On Wed, 15 Feb 2017 22:18:11 -0800
b...@skyportsystems.com wrote:
> From: Ben Warren <b...@skyportsystems.com>
>
> This is similar to the existing 'add pointer' functionality, but instead
> of instructing the guest (BIOS or UEFI) to patch memory, it instructs
> the guest to write the pointer back to QEMU via a writeable fw_cfg file.
>
> Signed-off-by: Ben Warren <b...@skyportsystems.com>
> ---
> hw/acpi/bios-linker-loader.c | 66
> ++++++++++++++++++++++++++++++++++--
> include/hw/acpi/bios-linker-loader.h | 7 ++++
> 2 files changed, 70 insertions(+), 3 deletions(-)
>
> diff --git a/hw/acpi/bios-linker-loader.c b/hw/acpi/bios-linker-loader.c
> index d963ebe..d5fb703 100644
> --- a/hw/acpi/bios-linker-loader.c
> +++ b/hw/acpi/bios-linker-loader.c
> @@ -78,6 +78,21 @@ struct BiosLinkerLoaderEntry {
> uint32_t length;
> } cksum;
>
> + /*
> + * COMMAND_WRITE_POINTER - write the fw_cfg file (originating from
> + * @dest_file) at @wr_pointer.offset, by adding a pointer to
> + * @src_offset within the table originating from @src_file.
> + * 1,2,4 or 8 byte unsigned addition is used depending on
> + * @wr_pointer.size.
> + */
> + struct {
> + char dest_file[BIOS_LINKER_LOADER_FILESZ];
> + char src_file[BIOS_LINKER_LOADER_FILESZ];
> + uint32_t dst_offset;
> + uint32_t src_offset;
> + uint8_t size;
> + } wr_pointer;
> +
> /* padding */
> char pad[124];
Shouldn't padding be reduced by 4 bytes to keep
sizeof(BiosLinkerLoaderEntry) the same as before patch,
so that old bios would be able to skip this unknown command
and read the next at the right offset?
> };
> @@ -85,9 +100,10 @@ struct BiosLinkerLoaderEntry {
> typedef struct BiosLinkerLoaderEntry BiosLinkerLoaderEntry;
>
> enum {
> - BIOS_LINKER_LOADER_COMMAND_ALLOCATE = 0x1,
> - BIOS_LINKER_LOADER_COMMAND_ADD_POINTER = 0x2,
> - BIOS_LINKER_LOADER_COMMAND_ADD_CHECKSUM = 0x3,
> + BIOS_LINKER_LOADER_COMMAND_ALLOCATE = 0x1,
> + BIOS_LINKER_LOADER_COMMAND_ADD_POINTER = 0x2,
> + BIOS_LINKER_LOADER_COMMAND_ADD_CHECKSUM = 0x3,
> + BIOS_LINKER_LOADER_COMMAND_WRITE_POINTER = 0x4,
> };
>
> enum {
> @@ -278,3 +294,47 @@ void bios_linker_loader_add_pointer(BIOSLinker *linker,
>
> g_array_append_vals(linker->cmd_blob, &entry, sizeof entry);
> }
> +
> +/*
> + * bios_linker_loader_write_pointer: ask guest to write a pointer to the
> + * source file into the destination file, and write it back to QEMU via
> + * fw_cfg DMA.
> + *
> + * @linker: linker object instance
> + * @dest_file: destination file that must be written
> + * @dst_patched_offset: location within destination file blob to be patched
> + * with the pointer to @src_file, in bytes
> + * @dst_patched_offset_size: size of the pointer to be patched
> + * at @dst_patched_offset in @dest_file blob, in bytes
> + * @src_file: source file who's address must be taken
> + * @src_offset: location within source file blob to which
> + * @dest_file+@dst_patched_offset will point to after
> + * firmware's executed WRITE_POINTER command
> + */
> +void bios_linker_loader_write_pointer(BIOSLinker *linker,
> + const char *dest_file,
> + uint32_t dst_patched_offset,
> + uint8_t dst_patched_size,
> + const char *src_file,
> + uint32_t src_offset)
> +{
> + BiosLinkerLoaderEntry entry;
> + const BiosLinkerFileEntry *source_file =
> + bios_linker_find_file(linker, src_file);
> +
> + assert(source_file);
> + assert(src_offset <= source_file->blob->len);
off by one, should be '<'
> + memset(&entry, 0, sizeof entry);
> + strncpy(entry.wr_pointer.dest_file, dest_file,
> + sizeof entry.wr_pointer.dest_file - 1);
> + strncpy(entry.wr_pointer.src_file, src_file,
> + sizeof entry.wr_pointer.src_file - 1);
> + entry.command = cpu_to_le32(BIOS_LINKER_LOADER_COMMAND_WRITE_POINTER);
> + entry.wr_pointer.dst_offset = cpu_to_le32(dst_patched_offset);
> + entry.wr_pointer.src_offset = cpu_to_le32(dst_patched_offset);
> + entry.wr_pointer.size = dst_patched_size;
> + assert(dst_patched_size == 1 || dst_patched_size == 2 ||
> + dst_patched_size == 4 || dst_patched_size == 8);
> +
> + g_array_append_vals(linker->cmd_blob, &entry, sizeof entry);
> +}
> diff --git a/include/hw/acpi/bios-linker-loader.h
> b/include/hw/acpi/bios-linker-loader.h
> index fa1e5d1..efe17b0 100644
> --- a/include/hw/acpi/bios-linker-loader.h
> +++ b/include/hw/acpi/bios-linker-loader.h
> @@ -26,5 +26,12 @@ void bios_linker_loader_add_pointer(BIOSLinker *linker,
> const char *src_file,
> uint32_t src_offset);
>
> +void bios_linker_loader_write_pointer(BIOSLinker *linker,
> + const char *dest_file,
> + uint32_t dst_patched_offset,
> + uint8_t dst_patched_size,
> + const char *src_file,
> + uint32_t src_offset);
> +
> void bios_linker_loader_cleanup(BIOSLinker *linker);
> #endif
Taking in account comments above are corner cases.
1: old bios running on new QEMU with vmgenid device and OLD/not supported bios
2: assert check
It's ok fixes for above issues being fixed in follow up patch
or as fixup while patch is staged in pci tree
Reviewed-by: Igor Mammedov <imamm...@redhat.com>
