From 45098e8a9aeefaf8405e4b772ffa2694efe507a0 Mon Sep 17 00:00:00 2001
From: Liran Alon <liran.alon@oracle.com>
Date: Sat, 28 Mar 2020 23:00:52 +0300
Subject: [PATCH] OvmfPkg/PvScsiDxe: Backup/Restore PCI attributes on
 Init/UnInit

This commit doesn't change semantics.
It is done as a preparation for future commits which will modify
PCI attributes.

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=2567
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Message-Id: <20200328200100.60786-10-liran.alon@oracle.com>
Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com>
---
 OvmfPkg/PvScsiDxe/PvScsi.c | 54 +++++++++++++++++++++++++++++++++++++-
 OvmfPkg/PvScsiDxe/PvScsi.h |  1 +
 2 files changed, 54 insertions(+), 1 deletion(-)

diff --git a/OvmfPkg/PvScsiDxe/PvScsi.c b/OvmfPkg/PvScsiDxe/PvScsi.c
index e0380d729b..5566b4cce4 100644
--- a/OvmfPkg/PvScsiDxe/PvScsi.c
+++ b/OvmfPkg/PvScsiDxe/PvScsi.c
@@ -283,18 +283,70 @@ PvScsiGetNextTarget (
   return EFI_NOT_FOUND;
 }
 
+STATIC
+EFI_STATUS
+PvScsiSetPciAttributes (
+  IN OUT PVSCSI_DEV *Dev
+  )
+{
+  EFI_STATUS Status;
+
+  //
+  // Backup original PCI Attributes
+  //
+  Status = Dev->PciIo->Attributes (
+                         Dev->PciIo,
+                         EfiPciIoAttributeOperationGet,
+                         0,
+                         &Dev->OriginalPciAttributes
+                         );
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  //
+  // TODO: Change PCI Attributes
+  //
+
+  return EFI_SUCCESS;
+}
+
+STATIC
+VOID
+PvScsiRestorePciAttributes (
+  IN PVSCSI_DEV *Dev
+  )
+{
+  Dev->PciIo->Attributes (
+                Dev->PciIo,
+                EfiPciIoAttributeOperationSet,
+                Dev->OriginalPciAttributes,
+                NULL
+                );
+}
+
 STATIC
 EFI_STATUS
 PvScsiInit (
   IN OUT PVSCSI_DEV *Dev
   )
 {
+  EFI_STATUS Status;
+
   //
   // Init configuration
   //
   Dev->MaxTarget = PcdGet8 (PcdPvScsiMaxTargetLimit);
   Dev->MaxLun = PcdGet8 (PcdPvScsiMaxLunLimit);
 
+  //
+  // Set PCI Attributes
+  //
+  Status = PvScsiSetPciAttributes (Dev);
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
   //
   // Populate the exported interface's attributes
   //
@@ -333,7 +385,7 @@ PvScsiUninit (
   IN OUT PVSCSI_DEV *Dev
   )
 {
-  // Currently nothing to do here
+  PvScsiRestorePciAttributes (Dev);
 }
 
 //
diff --git a/OvmfPkg/PvScsiDxe/PvScsi.h b/OvmfPkg/PvScsiDxe/PvScsi.h
index e1e5ae18eb..5f611dbbc9 100644
--- a/OvmfPkg/PvScsiDxe/PvScsi.h
+++ b/OvmfPkg/PvScsiDxe/PvScsi.h
@@ -20,6 +20,7 @@
 typedef struct {
   UINT32                          Signature;
   EFI_PCI_IO_PROTOCOL             *PciIo;
+  UINT64                          OriginalPciAttributes;
   UINT8                           MaxTarget;
   UINT8                           MaxLun;
   EFI_EXT_SCSI_PASS_THRU_PROTOCOL PassThru;
-- 
2.39.2