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>,
Maxim Levitsky <mlevitsk@redhat.com>,
Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>,
Li RongQing <lirongqing@baidu.com>,
Greg Edwards <gedwards@ddn.com>
Subject: [PATCH v5 02/33] KVM: x86: Purge "highest ISR" cache when updating APICv state
Date: Fri, 6 Jan 2023 01:12:35 +0000 [thread overview]
Message-ID: <20230106011306.85230-3-seanjc@google.com> (raw)
In-Reply-To: <20230106011306.85230-1-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>
Reviewed-by: Maxim Levitsky <mlevitsk@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 5c0f93fc073a..33a661d82da7 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;
}
void kvm_lapic_reset(struct kvm_vcpu *vcpu, bool init_event)
@@ -2479,7 +2480,6 @@ 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));
--
2.39.0.314.g84b9a713c41-goog
next prev parent reply other threads:[~2023-01-06 1:13 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-06 1:12 [PATCH v5 00/33] KVM: x86: AVIC and local APIC fixes+cleanups Sean Christopherson
2023-01-06 1:12 ` [PATCH v5 01/33] KVM: x86: Blindly get current x2APIC reg value on "nodecode write" traps Sean Christopherson
2023-01-06 1:12 ` Sean Christopherson [this message]
2023-01-06 1:12 ` [PATCH v5 03/33] KVM: SVM: Flush the "current" TLB when activating AVIC Sean Christopherson
2023-01-08 14:25 ` Maxim Levitsky
2023-01-06 1:12 ` [PATCH v5 04/33] KVM: SVM: Process ICR on AVIC IPI delivery failure due to invalid target Sean Christopherson
2023-01-06 1:12 ` [PATCH v5 05/33] KVM: x86: Don't inhibit APICv/AVIC on xAPIC ID "change" if APIC is disabled Sean Christopherson
2023-01-06 1:12 ` [PATCH v5 06/33] KVM: x86: Don't inhibit APICv/AVIC if xAPIC ID mismatch is due to 32-bit ID Sean Christopherson
2023-01-06 1:12 ` [PATCH v5 07/33] KVM: SVM: Don't put/load AVIC when setting virtual APIC mode Sean Christopherson
2023-01-06 1:12 ` [PATCH v5 08/33] KVM: x86: Handle APICv updates for APIC "mode" changes via request Sean Christopherson
2023-01-06 1:12 ` [PATCH v5 09/33] KVM: x86: Move APIC access page helper to common x86 code Sean Christopherson
2023-01-06 1:12 ` [PATCH v5 10/33] KVM: x86: Inhibit APIC memslot if x2APIC and AVIC are enabled Sean Christopherson
2023-01-08 14:30 ` Maxim Levitsky
2023-01-06 1:12 ` [PATCH v5 11/33] KVM: SVM: Replace "avic_mode" enum with "x2avic_enabled" boolean Sean Christopherson
2023-01-06 1:12 ` [PATCH v5 12/33] KVM: SVM: Compute dest based on sender's x2APIC status for AVIC kick Sean Christopherson
2023-01-06 1:12 ` [PATCH v5 13/33] KVM: SVM: Fix x2APIC Logical ID calculation for avic_kick_target_vcpus_fast Sean Christopherson
2023-01-06 1:12 ` [PATCH v5 14/33] Revert "KVM: SVM: Use target APIC ID to complete x2AVIC IRQs when possible" Sean Christopherson
2023-01-06 1:12 ` [PATCH v5 15/33] KVM: SVM: Document that vCPU ID == APIC ID in AVIC kick fastpatch Sean Christopherson
2023-01-06 1:12 ` [PATCH v5 16/33] KVM: SVM: Add helper to perform final AVIC "kick" of single vCPU Sean Christopherson
2023-01-06 1:12 ` [PATCH v5 17/33] KVM: x86: Explicitly skip optimized logical map setup if vCPU's LDR==0 Sean Christopherson
2023-01-06 1:12 ` [PATCH v5 18/33] KVM: x86: Explicitly track all possibilities for APIC map's logical modes Sean Christopherson
2023-01-08 15:14 ` Maxim Levitsky
2023-01-06 1:12 ` [PATCH v5 19/33] KVM: x86: Skip redundant x2APIC logical mode optimized cluster setup Sean Christopherson
2023-01-06 1:12 ` [PATCH v5 20/33] KVM: x86: Disable APIC logical map if logical ID covers multiple MDAs Sean Christopherson
2023-01-06 1:12 ` [PATCH v5 21/33] KVM: x86: Disable APIC logical map if vCPUs are aliased in logical mode Sean Christopherson
2023-01-06 1:12 ` [PATCH v5 22/33] KVM: x86: Honor architectural behavior for aliased 8-bit APIC IDs Sean Christopherson
2023-01-06 1:12 ` [PATCH v5 23/33] KVM: x86: Inhibit APICv/AVIC if the optimized physical map is disabled Sean Christopherson
2023-01-06 1:12 ` [PATCH v5 24/33] KVM: SVM: Inhibit AVIC if vCPUs are aliased in logical mode Sean Christopherson
2023-01-06 1:12 ` [PATCH v5 25/33] KVM: SVM: Always update local APIC on writes to logical dest register Sean Christopherson
2023-01-06 1:12 ` [PATCH v5 26/33] KVM: SVM: Update svm->ldr_reg cache even if LDR is "bad" Sean Christopherson
2023-01-06 1:13 ` [PATCH v5 27/33] KVM: SVM: Require logical ID to be power-of-2 for AVIC entry Sean Christopherson
2023-01-08 15:20 ` Maxim Levitsky
2023-01-06 1:13 ` [PATCH v5 28/33] KVM: SVM: Handle multiple logical targets in AVIC kick fastpath Sean Christopherson
2023-01-06 1:13 ` [PATCH v5 29/33] KVM: SVM: Ignore writes to Remote Read Data on AVIC write traps Sean Christopherson
2023-01-06 1:13 ` [PATCH v5 30/33] Revert "KVM: SVM: Do not throw warning when calling avic_vcpu_load on a running vcpu" Sean Christopherson
2023-01-06 1:13 ` [PATCH v5 31/33] KVM: x86: Track required APICv inhibits with variable, not callback Sean Christopherson
2023-01-06 1:13 ` [PATCH v5 32/33] KVM: x86: Allow APICv APIC ID inhibit to be cleared Sean Christopherson
2023-01-08 15:25 ` Maxim Levitsky
2023-01-06 1:13 ` [PATCH v5 33/33] KVM: x86: Add helpers to recalc physical vs. logical optimized APIC maps Sean Christopherson
2023-01-08 15:32 ` Maxim Levitsky
2023-02-15 20:25 ` [PATCH v5 00/33] KVM: x86: AVIC and local APIC fixes+cleanups Suthikulpanit, Suravee
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