linux/virt/kvm
Gavin Shan cf87ac739e KVM: x86: Introduce KVM_REQ_DIRTY_RING_SOFT_FULL
The VCPU isn't expected to be runnable when the dirty ring becomes soft
full, until the dirty pages are harvested and the dirty ring is reset
from userspace. So there is a check in each guest's entrace to see if
the dirty ring is soft full or not. The VCPU is stopped from running if
its dirty ring has been soft full. The similar check will be needed when
the feature is going to be supported on ARM64. As Marc Zyngier suggested,
a new event will avoid pointless overhead to check the size of the dirty
ring ('vcpu->kvm->dirty_ring_size') in each guest's entrance.

Add KVM_REQ_DIRTY_RING_SOFT_FULL. The event is raised when the dirty ring
becomes soft full in kvm_dirty_ring_push(). The event is only cleared in
the check, done in the newly added helper kvm_dirty_ring_check_request().
Since the VCPU is not runnable when the dirty ring becomes soft full, the
KVM_REQ_DIRTY_RING_SOFT_FULL event is always set to prevent the VCPU from
running until the dirty pages are harvested and the dirty ring is reset by
userspace.

kvm_dirty_ring_soft_full() becomes a private function with the newly added
helper kvm_dirty_ring_check_request(). The alignment for the various event
definitions in kvm_host.h is changed to tab character by the way. In order
to avoid using 'container_of()', the argument @ring is replaced by @vcpu
in kvm_dirty_ring_push().

Link: https://lore.kernel.org/kvmarm/87lerkwtm5.wl-maz@kernel.org
Suggested-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110104914.31280-2-gshan@redhat.com
2022-11-10 13:11:57 +00:00
..
async_pf.c KVM: Add helpers to wake/query blocking vCPU 2021-12-08 04:24:54 -05:00
async_pf.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 504 2019-06-19 17:09:56 +02:00
binary_stats.c KVM: stats: remove dead stores 2021-08-13 03:35:15 -04:00
coalesced_mmio.c KVM: mmio: Fix use-after-free Read in kvm_vm_ioctl_unregister_coalesced_mmio 2021-07-14 12:17:56 -04:00
coalesced_mmio.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
dirty_ring.c KVM: x86: Introduce KVM_REQ_DIRTY_RING_SOFT_FULL 2022-11-10 13:11:57 +00:00
eventfd.c KVM: eventfd: Fix false positive RCU usage warning 2022-05-20 09:10:33 -04:00
irqchip.c KVM/arm updates for 5.3 2019-07-11 15:14:16 +02:00
Kconfig KVM: Add KVM_CAP_DIRTY_LOG_RING_ACQ_REL capability and config option 2022-09-29 10:23:08 +01:00
kvm_main.c KVM: x86: Introduce KVM_REQ_DIRTY_RING_SOFT_FULL 2022-11-10 13:11:57 +00:00
kvm_mm.h KVM: SPDX style and spelling fixes 2022-04-21 13:16:13 -04:00
Makefile.kvm KVM: Reinstate gfn_to_pfn_cache with invalidation support 2022-01-07 10:44:44 -05:00
pfncache.c KVM: Rename mmu_notifier_* to mmu_invalidate_* 2022-08-19 04:05:41 -04:00
vfio.c vfio: Hold a reference to the iommu_group in kvm for SPAPR 2022-10-07 08:10:52 -06:00
vfio.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00