[edk2-devel] [Virtio-fs] [edk2 PATCH 01/48] OvmfPkg: introduce VirtioFsDxe
Dr. David Alan Gilbert
dgilbert at redhat.com
Fri Dec 18 18:13:35 UTC 2020
* Ard Biesheuvel (ard.biesheuvel at arm.com) wrote:
> On 12/16/20 10:10 PM, Laszlo Ersek wrote:
> > The purpose of the driver is to ease file exchange (file sharing) between
> > the guest firmware and the virtualization host. The driver is supposed to
> > interoperate with QEMU's "virtiofsd" (Virtio Filesystem Daemon).
> >
> > References:
> > - https://virtio-fs.gitlab.io/
> > - https://libvirt.org/kbase/virtiofs.html
> >
> > VirtioFsDxe will bind virtio-fs devices, and produce
> > EFI_SIMPLE_FILE_SYSTEM_PROTOCOL instances on them.
> >
> > In the longer term, assuming QEMU will create "bootorder" fw_cfg file
> > entries for virtio-fs devices, booting guest OSes from host-side
> > directories should become possible (dependent on the matching
> > QemuBootOrderLib enhancement).
> >
> > Add the skeleton of the driver. Install EFI_DRIVER_BINDING_PROTOCOL with
> > stub member functions. Install EFI_COMPONENT_NAME2_PROTOCOL with final
> > member functions. This suffices for the DRIVERS command in the UEFI Shell
> > to list the driver with a human-readable name.
> >
> > The file permission model is described immediately in the INF file as a
> > comment block, for future reference.
> >
> > Cc: Ard Biesheuvel <ard.biesheuvel at arm.com>
> > Cc: Jordan Justen <jordan.l.justen at intel.com>
> > Cc: Philippe Mathieu-Daudé <philmd at redhat.com>
> > Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3097
> > Signed-off-by: Laszlo Ersek <lersek at redhat.com>
> > ---
> > OvmfPkg/OvmfPkgIa32.dsc | 1 +
> > OvmfPkg/OvmfPkgIa32X64.dsc | 1 +
> > OvmfPkg/OvmfPkgX64.dsc | 1 +
> > OvmfPkg/OvmfPkgIa32.fdf | 1 +
> > OvmfPkg/OvmfPkgIa32X64.fdf | 1 +
> > OvmfPkg/OvmfPkgX64.fdf | 1 +
> > OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf | 92 ++++++++++++++++
> > OvmfPkg/VirtioFsDxe/DriverBinding.c | 112 ++++++++++++++++++++
> > 8 files changed, 210 insertions(+)
> >
> > diff --git a/OvmfPkg/OvmfPkgIa32.dsc b/OvmfPkg/OvmfPkgIa32.dsc
> > index 8eede796a8bd..4ff70674fb6e 100644
> > --- a/OvmfPkg/OvmfPkgIa32.dsc
> > +++ b/OvmfPkg/OvmfPkgIa32.dsc
> > @@ -807,16 +807,17 @@ [Components]
> > }
> > MdeModulePkg/Universal/PrintDxe/PrintDxe.inf
> > MdeModulePkg/Universal/Disk/DiskIoDxe/DiskIoDxe.inf
> > MdeModulePkg/Universal/Disk/PartitionDxe/PartitionDxe.inf
> > MdeModulePkg/Universal/Disk/RamDiskDxe/RamDiskDxe.inf
> > MdeModulePkg/Universal/Disk/UnicodeCollation/EnglishDxe/EnglishDxe.inf
> > FatPkg/EnhancedFatDxe/Fat.inf
> > MdeModulePkg/Universal/Disk/UdfDxe/UdfDxe.inf
> > + OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf
> > MdeModulePkg/Bus/Scsi/ScsiBusDxe/ScsiBusDxe.inf
> > MdeModulePkg/Bus/Scsi/ScsiDiskDxe/ScsiDiskDxe.inf
