Re: [PATCH RFC 13/14] OvmfPkg: Introduce XenIoPvhDxe to initialize Grant Tables

[Laszlo Ersek <lersek@redhat.com>]

On 12/08/16 16:33, Anthony PERARD wrote:
> This "device" use XenIoMmioLib to reserve some space to be use by grant
> tables. It's use 0xfc000000, which might not be a good choice...
> 
> There is probably a better way that using a device for this.
> ---
>  OvmfPkg/XenIoPvhDxe/XenIoPvhDxe.c   | 263 ++++++++++++++++++++++++++++++++++++
>  OvmfPkg/XenIoPvhDxe/XenIoPvhDxe.inf |  45 ++++++
>  OvmfPkg/XenOvmf.dsc                 |   2 +
>  OvmfPkg/XenOvmf.fdf                 |   1 +
>  4 files changed, 311 insertions(+)
>  create mode 100644 OvmfPkg/XenIoPvhDxe/XenIoPvhDxe.c
>  create mode 100644 OvmfPkg/XenIoPvhDxe/XenIoPvhDxe.inf

I recommend to check out the existent use of XenIoMmioLib, namely in
"ArmVirtPkg/XenioFdtDxe".

In brief, for such purposes a DXE_DRIVER is appropriate, where you
simply do the deed (call XenIoMmioInstall()) in the driver's entry point
function. No need for a UEFI_DRIVER module which conforms to the UEFI
Driver Model.

Regarding where to put the area: no clue. If it doesn't overlap any
memory area added in (Xen)PlatformPei with memory resource descriptors,
nor areas added later in DXE, with gDS->AddMemorySpace(), then it should
be fine.

>From a quick look, 0xFC000000 should work. For completeness, I'd also
modify the (DXE) driver to call gDS->AddMemorySpace() with type
EfiGcdMemoryTypeReserved, and also immediately call
gDS->AllocateMemorySpace() with the same type and EfiGcdAllocateAddress,
in order to allocate the exact reserved chunk.

(See "7.2 Global Coherency Domain Services" in vol2 of the Platform Init
spec for background.)

OTOH, I don't see why a simple AllocateReservedPages() call wouldn't
work (which would carve a chunk out of normal system memory for this).
Why did you comment that out in the code below?

Also, please don't forget the Citrix copyright notice etc etc.

