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-rw-r--r--0002-kvm-ioapic-Restrict-lazy-EOI-update-to-edge-triggere.patch79
1 files changed, 0 insertions, 79 deletions
diff --git a/0002-kvm-ioapic-Restrict-lazy-EOI-update-to-edge-triggere.patch b/0002-kvm-ioapic-Restrict-lazy-EOI-update-to-edge-triggere.patch
deleted file mode 100644
index ff2990023ef..00000000000
--- a/0002-kvm-ioapic-Restrict-lazy-EOI-update-to-edge-triggere.patch
+++ /dev/null
@@ -1,79 +0,0 @@
-From bb4a15eb06341e6cadc99de418c81375b560af85 Mon Sep 17 00:00:00 2001
-From: Paolo Bonzini <pbonzini@redhat.com>
-Date: Mon, 4 May 2020 12:19:45 -0400
-Subject: [PATCH 2/7] kvm: ioapic: Restrict lazy EOI update to edge-triggered
- interrupts
-
-Commit f458d039db7e ("kvm: ioapic: Lazy update IOAPIC EOI") introduces
-the following infinite loop:
-
-BUG: stack guard page was hit at 000000008f595917 \
-(stack is 00000000bdefe5a4..00000000ae2b06f5)
-kernel stack overflow (double-fault): 0000 [#1] SMP NOPTI
-RIP: 0010:kvm_set_irq+0x51/0x160 [kvm]
-Call Trace:
- irqfd_resampler_ack+0x32/0x90 [kvm]
- kvm_notify_acked_irq+0x62/0xd0 [kvm]
- kvm_ioapic_update_eoi_one.isra.0+0x30/0x120 [kvm]
- ioapic_set_irq+0x20e/0x240 [kvm]
- kvm_ioapic_set_irq+0x5c/0x80 [kvm]
- kvm_set_irq+0xbb/0x160 [kvm]
- ? kvm_hv_set_sint+0x20/0x20 [kvm]
- irqfd_resampler_ack+0x32/0x90 [kvm]
- kvm_notify_acked_irq+0x62/0xd0 [kvm]
- kvm_ioapic_update_eoi_one.isra.0+0x30/0x120 [kvm]
- ioapic_set_irq+0x20e/0x240 [kvm]
- kvm_ioapic_set_irq+0x5c/0x80 [kvm]
- kvm_set_irq+0xbb/0x160 [kvm]
- ? kvm_hv_set_sint+0x20/0x20 [kvm]
-....
-
-The re-entrancy happens because the irq state is the OR of
-the interrupt state and the resamplefd state. That is, we don't
-want to show the state as 0 until we've had a chance to set the
-resamplefd. But if the interrupt has _not_ gone low then
-ioapic_set_irq is invoked again, causing an infinite loop.
-
-This can only happen for a level-triggered interrupt, otherwise
-irqfd_inject would immediately set the KVM_USERSPACE_IRQ_SOURCE_ID high
-and then low. Fortunately, in the case of level-triggered interrupts the VMEXIT already happens because
-TMR is set. Thus, fix the bug by restricting the lazy invocation
-of the ack notifier to edge-triggered interrupts, the only ones that
-need it.
-
-Tested-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
-Reported-by: borisvk@bstnet.org
-Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
-Link: https://www.spinics.net/lists/kvm/msg213512.html
-Fixes: f458d039db7e ("kvm: ioapic: Lazy update IOAPIC EOI")
-Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=207489
-Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
----
- arch/x86/kvm/ioapic.c | 10 +++++-----
- 1 file changed, 5 insertions(+), 5 deletions(-)
-
-diff --git a/arch/x86/kvm/ioapic.c b/arch/x86/kvm/ioapic.c
-index 750ff0b29404..d057376bd3d3 100644
---- a/arch/x86/kvm/ioapic.c
-+++ b/arch/x86/kvm/ioapic.c
-@@ -225,12 +225,12 @@ static int ioapic_set_irq(struct kvm_ioapic *ioapic, unsigned int irq,
- }
-
- /*
-- * AMD SVM AVIC accelerate EOI write and do not trap,
-- * in-kernel IOAPIC will not be able to receive the EOI.
-- * In this case, we do lazy update of the pending EOI when
-- * trying to set IOAPIC irq.
-+ * AMD SVM AVIC accelerate EOI write iff the interrupt is edge
-+ * triggered, in which case the in-kernel IOAPIC will not be able
-+ * to receive the EOI. In this case, we do a lazy update of the
-+ * pending EOI when trying to set IOAPIC irq.
- */
-- if (kvm_apicv_activated(ioapic->kvm))
-+ if (edge && kvm_apicv_activated(ioapic->kvm))
- ioapic_lazy_update_eoi(ioapic, irq);
-
- /*
---
-2.26.2
-