diff options
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.9.21/0007-KVM-x86-ioapic-Fix-level-triggered-EOI-and-IOAPIC-re.patch')
| -rw-r--r-- | common/recipes-kernel/linux/linux-yocto-4.9.21/0007-KVM-x86-ioapic-Fix-level-triggered-EOI-and-IOAPIC-re.patch | 72 |
1 files changed, 0 insertions, 72 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.9.21/0007-KVM-x86-ioapic-Fix-level-triggered-EOI-and-IOAPIC-re.patch b/common/recipes-kernel/linux/linux-yocto-4.9.21/0007-KVM-x86-ioapic-Fix-level-triggered-EOI-and-IOAPIC-re.patch deleted file mode 100644 index 2ca432cf..00000000 --- a/common/recipes-kernel/linux/linux-yocto-4.9.21/0007-KVM-x86-ioapic-Fix-level-triggered-EOI-and-IOAPIC-re.patch +++ /dev/null @@ -1,72 +0,0 @@ -From 34cbfb000e9bd72eb48fb3d1e61be034053f743f Mon Sep 17 00:00:00 2001 -From: Nikita Leshenko <nikita.leshchenko@oracle.com> -Date: Sun, 5 Nov 2017 15:52:29 +0200 -Subject: [PATCH 07/33] KVM: x86: ioapic: Fix level-triggered EOI and IOAPIC - reconfigure race -MIME-Version: 1.0 -Content-Type: text/plain; charset=UTF-8 -Content-Transfer-Encoding: 8bit - -[ Upstream commit 0fc5a36dd6b345eb0d251a65c236e53bead3eef7 ] - -KVM uses ioapic_handled_vectors to track vectors that need to notify the -IOAPIC on EOI. The problem is that IOAPIC can be reconfigured while an -interrupt with old configuration is pending or running and -ioapic_handled_vectors only remembers the newest configuration; -thus EOI from the old interrupt is not delievered to the IOAPIC. - -A previous commit db2bdcbbbd32 -("KVM: x86: fix edge EOI and IOAPIC reconfig race") -addressed this issue by adding pending edge-triggered interrupts to -ioapic_handled_vectors, fixing this race for edge-triggered interrupts. -The commit explicitly ignored level-triggered interrupts, -but this race applies to them as well: - -1) IOAPIC sends a level triggered interrupt vector to VCPU0 -2) VCPU0's handler deasserts the irq line and reconfigures the IOAPIC - to route the vector to VCPU1. The reconfiguration rewrites only the - upper 32 bits of the IOREDTBLn register. (Causes KVM to update - ioapic_handled_vectors for VCPU0 and it no longer includes the vector.) -3) VCPU0 sends EOI for the vector, but it's not delievered to the - IOAPIC because the ioapic_handled_vectors doesn't include the vector. -4) New interrupts are not delievered to VCPU1 because remote_irr bit - is set forever. - -Therefore, the correct behavior is to add all pending and running -interrupts to ioapic_handled_vectors. - -This commit introduces a slight performance hit similar to -commit db2bdcbbbd32 ("KVM: x86: fix edge EOI and IOAPIC reconfig race") -for the rare case that the vector is reused by a non-IOAPIC source on -VCPU0. We prefer to keep solution simple and not handle this case just -as the original commit does. - -Fixes: db2bdcbbbd32 ("KVM: x86: fix edge EOI and IOAPIC reconfig race") - -Signed-off-by: Nikita Leshenko <nikita.leshchenko@oracle.com> -Reviewed-by: Liran Alon <liran.alon@oracle.com> -Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> -Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> -Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> -Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> ---- - arch/x86/kvm/ioapic.c | 3 +-- - 1 file changed, 1 insertion(+), 2 deletions(-) - -diff --git a/arch/x86/kvm/ioapic.c b/arch/x86/kvm/ioapic.c -index 6e219e5..a7ac868 100644 ---- a/arch/x86/kvm/ioapic.c -+++ b/arch/x86/kvm/ioapic.c -@@ -257,8 +257,7 @@ void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, ulong *ioapic_handled_vectors) - index == RTC_GSI) { - if (kvm_apic_match_dest(vcpu, NULL, 0, - e->fields.dest_id, e->fields.dest_mode) || -- (e->fields.trig_mode == IOAPIC_EDGE_TRIG && -- kvm_apic_pending_eoi(vcpu, e->fields.vector))) -+ kvm_apic_pending_eoi(vcpu, e->fields.vector)) - __set_bit(e->fields.vector, - ioapic_handled_vectors); - } --- -2.7.4 - |