Blame SOURCES/kvm-target-s390x-kvm-Enable-adapter-interruption-suppres.patch

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From c4fe37ae6d75ed72e6a3bde01fea053eb508274c Mon Sep 17 00:00:00 2001
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From: Thomas Huth <thuth@redhat.com>
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Date: Fri, 5 Jun 2020 07:41:11 -0400
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Subject: [PATCH 41/42] target/s390x/kvm: Enable adapter interruption
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 suppression again
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MIME-Version: 1.0
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Content-Type: text/plain; charset=UTF-8
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Content-Transfer-Encoding: 8bit
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RH-Author: Thomas Huth <thuth@redhat.com>
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Message-id: <20200605074111.2185-4-thuth@redhat.com>
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Patchwork-id: 97370
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O-Subject: [RHEL-8.3.0 qemu-kvm PATCH 3/3] target/s390x/kvm: Enable adapter interruption suppression again
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Bugzilla: 1756946
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RH-Acked-by: Philippe Mathieu-Daudé <philmd@redhat.com>
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RH-Acked-by: Cornelia Huck <cohuck@redhat.com>
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RH-Acked-by: David Hildenbrand <david@redhat.com>
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The AIS feature has been disabled late in the v2.10 development cycle since
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there were some issues with migration (see commit 3f2d07b3b01ea61126b -
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"s390x/ais: for 2.10 stable: disable ais facility"). We originally wanted
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to enable it again for newer machine types, but apparently we forgot to do
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this so far. Let's do it now for the machines that support proper CPU models.
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Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1756946
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Signed-off-by: Thomas Huth <thuth@redhat.com>
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Message-Id: <20200122101437.5069-1-thuth@redhat.com>
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Reviewed-by: David Hildenbrand <david@redhat.com>
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Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
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Signed-off-by: Cornelia Huck <cohuck@redhat.com>
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(cherry picked from commit a5c8617af6919515b84256978452edf07401c45e)
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Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>
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---
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 target/s390x/kvm.c | 9 ++++++---
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 1 file changed, 6 insertions(+), 3 deletions(-)
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diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
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index c589ef9034..0bbf8f81b0 100644
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--- a/target/s390x/kvm.c
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+++ b/target/s390x/kvm.c
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@@ -377,10 +377,13 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
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     /*
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      * The migration interface for ais was introduced with kernel 4.13
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      * but the capability itself had been active since 4.12. As migration
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-     * support is considered necessary let's disable ais in the 2.10
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-     * machine.
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+     * support is considered necessary, we only try to enable this for
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+     * newer machine types if KVM_CAP_S390_AIS_MIGRATION is available.
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      */
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-    /* kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0); */
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+    if (cpu_model_allowed() && kvm_kernel_irqchip_allowed() &&
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+        kvm_check_extension(s, KVM_CAP_S390_AIS_MIGRATION)) {
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+        kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0);
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+    }
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     kvm_set_max_memslot_size(KVM_SLOT_MAX_BYTES);
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     return 0;
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-- 
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2.27.0
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