On 08/14/17 13:36, Brijesh Singh wrote: > The function can be used for mapping the system physical address to virtio > device address using VIRTIO_DEVICE_PROTOCOL.MapSharedBuffer (). The > function helps centralizing error handling, and it allows caller to pass
(1) some grammar bikeshedding: - s/helps centralizing/helps with centralizing/ - s/allows caller/allows the caller/ > in constant or other evaluated expression for NumberOfBytes. - s/expression/expressions/ > > Cc: Ard Biesheuvel <[email protected]> > Cc: Jordan Justen <[email protected]> > Cc: Tom Lendacky <[email protected]> > Cc: Laszlo Ersek <[email protected]> > Contributed-under: TianoCore Contribution Agreement 1.1 > Signed-off-by: Brijesh Singh <[email protected]> > --- > OvmfPkg/Include/Library/VirtioLib.h | 44 +++++++++++ > OvmfPkg/Library/VirtioLib/VirtioLib.c | 78 ++++++++++++++++++++ > 2 files changed, 122 insertions(+) > > diff --git a/OvmfPkg/Include/Library/VirtioLib.h > b/OvmfPkg/Include/Library/VirtioLib.h > index 5badfb32917f..d8f24a5d68b1 100644 > --- a/OvmfPkg/Include/Library/VirtioLib.h > +++ b/OvmfPkg/Include/Library/VirtioLib.h > @@ -3,6 +3,7 @@ > Declarations of utility functions used by virtio device drivers. > > Copyright (C) 2012-2016, Red Hat, Inc. > + Copyright (C) 2017, AMD Inc, All rights reserved.<BR> > > This program and the accompanying materials are licensed and made available > under the terms and conditions of the BSD License which accompanies this > @@ -235,4 +236,47 @@ Virtio10WriteFeatures ( > IN OUT UINT8 *DeviceStatus > ); > > +/** > + Provides the virtio device address required to access system memory from a > + DMA bus master. > + This part is slightly out of synch with the protocol definition itself (i.e., with VIRTIO_MAP_SHARED): the UEFI spec reference is missing. However, that's fine: this function diverges slightly from the spec -- that's exactly where the extra convenience comes from. So this is OK. > + @param[in] This The protocol instance pointer. > + (2) This should say instead: @param[in] VirtIo The virtio device for which the mapping is requested. > + @param[in] Operation Indicates if the bus master is going to > + read or write to system memory. > + > + @param[in] HostAddress The system memory address to map to shared > + buffer address. > + > + @param[in,out] NumberOfBytes On input the number of bytes to map. > + On output the number of bytes that were > + mapped. (3) This is wrong. In my v1 review <[email protected]">http://mid.mail-archive.com/[email protected]>, point (3), I wrote, Basically you can copy the MapSharedBuffer() documentation, just point out the extra logic for NumberOfBytes. That description is missing -- NumberOfBytes is an IN-only parameter here, and it is interpreted as a hard requirement. > + > + @param[out] DeviceAddress The resulting shared map address for the > + bus master to access the hosts HostAddress. > + > + @param[out] Mapping A resulting taken to pass to > + VIRTIO_UNMAP_SHARED. (4) s/taken/token/, as discussed before > + > + > + @retval EFI_SUCCESS The range was mapped for the returned > + NumberOfBytes. (5) This too should be adapted to our particular NumberOfBytes interpretation. > + @retval EFI_UNSUPPORTED The HostAddress cannot be mapped as a > + common buffer. > + @retval EFI_INVALID_PARAMETER One or more parameters are invalid. > + @retval EFI_OUT_OF_RESOURCES The request could not be completed due to > + a lack of resources. (6) Please add, "This includes the case when NumberOfBytes