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Message-Id: <20180628135313.17468-2-vkuznets@redhat.com>
Date: Thu, 28 Jun 2018 15:53:09 +0200
From: Vitaly Kuznetsov <vkuznets@...hat.com>
To: kvm@...r.kernel.org
Cc: x86@...nel.org, Paolo Bonzini <pbonzini@...hat.com>,
Radim Krčmář <rkrcmar@...hat.com>,
Roman Kagan <rkagan@...tuozzo.com>,
"K. Y. Srinivasan" <kys@...rosoft.com>,
Haiyang Zhang <haiyangz@...rosoft.com>,
Stephen Hemminger <sthemmin@...rosoft.com>,
"Michael Kelley (EOSG)" <Michael.H.Kelley@...rosoft.com>,
Mohammed Gamal <mmorsy@...hat.com>,
Cathy Avery <cavery@...hat.com>,
Wanpeng Li <wanpeng.li@...mail.com>,
linux-kernel@...r.kernel.org
Subject: [PATCH v2 1/5] KVM: x86: hyperv: optimize 'all cpus' case in kvm_hv_flush_tlb()
We can use 'NULL' to represent 'all cpus' case in
kvm_make_vcpus_request_mask() and avoid building vCPU mask with
all vCPUs.
Suggested-by: Radim Krčmář <rkrcmar@...hat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@...hat.com>
---
arch/x86/kvm/hyperv.c | 42 +++++++++++++++++++++++-------------------
virt/kvm/kvm_main.c | 6 ++----
2 files changed, 25 insertions(+), 23 deletions(-)
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index af8caf965baa..63a17bbbf0e5 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -1310,35 +1310,39 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *current_vcpu, u64 ingpa,
cpumask_clear(&hv_current->tlb_lush);
+ if (all_cpus) {
+ kvm_make_vcpus_request_mask(kvm,
+ KVM_REQ_TLB_FLUSH | KVM_REQUEST_NO_WAKEUP,
+ NULL, &hv_current->tlb_lush);
+ goto ret_success;
+ }
+
kvm_for_each_vcpu(i, vcpu, kvm) {
struct kvm_vcpu_hv *hv = &vcpu->arch.hyperv;
int bank = hv->vp_index / 64, sbank = 0;
- if (!all_cpus) {
- /* Banks >64 can't be represented */
- if (bank >= 64)
- continue;
-
- /* Non-ex hypercalls can only address first 64 vCPUs */
- if (!ex && bank)
- continue;
+ /* Banks >64 can't be represented */
+ if (bank >= 64)
+ continue;
- if (ex) {
- /*
- * Check is the bank of this vCPU is in sparse
- * set and get the sparse bank number.
- */
- sbank = get_sparse_bank_no(valid_bank_mask,
- bank);
+ /* Non-ex hypercalls can only address first 64 vCPUs */
+ if (!ex && bank)
+ continue;
- if (sbank < 0)
- continue;
- }
+ if (ex) {
+ /*
+ * Check is the bank of this vCPU is in sparse
+ * set and get the sparse bank number.
+ */
+ sbank = get_sparse_bank_no(valid_bank_mask, bank);
- if (!(sparse_banks[sbank] & BIT_ULL(hv->vp_index % 64)))
+ if (sbank < 0)
continue;
}
+ if (!(sparse_banks[sbank] & BIT_ULL(hv->vp_index % 64)))
+ continue;
+
/*
* vcpu->arch.cr3 may not be up-to-date for running vCPUs so we
* can't analyze it here, flush TLB regardless of the specified
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index ada21f47f22b..153f14e91fb1 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -213,7 +213,7 @@ bool kvm_make_vcpus_request_mask(struct kvm *kvm, unsigned int req,
me = get_cpu();
kvm_for_each_vcpu(i, vcpu, kvm) {
- if (!test_bit(i, vcpu_bitmap))
+ if (vcpu_bitmap && !test_bit(i, vcpu_bitmap))
continue;
kvm_make_request(req, vcpu);
@@ -237,12 +237,10 @@ bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req)
{
cpumask_var_t cpus;
bool called;
- static unsigned long vcpu_bitmap[BITS_TO_LONGS(KVM_MAX_VCPUS)]
- = {[0 ... BITS_TO_LONGS(KVM_MAX_VCPUS)-1] = ULONG_MAX};
zalloc_cpumask_var(&cpus, GFP_ATOMIC);
- called = kvm_make_vcpus_request_mask(kvm, req, vcpu_bitmap, cpus);
+ called = kvm_make_vcpus_request_mask(kvm, req, NULL, cpus);
free_cpumask_var(cpus);
return called;
--
2.14.4
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