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,
Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>,
Maxim Levitsky <mlevitsk@redhat.com>,
Li RongQing <lirongqing@baidu.com>
Subject: [PATCH v2 19/23] KVM: SVM: Update svm->ldr_reg cache even if LDR is "bad"
Date: Sat, 3 Sep 2022 00:22:50 +0000 [thread overview]
Message-ID: <20220903002254.2411750-20-seanjc@google.com> (raw)
In-Reply-To: <20220903002254.2411750-1-seanjc@google.com>
Update SVM's cache of the LDR even if the new value is "bad". Leaving
stale information in the cache can result in KVM missing updates and/or
invalidating the wrong entry, e.g. if avic_invalidate_logical_id_entry()
is triggered after a different vCPU has "claimed" the old LDR.
Fixes: 18f40c53e10f ("svm: Add VMEXIT handlers for AVIC")
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/svm/avic.c | 17 +++++++----------
1 file changed, 7 insertions(+), 10 deletions(-)
diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c
index 456f24378961..894d0afd761b 100644
--- a/arch/x86/kvm/svm/avic.c
+++ b/arch/x86/kvm/svm/avic.c
@@ -566,23 +566,24 @@ static u32 *avic_get_logical_id_entry(struct kvm_vcpu *vcpu, u32 ldr, bool flat)
return &logical_apic_id_table[index];
}
-static int avic_ldr_write(struct kvm_vcpu *vcpu, u8 g_physical_id, u32 ldr)
+static void avic_ldr_write(struct kvm_vcpu *vcpu, u8 g_physical_id, u32 ldr)
{
bool flat;
u32 *entry, new_entry;
+ if (!ldr)
+ return;
+
flat = kvm_lapic_get_reg(vcpu->arch.apic, APIC_DFR) == APIC_DFR_FLAT;
entry = avic_get_logical_id_entry(vcpu, ldr, flat);
if (!entry)
- return -EINVAL;
+ return;
new_entry = READ_ONCE(*entry);
new_entry &= ~AVIC_LOGICAL_ID_ENTRY_GUEST_PHYSICAL_ID_MASK;
new_entry |= (g_physical_id & AVIC_LOGICAL_ID_ENTRY_GUEST_PHYSICAL_ID_MASK);
new_entry |= AVIC_LOGICAL_ID_ENTRY_VALID_MASK;
WRITE_ONCE(*entry, new_entry);
-
- return 0;
}
static void avic_invalidate_logical_id_entry(struct kvm_vcpu *vcpu)
@@ -602,7 +603,6 @@ static void avic_invalidate_logical_id_entry(struct kvm_vcpu *vcpu)
static void avic_handle_ldr_update(struct kvm_vcpu *vcpu)
{
- int ret = 0;
struct vcpu_svm *svm = to_svm(vcpu);
u32 ldr = kvm_lapic_get_reg(vcpu->arch.apic, APIC_LDR);
u32 id = kvm_xapic_id(vcpu->arch.apic);
@@ -616,11 +616,8 @@ static void avic_handle_ldr_update(struct kvm_vcpu *vcpu)
avic_invalidate_logical_id_entry(vcpu);
- if (ldr)
- ret = avic_ldr_write(vcpu, id, ldr);
-
- if (!ret)
- svm->ldr_reg = ldr;
+ svm->ldr_reg = ldr;
+ avic_ldr_write(vcpu, id, ldr);
}
static void avic_handle_dfr_update(struct kvm_vcpu *vcpu)
--
2.37.2.789.g6183377224-goog
next prev parent reply other threads:[~2022-09-03 0:25 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-03 0:22 [PATCH v2 00/23] KVM: x86: AVIC and local APIC fixes+cleanups Sean Christopherson
2022-09-03 0:22 ` [PATCH v2 01/23] KVM: x86: Purge "highest ISR" cache when updating APICv state Sean Christopherson
2022-09-05 21:58 ` Paolo Bonzini
2022-09-03 0:22 ` [PATCH v2 02/23] KVM: SVM: Flush the "current" TLB when activating AVIC Sean Christopherson
2022-09-05 21:58 ` Paolo Bonzini
