This implements a UEFI driver model driver for Virtio devices of type VIRTIO_SUBSYSTEM_ENTROPY_SOURCE, and exposes them via instances of the EFI_RNG_PROTOCOL protocol, supporting the EFI_RNG_ALGORITHM_RAW algorithm only.
Cc: Jordan Justen <jordan.l.jus...@intel.com> Cc: Laszlo Ersek <ler...@redhat.com> Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Ard Biesheuvel <ard.biesheu...@linaro.org> --- OvmfPkg/VirtioRngDxe/VirtioRng.c | 607 ++++++++++++++++++++ OvmfPkg/VirtioRngDxe/VirtioRng.h | 32 ++ OvmfPkg/VirtioRngDxe/VirtioRngDxe.inf | 45 ++ 3 files changed, 684 insertions(+) diff --git a/OvmfPkg/VirtioRngDxe/VirtioRng.c b/OvmfPkg/VirtioRngDxe/VirtioRng.c new file mode 100644 index 000000000000..5a3605b661dc --- /dev/null +++ b/OvmfPkg/VirtioRngDxe/VirtioRng.c @@ -0,0 +1,607 @@ +/** @file + + This driver produces EFI_RNG_PROTOCOL instances for virtio-rng devices. + + The implementation is based on OvmfPkg/VirtioScsiDxe/VirtioScsi.c + + Copyright (C) 2012, Red Hat, Inc. + Copyright (c) 2012 - 2014, Intel Corporation. All rights reserved.<BR> + + This driver: + + Copyright (C) 2016, Linaro Ltd. + + 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/VirtioLib.h> + +#include "VirtioRng.h" + +/** + Returns information about the random number generation implementation. + + @param[in] This A pointer to the EFI_RNG_PROTOCOL instance. + @param[in,out] RNGAlgorithmListSize On input, the size in bytes of RNGAlgorithmList. + On output with a return code of EFI_SUCCESS, the size + in bytes of the data returned in RNGAlgorithmList. On output + with a return code of EFI_BUFFER_TOO_SMALL, + the size of RNGAlgorithmList required to obtain the list. + @param[out] RNGAlgorithmList A caller-allocated memory buffer filled by the driver + with one EFI_RNG_ALGORITHM element for each supported + RNG algorithm. The list must not change across multiple + calls to the same driver. The first algorithm in the list + is the default algorithm for the driver. + + @retval EFI_SUCCESS The RNG algorithm list was returned successfully. + @retval EFI_UNSUPPORTED The services is not supported by this driver. + @retval EFI_DEVICE_ERROR The list of algorithms could not be retrieved due to a + hardware or firmware error. + @retval EFI_INVALID_PARAMETER One or more of the parameters are incorrect. + @retval EFI_BUFFER_TOO_SMALL The buffer RNGAlgorithmList is too small to hold the result. + +**/ +STATIC +EFI_STATUS +EFIAPI +VirtioRngGetInfo ( + IN EFI_RNG_PROTOCOL *This, + IN OUT UINTN *RNGAlgorithmListSize, + OUT EFI_RNG_ALGORITHM *RNGAlgorithmList + ) +{ + if (This == NULL || RNGAlgorithmListSize == NULL) { + return EFI_INVALID_PARAMETER; + } + + if (*RNGAlgorithmListSize < sizeof (EFI_RNG_ALGORITHM)) { + *RNGAlgorithmListSize = sizeof (EFI_RNG_ALGORITHM); + return EFI_BUFFER_TOO_SMALL; + } + + if (RNGAlgorithmList != NULL) { + return EFI_INVALID_PARAMETER; + } + + *RNGAlgorithmListSize = sizeof (EFI_RNG_ALGORITHM); + CopyGuid (RNGAlgorithmList, &gEfiRngAlgorithmRaw); + + return EFI_SUCCESS; +} + +/** + Produces and returns an RNG value using either the default or specified RNG algorithm. + + @param[in] This A pointer to the EFI_RNG_PROTOCOL instance. + @param[in] RNGAlgorithm A pointer to the EFI_RNG_ALGORITHM that identifies the RNG + algorithm to use. May be NULL in which case the function will + use its default RNG algorithm. + @param[in] RNGValueLength The length in bytes of