On Tue, 17 Aug 2021 01:26:39 +0100,
Jing Zhang <jingzhangos@xxxxxxxxxx> wrote:
>
> Add a new stat that counts the number of times a remote TLB flush is
> requested, regardless of whether it kicks vCPUs out of guest mode. This
> allows us to look at how often flushes are initiated.
nit: this is a very x86-centric view of things. On arm64, TLB
invalidation is broadcast in HW, and does not interrupt the guest
execution.
>
> Original-by: David Matlack <dmatlack@xxxxxxxxxx>
> Signed-off-by: Jing Zhang <jingzhangos@xxxxxxxxxx>
> ---
> arch/arm64/kvm/mmu.c | 1 +
> include/linux/kvm_host.h | 3 ++-
> include/linux/kvm_types.h | 1 +
> virt/kvm/kvm_main.c | 1 +
> 4 files changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
> index 0625bf2353c2..f5bb235bbb59 100644
> --- a/arch/arm64/kvm/mmu.c
> +++ b/arch/arm64/kvm/mmu.c
> @@ -80,6 +80,7 @@ static bool memslot_is_logging(struct kvm_memory_slot *memslot)
> */
> void kvm_flush_remote_tlbs(struct kvm *kvm)
> {
> + ++kvm->stat.generic.remote_tlb_flush_requests;
> kvm_call_hyp(__kvm_tlb_flush_vmid, &kvm->arch.mmu);
> }
We already have this queued for 5.15 [1].
Thanks,
M.
[1] https://lore.kernel.org/r/20210727103251.16561-1-pbonzini@xxxxxxxxxx
--
Without deviation from the norm, progress is not possible.