Thanks
Laszlo

> 
> diff --git a/OvmfPkg/XenIoPvhDxe/XenIoPvhDxe.c b/OvmfPkg/XenIoPvhDxe/XenIoPvhDxe.c
> new file mode 100644
> index 0000000..12e076f
> --- /dev/null
> +++ b/OvmfPkg/XenIoPvhDxe/XenIoPvhDxe.c
> @@ -0,0 +1,263 @@
> +/** @file
> +
> +  XXX
> +
> +  XXX
> +
> +  This program and the accompanying materials are licensed and made available
> +  under the terms and conditions of the BSD License which accompanies this
> +  distribution. The full text of the license may be found at
> +  http://opensource.org/licenses/bsd-license.php
> +
> +  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
> +  WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
> +
> +**/
> +
> +#include <Library/BaseMemoryLib.h>
> +#include <Library/DebugLib.h>
> +#include <Library/MemoryAllocationLib.h>
> +#include <Library/UefiBootServicesTableLib.h>
> +#include <Library/UefiLib.h>
> +#include <Library/XenIoMmioLib.h>
> +
> +/* #include <Protocol/XenIo.h> */
> +STATIC BOOLEAN mXenIoInitialized = FALSE;
> +
> +/**
> +
> +  Device probe function for this driver.
> +
> +  The DXE core calls this function for any given device in order to see if the
> +  driver can drive the device.
> +
> +  @param[in]  This                The EFI_DRIVER_BINDING_PROTOCOL object
> +                                  incorporating this driver (independently of
> +                                  any device).
> +
> +  @param[in] DeviceHandle         The device to probe.
> +
> +  @param[in] RemainingDevicePath  Relevant only for bus drivers, ignored.
> +
> +
> +  @retval EFI_SUCCESS      The driver supports the device being probed.
> +
> +  @retval EFI_UNSUPPORTED  The driver does not support the device being probed.
> +
> +  @return                  Error codes from the OpenProtocol() boot service or
> +                           the PciIo protocol.
> +
> +**/
> +#if 1
> +STATIC
> +EFI_STATUS
> +EFIAPI
> +XenIoPvhDeviceBindingSupported (
> +  IN EFI_DRIVER_BINDING_PROTOCOL *This,
> +  IN EFI_HANDLE                  DeviceHandle,
> +  IN EFI_DEVICE_PATH_PROTOCOL    *RemainingDevicePath
> +  )
> +{
> +
> +  // XXX check if running Xen PVH
> +  //
> +
> +  if (mXenIoInitialized) {
> +    return EFI_ALREADY_STARTED;
> +  }
> +
> +  DEBUG((EFI_D_INFO, "%a %d\n", __FUNCTION__, __LINE__));
> +  return EFI_SUCCESS;
> +}
> +#endif
> +
> +/**
> +
> +  After we've pronounced support for a specific device in
> +  DriverBindingSupported(), we start managing said device (passed in by the
> +  Driver Execution Environment) with the following service.
> +
> +  See DriverBindingSupported() for specification references.
> +
> +  @param[in]  This                The EFI_DRIVER_BINDING_PROTOCOL object
> +                                  incorporating this driver (independently of
> +                                  any device).
> +
> +  @param[in] DeviceHandle         The supported device to drive.
> +
> +  @param[in] RemainingDevicePath  Relevant only for bus drivers, ignored.
> +
> +
> +  @retval EFI_SUCCESS           The device was started.
> +
> +  @retval EFI_OUT_OF_RESOURCES  Memory allocation failed.
> +
> +  @return                       Error codes from the OpenProtocol() boot
> +                                service, the PciIo protocol or the
> +                                InstallProtocolInterface() boot service.
> +
> +**/
> +STATIC
> +EFI_STATUS
> +EFIAPI
> +XenIoPvhDeviceBindingStart (
> +  IN EFI_DRIVER_BINDING_PROTOCOL *This,
> +  IN EFI_HANDLE                  DeviceHandle,
> +  IN EFI_DEVICE_PATH_PROTOCOL    *RemainingDevicePath
> +  )
> +{
> +  EFI_STATUS                        Status;
> +  EFI_HANDLE Handle = NULL;
> +
> +  /* Status = XenIoMmioInstall(&Handle, (UINTN)AllocateReservedPages(4)); */
