From: Sean Christopherson <sean.j.christopherson@intel.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Ben Gardon <bgardon@google.com>,
Junaid Shahid <junaids@google.com>,
Liran Alon <liran.alon@oracle.com>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
John Haxby <john.haxby@oracle.com>,
Miaohe Lin <linmiaohe@huawei.com>,
Tom Lendacky <thomas.lendacky@amd.com>
Subject: Re: [PATCH v2 04/32] KVM: nVMX: Invalidate all L2 roots when emulating INVVPID without EPT
Date: Thu, 19 Mar 2020 21:11:02 -0700 [thread overview]
Message-ID: <20200320041102.GG11305@linux.intel.com> (raw)
In-Reply-To: <20200317045238.30434-5-sean.j.christopherson@intel.com>
On Mon, Mar 16, 2020 at 09:52:10PM -0700, Sean Christopherson wrote:
> From: Junaid Shahid <junaids@google.com>
>
> Free all L2 (guest_mmu) roots when emulating INVVPID for L1 and EPT is
> disabled, as outstanding changes to the page tables managed by L1 need
> to be recognized.
>
> Similar to handle_invpcid() and handle_invept(), rely on
> kvm_mmu_free_roots() to do a remote TLB flush if necessary, e.g. if L1
> has never entered L2 then there is nothing to be done.
>
> Fixes: 5c614b3583e7b ("KVM: nVMX: nested VPID emulation")
> Signed-off-by: Junaid Shahid <junaids@google.com>
> [sean: ported to upstream KVM, reworded the comment and changelog]
> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
> ---
> arch/x86/kvm/vmx/nested.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
> index 9624cea4ed9f..50bb7d8862aa 100644
> --- a/arch/x86/kvm/vmx/nested.c
> +++ b/arch/x86/kvm/vmx/nested.c
> @@ -5250,6 +5250,17 @@ static int handle_invvpid(struct kvm_vcpu *vcpu)
> return kvm_skip_emulated_instruction(vcpu);
> }
>
> + /*
> + * Sync L2's shadow page tables if EPT is disabled, L1 is effectively
> + * invalidating linear mappings for L2 (tagged with L2's VPID). Sync
> + * all roots as VPIDs are not tracked in the MMU role.
> + *
> + * TODO: sync only the affected SPTEs for INVDIVIDUAL_ADDR.
> + */
> + if (!enable_ept)
> + kvm_mmu_free_roots(vcpu, &vcpu->arch.guest_mmu,
Aha! This is wrong. guest_mmu is only used if EPT is enabled. The silver
lining is that I have confirmed that this code is needed and works as
intended (when the correct mmu is nuked).
> + KVM_MMU_ROOTS_ALL);
> +
> return nested_vmx_succeed(vcpu);
> }
>
> --
> 2.24.1
>
next prev parent reply other threads:[~2020-03-20 4:11 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-17 4:52 [PATCH v2 00/32] KVM: x86: TLB flushing fixes and enhancements Sean Christopherson
2020-03-17 4:52 ` [PATCH v2 01/32] KVM: VMX: Flush all EPTP/VPID contexts on remote TLB flush Sean Christopherson
2020-03-17 4:52 ` [PATCH v2 02/32] KVM: nVMX: Validate the EPTP when emulating INVEPT(EXTENT_CONTEXT) Sean Christopherson
2020-03-17 4:52 ` [PATCH v2 03/32] KVM: nVMX: Invalidate all EPTP contexts when emulating INVEPT for L1 Sean Christopherson
2020-03-17 4:52 ` [PATCH v2 04/32] KVM: nVMX: Invalidate all L2 roots when emulating INVVPID without EPT Sean Christopherson
2020-03-20 4:11 ` Sean Christopherson [this message]
2020-03-17 4:52 ` [PATCH v2 05/32] KVM: x86: Export kvm_propagate_fault() (as kvm_inject_emulated_page_fault) Sean Christopherson
2020-03-17 4:52 ` [PATCH v2 06/32] KVM: x86: Consolidate logic for injecting page faults to L1 Sean Christopherson
2020-03-17 4:52 ` [PATCH v2 07/32] KVM: x86: Sync SPTEs when injecting page/EPT fault into L1 Sean Christopherson
