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,
Alejandro Jimenez <alejandro.j.jimenez@oracle.com>,
Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>,
Maxim Levitsky <mlevitsk@redhat.com>,
Li RongQing <lirongqing@baidu.com>
Subject: [PATCH v3 02/28] KVM: x86: Purge "highest ISR" cache when updating APICv state
Date: Tue, 20 Sep 2022 23:31:08 +0000 [thread overview]
Message-ID: <20220920233134.940511-3-seanjc@google.com> (raw)
In-Reply-To: <20220920233134.940511-1-seanjc@google.com>
Purge the "highest ISR" cache when updating APICv state on a vCPU. The
cache must not be used when APICv is active as hardware may emulate EOIs
(and other operations) without exiting to KVM.
This fixes a bug where KVM will effectively block IRQs in perpetuity due
to the "highest ISR" never getting reset if APICv is activated on a vCPU
while an IRQ is in-service. Hardware emulates the EOI and KVM never gets
a chance to update its cache.
Fixes: b26a695a1d78 ("kvm: lapic: Introduce APICv update helper function")
Cc: stable@vger.kernel.org
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/lapic.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 8004c4d0a8e5..adac6ca9b7dc 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -2424,6 +2424,7 @@ void kvm_apic_update_apicv(struct kvm_vcpu *vcpu)
*/
apic->isr_count = count_vectors(apic->regs + APIC_ISR);
}
+ apic->highest_isr_cache = -1;
}
EXPORT_SYMBOL_GPL(kvm_apic_update_apicv);
@@ -2480,7 +2481,6 @@ void kvm_lapic_reset(struct kvm_vcpu *vcpu, bool init_event)
kvm_lapic_set_reg(apic, APIC_TMR + 0x10 * i, 0);
}
kvm_apic_update_apicv(vcpu);
- apic->highest_isr_cache = -1;
update_divide_count(apic);
atomic_set(&apic->lapic_timer.pending, 0);
@@ -2767,7 +2767,6 @@ int kvm_apic_set_state(struct kvm_vcpu *vcpu, struct kvm_lapic_state *s)
__start_apic_timer(apic, APIC_TMCCT);
kvm_lapic_set_reg(apic, APIC_TMCCT, 0);
kvm_apic_update_apicv(vcpu);
- apic->highest_isr_cache = -1;
if (apic->apicv_active) {
static_call_cond(kvm_x86_apicv_post_state_restore)(vcpu);
static_call_cond(kvm_x86_hwapic_irr_update)(vcpu, apic_find_highest_irr(apic));
--
2.37.3.968.ga6b4b080e4-goog
next prev parent reply other threads:[~2022-09-20 23:31 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-20 23:31 [PATCH v3 00/28] KVM: x86: AVIC and local APIC fixes+cleanups Sean Christopherson
2022-09-20 23:31 ` [PATCH v3 01/28] KVM: x86: Blindly get current x2APIC reg value on "nodecode write" traps Sean Christopherson
2022-09-20 23:31 ` Sean Christopherson [this message]
2022-09-20 23:31 ` [PATCH v3 03/28] KVM: SVM: Flush the "current" TLB when activating AVIC Sean Christopherson
2022-09-20 23:31 ` [PATCH v3 04/28] KVM: SVM: Process ICR on AVIC IPI delivery failure due to invalid target Sean Christopherson
2022-09-20 23:31 ` [PATCH v3 05/28] KVM: x86: Don't inhibit APICv/AVIC if xAPIC ID mismatch is due to 32-bit ID Sean Christopherson
2022-09-28 3:15 ` Alejandro Jimenez
2022-09-28 5:55 ` Maxim Levitsky
2022-09-28 16:51 ` Sean Christopherson
2022-09-28 17:51 ` Maxim Levitsky
2022-09-28 18:03 ` Sean Christopherson
2022-09-28 18:16 ` Maxim Levitsky
2022-09-28 20:44 ` Sean Christopherson