the memory buffer pointed to by + RNGValue. The driver shall return exactly this numbers of bytes. + @param[out] RNGValue A caller-allocated memory buffer filled by the driver with the + resulting RNG value. + + @retval EFI_SUCCESS The RNG value was returned successfully. + @retval EFI_UNSUPPORTED The algorithm specified by RNGAlgorithm is not supported by + this driver. + @retval EFI_DEVICE_ERROR An RNG value could not be retrieved due to a hardware or + firmware error. + @retval EFI_NOT_READY There is not enough random data available to satisfy the length + requested by RNGValueLength. + @retval EFI_INVALID_PARAMETER RNGValue is NULL or RNGValueLength is zero. + +**/ +STATIC +EFI_STATUS +EFIAPI +VirtioRngGetRNG ( + IN EFI_RNG_PROTOCOL *This, + IN EFI_RNG_ALGORITHM *RNGAlgorithm, OPTIONAL + IN UINTN RNGValueLength, + OUT UINT8 *RNGValue + ) +{ + VIRTIO_RNG_DEV *Dev; + DESC_INDICES Indices; + volatile UINT8 *Buffer; + UINTN Index; + UINT32 Len; + + if (This == NULL || RNGValueLength == 0 || RNGValue == NULL) { + return EFI_INVALID_PARAMETER; + } + + // + // We only support the raw algorithm, so reject requests for anything else + // + if (RNGAlgorithm && !CompareGuid (RNGAlgorithm, &gEfiRngAlgorithmRaw)) { + return EFI_UNSUPPORTED; + } + + Buffer = (volatile UINT8 *)AllocatePool (RNGValueLength); + if (Buffer == NULL) { + return EFI_DEVICE_ERROR; + } + + Dev = VIRTIO_ENTROPY_SOURCE_FROM_RNG (This); + + // + // The Virtio RNG device may return less data than we asked it to. + // So loop as long as needed to get all the entropy we were asked for + // + for (Index = 0; Index < RNGValueLength; Index += Len) { + + VirtioPrepare (&Dev->Ring, &Indices); + VirtioAppendDesc (&Dev->Ring, + (UINTN) Buffer + Index, + RNGValueLength - Index, + VRING_DESC_F_WRITE, + &Indices); + + if (VirtioFlush (Dev->VirtIo, 0, &Dev->Ring, &Indices, &Len) != EFI_SUCCESS) { + goto FreeBuffer; + } + } + + for (Index = 0; Index < RNGValueLength; Index++) { + RNGValue[Index] = Buffer[Index]; + } + FreePool ((VOID *)Buffer); + return EFI_SUCCESS; + +FreeBuffer: + FreePool ((VOID *)Buffer); + return EFI_DEVICE_ERROR; +} + +STATIC +EFI_STATUS +EFIAPI +VirtioRngInit ( + IN OUT VIRTIO_RNG_DEV *Dev + ) +{ + UINT8 NextDevStat; + EFI_STATUS Status; + UINT16 QueueSize; + + // + // Execute virtio-0.9.5, 2.2.1 Device Initialization Sequence. + // + NextDevStat = 0; // step 1 -- reset device + Status = Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, NextDevStat); + if (EFI_ERROR (Status)) { + goto Failed; + } + + NextDevStat |= VSTAT_ACK; // step 2 -- acknowledge device presence + Status = Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, NextDevStat); + if (EFI_ERROR (Status)) { + goto Failed; + } + + NextDevStat |= VSTAT_DRIVER; // step 3 -- we know how to drive it + Status = Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, NextDevStat); + if (EFI_ERROR (Status)) { + goto Failed; + } + + // + // Set Page Size - MMIO VirtIo Specific + // + Status = Dev->VirtIo->SetPageSize (Dev->VirtIo, EFI_PAGE_SIZE); + if (EFI_ERROR (Status)) { + goto Failed; + } + + // + // allocate request virtqueue, just use #0 + // + Status = Dev->VirtIo->SetQueueSel (Dev->VirtIo, 0); + if (EFI_ERROR (Status)) { + goto Failed; + } + Status = Dev->VirtIo->GetQueueNumMax (Dev->VirtIo, &QueueSize); + if (EFI_ERROR (Status)) { + goto Failed; + } + + // + // Single queue required + // + if (QueueSize < 