From: Sean Christopherson <seanjc@google.com>
To: Maxim Levitsky <mlevitsk@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Subject: Re: [PATCH v2 08/18] KVM: x86/mmu: do not pass vcpu to root freeing functions
Date: Wed, 23 Feb 2022 15:48:16 +0000 [thread overview]
Message-ID: <YhZXQOg+5/we5/1g@google.com> (raw)
In-Reply-To: <cda148b77e3615a4f1ac81de8be233204fb8f981.camel@redhat.com>
On Wed, Feb 23, 2022, Maxim Levitsky wrote:
> On Thu, 2022-02-17 at 16:03 -0500, Paolo Bonzini wrote:
> > @@ -1156,7 +1156,7 @@ static void kvm_invalidate_pcid(struct kvm_vcpu *vcpu, unsigned long pcid)
> > if (kvm_get_pcid(vcpu, mmu->prev_roots[i].pgd) == pcid)
> > roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i);
> >
> > - kvm_mmu_free_roots(vcpu, mmu, roots_to_free);
> > + kvm_mmu_free_roots(vcpu->kvm, mmu, roots_to_free);
> > }
> >
> > int kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
>
> IMHO anything that is related to guest memory should work on
> VM level (that is struct kvm).
No, because there are plently of per-CPU/vCPU properties that affect physical
memory accesseses. Some of them KVM mostly punts on, e.g. MTRRs and APIC base,
but others are relevant, e.g. SMM.
> It is just ironically sad that writing to a guest page requires
> these days a vCPU due to dirty ring tracking.
I dislike (understatement) that the dirty ring code uses the currently running
vCPU instead of passing it down the stack, but fundamentally all memory accesses
that originate from the "CPU", as opposed to a device or whatever, should be tied
to a vCPU.
next prev parent reply other threads:[~2022-02-23 15:48 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-17 21:03 [PATCH v2 00/18] KVM: MMU: do not unload MMU roots on all role changes Paolo Bonzini
2022-02-17 21:03 ` [PATCH v2 01/18] KVM: x86: host-initiated EFER.LME write affects the MMU Paolo Bonzini
2022-02-18 17:08 ` Sean Christopherson
2022-02-18 17:26 ` Paolo Bonzini
2022-02-23 13:40 ` Maxim Levitsky
2022-02-17 21:03 ` [PATCH v2 02/18] KVM: x86: do not deliver asynchronous page faults if CR0.PG=0 Paolo Bonzini
2022-02-18 17:12 ` Sean Christopherson
2022-02-23 14:07 ` Maxim Levitsky
2022-02-17 21:03 ` [PATCH v2 03/18] KVM: x86/mmu: WARN if PAE roots linger after kvm_mmu_unload Paolo Bonzini
2022-02-18 17:14 ` Sean Christopherson
2022-02-18 17:23 ` Paolo Bonzini
2022-02-23 14:11 ` Maxim Levitsky
2022-02-17 21:03 ` [PATCH v2 04/18] KVM: x86/mmu: avoid NULL-pointer dereference on page freeing bugs Paolo Bonzini
2022-02-18 17:15 ` Sean Christopherson
2022-02-23 14:12 ` Maxim Levitsky
2022-02-17 21:03 ` [PATCH v2 05/18] KVM: x86/mmu: use struct kvm_mmu_root_info for mmu->root Paolo Bonzini
2022-02-23 14:39 ` Maxim Levitsky
2022-02-23 15:42 ` Sean Christopherson
2022-02-17 21:03 ` [PATCH v2 06/18] KVM: x86/mmu: do not consult levels when freeing roots Paolo Bonzini
2022-02-18 17:27 ` Sean Christopherson
2022-02-23 14:59 ` Maxim Levitsky
2022-02-17 21:03 ` [PATCH v2 07/18] KVM: x86/mmu: Do not use guest root level in audit Paolo Bonzini
2022-02-18 18:37 ` Sean Christopherson
2022-02-18 18:46 ` Paolo Bonzini
2022-02-23 15:02 ` Maxim Levitsky
2022-02-17 21:03 ` [PATCH v2 08/18] KVM: x86/mmu: do not pass vcpu to root freeing functions Paolo Bonzini
2022-02-18 18:39 ` Sean Christopherson
2022-02-23 15:16 ` Maxim Levitsky
2022-02-23 15:48 ` Sean Christopherson [this message]
2022-02-17 21:03 ` [PATCH v2 09/18] KVM: x86/mmu: look for a cached PGD when going from 32-bit to 64-bit Paolo Bonzini
2022-02-18 18:08 ` Sean Christopherson
2022-02-23 16:01 ` Maxim Levitsky
2022-02-17 21:03 ` [PATCH v2 10/18] KVM: x86/mmu: load new PGD after the shadow MMU is initialized Paolo Bonzini
2022-02-18 23:59 ` Sean Christopherson
2022-02-23 16:20 ` Maxim Levitsky
2022-02-17 21:03 ` [PATCH v2 11/18] KVM: x86/mmu: Always use current mmu's role when loading new PGD Paolo Bonzini
2022-02-18 23:59 ` Sean Christopherson
2022-02-23 16:23 ` Maxim Levitsky
2022-02-17 21:03 ` [PATCH v2 12/18] KVM: x86/mmu: clear MMIO cache when unloading the MMU Paolo Bonzini
2022-02-18 23:59 ` Sean Christopherson
2022-02-23 16:32 ` Maxim Levitsky
2022-02-17 21:03 ` [PATCH v2 13/18] KVM: x86: reset and reinitialize the MMU in __set_sregs_common Paolo Bonzini
2022-02-19 0:22 ` Sean Christopherson
2022-02-23 16:48 ` Maxim Levitsky
2022-02-17 21:03 ` [PATCH v2 14/18] KVM: x86/mmu: avoid indirect call for get_cr3 Paolo Bonzini
2022-02-18 20:30 ` Sean Christopherson
2022-02-19 10:03 ` Paolo Bonzini
2022-02-24 11:02 ` Maxim Levitsky
2022-02-24 15:12 ` Sean Christopherson
2022-02-24 15:14 ` Maxim Levitsky
2022-02-17 21:03 ` [PATCH v2 15/18] KVM: x86/mmu: rename kvm_mmu_new_pgd, introduce variant that calls get_guest_pgd Paolo Bonzini
2022-02-18 9:39 ` Paolo Bonzini
2022-02-18 21:00 ` Sean Christopherson
2022-02-24 15:41 ` Maxim Levitsky
2022-02-25 17:40 ` Sean Christopherson
2022-02-17 21:03 ` [PATCH v2 16/18] KVM: x86: introduce KVM_REQ_MMU_UPDATE_ROOT Paolo Bonzini
2022-02-18 21:45 ` Sean Christopherson
2022-02-19 7:54 ` Paolo Bonzini
2022-02-22 16:06 ` Sean Christopherson
2022-02-24 15:50 ` Maxim Levitsky
2022-02-17 21:03 ` [PATCH v2 17/18] KVM: x86: flush TLB separately from MMU reset Paolo Bonzini
2022-02-18 23:57 ` Sean Christopherson
2022-02-21 15:01 ` Paolo Bonzini
2022-02-24 16:11 ` Maxim Levitsky
2022-02-17 21:03 ` [PATCH v2 18/18] KVM: x86: do not unload MMU roots on all role changes Paolo Bonzini
2022-02-24 16:25 ` Maxim Levitsky
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