2020-03-17 4:52 ` [PATCH v2 08/32] KVM: VMX: Skip global INVVPID fallback if vpid==0 in vpid_sync_context() Sean Christopherson
2020-03-17 4:52 ` [PATCH v2 09/32] KVM: VMX: Use vpid_sync_context() directly when possible Sean Christopherson
2020-03-17 4:52 ` [PATCH v2 10/32] KVM: VMX: Move vpid_sync_vcpu_addr() down a few lines Sean Christopherson
2020-03-17 4:52 ` [PATCH v2 11/32] KVM: VMX: Handle INVVPID fallback logic in vpid_sync_vcpu_addr() Sean Christopherson
2020-03-17 4:52 ` [PATCH v2 12/32] KVM: VMX: Drop redundant capability checks in low level INVVPID helpers Sean Christopherson
2020-03-17 4:52 ` [PATCH v2 13/32] KVM: nVMX: Use vpid_sync_vcpu_addr() to emulate INVVPID with address Sean Christopherson
2020-03-17 4:52 ` [PATCH v2 14/32] KVM: x86: Move "flush guest's TLB" logic to separate kvm_x86_ops hook Sean Christopherson
2020-03-17 4:52 ` [PATCH v2 15/32] KVM: VMX: Clean up vmx_flush_tlb_gva() Sean Christopherson
2020-03-17 4:52 ` [PATCH v2 16/32] KVM: x86: Drop @invalidate_gpa param from kvm_x86_ops' tlb_flush() Sean Christopherson
2020-03-17 4:52 ` [PATCH v2 17/32] KVM: SVM: Wire up ->tlb_flush_guest() directly to svm_flush_tlb() Sean Christopherson
2020-03-17 4:52 ` [PATCH v2 18/32] KVM: VMX: Move vmx_flush_tlb() to vmx.c Sean Christopherson
2020-03-17 4:52 ` [PATCH v2 19/32] KVM: nVMX: Move nested_get_vpid02() to vmx/nested.h Sean Christopherson
2020-03-17 4:52 ` [PATCH v2 20/32] KVM: VMX: Introduce vmx_flush_tlb_current() Sean Christopherson
2020-03-17 4:52 ` [PATCH v2 21/32] KVM: SVM: Document the ASID logic in svm_flush_tlb() Sean Christopherson
2020-03-17 4:52 ` [PATCH v2 22/32] KVM: x86: Rename ->tlb_flush() to ->tlb_flush_all() Sean Christopherson
2020-03-17 4:52 ` [PATCH v2 23/32] KVM: nVMX: Add helper to handle TLB flushes on nested VM-Enter/VM-Exit Sean Christopherson
2020-03-17 17:17 ` Paolo Bonzini
2020-03-17 18:18 ` Sean Christopherson
2020-03-18 10:45 ` Paolo Bonzini
2020-03-18 16:09 ` Sean Christopherson
2020-03-17 4:52 ` [PATCH v2 24/32] KVM: x86: Introduce KVM_REQ_TLB_FLUSH_CURRENT to flush current ASID Sean Christopherson
2020-03-17 4:52 ` [PATCH v2 25/32] KVM: x86/mmu: Use KVM_REQ_TLB_FLUSH_CURRENT for MMU specific flushes Sean Christopherson
2020-03-17 4:52 ` [PATCH v2 26/32] KVM: nVMX: Selectively use TLB_FLUSH_CURRENT for nested VM-Enter/VM-Exit Sean Christopherson
2020-03-17 4:52 ` [PATCH v2 27/32] KVM: nVMX: Reload APIC access page on nested VM-Exit only if necessary Sean Christopherson
2020-03-17 4:52 ` [PATCH v2 28/32] KVM: VMX: Retrieve APIC access page HPA only when necessary Sean Christopherson
2020-03-17 4:52 ` [PATCH v2 29/32] KVM: VMX: Don't reload APIC access page if its control is disabled Sean Christopherson
2020-03-17 4:52 ` [PATCH v2 30/32] KVM: x86/mmu: Add module param to force TLB flush on root reuse Sean Christopherson
2020-03-17 4:52 ` [PATCH v2 31/32] KVM: nVMX: Don't flush TLB on nested VM transition with EPT enabled Sean Christopherson
2020-03-17 17:18 ` Paolo Bonzini
2020-03-17 18:22 ` Sean Christopherson
2020-03-18 10:36 ` Paolo Bonzini
2020-03-18 17:02 ` Sean Christopherson
2020-03-18 17:11 ` Paolo Bonzini
2020-03-18 17:26 ` Sean Christopherson
2020-03-18 17:38 ` Paolo Bonzini
2020-03-17 4:52 ` [PATCH v2 32/32] KVM: nVMX: Free only the affected contexts when emulating INVEPT Sean Christopherson
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