1) { + Status = EFI_UNSUPPORTED; + goto Failed; + } + + Status = VirtioRingInit (QueueSize, &Dev->Ring); + if (EFI_ERROR (Status)) { + goto Failed; + } + + // + // Additional steps for MMIO: align the queue appropriately, and set the + // size. If anything fails from here on, we must release the ring resources. + // + Status = Dev->VirtIo->SetQueueNum (Dev->VirtIo, QueueSize); + if (EFI_ERROR (Status)) { + goto ReleaseQueue; + } + + Status = Dev->VirtIo->SetQueueAlign (Dev->VirtIo, EFI_PAGE_SIZE); + if (EFI_ERROR (Status)) { + goto ReleaseQueue; + } + + // + // Report GPFN (guest-physical frame number) of queue. + // + Status = Dev->VirtIo->SetQueueAddress (Dev->VirtIo, + (UINT32) ((UINTN) Dev->Ring.Base >> EFI_PAGE_SHIFT)); + if (EFI_ERROR (Status)) { + goto ReleaseQueue; + } + + // + // initialization complete + // + NextDevStat |= VSTAT_DRIVER_OK; + Status = Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, NextDevStat); + if (EFI_ERROR (Status)) { + goto ReleaseQueue; + } + + // + // populate the exported interface's attributes + // + Dev->Rng.GetInfo = VirtioRngGetInfo; + Dev->Rng.GetRNG = VirtioRngGetRNG; + + return EFI_SUCCESS; + +ReleaseQueue: + VirtioRingUninit (&Dev->Ring); + +Failed: + // + // Notify the host about our failure to setup: virtio-0.9.5, 2.2.2.1 Device + // Status. VirtIo access failure here should not mask the original error. + // + NextDevStat |= VSTAT_FAILED; + Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, NextDevStat); + + return Status; // reached only via Failed above +} + + +STATIC +VOID +EFIAPI +VirtioRngUninit ( + IN OUT VIRTIO_RNG_DEV *Dev + ) +{ + // + // Reset the virtual device -- see virtio-0.9.5, 2.2.2.1 Device Status. When + // VIRTIO_CFG_WRITE() returns, the host will have learned to stay away from + // the old comms area. + // + Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, 0); + VirtioRingUninit (&Dev->Ring); +} + +// +// Event notification function enqueued by ExitBootServices(). +// + +STATIC +VOID +EFIAPI +VirtioRngExitBoot ( + IN EFI_EVENT Event, + IN VOID *Context + ) +{ + VIRTIO_RNG_DEV *Dev; + + // + // Reset the device. This causes the hypervisor to forget about the virtio + // ring. + // + // We allocated said ring in EfiBootServicesData type memory, and code + // executing after ExitBootServices() is permitted to overwrite it. + // + Dev = Context; + Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, 0); +} + + +// +// Probe, start and stop functions of this driver, called by the DXE core for +// specific devices. +// +// The following specifications document these interfaces: +// - Driver Writer's Guide for UEFI 2.3.1 v1.01, 9 Driver Binding Protocol +// - UEFI Spec 2.3.1 + Errata C, 10.1 EFI Driver Binding Protocol +// +// The implementation follows: +// - Driver Writer's Guide for UEFI 2.3.1 v1.01 +// - 5.1.3.4 OpenProtocol() and CloseProtocol() +// - UEFI Spec 2.3.1 + Errata C +// - 6.3 Protocol Handler Services +// + +STATIC +EFI_STATUS +EFIAPI +VirtioRngDriverBindingSupported ( + IN EFI_DRIVER_BINDING_PROTOCOL *This, + IN EFI_HANDLE DeviceHandle, + IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath + ) +{ + EFI_STATUS Status; + VIRTIO_DEVICE_PROTOCOL *VirtIo; + + // + // Attempt to open the device with the VirtIo set of interfaces. On success, + // the protocol is "instantiated" for the VirtIo device. Covers duplicate open + // attempts (EFI_ALREADY_STARTED). + // + Status = gBS->OpenProtocol ( + DeviceHandle, // candidate device + &gVirtioDeviceProtocolGuid, // for generic VirtIo access + (VOID **)&VirtIo, // handle to instantiate + This->DriverBindingHandle, // requestor driver identity + DeviceHandle, // ControllerHandle, according to + // the UEFI Driver Model + EFI_OPEN_PROTOCOL_BY_DRIVER // get exclusive VirtIo access to + // the device; to be released + ); + if (EFI_ERROR (Status)) { + return Status; + } + + if (VirtIo->SubSystemDeviceId != VIRTIO_SUBSYSTEM_ENTROPY_SOURCE) { + Status = EFI_UNSUPPORTED; + } + + // + // We needed VirtIo access only transitorily, to see whether we support the + // device or not. + // + gBS->CloseProtocol (DeviceHandle, &gVirtioDeviceProtocolGuid, + This->DriverBindingHandle, DeviceHandle); + return Status; +} + +STATIC +EFI_STATUS +EFIAPI +VirtioRngDriverBindingStart ( + IN EFI_DRIVER_BINDING_PROTOCOL *This, + IN EFI_HANDLE DeviceHandle, + IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath + ) +{ + VIRTIO_RNG_DEV *Dev; + EFI_STATUS Status; + + Dev = (VIRTIO_RNG_DEV *) AllocateZeroPool (sizeof *Dev); + if (Dev == NULL) { + return EFI_OUT_OF_RESOURCES; + } + + Status = gBS->OpenProtocol (DeviceHandle, &gVirtioDeviceProtocolGuid, + (VOID **)&Dev->VirtIo, This->DriverBindingHandle, + DeviceHandle, EFI_OPEN_PROTOCOL_BY_DRIVER); + if (EFI_ERROR (Status)) { + goto FreeVirtioRng; + } + + // + // VirtIo access granted, configure virtio-rng device. + // + Status = VirtioRngInit (Dev); + if (EFI_ERROR (Status)) { + goto CloseVirtIo; + } + + Status = gBS->CreateEvent (EVT_SIGNAL_EXIT_BOOT_SERVICES, TPL_CALLBACK, + &VirtioRngExitBoot, Dev, &Dev->ExitBoot); + if (EFI_ERROR (Status)) { + goto UninitDev; + } + + // + // Setup complete, attempt to export the driver instance's EFI_RNG_PROTOCOL + // interface. + // + Dev->Signature = VIRTIO_RNG_SIG; + Status = gBS->InstallProtocolInterface (&DeviceHandle, + &gEfiRngProtocolGuid, EFI_NATIVE_INTERFACE, + &Dev->Rng); + if (EFI_ERROR (Status)) { + goto CloseExitBoot; + } + + return EFI_SUCCESS; + +CloseExitBoot: + gBS->CloseEvent (Dev->ExitBoot); + +UninitDev: + VirtioRngUninit (Dev); + +CloseVirtIo: + gBS->CloseProtocol (DeviceHandle, &gVirtioDeviceProtocolGuid, + This->DriverBindingHandle, DeviceHandle); + +FreeVirtioRng: + FreePool (Dev); + + return Status; +} + + +STATIC +EFI_STATUS +EFIAPI +VirtioRngDriverBindingStop ( + IN EFI_DRIVER_BINDING_PROTOCOL *This, + IN EFI_HANDLE DeviceHandle, + IN UINTN NumberOfChildren, + IN EFI_HANDLE *ChildHandleBuffer + ) +{ + EFI_STATUS Status; + EFI_RNG_PROTOCOL *Rng; + VIRTIO_RNG_DEV *Dev; + + Status = gBS->OpenProtocol ( + DeviceHandle, // candidate device + &gEfiRngProtocolGuid, // retrieve the RNG iface + (VOID **)&Rng, // target pointer + This->DriverBindingHandle, // requestor driver ident. + DeviceHandle, // lookup req. for dev. + EFI_OPEN_PROTOCOL_GET_PROTOCOL // lookup only, no new ref. + ); + if (EFI_ERROR (Status)) { + return Status; + } + + Dev = VIRTIO_ENTROPY_SOURCE_FROM_RNG (Rng); + + // + // Handle Stop() requests for in-use driver instances gracefully. + // + Status = gBS->UninstallProtocolInterface (DeviceHandle, + &gEfiRngProtocolGuid, &Dev->Rng); + if (EFI_ERROR (Status)) { + return Status; + } + + gBS->CloseEvent (Dev->ExitBoot); + + VirtioRngUninit (Dev); + + gBS->CloseProtocol (DeviceHandle, &gVirtioDeviceProtocolGuid, + This->DriverBindingHandle, DeviceHandle); + + FreePool (Dev); + + 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 = { + &VirtioRngDriverBindingSupported, + &VirtioRngDriverBindingStart, + &VirtioRngDriverBindingStop, + 0x10, // Version, must be in [0x10 .. 