> +  Status = XenIoMmioInstall(&Handle, (UINTN)0xfc000000);
> +
> +  if (!EFI_ERROR (Status)) {
> +    mXenIoInitialized = TRUE;
> +    return EFI_SUCCESS;
> +  }
> +
> +  return Status;
> +}
> +
> +#if 1
> +/**
> +
> +  Stop driving the XenIo PCI device
> +
> +  @param[in] This               The EFI_DRIVER_BINDING_PROTOCOL object
> +                                incorporating this driver (independently of any
> +                                device).
> +
> +  @param[in] DeviceHandle       Stop driving this device.
> +
> +  @param[in] NumberOfChildren   Since this function belongs to a device driver
> +                                only (as opposed to a bus driver), the caller
> +                                environment sets NumberOfChildren to zero, and
> +                                we ignore it.
> +
> +  @param[in] ChildHandleBuffer  Ignored (corresponding to NumberOfChildren).
> +
> +  @retval EFI_SUCCESS           Driver instance has been stopped and the PCI
> +                                configuration attributes have been restored.
> +
> +  @return                       Error codes from the OpenProtocol() or
> +                                CloseProtocol(), UninstallProtocolInterface()
> +                                boot services.
> +
> +**/
> +STATIC
> +EFI_STATUS
> +EFIAPI
> +XenIoPvhDeviceBindingStop (
> +  IN EFI_DRIVER_BINDING_PROTOCOL *This,
> +  IN EFI_HANDLE                  DeviceHandle,
> +  IN UINTN                       NumberOfChildren,
> +  IN EFI_HANDLE                  *ChildHandleBuffer
> +  )
> +{
> +  /* return XenIoMmioUninstall(Handle); */
> +  return EFI_SUCCESS;
> +}
> +
> +
> +//
> +// The static object that groups the Supported() (ie. probe), Start() and
> +// Stop() functions of the driver together. Refer to UEFI Spec 2.3.1 + Errata
> +// C, 10.1 EFI Driver Binding Protocol.
> +//
> +STATIC EFI_DRIVER_BINDING_PROTOCOL gDriverBinding = {
> +  &XenIoPvhDeviceBindingSupported,
> +  &XenIoPvhDeviceBindingStart,
> +  &XenIoPvhDeviceBindingStop,
> +  0x10, // Version, must be in [0x10 .. 0xFFFFFFEF] for IHV-developed drivers
> +  NULL, // ImageHandle, to be overwritten by
> +        // EfiLibInstallDriverBindingComponentName2() in XenIoPvhDeviceEntryPoint()
> +  NULL  // DriverBindingHandle, ditto
> +};
> +
> +
> +//
> +// The purpose of the following scaffolding (EFI_COMPONENT_NAME_PROTOCOL and
> +// EFI_COMPONENT_NAME2_PROTOCOL implementation) is to format the driver's name
> +// in English, for display on standard console devices. This is recommended for
> +// UEFI drivers that follow the UEFI Driver Model. Refer to the Driver Writer's
> +// Guide for UEFI 2.3.1 v1.01, 11 UEFI Driver and Controller Names.
> +//
> +STATIC
> +EFI_UNICODE_STRING_TABLE mDriverNameTable[] = {
> +  { "eng;en", L"XenIo PVH Driver" },
> +  { NULL,     NULL                }
> +};
> +
> +STATIC
> +EFI_COMPONENT_NAME_PROTOCOL gComponentName;
> +
> +EFI_STATUS
> +EFIAPI
> +XenIoPvhGetDriverName (
> +  IN  EFI_COMPONENT_NAME_PROTOCOL *This,
> +  IN  CHAR8                       *Language,
> +  OUT CHAR16                      **DriverName
> +  )
> +{
> +  return LookupUnicodeString2 (
> +           Language,
> +           This->SupportedLanguages,
> +           mDriverNameTable,
> +           DriverName,
> +           (BOOLEAN)(This == &gComponentName) // Iso639Language
> +           );
> +}
> +
> +EFI_STATUS
> +EFIAPI
> +XenIoPvhGetDeviceName (
> +  IN  EFI_COMPONENT_NAME_PROTOCOL *This,
> +  IN  EFI_HANDLE                  DeviceHandle,
> +  IN  EFI_HANDLE                  ChildHandle,
> +  IN  CHAR8                       *Language,
> +  OUT CHAR16                      **ControllerName
> +  )
> +{
> +  return EFI_UNSUPPORTED;
> +}
> +
> +STATIC
> +EFI_COMPONENT_NAME_PROTOCOL gComponentName = {