2022-09-28 20:50 ` Alejandro Jimenez
2022-09-20 23:31 ` [PATCH v3 06/28] KVM: x86: Move APIC access page helper to common x86 code Sean Christopherson
2022-09-20 23:31 ` [PATCH v3 07/28] KVM: x86: Inhibit APIC memslot if x2APIC and AVIC are enabled Sean Christopherson
2022-09-23 10:27 ` Maxim Levitsky
2022-09-26 17:00 ` Sean Christopherson
2022-09-28 6:21 ` Maxim Levitsky
2022-09-28 16:33 ` Sean Christopherson
2022-09-28 17:40 ` Maxim Levitsky
2022-09-28 22:35 ` Sean Christopherson
2022-09-20 23:31 ` [PATCH v3 08/28] KVM: SVM: Don't put/load AVIC when setting virtual APIC mode Sean Christopherson
2022-09-20 23:31 ` [PATCH v3 09/28] KVM: SVM: Replace "avic_mode" enum with "x2avic_enabled" boolean Sean Christopherson
2022-09-20 23:31 ` [PATCH v3 10/28] KVM: SVM: Compute dest based on sender's x2APIC status for AVIC kick Sean Christopherson
2022-09-20 23:31 ` [PATCH v3 11/28] KVM: SVM: Fix x2APIC Logical ID calculation for avic_kick_target_vcpus_fast Sean Christopherson
2022-09-20 23:31 ` [PATCH v3 12/28] Revert "KVM: SVM: Use target APIC ID to complete x2AVIC IRQs when possible" Sean Christopherson
2022-09-20 23:31 ` [PATCH v3 13/28] KVM: SVM: Document that vCPU ID == APIC ID in AVIC kick fastpatch Sean Christopherson
2022-09-20 23:31 ` [PATCH v3 14/28] KVM: SVM: Add helper to perform final AVIC "kick" of single vCPU Sean Christopherson
2022-09-20 23:31 ` [PATCH v3 15/28] KVM: x86: Explicitly skip optimized logical map setup if vCPU's LDR==0 Sean Christopherson
2022-09-20 23:31 ` [PATCH v3 16/28] KVM: x86: Explicitly track all possibilities for APIC map's logical modes Sean Christopherson
2022-09-20 23:31 ` [PATCH v3 17/28] KVM: x86: Skip redundant x2APIC logical mode optimized cluster setup Sean Christopherson
2022-09-20 23:31 ` [PATCH v3 18/28] KVM: x86: Disable APIC logical map if logical ID covers multiple MDAs Sean Christopherson
2022-09-20 23:31 ` [PATCH v3 19/28] KVM: x86: Disable APIC logical map if vCPUs are aliased in logical mode Sean Christopherson
2022-09-20 23:31 ` [PATCH v3 20/28] KVM: x86: Honor architectural behavior for aliased 8-bit APIC IDs Sean Christopherson
2022-09-20 23:31 ` [PATCH v3 21/28] KVM: x86: Inhibit APICv/AVIC if the optimized physical map is disabled Sean Christopherson
2022-09-20 23:31 ` [PATCH v3 22/28] KVM: SVM: Inhibit AVIC if vCPUs are aliased in logical mode Sean Christopherson
2022-09-20 23:31 ` [PATCH v3 23/28] KVM: SVM: Always update local APIC on writes to logical dest register Sean Christopherson
2022-09-20 23:31 ` [PATCH v3 24/28] KVM: SVM: Update svm->ldr_reg cache even if LDR is "bad" Sean Christopherson
2022-09-20 23:31 ` [PATCH v3 25/28] KVM: SVM: Require logical ID to be power-of-2 for AVIC entry Sean Christopherson
2022-09-20 23:31 ` [PATCH v3 26/28] KVM: SVM: Handle multiple logical targets in AVIC kick fastpath Sean Christopherson
2022-09-20 23:31 ` [PATCH v3 27/28] KVM: SVM: Ignore writes to Remote Read Data on AVIC write traps Sean Christopherson
2022-09-20 23:31 ` [PATCH v3 28/28] Revert "KVM: SVM: Do not throw warning when calling avic_vcpu_load on a running vcpu" Sean Christopherson
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