0xFFFFFFEF] for IHV-developed drivers + NULL, // ImageHandle, to be overwritten by + // EfiLibInstallDriverBindingComponentName2() in VirtioRngEntryPoint() + 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"Virtio Random Number Generator Driver" }, + { NULL, NULL } +}; + +STATIC +EFI_COMPONENT_NAME_PROTOCOL gComponentName; + +STATIC +EFI_STATUS +EFIAPI +VirtioRngGetDriverName ( + IN EFI_COMPONENT_NAME_PROTOCOL *This, + IN CHAR8 *Language, + OUT CHAR16 **DriverName + ) +{ + return LookupUnicodeString2 ( + Language, + This->SupportedLanguages, + mDriverNameTable, + DriverName, + (BOOLEAN)(This == &gComponentName) // Iso639Language + ); +} + +STATIC +EFI_STATUS +EFIAPI +VirtioRngGetDeviceName ( + 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 = { + &VirtioRngGetDriverName, + &VirtioRngGetDeviceName, + "eng" // SupportedLanguages, ISO 639-2 language codes +}; + +STATIC +EFI_COMPONENT_NAME2_PROTOCOL gComponentName2 = { + (EFI_COMPONENT_NAME2_GET_DRIVER_NAME) &VirtioRngGetDriverName, + (EFI_COMPONENT_NAME2_GET_CONTROLLER_NAME) &VirtioRngGetDeviceName, + "en" // SupportedLanguages, RFC 4646 language codes +}; + + +// +// Entry point of this driver. +// +EFI_STATUS +EFIAPI +VirtioRngEntryPoint ( + IN EFI_HANDLE ImageHandle, + IN EFI_SYSTEM_TABLE *SystemTable + ) +{ + return EfiLibInstallDriverBindingComponentName2 ( + ImageHandle, + SystemTable, + &gDriverBinding, + ImageHandle, + &gComponentName, + &gComponentName2 + ); +} diff --git a/OvmfPkg/VirtioRngDxe/VirtioRng.h b/OvmfPkg/VirtioRngDxe/VirtioRng.h new file mode 100644 index 000000000000..38ddd667d11f --- /dev/null +++ b/OvmfPkg/VirtioRngDxe/VirtioRng.h @@ -0,0 +1,32 @@ +/** @file + + Copyright (C) 2016, Linaro Ltd. + + 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 <Protocol/ComponentName.h> +#include <Protocol/DriverBinding.h> +#include <Protocol/Rng.h> + +#include <IndustryStandard/Virtio.h> + +#define VIRTIO_RNG_SIG SIGNATURE_32 ('V', 'R', 'N', 'G') + +typedef struct { + UINT32 Signature; + VIRTIO_DEVICE_PROTOCOL *VirtIo; + EFI_EVENT ExitBoot; + VRING Ring; + EFI_RNG_PROTOCOL Rng; +} VIRTIO_RNG_DEV; + +#define VIRTIO_ENTROPY_SOURCE_FROM_RNG(RngPointer) \ + CR (RngPointer, VIRTIO_RNG_DEV, Rng, VIRTIO_RNG_SIG) diff --git a/OvmfPkg/VirtioRngDxe/VirtioRngDxe.inf b/OvmfPkg/VirtioRngDxe/VirtioRngDxe.inf new file mode 100644 index 000000000000..471beb37bc7f --- /dev/null +++ b/OvmfPkg/VirtioRngDxe/VirtioRngDxe.inf @@ -0,0 +1,45 @@ +## @file +# This driver produces EFI_RNG_PROTOCOL instances for virtio-rng devices. +# +# Copyright (C) 2016, Linaro Ltd. +# +# 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 = VirtioRngDxe + FILE_GUID = 58E26F0D-CBAC-4BBA-B70F-18221415665A + MODULE_TYPE = UEFI_DRIVER + VERSION_STRING = 1.0 + ENTRY_POINT = VirtioRngEntryPoint + +[Sources] + VirtioRng.c + +[Packages] + MdePkg/MdePkg.dec + OvmfPkg/OvmfPkg.dec + +[LibraryClasses] + BaseMemoryLib + DebugLib + MemoryAllocationLib + UefiBootServicesTableLib + UefiDriverEntryPoint + UefiLib + VirtioLib + +[Protocols] + gEfiRngProtocolGuid ## BY_START + gVirtioDeviceProtocolGuid ## TO_START + +[Guids] + gEfiRngAlgorithmRaw -- 2.5.0 _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel