Add support for irqfd 2023-08-22 12:12:50 +02:00
privcmd.h
pvcalls-back.c workqueue: Ordered workqueue creation cleanups 2023-06-27 16:46:06 -07:00
pvcalls-front.c xen/pvcalls: don't call bind_evtchn_to_irqhandler() under lock 2023-04-24 07:27:10 +02:00
pvcalls-front.h
swiotlb-xen.c swiotlb-xen: fix DMA_ATTR_NO_KERNEL_MAPPING on arm 2022-05-11 19:48:32 +02:00
sys-hypervisor.c xen: sysfs: make kobj_type structure constant 2023-02-18 16:50:21 +01:00
time.c
unpopulated-alloc.c xen/balloon: don't use PV mode extra memory for zone device allocations 2022-04-07 15:08:37 -05:00
xen-acpi-pad.c ACPI: make remove callback of ACPI driver void 2022-11-23 19:11:22 +01:00
xen-acpi-processor.c xen: Switch to use kmemdup() helper 2023-08-21 09:54:05 +02:00
xen-balloon.c xen: Use DEVICE_ATTR_*() macro 2021-07-05 09:23:31 +02:00
xen-front-pgdir-shbuf.c xen: Replace one-element array with flexible-array member 2023-02-13 09:15:45 +01:00
xen-scsiback.c xen: branch for v6.4-rc1 2023-04-27 17:27:06 -07:00
xlate_mmu.c xen: unexport __init-annotated xen_xlate_map_ballooned_pages() 2022-06-07 08:11:35 +02:00