| Message ID | 20231016221228.1348318-1-dmatlack@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: x86/mmu: Stop kicking vCPUs to sync the dirty log when PML is disabled | expand |
On Mon, 16 Oct 2023 15:12:28 -0700, David Matlack wrote: > Stop kicking vCPUs in kvm_arch_sync_dirty_log() when PML is disabled. > Kicking vCPUs when PML is disabled serves no purpose and could > negatively impact guest performance. > > This restores KVM's behavior to prior to 5.12 commit a018eba53870 ("KVM: > x86: Move MMU's PML logic to common code"), which replaced a > static_call_cond(kvm_x86_flush_log_dirty) with unconditional calls to > kvm_vcpu_kick(). > > [...] Applied to kvm-x86 misc, thanks! [1/1] KVM: x86/mmu: Stop kicking vCPUs to sync the dirty log when PML is disabled https://github.com/kvm-x86/linux/commit/3d30bfcbdc26 -- https://github.com/kvm-x86/linux/tree/next
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 41cce5031126..af97de19b2ce 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6259,6 +6259,9 @@ void kvm_arch_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot) struct kvm_vcpu *vcpu; unsigned long i; + if (!kvm_x86_ops.cpu_dirty_log_size) + return; + kvm_for_each_vcpu(i, vcpu, kvm) kvm_vcpu_kick(vcpu); }
Stop kicking vCPUs in kvm_arch_sync_dirty_log() when PML is disabled. Kicking vCPUs when PML is disabled serves no purpose and could negatively impact guest performance. This restores KVM's behavior to prior to 5.12 commit a018eba53870 ("KVM: x86: Move MMU's PML logic to common code"), which replaced a static_call_cond(kvm_x86_flush_log_dirty) with unconditional calls to kvm_vcpu_kick(). Fixes: a018eba53870 ("KVM: x86: Move MMU's PML logic to common code") Signed-off-by: David Matlack <dmatlack@google.com> --- arch/x86/kvm/x86.c | 3 +++ 1 file changed, 3 insertions(+) base-commit: ba8c993c3748931a307648616f68892bcb6afe28