docs: pcie: Spell out machine type needs for PCIe features

PCIe features are available only via the 'q35' machine type for x86 and
the 'virt' machine type for AArch64 architecture.

Mention that explicitly.

Thanks: Daniel Berrangé

Signed-off-by: Kashyap Chamarthy <kchamart@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/docs/pcie.txt b/docs/pcie.txt
index 8d3694970eacd7a7b97bd3ae2d8ba58e2b5b3576..89e35020752de10ffd946f712e7181c81f5f0c93 100644 (file)
--- a/docs/pcie.txt
+++ b/docs/pcie.txt
@@ -3,8 +3,13 @@ PCI EXPRESS GUIDELINES
 
 1. Introduction
 ================
-The doc proposes best practices on how to use PCI Express/PCI device
-in PCI Express based machines and explains the reasoning behind them.
+The doc proposes best practices on how to use PCI Express (PCIe) / PCI
+devices in PCI Express based machines and explains the reasoning behind
+them.
+
+Note that the PCIe features are available only when using the 'q35'
+machine type on x86 architecture and the 'virt' machine type on AArch64.
+Other machine types do not use PCIe at this time.
 
 The following presentations accompany this document:
  (1) Q35 overview.