> > OvmfPkg/SataControllerDxe/SataControllerDxe.inf
> > MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AtaAtapiPassThru.inf
> > MdeModulePkg/Bus/Ata/AtaBusDxe/AtaBusDxe.inf
> > MdeModulePkg/Bus/Pci/NvmExpressDxe/NvmExpressDxe.inf
> > MdeModulePkg/Universal/HiiDatabaseDxe/HiiDatabaseDxe.inf
> > MdeModulePkg/Universal/SetupBrowserDxe/SetupBrowserDxe.inf
> > diff --git a/OvmfPkg/OvmfPkgIa32X64.dsc b/OvmfPkg/OvmfPkgIa32X64.dsc
> > index f9f82a48f4b9..d40a59183c79 100644
> > --- a/OvmfPkg/OvmfPkgIa32X64.dsc
> > +++ b/OvmfPkg/OvmfPkgIa32X64.dsc
> > @@ -821,16 +821,17 @@ [Components.X64]
> > }
> > MdeModulePkg/Universal/PrintDxe/PrintDxe.inf
> > MdeModulePkg/Universal/Disk/DiskIoDxe/DiskIoDxe.inf
> > MdeModulePkg/Universal/Disk/PartitionDxe/PartitionDxe.inf
> > MdeModulePkg/Universal/Disk/RamDiskDxe/RamDiskDxe.inf
> > MdeModulePkg/Universal/Disk/UnicodeCollation/EnglishDxe/EnglishDxe.inf
> > FatPkg/EnhancedFatDxe/Fat.inf
> > MdeModulePkg/Universal/Disk/UdfDxe/UdfDxe.inf
> > + OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf
> > MdeModulePkg/Bus/Scsi/ScsiBusDxe/ScsiBusDxe.inf
> > MdeModulePkg/Bus/Scsi/ScsiDiskDxe/ScsiDiskDxe.inf
> > OvmfPkg/SataControllerDxe/SataControllerDxe.inf
> > MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AtaAtapiPassThru.inf
> > MdeModulePkg/Bus/Ata/AtaBusDxe/AtaBusDxe.inf
> > MdeModulePkg/Bus/Pci/NvmExpressDxe/NvmExpressDxe.inf
> > MdeModulePkg/Universal/HiiDatabaseDxe/HiiDatabaseDxe.inf
> > MdeModulePkg/Universal/SetupBrowserDxe/SetupBrowserDxe.inf
> > diff --git a/OvmfPkg/OvmfPkgX64.dsc b/OvmfPkg/OvmfPkgX64.dsc
> > index e59ae05b73aa..ec7886235acf 100644
> > --- a/OvmfPkg/OvmfPkgX64.dsc
> > +++ b/OvmfPkg/OvmfPkgX64.dsc
> > @@ -817,16 +817,17 @@ [Components]
> > }
> > MdeModulePkg/Universal/PrintDxe/PrintDxe.inf
> > MdeModulePkg/Universal/Disk/DiskIoDxe/DiskIoDxe.inf
> > MdeModulePkg/Universal/Disk/PartitionDxe/PartitionDxe.inf
> > MdeModulePkg/Universal/Disk/RamDiskDxe/RamDiskDxe.inf
> > MdeModulePkg/Universal/Disk/UnicodeCollation/EnglishDxe/EnglishDxe.inf
> > FatPkg/EnhancedFatDxe/Fat.inf
> > MdeModulePkg/Universal/Disk/UdfDxe/UdfDxe.inf
> > + OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf
> > MdeModulePkg/Bus/Scsi/ScsiBusDxe/ScsiBusDxe.inf
> > MdeModulePkg/Bus/Scsi/ScsiDiskDxe/ScsiDiskDxe.inf
> > OvmfPkg/SataControllerDxe/SataControllerDxe.inf
> > MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AtaAtapiPassThru.inf
> > MdeModulePkg/Bus/Ata/AtaBusDxe/AtaBusDxe.inf
> > MdeModulePkg/Bus/Pci/NvmExpressDxe/NvmExpressDxe.inf
> > MdeModulePkg/Universal/HiiDatabaseDxe/HiiDatabaseDxe.inf
> > MdeModulePkg/Universal/SetupBrowserDxe/SetupBrowserDxe.inf
> > diff --git a/OvmfPkg/OvmfPkgIa32.fdf b/OvmfPkg/OvmfPkgIa32.fdf
> > index c07b775d0a2d..f400c845b9c9 100644
> > --- a/OvmfPkg/OvmfPkgIa32.fdf
> > +++ b/OvmfPkg/OvmfPkgIa32.fdf
