Re: [PATCH] KVM: stats: Add VM stat for remote tlb flush requests
From: Marc Zyngier <maz@kernel.org>
Date: 2021-08-18 08:12:05
Also in:
kvmarm
On Tue, 17 Aug 2021 01:26:39 +0100, Jing Zhang [off-list ref] 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.
quoted hunk ↗ jump to hunk
Original-by: David Matlack [off-list ref] Signed-off-by: Jing Zhang <redacted> --- 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@redhat.com (local) -- Without deviation from the norm, progress is not possible.