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authorAlex Williamson <alex.williamson@redhat.com>2012-04-05 11:07:08 -0600
committerMichael S. Tsirkin <mst@redhat.com>2012-04-15 12:17:22 +0300
commitba737541edddf9d0026460eb7b1d1c599b4c8ae9 (patch)
tree46c6aeb0792aeb7cf0dc7ef404063d5cbf60d4d2 /docs
parent2ba1d381c2f5f5868fe071b45977c2ed459d78f0 (diff)
acpi_piix4: Disallow write to up/down PCI hotplug registers
The write side of these registers is never used and actually can't be used as defined because any read/modify/write sequence from the guest potentially races with qemu. Drop the write support and define these as read-only registers. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'docs')
-rw-r--r--docs/specs/acpi_pci_hotplug.txt4
1 files changed, 2 insertions, 2 deletions
diff --git a/docs/specs/acpi_pci_hotplug.txt b/docs/specs/acpi_pci_hotplug.txt
index f0f74a7c7c..1e2c8a22eb 100644
--- a/docs/specs/acpi_pci_hotplug.txt
+++ b/docs/specs/acpi_pci_hotplug.txt
@@ -15,14 +15,14 @@ PCI slot injection notification pending (IO port 0xae00-0xae03, 4-byte access):
Slot injection notification pending. One bit per slot.
Read by ACPI BIOS GPE.1 handler to notify OS of injection
-events.
+events. Read-only.
PCI slot removal notification (IO port 0xae04-0xae07, 4-byte access):
-----------------------------------------------------
Slot removal notification pending. One bit per slot.
Read by ACPI BIOS GPE.1 handler to notify OS of removal
-events.
+events. Read-only.
PCI device eject (IO port 0xae08-0xae0b, 4-byte access):
----------------------------------------