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OvmfPkg/VirtioFsDxe: implement virtio device (un)initialization

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Add the VirtioFsInit(), VirtioFsUninit(), and VirtioFsExitBoot()
functions.

In VirtioFsInit():

- Verify the host-side config of the virtio-fs device.

- Save the filesystem label ("tag") for later, from the configuration area
  of the virtio-fs device.

- Save the virtio queue size for later as well.

- Set up the virtio ring for sending requests.

In VirtioFsUninit():

- Reset the device.

- Tear down the virtio ring.

In VirtioFsExitBoot():

- Reset the device.

With this patch, the UEFI connect / disconnect controller operations
involve virtio setup / teardown; they are visible in the virtio-fs
daemon's log file. The virtiofsd log also confirms the device reset in
VirtioFsExitBoot(), when an OS is booted while the virtio-fs device is
bound.

Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3097
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20201216211125.19496-5-lersek@redhat.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@arm.com>
This commit is contained in:
Laszlo Ersek
2020-12-16 22:10:41 +01:00
committed by mergify[bot]
parent b55d6622d4
commit eaa7115d60
5 changed files with 412 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

299
OvmfPkg/VirtioFsDxe/Helpers.c Normal file
View File

@@ -0,0 +1,299 @@
/** @file
Initialization and helper routines for the Virtio Filesystem device.
Copyright (C) 2020, Red Hat, Inc.
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include <Library/VirtioLib.h> // Virtio10WriteFeatures()
#include "VirtioFsDxe.h"
/**
Read the Virtio Filesystem device configuration structure in full.
@param[in] Virtio The Virtio protocol underlying the VIRTIO_FS object.
@param[out] Config The fully populated VIRTIO_FS_CONFIG structure.
@retval EFI_SUCCESS Config has been filled in.
@return Error codes propagated from Virtio->ReadDevice(). The
contents of Config are indeterminate.
**/
STATIC
EFI_STATUS
VirtioFsReadConfig (
IN VIRTIO_DEVICE_PROTOCOL *Virtio,
OUT VIRTIO_FS_CONFIG *Config
)
{
UINTN Idx;
EFI_STATUS Status;
for (Idx = 0; Idx < VIRTIO_FS_TAG_BYTES; Idx++) {
Status = Virtio->ReadDevice (
Virtio, // This
OFFSET_OF (VIRTIO_FS_CONFIG, Tag[Idx]), // FieldOffset
sizeof Config->Tag[Idx], // FieldSize
sizeof Config->Tag[Idx], // BufferSize
&Config->Tag[Idx] // Buffer
);
if (EFI_ERROR (Status)) {
return Status;
}
}
Status = Virtio->ReadDevice (
Virtio, // This
OFFSET_OF (VIRTIO_FS_CONFIG, NumReqQueues), // FieldOffset
sizeof Config->NumReqQueues, // FieldSize
sizeof Config->NumReqQueues, // BufferSize
&Config->NumReqQueues // Buffer
);
return Status;
}
/**
Configure the Virtio Filesystem device underlying VirtioFs.
@param[in,out] VirtioFs The VIRTIO_FS object for which Virtio communication
should be set up. On input, the caller is
responsible for VirtioFs->Virtio having been
initialized. On output, synchronous Virtio
Filesystem commands (primitives) may be submitted to
the device.
@retval EFI_SUCCESS Virtio machinery has been set up.
@retval EFI_UNSUPPORTED The host-side configuration of the Virtio Filesystem
is not supported by this driver.
@return Error codes from underlying functions.
**/
EFI_STATUS
VirtioFsInit (
IN OUT VIRTIO_FS *VirtioFs
)
{
UINT8 NextDevStat;
EFI_STATUS Status;
UINT64 Features;
VIRTIO_FS_CONFIG Config;
UINTN Idx;
UINT64 RingBaseShift;
//
// Execute virtio-v1.1-cs01-87fa6b5d8155, 3.1.1 Driver Requirements: Device
// Initialization.
//
// 1. Reset the device.
//
NextDevStat = 0;
Status = VirtioFs->Virtio->SetDeviceStatus (VirtioFs->Virtio, NextDevStat);
if (EFI_ERROR (Status)) {
goto Failed;
}
//
// 2. Set the ACKNOWLEDGE status bit [...]
//
NextDevStat |= VSTAT_ACK;
Status = VirtioFs->Virtio->SetDeviceStatus (VirtioFs->Virtio, NextDevStat);
if (EFI_ERROR (Status)) {
goto Failed;
}
//
// 3. Set the DRIVER status bit [...]
//
NextDevStat |= VSTAT_DRIVER;
Status = VirtioFs->Virtio->SetDeviceStatus (VirtioFs->Virtio, NextDevStat);
if (EFI_ERROR (Status)) {
goto Failed;
}
//
// 4. Read device feature bits...
//
Status = VirtioFs->Virtio->GetDeviceFeatures (VirtioFs->Virtio, &Features);
if (EFI_ERROR (Status)) {
goto Failed;
}
if ((Features & VIRTIO_F_VERSION_1) == 0) {
Status = EFI_UNSUPPORTED;
goto Failed;
}
//
// No device-specific feature bits have been defined in file "virtio-fs.tex"
// of the virtio spec at <https://github.com/oasis-tcs/virtio-spec.git>, as
