From: Sean Christopherson <seanjc@google.com>
To: Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
David Matlack <dmatlack@google.com>,
Isaku Yamahata <isaku.yamahata@intel.com>
Subject: [PATCH v4 11/11] KVM: x86/mmu: Stop needlessly making MMU pages available for TDP MMU
Date: Wed, 12 Oct 2022 18:17:02 +0000 [thread overview]
Message-ID: <20221012181702.3663607-12-seanjc@google.com> (raw)
In-Reply-To: <20221012181702.3663607-1-seanjc@google.com>
From: David Matlack <dmatlack@google.com>
Stop calling make_mmu_pages_available() when handling TDP MMU faults and
when allocating TDP MMU roots. The TDP MMU does not participate in the
"available MMU pages" tracking and limiting so calling this function is
unnecessary work when handling TDP MMU faults.
Signed-off-by: David Matlack <dmatlack@google.com>
[sean: apply to root allocation too]
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/mmu/mmu.c | 22 +++++++++++++---------
1 file changed, 13 insertions(+), 9 deletions(-)
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index a5ba7b41263d..0fcf4560f4d8 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -3569,9 +3569,12 @@ static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu)
int r;
write_lock(&vcpu->kvm->mmu_lock);
- r = make_mmu_pages_available(vcpu);
- if (r < 0)
- goto out_unlock;
+
+ if (!is_tdp_mmu_enabled()) {
+ r = make_mmu_pages_available(vcpu);
+ if (r < 0)
+ goto out_unlock;
+ }
if (is_tdp_mmu_enabled()) {
root = kvm_tdp_mmu_get_vcpu_root_hpa(vcpu);
@@ -4289,14 +4292,15 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
if (is_page_fault_stale(vcpu, fault))
goto out_unlock;
- r = make_mmu_pages_available(vcpu);
- if (r)
- goto out_unlock;
-
- if (is_tdp_mmu_enabled())
+ if (is_tdp_mmu_enabled()) {
r = kvm_tdp_mmu_map(vcpu, fault);
- else
+ } else {
+ r = make_mmu_pages_available(vcpu);
+ if (r)
+ goto out_unlock;
+
r = __direct_map(vcpu, fault);
+ }
out_unlock:
if (is_tdp_mmu_enabled())
--
2.38.0.rc1.362.ged0d419d3c-goog
next prev parent reply other threads:[~2022-10-12 18:17 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-12 18:16 [PATCH v4 00/11] KVM: x86/mmu: Make tdp_mmu a read-only parameter Sean Christopherson
2022-10-12 18:16 ` [PATCH v4 01/11] KVM: x86/mmu: Change tdp_mmu to " Sean Christopherson
2022-10-12 21:37 ` Huang, Kai
2022-10-12 18:16 ` [PATCH v4 02/11] KVM: x86/mmu: Move TDP MMU VM init/uninit behind tdp_mmu_enabled Sean Christopherson
2022-10-12 18:16 ` [PATCH v4 03/11] KVM: x86/mmu: Grab mmu_invalidate_seq in kvm_faultin_pfn() Sean Christopherson
2022-10-12 18:16 ` [PATCH v4 04/11] KVM: x86/mmu: Handle error PFNs " Sean Christopherson
2022-10-12 18:16 ` [PATCH v4 05/11] KVM: x86/mmu: Avoid memslot lookup during KVM_PFN_ERR_HWPOISON handling Sean Christopherson
2022-10-12 18:16 ` [PATCH v4 06/11] KVM: x86/mmu: Handle no-slot faults in kvm_faultin_pfn() Sean Christopherson
2022-10-12 18:16 ` [PATCH v4 07/11] KVM: x86/mmu: Pivot on "TDP MMU enabled" when handling direct page faults Sean Christopherson
2022-10-12 18:16 ` [PATCH v4 08/11] KVM: x86/mmu: Pivot on "TDP MMU enabled" to check if active MMU is TDP MMU Sean Christopherson
2022-10-12 18:17 ` [PATCH v4 09/11] KVM: x86/mmu: Replace open coded usage of tdp_mmu_page with is_tdp_mmu_page() Sean Christopherson
2022-10-12 18:17 ` [PATCH v4 10/11] KVM: x86/mmu: Use static key/branches for checking if TDP MMU is enabled Sean Christopherson
2022-10-12 18:17 ` Sean Christopherson [this message]
2022-10-13 17:21 ` [PATCH v4 00/11] KVM: x86/mmu: Make tdp_mmu a read-only parameter David Matlack
2022-10-13 20:12 ` Sean Christopherson
2022-10-13 22:56 ` David Matlack
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