[Xen-devel] [PATCH v5 09/35] OvmfPkg/OvmfXen: use a TimerLib instance that depends only on the CPU

[Anthony PERARD <anthony.perard@citrix.com>]

The ACPI Timer isn't present in a PVH guest, but local APIC works on
both PVH and HVM.

Note that the use of SecPeiDxeTimerLibCpu might be an issue with a
driver of type DXE_RUNTIME_DRIVER. I've attempted to find out which of
the DXE_RUNTIME_DRIVER uses the TimerLib at runtime. I've done that by
replacing the TimerLib evaluation in
[LibraryClasses.common.DXE_RUNTIME_DRIVER] by a different one and
checking every module that uses it (with the --report-file=report
build option).

ResetSystemRuntimeDxe is calling the TimerLib API at runtime to do the
operation "EfiResetCold", so this may never complete if the OS have
disabled the Local APIC Timer.

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1689
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
---

Notes:
    v4:
    - reworded the first sentence, use "not present" instead of "don't work".
    
    v3:
    - cleanup .dsc, leave only one TimerLib resolution
    - Added a note in the commit message regarding the use of the local apic
      by runtime drivers

 OvmfPkg/OvmfXen.dsc | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/OvmfPkg/OvmfXen.dsc b/OvmfPkg/OvmfXen.dsc
index 7619a89382..b40d39e003 100644
--- a/OvmfPkg/OvmfXen.dsc
+++ b/OvmfPkg/OvmfXen.dsc
@@ -104,7 +104,7 @@ [SkuIds]
 ################################################################################
 [LibraryClasses]
   PcdLib|MdePkg/Library/BasePcdLibNull/BasePcdLibNull.inf
-  TimerLib|OvmfPkg/Library/AcpiTimerLib/BaseAcpiTimerLib.inf
+  TimerLib|MdePkg/Library/SecPeiDxeTimerLibCpu/SecPeiDxeTimerLibCpu.inf
   PrintLib|MdePkg/Library/BasePrintLib/BasePrintLib.inf
   BaseMemoryLib|MdePkg/Library/BaseMemoryLibRepStr/BaseMemoryLibRepStr.inf
   BaseLib|MdePkg/Library/BaseLib/BaseLib.inf
@@ -202,7 +202,6 @@ [LibraryClasses.common]
   BaseCryptLib|CryptoPkg/Library/BaseCryptLib/BaseCryptLib.inf
 
 [LibraryClasses.common.SEC]
-  TimerLib|OvmfPkg/Library/AcpiTimerLib/BaseRomAcpiTimerLib.inf
   QemuFwCfgLib|OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgSecLib.inf
 !ifdef $(DEBUG_ON_SERIAL_PORT)
   DebugLib|MdePkg/Library/BaseDebugLibSerialPort/BaseDebugLibSerialPort.inf
@@ -281,7 +280,6 @@ [LibraryClasses.common.DXE_CORE]
 
 [LibraryClasses.common.DXE_RUNTIME_DRIVER]
   PcdLib|MdePkg/Library/DxePcdLib/DxePcdLib.inf
-  TimerLib|OvmfPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.inf
   HobLib|MdePkg/Library/DxeHobLib/DxeHobLib.inf
   DxeCoreEntryPoint|MdePkg/Library/DxeCoreEntryPoint/DxeCoreEntryPoint.inf
   MemoryAllocationLib|MdePkg/Library/UefiMemoryAllocationLib/UefiMemoryAllocationLib.inf
@@ -298,7 +296,6 @@ [LibraryClasses.common.DXE_RUNTIME_DRIVER]
 
 [LibraryClasses.common.UEFI_DRIVER]
   PcdLib|MdePkg/Library/DxePcdLib/DxePcdLib.inf
-  TimerLib|OvmfPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.inf
   HobLib|MdePkg/Library/DxeHobLib/DxeHobLib.inf
   DxeCoreEntryPoint|MdePkg/Library/DxeCoreEntryPoint/DxeCoreEntryPoint.inf
   MemoryAllocationLib|MdePkg/Library/UefiMemoryAllocationLib/UefiMemoryAllocationLib.inf
@@ -313,7 +310,6 @@ [LibraryClasses.common.UEFI_DRIVER]
 
 [LibraryClasses.common.DXE_DRIVER]
   PcdLib|MdePkg/Library/DxePcdLib/DxePcdLib.inf
-  TimerLib|OvmfPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.inf
   HobLib|MdePkg/Library/DxeHobLib/DxeHobLib.inf
   MemoryAllocationLib|MdePkg/Library/UefiMemoryAllocationLib/UefiMemoryAllocationLib.inf
   ReportStatusCodeLib|MdeModulePkg/Library/DxeReportStatusCodeLib/DxeReportStatusCodeLib.inf
@@ -337,7 +333,6 @@ [LibraryClasses.common.DXE_DRIVER]
 
 [LibraryClasses.common.UEFI_APPLICATION]
   PcdLib|MdePkg/Library/DxePcdLib/DxePcdLib.inf
-  TimerLib|OvmfPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.inf
   HobLib|MdePkg/Library/DxeHobLib/DxeHobLib.inf
   MemoryAllocationLib|MdePkg/Library/UefiMemoryAllocationLib/UefiMemoryAllocationLib.inf
   ReportStatusCodeLib|MdeModulePkg/Library/DxeReportStatusCodeLib/DxeReportStatusCodeLib.inf
-- 
Anthony PERARD

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