Hi, Devkate
I agree the first one is a bug and need to be fixed like your proposal.
For the second one, sorry I couldn’t catch your point.
When the requested buffer size is larger than 2M, it means we need multiple PRP
list pages.
For example, when block size is 4K, memory page size is 4K
1) Offset = 0B, Transfer Length = 4K * 512 blocks = 2MB
Prp1 = 0 to 4KB
Prp2 = pointer to a Prp List which contains 511 entries to read data from
offset 4KB to offset 2MB.
2) Offset = 2KB, Transfer Length = 4K * 513 blocks = 2MB + 4K
Prp1 = 2K to 4KB
Prp2 = pointer to a Prp List which is followed by another Prp List.
The first Prp List contains 511 entries to read data from offset 4KB to offset
2MB. the last one entry is a pointer to 2nd Prp List. The second Prp List
contains 2 entries to read data from offset 2MB to offset 2MB +4k and from
offset 2MB + 4K to offset 2MB + 6K.
So for the first sample, EFI_SIZE_TO_PAGES(Offset + Bytes) – 1 = 511. For the
second sample, EFI_SIZE_TO_PAGES(Offset + Bytes) – 1 = 513. In
NvmeCreatePrpList(), PrpListNo = 1 for first sample and PrpListNo = 2 for
second sample.
So do I misunderstand something?
Thanks
Feng
From: Baban Devkate [mailto:baban.devk...@seagate.com]
Sent: Thursday, April 09, 2015 09:37
To: edk2-devel@lists.sourceforge.net
Cc: Tian, Feng
Subject: MdeModulePkg:Fix required in NvmExpressDxe driver
Hi,
Commit Message
============
MdeModulePkg: Fixed Pointer truncation and incorrect bytes passed for PRP list
creation.
There were two issues in NvmExpressPassthru.c(
MdeModulePkg/Bus/Pci/NvmExpressDxe/NvmExpressPassthru.c)-
1.PRP list entries were zeroed out as "PrpListBase" was getting truncated to
UINT8, changed to UINT64.
Old code- PrpListBase = *(UINT8*)PrpListHost + PrpListIndex * EFI_PAGE_SIZE;
New code- PrpListBase = *(UINT64*)PrpListHost + PrpListIndex * EFI_PAGE_SIZE;
2. Number of bytes passed to PRP list creation function corrected.
Actual payload length will not match requested whenever nested PRP list is
required. With current 1024 max transfer size and 4K Blocksize if the
requested buffer is greater than 2MB then nested PRP list will be required and
NvmeCreatePrpList (.., Pages-1 , ..) will result into above failure.
Old code-
Prp = NvmeCreatePrpList (PciIo, PhyAddr, EFI_SIZE_TO_PAGES(Offset + Bytes) - 1,
&PrpListHost, &PrpListNo, &MapPrpList);
New code-
Prp = NvmeCreatePrpList (PciIo, PhyAddr, EFI_SIZE_TO_PAGES(Offset + Bytes),
&PrpListHost, &PrpListNo, &MapPrpList);
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: baban.devk...@seagate.com<mailto:baban.devk...@seagate.com>
Name-Baban Devkate
email-baban.devk...@seagate.com<mailto:email-baban.devk...@seagate.com>
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