bytes cannot be mapped in one consecutive range." > + @retval EFI_DEVICE_ERROR The system hardware could not map the > + requested address. > +**/ > +EFI_STATUS > +EFIAPI > +VirtioMapAllBytesInSharedBuffer ( > + IN VIRTIO_DEVICE_PROTOCOL *VirtIo, > + IN VIRTIO_MAP_OPERATION Operation, > + IN VOID *HostAddress, > + IN UINTN NumberOfBytes, > + OUT EFI_PHYSICAL_ADDRESS *DeviceAddress, > + OUT VOID **Mapping > + ); > #endif // _VIRTIO_LIB_H_ > diff --git a/OvmfPkg/Library/VirtioLib/VirtioLib.c > b/OvmfPkg/Library/VirtioLib/VirtioLib.c > index 845f206369a3..ac0ae97f3692 100644 > --- a/OvmfPkg/Library/VirtioLib/VirtioLib.c > +++ b/OvmfPkg/Library/VirtioLib/VirtioLib.c > @@ -4,6 +4,7 @@ > > Copyright (C) 2012-2016, Red Hat, Inc. > Portion of Copyright (C) 2013, ARM Ltd. > + Copyright (C) 2017, AMD Inc, All rights reserved.<BR> > > This program and the accompanying materials are licensed and made available > under the terms and conditions of the BSD License which accompanies this > @@ -414,3 +415,80 @@ Virtio10WriteFeatures ( > > return Status; > } > + > +/** > + Provides the virtio device address required to access system memory from a > + DMA bus master. > + > + @param[in] This The protocol instance pointer. > + > + @param[in] Operation Indicates if the bus master is going to > + read or write to system memory. > + > + @param[in] HostAddress The system memory address to map to shared > + buffer address. > + > + @param[in,out] NumberOfBytes On input the number of bytes to map. > + On output the number of bytes that were > + mapped. > + > + @param[out] DeviceAddress The resulting shared map address for the > + bus master to access the hosts HostAddress. > + > + @param[out] Mapping A resulting taken to pass to > + VIRTIO_UNMAP_SHARED. > + > + > + @retval EFI_SUCCESS The range was mapped for the returned > + NumberOfBytes. > + @retval EFI_UNSUPPORTED The HostAddress cannot be mapped as a > + common buffer. > + @retval EFI_INVALID_PARAMETER One or more parameters are invalid. > + @retval EFI_OUT_OF_RESOURCES The request could not be completed due to > + a lack of resources. > + @retval EFI_DEVICE_ERROR The system hardware could not map the > + requested address. > +**/ (7) Please sync this with points (2) through (6) above. > +EFI_STATUS > +EFIAPI > +VirtioMapAllBytesInSharedBuffer ( > + IN VIRTIO_DEVICE_PROTOCOL *VirtIo, > + IN VIRTIO_MAP_OPERATION Operation, > + IN VOID *HostAddress, > + IN UINTN NumberOfBytes, > + OUT EFI_PHYSICAL_ADDRESS *DeviceAddress, > + OUT VOID **Mapping > + ) > +{ > + EFI_STATUS Status; > + VOID *MapInfo; > + UINTN Size; > + EFI_PHYSICAL_ADDRESS PhysicalAddress; > + > + Size = NumberOfBytes; > + Status = VirtIo->MapSharedBuffer ( > + VirtIo, > + Operation, > + HostAddress, > + &Size, > + &PhysicalAddress, > + &MapInfo > + ); > + if (EFI_ERROR (Status)) { > + return Status; > + } > + > + if (Size < NumberOfBytes) { > + goto Failed; > + } > + > + *Mapping = MapInfo; > + *DeviceAddress = PhysicalAddress; > + > + return EFI_SUCCESS; > + > +Failed: > + VirtIo->UnmapSharedBuffer (VirtIo, MapInfo); > + *Mapping = NULL; > + return EFI_OUT_OF_RESOURCES; > +} > (8) The logic differs slightly from the previous version: in this version you set Mapping to NULL on error. I liked the previous version more; IMO we should not touch output parameters on error (that's why you introduced MapInfo earlier, to begin with). So I suggest dropping the NULL-ing on error. Thanks Laszlo _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
