Re: [edk2-devel] [PATCH 0/4] OvmfPkg/VirtNorFlashDxe: fix corruption + misc small improvements

["Laszlo Ersek" <lersek@redhat.com>]

On 1/15/24 18:56, Ard Biesheuvel wrote:
> On Mon, 15 Jan 2024 at 11:21, Laszlo Ersek <lersek@redhat.com> wrote:
>>
>> On 1/12/24 12:37, Gerd Hoffmann wrote:
>>> This is a little series containing the flash corruption fix sent
>>> yesterday with an slightly improved commit message and some small
>>> improvements on top of this.
>>>
>>> Gerd Hoffmann (4):
>>>   OvmfPkg/VirtNorFlashDxe: fix shadowbuffer reads
>>>   OvmfPkg/VirtNorFlashDxe: clarify block write logic
>>>   OvmfPkg/VirtNorFlashDxe: allow larger writes without block erase
>>>   OvmfPkg/VirtNorFlashDxe: ValidateFvHeader: unwritten state is EOL too
>>>
>>>  OvmfPkg/VirtNorFlashDxe/VirtNorFlash.c    | 33 +++++++++++------------
>>>  OvmfPkg/VirtNorFlashDxe/VirtNorFlashFvb.c |  5 ++++
>>>  2 files changed, 21 insertions(+), 17 deletions(-)
>>>
>>
>> Looking at the original code makes me throw a fit (no offense -- I don't
>> know who wrote it, and I don't want to check).
>>
> 
> Hi Laszlo,
> 
> I am not the author of the original code, but I suppose I should take
> at least some of the blame here, having added some of the logic to
> reduce the number of MMIO accesses (which are disproportionately
> expensive under virtualization), and this is where the bug got
> introduced afaict.

... sorry about being needlessly harsh. If it's any excuse: in all such
cases I make a fully committed, honest effort to dig down to the "roots"
of the code, and the more I struggle to form a mental image, the more
annoyed/stressed I get. Comments and diagrams would definitely help with
my efforts, but just because I get annoyed during first analysis, that
is not sufficient reason to let that *leak* to the list. It's a
personality defect on my end. I'll keep working on it.

Laszlo



-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#113881): https://edk2.groups.io/g/devel/message/113881
Mute This Topic: https://groups.io/mt/103680930/7686176
Group Owner: devel+owner@edk2.groups.io
Unsubscribe: https://edk2.groups.io/g/devel/leave/12367111/7686176/1913456212/xyzzy [rebecca@openfw.io]
-=-=-=-=-=-=-=-=-=-=-=-