OvmfPkg/PvScsiDxe: Report the number of targets and LUNs

Implement EXT_SCSI_PASS_THRU.GetNextTarget() and
EXT_SCSI_PASS_THRU.GetNextTargetLun().

ScsiBusDxe scans all MaxTarget * MaxLun possible devices.
This can take unnecessarily long for large number of targets.
To deal with this, VirtioScsiDxe has defined PCDs to limit the
MaxTarget & MaxLun to desired values which gives sufficient
performance. It is very important in virtio-scsi as it can have
very big MaxTarget & MaxLun.
Even though a common PVSCSI device has a default MaxTarget=64 and
MaxLun=0, we implement similar mechanism as virtio-scsi for completeness.
This may be useful in the future when PVSCSI will have bigger values
for MaxTarget and MaxLun.

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=2567
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Message-Id: <20200328200100.60786-7-liran.alon@oracle.com>
Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com>

4 files changed, 136 insertions, 2 deletions

diff --git a/OvmfPkg/OvmfPkg.dec b/OvmfPkg/OvmfPkg.dec
index 913345d..adb7ac2 100644
--- a/OvmfPkg/OvmfPkg.dec
+++ b/OvmfPkg/OvmfPkg.dec
@@ -134,6 +134,15 @@
   gUefiOvmfPkgTokenSpaceGuid.PcdVirtioScsiMaxTargetLimit|31|UINT16|6

   gUefiOvmfPkgTokenSpaceGuid.PcdVirtioScsiMaxLunLimit|7|UINT32|7

 

+  ## Sets the *inclusive* number of targets and LUNs that PvScsi exposes for

+  #  scan by ScsiBusDxe.

+  #  As specified above for VirtioScsi, ScsiBusDxe scans all MaxTarget * MaxLun

+  #  possible devices, which can take extremely long. Thus, the below constants

+  #  are used so that scanning the number of devices given by their product

+  #  is still acceptably fast.

+  gUefiOvmfPkgTokenSpaceGuid.PcdPvScsiMaxTargetLimit|64|UINT8|0x36

+  gUefiOvmfPkgTokenSpaceGuid.PcdPvScsiMaxLunLimit|0|UINT8|0x37

+

   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfFlashNvStorageEventLogBase|0x0|UINT32|0x8

   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfFlashNvStorageEventLogSize|0x0|UINT32|0x9

   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfFirmwareFdSize|0x0|UINT32|0xa

diff --git a/OvmfPkg/PvScsiDxe/PvScsi.c b/OvmfPkg/PvScsiDxe/PvScsi.c
index 04c0803..7f51ada 100644
--- a/OvmfPkg/PvScsiDxe/PvScsi.c
+++ b/OvmfPkg/PvScsiDxe/PvScsi.c
@@ -11,6 +11,7 @@
 

 #include <IndustryStandard/Pci.h>

 #include <IndustryStandard/PvScsi.h>

+#include <Library/BaseMemoryLib.h>

 #include <Library/MemoryAllocationLib.h>

 #include <Library/UefiBootServicesTableLib.h>

 #include <Library/UefiLib.h>

@@ -26,6 +27,30 @@
 #define PVSCSI_BINDING_VERSION      0x10

 

 //

+// Ext SCSI Pass Thru utilities

+//

+

+/**

+  Check if Target argument to EXT_SCSI_PASS_THRU.GetNextTarget() and

+  EXT_SCSI_PASS_THRU.GetNextTargetLun() is initialized

+**/

+STATIC

+BOOLEAN

+IsTargetInitialized (

+  IN UINT8                                          *Target

+  )

+{

+  UINTN Idx;

+

+  for (Idx = 0; Idx < TARGET_MAX_BYTES; ++Idx) {

+    if (Target[Idx] != 0xFF) {

+      return TRUE;

+    }

+  }

+  return FALSE;

+}

+

+//

 // Ext SCSI Pass Thru

 //

 

@@ -52,7 +77,54 @@ PvScsiGetNextTargetLun (
   IN OUT UINT64                                     *Lun

   )

 {

-  return EFI_UNSUPPORTED;

+  UINT8      *TargetPtr;

+  UINT8      LastTarget;

+  PVSCSI_DEV *Dev;

+

+  if (Target == NULL) {

+    return EFI_INVALID_PARAMETER;

+  }

+

+  //

+  // The Target input parameter is unnecessarily a pointer-to-pointer

+  //

+  TargetPtr = *Target;

+

+  //

+  // If target not initialized, return first target & LUN

+  //

+  if (!IsTargetInitialized (TargetPtr)) {

+    ZeroMem (TargetPtr, TARGET_MAX_BYTES);

