From: Ben Gardon <bgardon@google.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: Cannon Matthews <cannonmatthews@google.com>,
Paolo Bonzini <pbonzini@redhat.com>, Peter Xu <peterx@redhat.com>,
Sean Christopherson <sean.j.christopherson@intel.com>,
Peter Shier <pshier@google.com>,
Peter Feiner <pfeiner@google.com>,
Junaid Shahid <junaids@google.com>,
Jim Mattson <jmattson@google.com>,
Yulei Zhang <yulei.kernel@gmail.com>,
Wanpeng Li <kernellwp@gmail.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Xiao Guangrong <xiaoguangrong.eric@gmail.com>,
Ben Gardon <bgardon@google.com>
Subject: [PATCH v2 19/20] kvm: x86/mmu: Don't clear write flooding count for direct roots
Date: Wed, 14 Oct 2020 11:26:59 -0700 [thread overview]
Message-ID: <20201014182700.2888246-20-bgardon@google.com> (raw)
In-Reply-To: <20201014182700.2888246-1-bgardon@google.com>
Direct roots don't have a write flooding count because the guest can't
affect that paging structure. Thus there's no need to clear the write
flooding count on a fast CR3 switch for direct roots.
Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell
machine. This series introduced no new failures.
This series can be viewed in Gerrit at:
https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538
Signed-off-by: Ben Gardon <bgardon@google.com>
---
arch/x86/kvm/mmu/mmu.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 2e8bf8d19c35a..3935c10278736 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4266,7 +4266,13 @@ static void __kvm_mmu_new_pgd(struct kvm_vcpu *vcpu, gpa_t new_pgd,
*/
vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY);
- __clear_sp_write_flooding_count(to_shadow_page(vcpu->arch.mmu->root_hpa));
+ /*
+ * If this is a direct root page, it doesn't have a write flooding
+ * count. Otherwise, clear the write flooding count.
+ */
+ if (!new_role.direct)
+ __clear_sp_write_flooding_count(
+ to_shadow_page(vcpu->arch.mmu->root_hpa));
}
void kvm_mmu_new_pgd(struct kvm_vcpu *vcpu, gpa_t new_pgd, bool skip_tlb_flush,
--
2.28.0.1011.ga647a8990f-goog
next prev parent reply other threads:[~2020-10-14 18:28 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-14 18:26 [PATCH v2 00/20] Introduce the TDP MMU Ben Gardon
2020-10-14 18:26 ` [PATCH v2 01/20] kvm: x86/mmu: Separate making SPTEs from set_spte Ben Gardon
2020-10-14 18:26 ` [PATCH v2 02/20] kvm: x86/mmu: Introduce tdp_iter Ben Gardon
2020-10-21 14:58 ` Yu Zhang
2020-10-21 18:08 ` Ben Gardon
2020-10-22 2:34 ` Yu Zhang
2020-10-14 18:26 ` [PATCH v2 03/20] kvm: x86/mmu: Init / Uninit the TDP MMU Ben Gardon
2020-10-14 18:26 ` [PATCH v2 04/20] kvm: x86/mmu: Allocate and free TDP MMU roots Ben Gardon
2020-10-16 14:56 ` Paolo Bonzini
2020-10-19 17:02 ` Ben Gardon
2020-10-21 15:09 ` Yu Zhang
2020-10-21 17:54 ` Ben Gardon
2020-10-21 18:01 ` Paolo Bonzini
2020-10-14 18:26 ` [PATCH v2 05/20] kvm: x86/mmu: Add functions to handle changed TDP SPTEs Ben Gardon
2020-10-14 18:26 ` [PATCH v2 06/20] KVM: Cache as_id in kvm_memory_slot Ben Gardon
2020-10-14 18:26 ` [PATCH v2 07/20] kvm: x86/mmu: Support zapping SPTEs in the TDP MMU Ben Gardon
2020-10-19 20:49 ` Edgecombe, Rick P
2020-10-19 21:33 ` Ben Gardon
2020-10-21 15:02 ` Yu Zhang
2020-10-21 17:20 ` Paolo Bonzini
2020-10-21 17:24 ` Yu Zhang
2020-10-21 18:00 ` Paolo Bonzini
2020-10-22 2:24 ` Yu Zhang
2020-10-14 18:26 ` [PATCH v2 08/20] kvm: x86/mmu: Separate making non-leaf sptes from link_shadow_page Ben Gardon
2020-10-14 18:26 ` [PATCH v2 09/20] kvm: x86/mmu: Remove disallowed_hugepage_adjust shadow_walk_iterator arg Ben Gardon
2020-10-14 18:26 ` [PATCH v2 10/20] kvm: x86/mmu: Add TDP MMU PF handler Ben Gardon
2020-10-16 15:12 ` Paolo Bonzini
2020-10-14 18:26 ` [PATCH v2 11/20] kvm: x86/mmu: Allocate struct kvm_mmu_pages for all pages in TDP MMU Ben Gardon
2020-10-14 18:26 ` [PATCH v2 12/20] kvm: x86/mmu: Support invalidate range MMU notifier for " Ben Gardon
2020-10-14 18:26 ` [PATCH v2 13/20] kvm: x86/mmu: Add access tracking for tdp_mmu Ben Gardon
2020-10-14 18:26 ` [PATCH v2 14/20] kvm: x86/mmu: Support changed pte notifier in tdp MMU Ben Gardon
2020-10-14 18:26 ` [PATCH v2 15/20] kvm: x86/mmu: Support dirty logging for the TDP MMU Ben Gardon
2020-10-16 16:18 ` Paolo Bonzini
2020-10-19 17:07 ` Ben Gardon
2020-10-19 17:42 ` Paolo Bonzini
2020-10-14 18:26 ` [PATCH v2 16/20] kvm: x86/mmu: Support disabling dirty logging for the tdp MMU Ben Gardon
2020-10-14 18:26 ` [PATCH v2 17/20] kvm: x86/mmu: Support write protection for nesting in " Ben Gardon
2020-10-16 16:18 ` Paolo Bonzini
2020-10-14 18:26 ` [PATCH v2 18/20] kvm: x86/mmu: Support MMIO in the TDP MMU Ben Gardon
2020-10-14 18:26 ` Ben Gardon [this message]
2020-10-14 18:27 ` [PATCH v2 20/20] kvm: x86/mmu: NX largepage recovery for " Ben Gardon
2020-10-16 16:50 ` [PATCH v2 00/20] Introduce the " Paolo Bonzini
2020-10-19 18:15 ` Ben Gardon
2020-10-20 8:07 ` Paolo Bonzini
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