From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sean Christopherson Date: Fri, 02 Apr 2021 00:56:58 +0000 Subject: [PATCH v2 10/10] KVM: x86/mmu: Allow yielding during MMU notifier unmap/zap, if possible Message-Id: <20210402005658.3024832-11-seanjc@google.com> List-Id: References: <20210402005658.3024832-1-seanjc@google.com> In-Reply-To: <20210402005658.3024832-1-seanjc@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Marc Zyngier , Huacai Chen , Aleksandar Markovic , Paul Mackerras , Paolo Bonzini Cc: James Morse , Julien Thierry , Suzuki K Poulose , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-mips@vger.kernel.org, kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, linux-kernel@vger.kernel.org, Ben Gardon Let the TDP MMU yield when unmapping a range in response to a MMU notification, if yielding is allowed by said notification. There is no reason to disallow yielding in this case, and in theory the range being invalidated could be quite large. Cc: Ben Gardon Signed-off-by: Sean Christopherson --- arch/x86/kvm/mmu/tdp_mmu.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index 7797d24f0937..dd17d9673ff2 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -885,7 +885,7 @@ bool kvm_tdp_mmu_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range, for_each_tdp_mmu_root(kvm, root, range->slot->as_id) flush |= zap_gfn_range(kvm, root, range->start, range->end, - false, flush); + range->may_block, flush); return flush; } @@ -903,6 +903,10 @@ static __always_inline bool kvm_tdp_mmu_handle_gfn(struct kvm *kvm, rcu_read_lock(); + /* + * Don't support rescheduling, none of the MMU notifiers that funnel + * into this helper allow blocking; it'd be dead, wasteful code. + */ for_each_tdp_mmu_root(kvm, root, range->slot->as_id) { tdp_root_for_each_leaf_pte(iter, root, range->start, range->end) ret |= handler(kvm, &iter, range); -- 2.31.0.208.g409f899ff0-goog