diff options
| 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/Include/Library/VirtioLib.h | |
| parent | acb81416cceda0da2f1d89137d70d167f2a83ca4 (diff) | |
| download | edk2-platforms-d0ece0d85050022f96f31291e2f0033ebcdb3c6f.tar.xz | |
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/Include/Library/VirtioLib.h')
| -rw-r--r-- | OvmfPkg/Include/Library/VirtioLib.h | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/OvmfPkg/Include/Library/VirtioLib.h b/OvmfPkg/Include/Library/VirtioLib.h index decd4418af..5badfb3291 100644 --- a/OvmfPkg/Include/Library/VirtioLib.h +++ b/OvmfPkg/Include/Library/VirtioLib.h @@ -189,4 +189,50 @@ VirtioFlush ( OUT UINT32 *UsedLen OPTIONAL
);
+
+/**
+
+ 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
+ );
+
#endif // _VIRTIO_LIB_H_
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