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| author | Laszlo Ersek <lersek@redhat.com> | 2016-03-12 20:37:42 +0100 |
|---|---|---|
| committer | Laszlo Ersek <lersek@redhat.com> | 2016-04-06 19:21:50 +0200 |
| commit | d0ece0d85050022f96f31291e2f0033ebcdb3c6f (patch) | |
| tree | ac9ef3463ee167bfbffc34034fcdec865c264f3a /OvmfPkg/Library/VirtioLib | |
| parent | acb81416cceda0da2f1d89137d70d167f2a83ca4 (diff) | |
| download | edk2-d0ece0d85050022f96f31291e2f0033ebcdb3c6f.tar.gz edk2-d0ece0d85050022f96f31291e2f0033ebcdb3c6f.tar.bz2 edk2-d0ece0d85050022f96f31291e2f0033ebcdb3c6f.zip | |
OvmfPkg: VirtioLib: add Virtio10WriteFeatures() function
In VirtIo 1.0, a device can reject a self-inconsistent feature bitmap
through the new VSTAT_FEATURES_OK status bit. (For example if the driver
requests a higher level feature but clears a prerequisite feature.) This
function is a small wrapper around
VIRTIO_DEVICE_PROTOCOL.SetGuestFeatures() that also verifies if the VirtIo
1.0 device accepts the feature bitmap.
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Diffstat (limited to 'OvmfPkg/Library/VirtioLib')
| -rw-r--r-- | OvmfPkg/Library/VirtioLib/VirtioLib.c | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/OvmfPkg/Library/VirtioLib/VirtioLib.c b/OvmfPkg/Library/VirtioLib/VirtioLib.c index 4b1d78b5a0..845f206369 100644 --- a/OvmfPkg/Library/VirtioLib/VirtioLib.c +++ b/OvmfPkg/Library/VirtioLib/VirtioLib.c @@ -339,3 +339,78 @@ VirtioFlush ( return EFI_SUCCESS;
}
+
+
+/**
+
+ Report the feature bits to the VirtIo 1.0 device that the VirtIo 1.0 driver
+ understands.
+
+ In VirtIo 1.0, a device can reject a self-inconsistent feature bitmap through
+ the new VSTAT_FEATURES_OK status bit. (For example if the driver requests a
+ higher level feature but clears a prerequisite feature.) This function is a
+ small wrapper around VIRTIO_DEVICE_PROTOCOL.SetGuestFeatures() that also
+ verifies if the VirtIo 1.0 device accepts the feature bitmap.
+
+ @param[in] VirtIo Report feature bits to this device.
+
+ @param[in] Features The set of feature bits that the driver wishes
+ to report. The caller is responsible to perform
+ any masking before calling this function; the
+ value is directly written with
+ VIRTIO_DEVICE_PROTOCOL.SetGuestFeatures().
+
+ @param[in,out] DeviceStatus On input, the status byte most recently written
+ to the device's status register. On output (even
+ on error), DeviceStatus will be updated so that
+ it is suitable for further status bit
+ manipulation and writing to the device's status
+ register.
+
+ @retval EFI_SUCCESS The device accepted the configuration in Features.
+
+ @return EFI_UNSUPPORTED The device rejected the configuration in Features.
+
+ @retval EFI_UNSUPPORTED VirtIo->Revision is smaller than 1.0.0.
+
+ @return Error codes from the SetGuestFeatures(),
+ SetDeviceStatus(), GetDeviceStatus() member
+ functions.
+
+**/
+EFI_STATUS
+EFIAPI
+Virtio10WriteFeatures (
+ IN VIRTIO_DEVICE_PROTOCOL *VirtIo,
+ IN UINT64 Features,
+ IN OUT UINT8 *DeviceStatus
+ )
+{
+ EFI_STATUS Status;
+
+ if (VirtIo->Revision < VIRTIO_SPEC_REVISION (1, 0, 0)) {
+ return EFI_UNSUPPORTED;
+ }
+
+ Status = VirtIo->SetGuestFeatures (VirtIo, Features);
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ *DeviceStatus |= VSTAT_FEATURES_OK;
+ Status = VirtIo->SetDeviceStatus (VirtIo, *DeviceStatus);
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ Status = VirtIo->GetDeviceStatus (VirtIo, DeviceStatus);
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ if ((*DeviceStatus & VSTAT_FEATURES_OK) == 0) {
+ Status = EFI_UNSUPPORTED;
+ }
+
+ return Status;
+}
|