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authorGavin Shan <gshan@redhat.com>2022-11-10 13:49:10 +0300
committerMarc Zyngier <maz@kernel.org>2022-11-10 16:11:58 +0300
commit86bdf3ebcfe1ded055282536fecce13001874740 (patch)
treea5d026afbabe42b47025a8f9fdcec9e652898d47 /include/linux/kvm_dirty_ring.h
parente8a18565e59303ac12c626a161d72bd890bd2062 (diff)
downloadlinux-86bdf3ebcfe1ded055282536fecce13001874740.tar.xz
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
Diffstat (limited to 'include/linux/kvm_dirty_ring.h')
-rw-r--r--include/linux/kvm_dirty_ring.h7
1 files changed, 7 insertions, 0 deletions
diff --git a/include/linux/kvm_dirty_ring.h b/include/linux/kvm_dirty_ring.h
index 199ead37b104..4862c98d80d3 100644
--- a/include/linux/kvm_dirty_ring.h
+++ b/include/linux/kvm_dirty_ring.h
@@ -37,6 +37,11 @@ static inline u32 kvm_dirty_ring_get_rsvd_entries(void)
return 0;
}
+static inline bool kvm_use_dirty_bitmap(struct kvm *kvm)
+{
+ return true;
+}
+
static inline int kvm_dirty_ring_alloc(struct kvm_dirty_ring *ring,
int index, u32 size)
{
@@ -67,6 +72,8 @@ static inline void kvm_dirty_ring_free(struct kvm_dirty_ring *ring)
#else /* CONFIG_HAVE_KVM_DIRTY_RING */
int kvm_cpu_dirty_log_size(void);
+bool kvm_use_dirty_bitmap(struct kvm *kvm);
+bool kvm_arch_allow_write_without_running_vcpu(struct kvm *kvm);
u32 kvm_dirty_ring_get_rsvd_entries(void);
int kvm_dirty_ring_alloc(struct kvm_dirty_ring *ring, int index, u32 size);