// of commit 87fa6b5d8155.
//
Features &= VIRTIO_F_VERSION_1 | VIRTIO_F_IOMMU_PLATFORM;
//
// ... and write the subset of feature bits understood by the [...] driver to
// the device. [...]
// 5. Set the FEATURES_OK status bit.
// 6. Re-read device status to ensure the FEATURES_OK bit is still set [...]
//
Status = Virtio10WriteFeatures (VirtioFs->Virtio, Features, &NextDevStat);
if (EFI_ERROR (Status)) {
goto Failed;
}
//
// 7. Perform device-specific setup, including discovery of virtqueues for
// the device, [...] reading [...] the device's virtio configuration space
//
Status = VirtioFsReadConfig (VirtioFs->Virtio, &Config);
if (EFI_ERROR (Status)) {
goto Failed;
}
//
// 7.a. Convert the filesystem label from UTF-8 to UCS-2. Only labels with
// printable ASCII code points (U+0020 through U+007E) are supported.
// NUL-terminate at either the terminator we find, or right after the
// original label.
//
for (Idx = 0; Idx < VIRTIO_FS_TAG_BYTES && Config.Tag[Idx] != '\0'; Idx++) {
if (Config.Tag[Idx] < 0x20 || Config.Tag[Idx] > 0x7E) {
Status = EFI_UNSUPPORTED;
goto Failed;
}
VirtioFs->Label[Idx] = Config.Tag[Idx];
}
VirtioFs->Label[Idx] = L'\0';
//
// 7.b. We need one queue for sending normal priority requests.
//
if (Config.NumReqQueues < 1) {
Status = EFI_UNSUPPORTED;
goto Failed;
}
//
// 7.c. Fetch and remember the number of descriptors we can place on the
// queue at once. We'll need two descriptors per request, as a minimum --
// request header, response header.
//
Status = VirtioFs->Virtio->SetQueueSel (VirtioFs->Virtio,
VIRTIO_FS_REQUEST_QUEUE);
if (EFI_ERROR (Status)) {
goto Failed;
}
Status = VirtioFs->Virtio->GetQueueNumMax (VirtioFs->Virtio,
&VirtioFs->QueueSize);
if (EFI_ERROR (Status)) {
goto Failed;
}
if (VirtioFs->QueueSize < 2) {
Status = EFI_UNSUPPORTED;
goto Failed;
}
//
// 7.d. [...] population of virtqueues [...]
//
Status = VirtioRingInit (VirtioFs->Virtio, VirtioFs->QueueSize,
&VirtioFs->Ring);
if (EFI_ERROR (Status)) {
goto Failed;
}
Status = VirtioRingMap (VirtioFs->Virtio, &VirtioFs->Ring, &RingBaseShift,
&VirtioFs->RingMap);
if (EFI_ERROR (Status)) {
goto ReleaseQueue;
}
Status = VirtioFs->Virtio->SetQueueAddress (VirtioFs->Virtio,
&VirtioFs->Ring, RingBaseShift);
if (EFI_ERROR (Status)) {
goto UnmapQueue;
}
//
// 8. Set the DRIVER_OK status bit.
//
NextDevStat |= VSTAT_DRIVER_OK;
Status = VirtioFs->Virtio->SetDeviceStatus (VirtioFs->Virtio, NextDevStat);
if (EFI_ERROR (Status)) {
goto UnmapQueue;
}
return EFI_SUCCESS;
UnmapQueue:
VirtioFs->Virtio->UnmapSharedBuffer (VirtioFs->Virtio, VirtioFs->RingMap);
ReleaseQueue:
VirtioRingUninit (VirtioFs->Virtio, &VirtioFs->Ring);
Failed:
//
// If any of these steps go irrecoverably wrong, the driver SHOULD set the
// FAILED status bit to indicate that it has given up on the device (it can
// reset the device later to restart if desired). [...]
//
// Virtio access failure here should not mask the original error.
//
NextDevStat |= VSTAT_FAILED;
VirtioFs->Virtio->SetDeviceStatus (VirtioFs->Virtio, NextDevStat);
return Status;
}
/**
De-configure the Virtio Filesystem device underlying VirtioFs.
@param[in] VirtioFs The VIRTIO_FS object for which Virtio communication
should be torn down. On input, the caller is responsible
for having called VirtioFsInit(). On output, Virtio
Filesystem commands (primitives) must no longer be
submitted to the device.
**/
VOID
VirtioFsUninit (
IN OUT VIRTIO_FS *VirtioFs
)
{
//
// Resetting the Virtio device makes it release its resources and forget its
// configuration.
//
VirtioFs->Virtio->SetDeviceStatus (VirtioFs->Virtio, 0);
VirtioFs->Virtio->UnmapSharedBuffer (VirtioFs->Virtio, VirtioFs->RingMap);
VirtioRingUninit (VirtioFs->Virtio, &VirtioFs->Ring);
}
/**
ExitBootServices event notification function for a Virtio Filesystem object.
This function resets the VIRTIO_FS.Virtio device, causing it to release all
references to guest-side resources. The function may only be called after
VirtioFsInit() returns successfully and before VirtioFsUninit() is called.
@param[in] ExitBootEvent The VIRTIO_FS.ExitBoot event that has been
signaled.
@param[in] VirtioFsAsVoid Pointer to the VIRTIO_FS object, passed in as
(VOID*).
**/
VOID
EFIAPI
VirtioFsExitBoot (
IN EFI_EVENT ExitBootEvent,
IN VOID *VirtioFsAsVoid
)
{
VIRTIO_FS *VirtioFs;
VirtioFs = VirtioFsAsVoid;
DEBUG ((DEBUG_VERBOSE, "%a: VirtioFs=0x%p Label=\"%s\"\n", __FUNCTION__,
VirtioFsAsVoid, VirtioFs->Label));
VirtioFs->Virtio->SetDeviceStatus (VirtioFs->Virtio, 0);
}