> > @@ -285,16 +285,17 @@ [FV.DXEFV]
> > INF OvmfPkg/AcpiPlatformDxe/AcpiPlatformDxe.inf
> > INF RuleOverride=ACPITABLE OvmfPkg/AcpiTables/AcpiTables.inf
> > INF MdeModulePkg/Universal/Acpi/S3SaveStateDxe/S3SaveStateDxe.inf
> > INF MdeModulePkg/Universal/Acpi/BootScriptExecutorDxe/BootScriptExecutorDxe.inf
> > INF MdeModulePkg/Universal/Acpi/BootGraphicsResourceTableDxe/BootGraphicsResourceTableDxe.inf
> >
> > INF FatPkg/EnhancedFatDxe/Fat.inf
> > INF MdeModulePkg/Universal/Disk/UdfDxe/UdfDxe.inf
> > +INF OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf
> >
> > !if $(TOOL_CHAIN_TAG) != "XCODE5"
> > INF ShellPkg/DynamicCommand/TftpDynamicCommand/TftpDynamicCommand.inf
> > INF ShellPkg/DynamicCommand/HttpDynamicCommand/HttpDynamicCommand.inf
> > INF OvmfPkg/LinuxInitrdDynamicShellCommand/LinuxInitrdDynamicShellCommand.inf
> > !endif
> > INF ShellPkg/Application/Shell/Shell.inf
> >
> > diff --git a/OvmfPkg/OvmfPkgIa32X64.fdf b/OvmfPkg/OvmfPkgIa32X64.fdf
> > index 9adf1525c135..d055552fd09f 100644
> > --- a/OvmfPkg/OvmfPkgIa32X64.fdf
> > +++ b/OvmfPkg/OvmfPkgIa32X64.fdf
> > @@ -286,16 +286,17 @@ [FV.DXEFV]
> > INF OvmfPkg/AcpiPlatformDxe/AcpiPlatformDxe.inf
> > INF RuleOverride=ACPITABLE OvmfPkg/AcpiTables/AcpiTables.inf
> > INF MdeModulePkg/Universal/Acpi/S3SaveStateDxe/S3SaveStateDxe.inf
> > INF MdeModulePkg/Universal/Acpi/BootScriptExecutorDxe/BootScriptExecutorDxe.inf
> > INF MdeModulePkg/Universal/Acpi/BootGraphicsResourceTableDxe/BootGraphicsResourceTableDxe.inf
> >
> > INF FatPkg/EnhancedFatDxe/Fat.inf
> > INF MdeModulePkg/Universal/Disk/UdfDxe/UdfDxe.inf
> > +INF OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf
> >
> > !if $(TOOL_CHAIN_TAG) != "XCODE5"
> > INF ShellPkg/DynamicCommand/TftpDynamicCommand/TftpDynamicCommand.inf
> > INF ShellPkg/DynamicCommand/HttpDynamicCommand/HttpDynamicCommand.inf
> > INF OvmfPkg/LinuxInitrdDynamicShellCommand/LinuxInitrdDynamicShellCommand.inf
> > !endif
> > INF ShellPkg/Application/Shell/Shell.inf
> >
> > diff --git a/OvmfPkg/OvmfPkgX64.fdf b/OvmfPkg/OvmfPkgX64.fdf
> > index 17ba9e177ac3..1a2ef5bf2ae3 100644
> > --- a/OvmfPkg/OvmfPkgX64.fdf
> > +++ b/OvmfPkg/OvmfPkgX64.fdf
> > @@ -295,16 +295,17 @@ [FV.DXEFV]
> > INF OvmfPkg/AcpiPlatformDxe/AcpiPlatformDxe.inf
> > INF RuleOverride=ACPITABLE OvmfPkg/AcpiTables/AcpiTables.inf
> > INF MdeModulePkg/Universal/Acpi/S3SaveStateDxe/S3SaveStateDxe.inf
> > INF MdeModulePkg/Universal/Acpi/BootScriptExecutorDxe/BootScriptExecutorDxe.inf
> > INF MdeModulePkg/Universal/Acpi/BootGraphicsResourceTableDxe/BootGraphicsResourceTableDxe.inf
> >
> > INF FatPkg/EnhancedFatDxe/Fat.inf
> > INF MdeModulePkg/Universal/Disk/UdfDxe/UdfDxe.inf
> > +INF OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf
> >
> > !if $(TOOL_CHAIN_TAG) != "XCODE5"
> > INF ShellPkg/DynamicCommand/TftpDynamicCommand/TftpDynamicCommand.inf
> > INF ShellPkg/DynamicCommand/HttpDynamicCommand/HttpDynamicCommand.inf
> > INF OvmfPkg/LinuxInitrdDynamicShellCommand/LinuxInitrdDynamicShellCommand.inf
> > !endif
> > INF ShellPkg/Application/Shell/Shell.inf
> >
> > diff --git a/OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf b/OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf
> > new file mode 100644
> > index 000000000000..69cb44bc7c96
> > --- /dev/null
> > +++ b/OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf
> > @@ -0,0 +1,92 @@
> > +## @file
> > +# Provide EFI_SIMPLE_FILE_SYSTEM_PROTOCOL instances on virtio-fs devices.
> > +#
> > +# Copyright (C) 2020, Red Hat, Inc.
> > +#
> > +# SPDX-License-Identifier: BSD-2-Clause-Patent
> > +#
> > +#
> > +# Permission Model of this driver:
> > +#
> > +# Regardless of the UID and GID values this driver send in the FUSE request
> > +# header, the daemon (that is, the Virtio Filesystem device) always acts with
> > +# root privileges on the host side. The only time the daemon considers said UID
> > +# and GID fields is when creating a new file or directory. Thus, the guest
> > +# driver cannot rely on the host for enforcing any file mode permissions,
> > +# regardless of the "personality" that the guest driver poses as, because
> > +# "root" on the host side ignores all file mode bits.
> > +#
> > +# Therefore the guest driver has to do its own permission checking, and use the
> > +# host-side file mode bits only as a kind of "metadata storage" or "reminder"
> > +# -- hopefully in a way that makes some sense on the host side too.
> > +#
>
> Can you please explain why this is safe? Or should virtio-fs only be
> used with guests that can be trusted with root privileges on the host?
The daemon sandboxes itself and generally you only expose a private area
of a filesystem to the guest; i.e. a per-guest rootfs or temporary or
whatever.
Dave
> --
> Ard.
>
>
>
> > +# The complete mapping between the EFI_FILE_PROTOCOL and the host-side file
> > +# mode bits is described below.
> > +#
> > +# - The guest driver poses as UID 0, GID 0, PID 1.
> > +#
> > +# - If and only if all "w" bits are missing from a file on the host side, then
> > +# the file or directory is reported as EFI_FILE_READ_ONLY in the guest. When
> > +# setting EFI_FILE_READ_ONLY in the guest, all "w" bits (0222) are cleared on
> > +# the host; when clearing EFI_FILE_READ_ONLY in the guest, all "w" bits are
> > +# set on the host. Viewed from the host side, this sort of reflects that an
> > +# EFI_FILE_READ_ONLY file should not be written by anyone.
> > +#
> > +# - The attributes EFI_FILE_HIDDEN, EFI_FILE_SYSTEM, EFI_FILE_RESERVED, and
> > +# EFI_FILE_ARCHIVE are never reported in the guest, and they are silently
> > +# ignored when a SetInfo() call or a file-creating Open() call requests them.
