linux/virt/kvm/Kconfig
Gavin Shan 86bdf3ebcf KVM: Support dirty ring in conjunction with bitmap
ARM64 needs to dirty memory outside of a VCPU context when VGIC/ITS is
enabled. It's conflicting with that ring-based dirty page tracking always
requires a running VCPU context.

Introduce a new flavor of dirty ring that requires the use of both VCPU
dirty rings and a dirty bitmap. The expectation is that for non-VCPU
sources of dirty memory (such as the VGIC/ITS on arm64), KVM writes to
the dirty bitmap. Userspace should scan the dirty bitmap before migrating
the VM to the target.

Use an additional capability to advertise this behavior. The newly added
capability (KVM_CAP_DIRTY_LOG_RING_WITH_BITMAP) can't be enabled before
KVM_CAP_DIRTY_LOG_RING_ACQ_REL on ARM64. In this way, the newly added
capability is treated as an extension of KVM_CAP_DIRTY_LOG_RING_ACQ_REL.

Suggested-by: Marc Zyngier <maz@kernel.org>
Suggested-by: Peter Xu <peterx@redhat.com>
Co-developed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Gavin Shan <gshan@redhat.com>
Acked-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110104914.31280-4-gshan@redhat.com
2022-11-10 13:11:58 +00:00

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# SPDX-License-Identifier: GPL-2.0
# KVM common configuration items and defaults
config HAVE_KVM
bool
config HAVE_KVM_PFNCACHE
bool
config HAVE_KVM_IRQCHIP
bool
config HAVE_KVM_IRQFD
bool
config HAVE_KVM_IRQ_ROUTING
bool
config HAVE_KVM_DIRTY_RING
bool
# Only strongly ordered architectures can select this, as it doesn't
# put any explicit constraint on userspace ordering. They can also
# select the _ACQ_REL version.
config HAVE_KVM_DIRTY_RING_TSO
bool
select HAVE_KVM_DIRTY_RING
depends on X86
# Weakly ordered architectures can only select this, advertising
# to userspace the additional ordering requirements.
config HAVE_KVM_DIRTY_RING_ACQ_REL
bool
select HAVE_KVM_DIRTY_RING
# Allow enabling both the dirty bitmap and dirty ring. Only architectures
# that need to dirty memory outside of a vCPU context should select this.
config NEED_KVM_DIRTY_RING_WITH_BITMAP
bool
depends on HAVE_KVM_DIRTY_RING
config HAVE_KVM_EVENTFD
bool
select EVENTFD
config KVM_MMIO
bool
config KVM_ASYNC_PF
bool
# Toggle to switch between direct notification and batch job
config KVM_ASYNC_PF_SYNC
bool
config HAVE_KVM_MSI
bool
config HAVE_KVM_CPU_RELAX_INTERCEPT
bool
config KVM_VFIO
bool
config HAVE_KVM_ARCH_TLB_FLUSH_ALL
bool
config HAVE_KVM_INVALID_WAKEUPS
bool
config KVM_GENERIC_DIRTYLOG_READ_PROTECT
bool
config KVM_COMPAT
def_bool y
depends on KVM && COMPAT && !(S390 || ARM64 || RISCV)
config HAVE_KVM_IRQ_BYPASS
bool
config HAVE_KVM_VCPU_ASYNC_IOCTL
bool
config HAVE_KVM_VCPU_RUN_PID_CHANGE
bool
config HAVE_KVM_NO_POLL
bool
config KVM_XFER_TO_GUEST_WORK
bool
config HAVE_KVM_PM_NOTIFIER
bool