> +  &XenIoPvhGetDriverName,
> +  &XenIoPvhGetDeviceName,
> +  "eng" // SupportedLanguages, ISO 639-2 language codes
> +};
> +
> +STATIC
> +EFI_COMPONENT_NAME2_PROTOCOL gComponentName2 = {
> +  (EFI_COMPONENT_NAME2_GET_DRIVER_NAME)     &XenIoPvhGetDriverName,
> +  (EFI_COMPONENT_NAME2_GET_CONTROLLER_NAME) &XenIoPvhGetDeviceName,
> +  "en" // SupportedLanguages, RFC 4646 language codes
> +};
> +
> +#endif
> +
> +//
> +// Entry point of this driver.
> +//
> +EFI_STATUS
> +EFIAPI
> +XenIoPvhDeviceEntryPoint (
> +  IN EFI_HANDLE       ImageHandle,
> +  IN EFI_SYSTEM_TABLE *SystemTable
> +  )
> +{
> +  /* DEBUG((EFI_D_ERROR, "%a %d\n", __FUNCTION__, __LINE__)); */
> +  /* return XenIoPvhDeviceBindingStart(ImageHandle); */
> +
> +  return EfiLibInstallDriverBindingComponentName2 (
> +           ImageHandle,
> +           SystemTable,
> +           &gDriverBinding,
> +           ImageHandle,
> +           &gComponentName,
> +           &gComponentName2
> +           );
> +}
> diff --git a/OvmfPkg/XenIoPvhDxe/XenIoPvhDxe.inf b/OvmfPkg/XenIoPvhDxe/XenIoPvhDxe.inf
> new file mode 100644
> index 0000000..dbdfd6e
> --- /dev/null
> +++ b/OvmfPkg/XenIoPvhDxe/XenIoPvhDxe.inf
> @@ -0,0 +1,45 @@
> +## @file
> +#  XXX
> +#
> +#  Copyright (C) XXX
> +#
> +#  This program and the accompanying materials
> +#  are licensed and made available under the terms and conditions of the BSD License
> +#  which accompanies this distribution.  The full text of the license may be found at
> +#  http://opensource.org/licenses/bsd-license.php
> +#
> +#  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
> +#  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
> +#
> +##
> +
> +[Defines]
> +  INF_VERSION               = 0x00010005
> +  BASE_NAME                 = XenIoPvhDxe
> +  FILE_GUID                 = 7a567cc4-0e75-4d7a-a305-c3db109b53ad
> +  MODULE_TYPE               = UEFI_DRIVER
> +  VERSION_STRING            = 1.0
> +  ENTRY_POINT               = XenIoPvhDeviceEntryPoint
> +
> +[Packages]
> +  MdePkg/MdePkg.dec
> +  OvmfPkg/OvmfPkg.dec
> +
> +[Sources]
> +  XenIoPvhDxe.c
> +
> +[LibraryClasses]
> +  UefiDriverEntryPoint
> +  UefiBootServicesTableLib
> +  MemoryAllocationLib
> +  BaseMemoryLib
> +  BaseLib
> +  UefiLib
> +  DebugLib
> +  XenIoMmioLib
> +
> +[Protocols]
> +  gEfiDriverBindingProtocolGuid
> +  gEfiComponentName2ProtocolGuid
> +  gEfiComponentNameProtocolGuid
> +  gXenIoProtocolGuid
> diff --git a/OvmfPkg/XenOvmf.dsc b/OvmfPkg/XenOvmf.dsc
> index 8bce996..a7a884e 100644
> --- a/OvmfPkg/XenOvmf.dsc
> +++ b/OvmfPkg/XenOvmf.dsc
> @@ -168,6 +168,7 @@
>    SmbusLib|MdePkg/Library/BaseSmbusLibNull/BaseSmbusLibNull.inf
>    OrderedCollectionLib|MdePkg/Library/BaseOrderedCollectionRedBlackTreeLib/BaseOrderedCollectionRedBlackTreeLib.inf
>    XenHypercallLib|OvmfPkg/Library/XenHypercallLib/XenHypercallLib.inf
> +  XenIoMmioLib|OvmfPkg/Library/XenIoMmioLib/XenIoMmioLib.inf
>  
>  [LibraryClasses.common]
>  !if $(SECURE_BOOT_ENABLE) == TRUE
> @@ -587,6 +588,7 @@
>  !endif
>    }
>    OvmfPkg/BlockMmioToBlockIoDxe/BlockIo.inf
> +  OvmfPkg/XenIoPvhDxe/XenIoPvhDxe.inf
>    OvmfPkg/XenIoPciDxe/XenIoPciDxe.inf
>    OvmfPkg/XenBusDxe/XenBusDxe.inf
>    OvmfPkg/XenPvBlkDxe/XenPvBlkDxe.inf
> diff --git a/OvmfPkg/XenOvmf.fdf b/OvmfPkg/XenOvmf.fdf
> index a40d186..a500ab6 100644
> --- a/OvmfPkg/XenOvmf.fdf
> +++ b/OvmfPkg/XenOvmf.fdf
> @@ -220,6 +220,7 @@ INF  MdeModulePkg/Universal/Metronome/Metronome.inf
>  INF  PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcatRealTimeClockRuntimeDxe.inf
>  
>  INF  OvmfPkg/BlockMmioToBlockIoDxe/BlockIo.inf
> +INF  OvmfPkg/XenIoPvhDxe/XenIoPvhDxe.inf
>  INF  OvmfPkg/XenIoPciDxe/XenIoPciDxe.inf
>  INF  OvmfPkg/XenBusDxe/XenBusDxe.inf
>  INF  OvmfPkg/XenPvBlkDxe/XenPvBlkDxe.inf
>