+    *Lun = 0;

+    return EFI_SUCCESS;

+  }

+

+  //

+  // We only use first byte of target identifer

+  //

+  LastTarget = *TargetPtr;

+

+  //

+  // Increment (target, LUN) pair if valid on input

+  //

+  Dev = PVSCSI_FROM_PASS_THRU (This);

+  if (LastTarget > Dev->MaxTarget || *Lun > Dev->MaxLun) {

+    return EFI_INVALID_PARAMETER;

+  }

+

+  if (*Lun < Dev->MaxLun) {

+    ++*Lun;

+    return EFI_SUCCESS;

+  }

+

+  if (LastTarget < Dev->MaxTarget) {

+    *Lun = 0;

+    ++LastTarget;

+    *TargetPtr = LastTarget;

+    return EFI_SUCCESS;

+  }

+

+  return EFI_NOT_FOUND;

 }

 

 STATIC

@@ -111,7 +183,47 @@ PvScsiGetNextTarget (
   IN OUT UINT8                                      **Target

   )

 {

-  return EFI_UNSUPPORTED;

+  UINT8      *TargetPtr;

+  UINT8      LastTarget;

+  PVSCSI_DEV *Dev;

+

+  if (Target == NULL) {

+    return EFI_INVALID_PARAMETER;

+  }

+

+  //

+  // The Target input parameter is unnecessarily a pointer-to-pointer

+  //

+  TargetPtr = *Target;

+

+  //

+  // If target not initialized, return first target

+  //

+  if (!IsTargetInitialized (TargetPtr)) {

+    ZeroMem (TargetPtr, TARGET_MAX_BYTES);

+    return EFI_SUCCESS;

+  }

+

+  //

+  // We only use first byte of target identifer

+  //

+  LastTarget = *TargetPtr;

+

+  //

+  // Increment target if valid on input

+  //

+  Dev = PVSCSI_FROM_PASS_THRU (This);

+  if (LastTarget > Dev->MaxTarget) {

+    return EFI_INVALID_PARAMETER;

+  }

+

+  if (LastTarget < Dev->MaxTarget) {

+    ++LastTarget;

+    *TargetPtr = LastTarget;

+    return EFI_SUCCESS;

+  }

+

+  return EFI_NOT_FOUND;

 }

 

 STATIC

@@ -121,6 +233,12 @@ PvScsiInit (
   )

 {

   //

+  // Init configuration

+  //

+  Dev->MaxTarget = PcdGet8 (PcdPvScsiMaxTargetLimit);

+  Dev->MaxLun = PcdGet8 (PcdPvScsiMaxLunLimit);

+

+  //

   // Populate the exported interface's attributes

   //

   Dev->PassThru.Mode             = &Dev->PassThruMode;

diff --git a/OvmfPkg/PvScsiDxe/PvScsi.h b/OvmfPkg/PvScsiDxe/PvScsi.h
index 3940b4c..dd3e0c6 100644
--- a/OvmfPkg/PvScsiDxe/PvScsi.h
+++ b/OvmfPkg/PvScsiDxe/PvScsi.h
@@ -19,6 +19,8 @@
 

 typedef struct {

   UINT32                          Signature;

+  UINT8                           MaxTarget;

+  UINT8                           MaxLun;

   EFI_EXT_SCSI_PASS_THRU_PROTOCOL PassThru;

   EFI_EXT_SCSI_PASS_THRU_MODE     PassThruMode;

 } PVSCSI_DEV;

diff --git a/OvmfPkg/PvScsiDxe/PvScsiDxe.inf b/OvmfPkg/PvScsiDxe/PvScsiDxe.inf
index f4d452c..fcffc90 100644
--- a/OvmfPkg/PvScsiDxe/PvScsiDxe.inf
+++ b/OvmfPkg/PvScsiDxe/PvScsiDxe.inf
@@ -26,6 +26,7 @@
   OvmfPkg/OvmfPkg.dec

 

 [LibraryClasses]

+  BaseMemoryLib

   DebugLib

   MemoryAllocationLib

   UefiBootServicesTableLib

@@ -35,3 +36,7 @@
 [Protocols]

   gEfiExtScsiPassThruProtocolGuid   ## BY_START

   gEfiPciIoProtocolGuid             ## TO_START

+

+[Pcd]

+  gUefiOvmfPkgTokenSpaceGuid.PcdPvScsiMaxLunLimit       ## CONSUMES

+  gUefiOvmfPkgTokenSpaceGuid.PcdPvScsiMaxTargetLimit    ## CONSUMES