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KVM: x86: hyper-v: Avoid calling kvm_make_vcpus_request_mask() with vcpu_mask==NULL

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commit 6470accc7ba948b0b3aca22b273fe84ec638a116 upstream.

In preparation to making kvm_make_vcpus_request_mask() use for_each_set_bit()
switch kvm_hv_flush_tlb() to calling kvm_make_all_cpus_request() for 'all cpus'
case.

Note: kvm_make_all_cpus_request() (unlike kvm_make_vcpus_request_mask())
currently dynamically allocates cpumask on each call and this is suboptimal.
Both kvm_make_all_cpus_request() and kvm_make_vcpus_request_mask() are
going to be switched to using pre-allocated per-cpu masks.

Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210903075141.403071-4-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Mathias Krause <minipli@grsecurity.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Vitaly Kuznetsov 2021-09-03 09:51:36 +02:00 committed by Greg Kroah-Hartman
parent 6f682b070f
commit 52e7ac8499
1 changed files with 9 additions and 6 deletions
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15
arch/x86/kvm/hyperv.c
View File

@ -1846,16 +1846,19 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc)
cpumask_clear(&hv_vcpu->tlb_flush);
vcpu_mask = all_cpus ? NULL :
sparse_set_to_vcpu_mask(kvm, sparse_banks, valid_bank_mask,
vp_bitmap, vcpu_bitmap);
/*
* 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 address space.
*/
kvm_make_vcpus_request_mask(kvm, KVM_REQ_TLB_FLUSH_GUEST,
NULL, vcpu_mask, &hv_vcpu->tlb_flush);
if (all_cpus) {
kvm_make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH_GUEST);
} else {
vcpu_mask = sparse_set_to_vcpu_mask(kvm, sparse_banks, valid_bank_mask,
vp_bitmap, vcpu_bitmap);
kvm_make_vcpus_request_mask(kvm, KVM_REQ_TLB_FLUSH_GUEST,
NULL, vcpu_mask, &hv_vcpu->tlb_flush);
}
ret_success:
/* We always do full TLB flush, set 'Reps completed' = 'Rep Count' */