On 03/03/20 11:08, Ard Biesheuvel wrote: > On Tue, 3 Mar 2020 at 10:45, Laszlo Ersek <ler...@redhat.com> wrote:
>> (13) I'm worried that we are installing custom protocols on a handle >> that was first created by LoadImage(), before we pass it to >> UnloadImage(). I don't know if, per spec, LoadImage() / UnloadImage() >> are allowed to associate such information with the specific image handle >> that is *beyond* the protocol interfaces visible on the handle. >> > > I'm not sure I follow. Why would it not be allowed to install > additional protocols on that handle? Note that it is rather common for > drivers to install arbitrary protocols on the handle that they receive > via the PE/COFF entry point. Yes, that's correct; however what doesn't happen is that protocols installed on the image handle *survive* unloading the image with gBS->UnloadImage(). Put differently, if the image handle was created by LoadImage() -- by virtue of LoadImage() installing the first protocol interface --, then I *think* there might be a silent expectation that UnloadImage() will also uninstall the last protocol interface, thereby releasing the image handle itself. >> Can we modify the logic somehow so that we don't have to silently call >> QemuLoadLegacyImage() inside QemuStartKernelImage()? If not, we should >> at least document that this is arguably a grey area per UEFI spec. >> > > That would require QemuStartImage() to take a EFI_HANDLE* rather than > a EFI_HANDLE, Yes, I agree. > which is what I was trying to avoid here. I perceive this as a lifecycle risk / grey area in the spec. If we can make it disappear by having QemuStartImage() take an "IN OUT EFI_HANDLE*", IMO that's a significant improvement, and hopefully not much additional complexity. I think the underlying use case is intricate enough for us to let it affect the abstract QemuStartKernelImage() interface. Thanks! Laszlo -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#55314): https://edk2.groups.io/g/devel/message/55314 Mute This Topic: https://groups.io/mt/71669022/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