> > +#
> > +# - On the host, files are created with 0666 file mode bits, directories are
> > +# created with 0777 file mode bits.
> > +#
> > +# - In the guest, the EFI_FILE_READ_ONLY attribute only controls the permitted
> > +# open mode. In particular, on directories, the EFI_FILE_READ_ONLY attribute
> > +# does not prevent the creation or deletion of entries inside the directory;
> > +# EFI_FILE_READ_ONLY only prevents the renaming, deleting, flushing (syncing)
> > +# and touching of the directory itself (with "touching" meaning updating the
> > +# timestamps). The fact that EFI_FILE_READ_ONLY being set on a directory is
> > +# irrelevant in the guest with regard to entry creation/deletion, is
> > +# well-mirrored by the fact that virtiofsd -- which runs as root, regardless
> > +# of guest driver personality -- ignores the absence of "w" permissions on a
> > +# host-side directory, when creating or removing entries in it.
> > +#
> > +# - When an EFI_FILE_PROTOCOL is opened read-only, then the Delete(), Write()
> > +# and Flush() member functions are disabled for it. Additionally, SetInfo()
> > +# is restricted to flipping the EFI_FILE_READ_ONLY bit (which takes effect at
> > +# the next Open()).
> > +#
> > +# - As a consequence of the above, for deleting a directory, it must be
> > +# presented in the guest as openable for writing.
> > +#
> > +# - We diverge from the UEFI spec, and permit Flush() on a directory that has
> > +# been opened read-write; otherwise the only way to invoke FUSE_FSYNCDIR on a
> > +# directory would be to Close() it.
> > +#
> > +# - OpenVolume() opens the root directory for read-only access. The Open()
> > +# member function may open it for read-write access. While the root directory
> > +# cannot be renamed or deleted, opening it for read-write access is useful
> > +# for calling Flush(), according to the previous paragraph, or for updating
> > +# the root directory's timestamps with SetInfo().
> > +##
> > +
> > +[Defines]
> > + INF_VERSION = 1.29
> > + BASE_NAME = VirtioFsDxe
> > + FILE_GUID = 7BD9DDF7-8B83-488E-AEC9-24C78610289C
> > + MODULE_TYPE = UEFI_DRIVER
> > + ENTRY_POINT = VirtioFsEntryPoint
> > +
> > +[Packages]
> > + MdePkg/MdePkg.dec
> > +
> > +[Sources]
> > + DriverBinding.c
> > +
> > +[LibraryClasses]
> > + BaseLib
> > + UefiBootServicesTableLib
> > + UefiDriverEntryPoint
> > +
> > +[Protocols]
> > + gEfiComponentName2ProtocolGuid ## PRODUCES
> > + gEfiDriverBindingProtocolGuid ## PRODUCES
> > diff --git a/OvmfPkg/VirtioFsDxe/DriverBinding.c b/OvmfPkg/VirtioFsDxe/DriverBinding.c
> > new file mode 100644
> > index 000000000000..ac0a6330f01b
> > --- /dev/null
> > +++ b/OvmfPkg/VirtioFsDxe/DriverBinding.c
> > @@ -0,0 +1,112 @@
> > +/** @file
> > + Provide EFI_SIMPLE_FILE_SYSTEM_PROTOCOL instances on virtio-fs devices.
> > +
> > + Copyright (C) 2020, Red Hat, Inc.
> > +
> > + SPDX-License-Identifier: BSD-2-Clause-Patent
> > +**/
> > +
> > +#include <Library/BaseLib.h> // AsciiStrCmp()
> > +#include <Library/UefiBootServicesTableLib.h> // gBS
> > +#include <Protocol/ComponentName2.h> // EFI_COMPONENT_NAME2_PROTOCOL
> > +#include <Protocol/DriverBinding.h> // EFI_DRIVER_BINDING_PROTOCOL
> > +
> > +//
> > +// UEFI Driver Model protocol instances.