2022-09-03 0:22 ` [PATCH v2 03/23] KVM: SVM: Process ICR on AVIC IPI delivery failure due to invalid target Sean Christopherson
2022-09-05 21:59 ` Paolo Bonzini
2022-09-03 0:22 ` [PATCH v2 04/23] KVM: x86: Inhibit AVIC SPTEs if any vCPU enables x2APIC Sean Christopherson
2022-09-05 22:02 ` Paolo Bonzini
2022-09-13 19:52 ` Suthikulpanit, Suravee
2022-09-14 7:39 ` Sean Christopherson
2022-09-14 17:41 ` Suthikulpanit, Suravee
2022-09-16 17:47 ` Sean Christopherson
2022-09-16 19:10 ` Sean Christopherson
2022-09-20 13:07 ` Maxim Levitsky
2022-09-20 15:46 ` Sean Christopherson
2022-09-20 16:50 ` Sean Christopherson
2022-09-23 10:18 ` Maxim Levitsky
2022-09-23 10:19 ` Maxim Levitsky
2022-09-03 0:22 ` [PATCH v2 05/23] KVM: SVM: Don't put/load AVIC when setting virtual APIC mode Sean Christopherson
2022-09-03 0:22 ` [PATCH v2 06/23] KVM: SVM: Replace "avic_mode" enum with "x2avic_enabled" boolean Sean Christopherson
2022-09-03 0:22 ` [PATCH v2 07/23] KVM: SVM: Compute dest based on sender's x2APIC status for AVIC kick Sean Christopherson
2022-09-03 0:22 ` [PATCH v2 08/23] KVM: SVM: Fix x2APIC Logical ID calculation for avic_kick_target_vcpus_fast Sean Christopherson
2022-09-03 0:22 ` [PATCH v2 09/23] Revert "KVM: SVM: Use target APIC ID to complete x2AVIC IRQs when possible" Sean Christopherson
2022-09-03 0:22 ` [PATCH v2 10/23] KVM: SVM: Document that vCPU ID == APIC ID in AVIC kick fastpatch Sean Christopherson
2022-09-03 0:22 ` [PATCH v2 11/23] KVM: SVM: Add helper to perform final AVIC "kick" of single vCPU Sean Christopherson
2022-09-03 0:22 ` [PATCH v2 12/23] KVM: x86: Disable APIC logical map if logical ID covers multiple MDAs Sean Christopherson
2022-09-03 0:22 ` [PATCH v2 13/23] KVM: x86: Disable APIC logical map if vCPUs are aliased in logical mode Sean Christopherson
2022-09-13 23:32 ` Suthikulpanit, Suravee
2022-09-14 7:42 ` Sean Christopherson
2022-09-15 2:11 ` Suthikulpanit, Suravee
2022-09-16 18:52 ` Sean Christopherson
2022-09-03 0:22 ` [PATCH v2 14/23] KVM: x86: Honor architectural behavior for aliased 8-bit APIC IDs Sean Christopherson
2022-09-03 0:22 ` [PATCH v2 15/23] KVM: x86: Explicitly skip adding vCPU to optimized logical map if LDR==0 Sean Christopherson
2022-09-03 0:22 ` [PATCH v2 16/23] KVM: x86: Explicitly track all possibilities for APIC map's logical modes Sean Christopherson
2022-09-03 0:22 ` [PATCH v2 17/23] KVM: SVM: Inhibit AVIC if vCPUs are aliased in logical mode Sean Christopherson
2022-09-03 0:22 ` [PATCH v2 18/23] KVM: SVM: Always update local APIC on writes to logical dest register Sean Christopherson
2022-09-03 0:22 ` Sean Christopherson [this message]
2022-09-03 0:22 ` [PATCH v2 20/23] KVM: SVM: Require logical ID to be power-of-2 for AVIC entry Sean Christopherson
2022-09-03 0:22 ` [PATCH v2 21/23] KVM: SVM: Handle multiple logical targets in AVIC kick fastpath Sean Christopherson
2022-09-03 0:22 ` [PATCH v2 22/23] KVM: SVM: Ignore writes to Remote Read Data on AVIC write traps Sean Christopherson
2022-09-03 0:22 ` [PATCH v2 23/23] Revert "KVM: SVM: Do not throw warning when calling avic_vcpu_load on a running vcpu" Sean Christopherson
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