[PATCH v2 8/8] OvmfPkg: mention the extended TSEG near the PcdQ35TsegMbytes declaration

[Laszlo Ersek <lersek@redhat.com>]

PlatformPei can now overwrite PcdQ35TsegMbytes; document this in
"OvmfPkg/OvmfPkg.dec".

Cc: Jordan Justen <jordan.l.justen@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
---
 OvmfPkg/OvmfPkg.dec | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/OvmfPkg/OvmfPkg.dec b/OvmfPkg/OvmfPkg.dec
index c46b72f069ef..e5f74a1248ed 100644
--- a/OvmfPkg/OvmfPkg.dec
+++ b/OvmfPkg/OvmfPkg.dec
@@ -125,18 +125,19 @@ [PcdsDynamic, PcdsDynamicEx]
 
   ## The 64-bit MMIO aperture shared by all PCI root bridges.
   #
   gUefiOvmfPkgTokenSpaceGuid.PcdPciMmio64Base|0x0|UINT64|0x26
   gUefiOvmfPkgTokenSpaceGuid.PcdPciMmio64Size|0x0|UINT64|0x27
 
   ## The following setting controls how many megabytes we configure as TSEG on
-  #  Q35, for SMRAM purposes. Permitted values are: 1, 2, 8. Other values cause
-  #  undefined behavior.
+  #  Q35, for SMRAM purposes. Permitted defaults are: 1, 2, 8. Other defaults
+  #  cause undefined behavior. During boot, the PCD is updated by PlatformPei
+  #  to reflect the extended TSEG size, if one is advertized by QEMU.
   #
-  #  This PCD is only consulted if PcdSmmSmramRequire is TRUE (see below).
+  #  This PCD is only accessed if PcdSmmSmramRequire is TRUE (see below).
   gUefiOvmfPkgTokenSpaceGuid.PcdQ35TsegMbytes|8|UINT16|0x20
 
 [PcdsFeatureFlag]
   gUefiOvmfPkgTokenSpaceGuid.PcdQemuBootOrderPciTranslation|TRUE|BOOLEAN|0x1c
   gUefiOvmfPkgTokenSpaceGuid.PcdQemuBootOrderMmioTranslation|FALSE|BOOLEAN|0x1d
 
   ## This feature flag enables SMM/SMRAM support. Note that it also requires
-- 
2.13.1.3.g8be5a757fa67