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MdeModulePkg/ScsiBusDxe: don't produce ScsiIo for nonexistent LUNs, part 2

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The SPC-4 says about INQUIRY,

> In response to an INQUIRY command received by an incorrect logical unit,
> the SCSI target device shall return the INQUIRY data with the peripheral
> qualifier set to the value defined in 6.4.2. The INQUIRY command shall
> return CHECK CONDITION status only when the device server is unable to
> return the requested INQUIRY data.

When a device server takes the second branch, and returns CHECK CONDITION
for a nonexistent LUN, the InquiryData structure in the
DiscoverScsiDevice() function remains filled with the original zeros.

DiscoverScsiDevice() then sees zero in both Peripheral_Qualifier and
Peripheral_Type, and therefore ScsiBusDxe produces a ScsiIo protocol
instance with device type zero, for the nonexistent LUN.

Device type zero is EFI_SCSI_TYPE_DISK. Thus ScsiDiskDxe binds the bogus
ScsiIo protocol interface, and produces a similarly bogus BlockIo
interface on top. This ripples up to BDS, where UefiBootManagerLib can
auto-generate bogus UEFI boot options for the nonexistent LUNs.

This has been encountered with QEMU, after commit ded6ddc5a7b9 ("scsi:
clarify sense codes for LUN0 emulation", 2017-08-04). QEMU now answers
INQUIRY commands that were directed to nonexistent LUNs with:

> DiscoverScsiDevice:1361: Lun=2 HostAdapterStatus=0 TargetStatus=2
>                          SenseDataLength=18 InquiryDataLength=96
> Sense {
> Sense 000000 70 00 05 00 00 00 00 0A 00 00 00 00 25 00 00 00
> Sense 000010 00 00
> Sense }
> Inquiry {
> Inquiry 000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> Inquiry 000010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> Inquiry 000020 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> Inquiry 000030 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> Inquiry 000040 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> Inquiry 000050 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> Inquiry }

The interesting fields are:
- HostAdapterStatus=0 (OK),
- TargetStatus=2 (CHECK CONDITION),
- Sense/Error_Code=0x70 (Current error, Fixed description)
- Sense/Sense_Key=0x05 (ILLEGAL REQUEST)

According to SPC-4 "Table 41 -- Sense key descriptions (part 2 of 2)",
ILLEGAL REQUEST is justified when "the command was addressed to an
incorrect logical unit number".

Thus, recognize this kind of answer for nonexistent LUNs.

(

Checking the status fields and the sense data is justified anyway,
according to the documentation of ScsiInquiryCommand():

>   @retval EFI_SUCCESS                    The command was executed
>                                          successfully. See
>                                          HostAdapterStatus,
>                                          TargetStatus, SenseDataLength,
>                                          and SenseData in that order for
>                                          additional status information.

)

Cc: Eric Dong <eric.dong@intel.com>
Cc: Feng Tian <feng.tian@intel.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Star Zeng <star.zeng@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>
This commit is contained in:
Laszlo Ersek 2017-08-18 04:30:40 +02:00
parent c09e481bbb
commit ce13d2d8c8
1 changed files with 22 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
MdeModulePkg/Bus/Scsi/ScsiBusDxe/ScsiBus.c
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@ -1298,12 +1298,14 @@ DiscoverScsiDevice (
UINT8 HostAdapterStatus;
UINT8 TargetStatus;
EFI_SCSI_INQUIRY_DATA *InquiryData;
EFI_SCSI_SENSE_DATA *SenseData;
UINT8 MaxRetry;
UINT8 Index;
BOOLEAN ScsiDeviceFound;
HostAdapterStatus = 0;
TargetStatus = 0;
SenseData = NULL;
InquiryData = AllocateAlignedBuffer (ScsiIoDevice, sizeof (EFI_SCSI_INQUIRY_DATA));
if (InquiryData == NULL) {
@ -1311,19 +1313,29 @@ DiscoverScsiDevice (
goto Done;
}
SenseData = AllocateAlignedBuffer (
ScsiIoDevice,
sizeof (EFI_SCSI_SENSE_DATA)
);
if (SenseData == NULL) {
ScsiDeviceFound = FALSE;
goto Done;
}
//
// Using Inquiry command to scan for the device
//
InquiryDataLength = sizeof (EFI_SCSI_INQUIRY_DATA);
SenseDataLength = 0;
SenseDataLength = sizeof (EFI_SCSI_SENSE_DATA);
ZeroMem (InquiryData, InquiryDataLength);
ZeroMem (SenseData, SenseDataLength);
MaxRetry = 2;
for (Index = 0; Index < MaxRetry; Index++) {
Status = ScsiInquiryCommand (
&ScsiIoDevice->ScsiIo,
SCSI_BUS_TIMEOUT,
NULL,
SenseData,
&SenseDataLength,
&HostAdapterStatus,
&TargetStatus,
@ -1332,6 +1344,13 @@ DiscoverScsiDevice (
FALSE
);
if (!EFI_ERROR (Status)) {
if ((HostAdapterStatus == EFI_SCSI_IO_STATUS_HOST_ADAPTER_OK) &&
(TargetStatus == EFI_SCSI_IO_STATUS_TARGET_CHECK_CONDITION) &&
(SenseData->Error_Code == 0x70) &&
(SenseData->Sense_Key == EFI_SCSI_SK_ILLEGAL_REQUEST)) {
ScsiDeviceFound = FALSE;
goto Done;
}
break;
}
if ((Status == EFI_BAD_BUFFER_SIZE) ||
@ -1377,6 +1396,7 @@ DiscoverScsiDevice (
ScsiDeviceFound = TRUE;
Done:
FreeAlignedBuffer (SenseData, sizeof (EFI_SCSI_SENSE_DATA));
FreeAlignedBuffer (InquiryData, sizeof (EFI_SCSI_INQUIRY_DATA));
return ScsiDeviceFound;