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From: Igor Mammedov <imammedo@redhat.com>
To: qemu-devel@nongnu.org
Cc: ehabkost@redhat.com, mst@redhat.com, marcel.apfelbaum@gmail.com,
	Paolo Bonzini <pbonzini@redhat.com>,
	Igor Mammedov <imammedo@redhat.com>,
	Richard Henderson <rth@twiddle.net>
Subject: [Qemu-devel] [PATCH v3 8/8] pc: acpi: clarify why possible LAPIC entries must be present in MADT
Date: Tue, 23 Feb 2016 17:06:00 +0100	[thread overview]
Message-ID: <1456243560-67516-9-git-send-email-imammedo@redhat.com> (raw)
In-Reply-To: <1456243560-67516-1-git-send-email-imammedo@redhat.com>

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
---
 hw/i386/acpi-build.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index e66c8b7..534a855 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -361,6 +361,12 @@ build_madt(GArray *table_data, GArray *linker, PCMachineState *pcms)
         if (apic_ids->cpus[i].cpu != NULL) {
             apic->flags = cpu_to_le32(1);
         } else {
+            /* ACPI spec says that LAPIC entry for non present
+             * CPU may be omitted from MADT or it must be marked
+             * as disabled. However omitting non present CPU from
+             * MADT breaks hotplug on linux. So possible CPUs
+             * should be put in MADT but kept disabled.
+             */
             apic->flags = cpu_to_le32(0);
         }
     }
-- 
1.8.3.1

      parent reply	other threads:[~2016-02-23 16:06 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-23 16:05 [Qemu-devel] [PATCH v3 0/8] pc: do not create invalid MADT.LAPIC/Processor entries Igor Mammedov
2016-02-23 16:05 ` [Qemu-devel] [PATCH v3 1/8] pc: init pcms->apic_id_limit once and use it throughout pc.c Igor Mammedov
2016-02-23 16:05 ` [Qemu-devel] [PATCH v3 2/8] cpu: introduce possible-cpus interface Igor Mammedov
2016-02-23 21:38   ` Eduardo Habkost
2016-02-24  8:36     ` Igor Mammedov
2016-02-23 16:05 ` [Qemu-devel] [PATCH v3 3/8] pc: acpi: cleanup qdev_get_machine() calls Igor Mammedov
2016-02-23 16:05 ` [Qemu-devel] [PATCH v3 4/8] pc: acpi: SRAT: create only valid processor lapic entries Igor Mammedov
2016-02-23 16:05 ` [Qemu-devel] [PATCH v3 5/8] pc: acpi: create MADT.lapic entries only for valid lapics Igor Mammedov
2016-02-23 16:05 ` [Qemu-devel] [PATCH v3 6/8] pc: acpi: create Processor and Notify objects " Igor Mammedov
2016-02-23 16:05 ` [Qemu-devel] [PATCH v3 7/8] pc: acpi: drop cpu->found_cpus bitmap Igor Mammedov
2016-02-23 16:06 ` Igor Mammedov [this message]

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