From: Maxim Levitsky <mlevitsk@redhat.com>
To: kvm@vger.kernel.org
Cc: Wanpeng Li <wanpengli@tencent.com>,
David Airlie <airlied@linux.ie>,
Dave Hansen <dave.hansen@linux.intel.com>,
dri-devel@lists.freedesktop.org, "H. Peter Anvin" <hpa@zytor.com>,
Brijesh Singh <brijesh.singh@amd.com>,
Joerg Roedel <joro@8bytes.org>,
x86@kernel.org, Maxim Levitsky <mlevitsk@redhat.com>,
Ingo Molnar <mingo@redhat.com>, Zhi Wang <zhi.a.wang@intel.com>,
Tom Lendacky <thomas.lendacky@amd.com>,
intel-gfx@lists.freedesktop.org, Borislav Petkov <bp@alien8.de>,
Rodrigo Vivi <rodrigo.vivi@intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
intel-gvt-dev@lists.freedesktop.org,
Jim Mattson <jmattson@google.com>,
Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>,
Sean Christopherson <seanjc@google.com>,
linux-kernel@vger.kernel.org, Paolo Bonzini <pbonzini@redhat.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>
Subject: [RFC PATCH v3 15/19] KVM: x86: nSVM: add code to reload AVIC physid table when it is invalidated
Date: Wed, 27 Apr 2022 23:03:10 +0300 [thread overview]
Message-ID: <20220427200314.276673-16-mlevitsk@redhat.com> (raw)
In-Reply-To: <20220427200314.276673-1-mlevitsk@redhat.com>
An AVIC table invalidation is not supposed to happen often, and can
only happen when the guest does something suspicious such as:
- It places physid page in a memslot that is enabled/disabled and memslot
flushing happens.
- It tries to update apic backing page addresses - guest has no
reason to touch this, and doing so on real hardware will likely
result in unpredictable results.
- It writes to reserved bits of a tracked page.
- It write floods a physid table while no vCPU is using it
(the page is likely reused at that point to contain something else)
All of the above causes a KVM_REQ_APIC_PAGE_RELOAD request to be raised
on all vCPUS, which kicks them out of the guest mode,
and then first vCPU to reach the handler will re-create the entries of
the physid page, and others will notice this and do nothing.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
---
arch/x86/kvm/svm/avic.c | 13 +++++++++++++
arch/x86/kvm/svm/svm.c | 1 +
arch/x86/kvm/svm/svm.h | 1 +
3 files changed, 15 insertions(+)
diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c
index e6ec525a88625..f13ca1e7b2845 100644
--- a/arch/x86/kvm/svm/avic.c
+++ b/arch/x86/kvm/svm/avic.c
@@ -379,6 +379,7 @@ static void avic_physid_shadow_table_invalidate(struct kvm *kvm,
struct kvm_svm *kvm_svm = to_kvm_svm(kvm);
lockdep_assert_held(&kvm_svm->avic.tables_lock);
+ kvm_make_all_cpus_request(kvm, KVM_REQ_APIC_PAGE_RELOAD);
avic_physid_shadow_table_erase(kvm, t);
}
@@ -1638,3 +1639,15 @@ bool avic_nested_has_interrupt(struct kvm_vcpu *vcpu)
return true;
return false;
}
+
+void avic_reload_apic_pages(struct kvm_vcpu *vcpu)
+{
+ struct vcpu_svm *vcpu_svm = to_svm(vcpu);
+ struct avic_physid_table *t = vcpu_svm->nested.l2_physical_id_table;
+
+ int nentries = vcpu_svm->nested.ctl.avic_physical_id &
+ AVIC_PHYSICAL_ID_TABLE_SIZE_MASK;
+
+ if (t && is_guest_mode(vcpu) && nested_avic_in_use(vcpu))
+ avic_physid_shadow_table_sync(vcpu, t, nentries);
+}
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index a39bb0b27a51d..d96a73931d1e5 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4677,6 +4677,7 @@ static struct kvm_x86_ops svm_x86_ops __initdata = {
.enable_nmi_window = svm_enable_nmi_window,
.enable_irq_window = svm_enable_irq_window,
.update_cr8_intercept = svm_update_cr8_intercept,
+ .reload_apic_pages = avic_reload_apic_pages,
.refresh_apicv_exec_ctrl = avic_refresh_apicv_exec_ctrl,
.check_apicv_inhibit_reasons = avic_check_apicv_inhibit_reasons,
.apicv_post_state_restore = avic_apicv_post_state_restore,
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 17fcc09cf4be1..93fd9d6f5fd85 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -711,6 +711,7 @@ void avic_vcpu_blocking(struct kvm_vcpu *vcpu);
void avic_vcpu_unblocking(struct kvm_vcpu *vcpu);
void avic_ring_doorbell(struct kvm_vcpu *vcpu);
