diff options
| author | Gavin Shan <gshan@redhat.com> | 2022-11-10 13:49:08 +0300 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2022-11-10 16:11:57 +0300 |
| commit | cf87ac739e488055a6046a410caa8f4da108948f (patch) | |
| tree | 0e41491aeff31658cfa271b4b8983d77556c8117 /include/linux/kvm_host.h | |
| parent | 590925a178a3c8e9b694bce8e55bf9851c4b92f4 (diff) | |
| download | linux-cf87ac739e488055a6046a410caa8f4da108948f.tar.xz | |
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
Diffstat (limited to 'include/linux/kvm_host.h')
| -rw-r--r-- | include/linux/kvm_host.h | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 00c3448ba7f8..648d663f32c4 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -153,10 +153,11 @@ static inline bool is_error_page(struct page *page) * Architecture-independent vcpu->requests bit members * Bits 3-7 are reserved for more arch-independent bits. */ -#define KVM_REQ_TLB_FLUSH (0 | KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP) -#define KVM_REQ_VM_DEAD (1 | KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP) -#define KVM_REQ_UNBLOCK 2 -#define KVM_REQUEST_ARCH_BASE 8 +#define KVM_REQ_TLB_FLUSH (0 | KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP) +#define KVM_REQ_VM_DEAD (1 | KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP) +#define KVM_REQ_UNBLOCK 2 +#define KVM_REQ_DIRTY_RING_SOFT_FULL 3 +#define KVM_REQUEST_ARCH_BASE 8 /* * KVM_REQ_OUTSIDE_GUEST_MODE exists is purely as way to force the vCPU to |