> > +//
> > +STATIC EFI_DRIVER_BINDING_PROTOCOL mDriverBinding;
> > +STATIC EFI_COMPONENT_NAME2_PROTOCOL mComponentName2;
> > +
> > +//
> > +// UEFI Driver Model protocol member functions.
> > +//
> > +EFI_STATUS
> > +EFIAPI
> > +VirtioFsBindingSupported (
> > + IN EFI_DRIVER_BINDING_PROTOCOL *This,
> > + IN EFI_HANDLE ControllerHandle,
> > + IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath OPTIONAL
> > + )
> > +{
> > + return EFI_UNSUPPORTED;
> > +}
> > +
> > +EFI_STATUS
> > +EFIAPI
> > +VirtioFsBindingStart (
> > + IN EFI_DRIVER_BINDING_PROTOCOL *This,
> > + IN EFI_HANDLE ControllerHandle,
> > + IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath OPTIONAL
> > + )
> > +{
> > + return EFI_DEVICE_ERROR;
> > +}
> > +
> > +EFI_STATUS
> > +EFIAPI
> > +VirtioFsBindingStop (
> > + IN EFI_DRIVER_BINDING_PROTOCOL *This,
> > + IN EFI_HANDLE ControllerHandle,
> > + IN UINTN NumberOfChildren,
> > + IN EFI_HANDLE *ChildHandleBuffer OPTIONAL
> > + )
> > +{
> > + return EFI_DEVICE_ERROR;
> > +}
> > +
> > +EFI_STATUS
> > +EFIAPI
> > +VirtioFsGetDriverName (
> > + IN EFI_COMPONENT_NAME2_PROTOCOL *This,
> > + IN CHAR8 *Language,
> > + OUT CHAR16 **DriverName
> > + )
> > +{
> > + if (AsciiStrCmp (Language, "en") != 0) {
> > + return EFI_UNSUPPORTED;
> > + }
> > + *DriverName = L"Virtio Filesystem Driver";
> > + return EFI_SUCCESS;
> > +}
> > +
> > +EFI_STATUS
> > +EFIAPI
> > +VirtioFsGetControllerName (
> > + IN EFI_COMPONENT_NAME2_PROTOCOL *This,
> > + IN EFI_HANDLE ControllerHandle,
> > + IN EFI_HANDLE ChildHandle OPTIONAL,
> > + IN CHAR8 *Language,
> > + OUT CHAR16 **ControllerName
> > + )
> > +{
> > + return EFI_UNSUPPORTED;
> > +}
> > +
> > +//
> > +// Entry point of this driver.
> > +//
> > +EFI_STATUS
> > +EFIAPI
> > +VirtioFsEntryPoint (
> > + IN EFI_HANDLE ImageHandle,
> > + IN EFI_SYSTEM_TABLE *SystemTable
> > + )
> > +{
> > + EFI_STATUS Status;
> > +
> > + mDriverBinding.Supported = VirtioFsBindingSupported;
> > + mDriverBinding.Start = VirtioFsBindingStart;
> > + mDriverBinding.Stop = VirtioFsBindingStop;
> > + mDriverBinding.Version = 0x10;
> > + mDriverBinding.ImageHandle = ImageHandle;
> > + mDriverBinding.DriverBindingHandle = ImageHandle;
> > +
> > + mComponentName2.GetDriverName = VirtioFsGetDriverName;
> > + mComponentName2.GetControllerName = VirtioFsGetControllerName;
> > + mComponentName2.SupportedLanguages = "en";
> > +
> > + Status = gBS->InstallMultipleProtocolInterfaces (&ImageHandle,
> > + &gEfiDriverBindingProtocolGuid, &mDriverBinding,
> > + &gEfiComponentName2ProtocolGuid, &mComponentName2, NULL);
> > + return Status;
> > +}
> >
>
>
> _______________________________________________
> Virtio-fs mailing list
> Virtio-fs at redhat.com
> https://www.redhat.com/mailman/listinfo/virtio-fs
--
Dr. David Alan Gilbert / dgilbert at redhat.com / Manchester, UK
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