unsigned long avic_vcpu_get_apicv_inhibit_reasons(struct kvm_vcpu *vcpu);
+void avic_reload_apic_pages(struct kvm_vcpu *vcpu);
void avic_free_nested(struct kvm_vcpu *vcpu);
bool avic_nested_has_interrupt(struct kvm_vcpu *vcpu);
--
2.26.3
next prev parent reply other threads:[~2022-04-27 20:05 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-27 20:02 [RFC PATCH v3 00/19] RFC: nested AVIC Maxim Levitsky
2022-04-27 20:02 ` [RFC PATCH v3 01/19] KVM: x86: document AVIC/APICv inhibit reasons Maxim Levitsky
2022-05-18 15:56 ` Sean Christopherson
2022-05-18 17:13 ` Maxim Levitsky
2022-04-27 20:02 ` [RFC PATCH v3 02/19] KVM: x86: inhibit APICv/AVIC when the guest and/or host changes apic id/base from the defaults Maxim Levitsky
2022-05-18 8:28 ` Chao Gao
2022-05-18 9:50 ` Maxim Levitsky
2022-05-18 11:51 ` Chao Gao
2022-05-18 12:36 ` Maxim Levitsky
2022-05-18 15:39 ` Sean Christopherson
2022-05-18 17:15 ` Maxim Levitsky
2022-05-19 16:06 ` Sean Christopherson
2022-05-22 9:03 ` Maxim Levitsky
2022-05-22 14:47 ` Jim Mattson
2022-05-23 6:50 ` Maxim Levitsky
2022-05-23 17:22 ` Jim Mattson
2022-05-23 17:31 ` Sean Christopherson
2022-06-23 9:44 ` Maxim Levitsky
2022-04-27 20:02 ` [RFC PATCH v3 03/19] KVM: x86: SVM: remove avic's broken code that updated APIC ID Maxim Levitsky
2022-05-19 16:10 ` Sean Christopherson
2022-05-22 9:01 ` Maxim Levitsky
2022-05-23 17:19 ` Sean Christopherson
2022-04-27 20:02 ` [RFC PATCH v3 04/19] KVM: x86: mmu: allow to enable write tracking externally Maxim Levitsky
2022-05-19 16:27 ` Sean Christopherson
2022-05-22 10:21 ` Maxim Levitsky
2022-05-19 16:37 ` Sean Christopherson
2022-05-22 10:22 ` Maxim Levitsky
2022-07-20 14:42 ` Maxim Levitsky
2022-07-25 16:08 ` Sean Christopherson
2022-07-28 7:46 ` Maxim Levitsky
2022-08-01 15:53 ` Maxim Levitsky
2022-08-01 17:20 ` Sean Christopherson
2022-08-08 13:13 ` Nested AVIC design (was:Re: [RFC PATCH v3 04/19] KVM: x86: mmu: allow to enable write tracking externally) Maxim Levitsky
2022-09-29 22:38 ` Sean Christopherson
2022-10-03 7:27 ` Maxim Levitsky
2022-11-10 0:47 ` Sean Christopherson
2022-04-27 20:03 ` [RFC PATCH v3 05/19] x86: KVMGT: use kvm_page_track_write_tracking_enable Maxim Levitsky
2022-05-19 16:38 ` Sean Christopherson
2022-04-27 20:03 ` [RFC PATCH v3 06/19] KVM: x86: mmu: add gfn_in_memslot helper Maxim Levitsky
2022-05-19 16:43 ` Sean Christopherson
2022-05-22 10:22 ` Maxim Levitsky
2022-05-22 12:12 ` Maxim Levitsky
2022-04-27 20:03 ` [RFC PATCH v3 07/19] KVM: x86: mmu: tweak fast path for emulation of access to nested NPT pages Maxim Levitsky
2022-04-27 20:03 ` [RFC PATCH v3 08/19] KVM: x86: SVM: move avic state to separate struct Maxim Levitsky
2022-04-27 20:03 ` [RFC PATCH v3 09/19] KVM: x86: nSVM: add nested AVIC tracepoints Maxim Levitsky
2022-04-27 20:03 ` [RFC PATCH v3 10/19] KVM: x86: nSVM: implement AVIC's physid/logid table access helpers Maxim Levitsky
2022-04-27 20:03 ` [RFC PATCH v3 11/19] KVM: x86: nSVM: implement shadowing of AVIC's physical id table Maxim Levitsky
2022-04-27 20:03 ` [RFC PATCH v3 12/19] KVM: x86: nSVM: make nested AVIC physid write tracking be aware of the host scheduling Maxim Levitsky
2022-04-27 20:03 ` [RFC PATCH v3 13/19] KVM: x86: nSVM: wire nested AVIC to nested guest entry/exit Maxim Levitsky
2022-04-27 20:03 ` [RFC PATCH v3 14/19] KVM: x86: rename .set_apic_access_page_addr to reload_apic_access_page Maxim Levitsky
2022-05-19 16:55 ` Sean Christopherson
2022-05-22 10:22 ` Maxim Levitsky
2022-04-27 20:03 ` Maxim Levitsky [this message]
2022-04-27 20:03 ` [RFC PATCH v3 16/19] KVM: x86: nSVM: implement support for nested AVIC vmexits Maxim Levitsky
2022-04-27 20:03 ` [RFC PATCH v3 17/19] KVM: x86: nSVM: implement nested AVIC doorbell emulation Maxim Levitsky
2022-04-27 20:03 ` [RFC PATCH v3 18/19] KVM: x86: SVM/nSVM: add optional non strict AVIC doorbell mode Maxim Levitsky
2022-04-27 20:03 ` [RFC PATCH v3 19/19] KVM: x86: nSVM: expose the nested AVIC to the guest Maxim Levitsky
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