[PATCH v3 0/4] Add ASPEED ACRY RSA model for the AST2600

[Jamin Lin <jamin_lin@aspeedtech.com>]

This series adds a model of the ASPEED ACRY engine found on the AST2600
SoC, wires it into the SoC, and adds a qtest.

The ACRY engine performs RSA modular exponentiation (c = m^e mod n). It
DMAs the operands (data, exponent, and modulus) from guest DRAM and writes
the result to a dedicated 64 KiB SRAM region.

Guest firmware uses the engine for RSA signature verification during boot.
Without a model, the guest starts the engine and waits indefinitely for a
completion interrupt, causing the boot to hang.

The model uses QEMU's generic akcipher API to perform raw (unpadded) RSA.
Raw RSA is currently supported only by the libgcrypt backend, which can be
enabled alongside gnutls with -Dgcrypt=enabled, so a build does not have to
choose between the two. When raw RSA is unavailable, the engine still
completes and raises its interrupt, but returns an all-zero result. This
allows the guest's signature verification to fail cleanly instead of
hanging. The qtest is skipped when the selected crypto backend does not
support raw RSA.

Although the hardware documentation describes both RSA and ECDSA support,
ECDSA is known to be broken on this hardware and is therefore not modeled.

v1:
 1. Add ASPEED ACRY RSA model for the AST2600
 2. Add qtest for AST2600 ASPEED ACRY RSA model
 
v2:
 1. squash "Add the ACRY model to AspeedSoCState" into "Wire up the ACRY
    model"
 2. wrap the ACRY SRAM in a container mapped at offset 0 so the device
    addresses it by relative offset (drop the "sram-base" property)
 3. build the scattered SRAM byte offsets on the fly instead of caching
    them in per-instance lookup tables
 4. write the result with address_space_stl_le() and check the MemTxResult

v3:
  1. Return early when the DMA read of the operand buffer fails 
  2. Replace g_printerr with g_test_skip

Jamin Lin (4):
  hw/misc/aspeed_acry: Add ASPEED ACRY model
  hw/arm/aspeed_ast2600: Introduce the ACRY SRAM
  hw/arm/aspeed_ast2600: Wire up the ACRY model
  tests/qtest/aspeed-acry-test: Add RSA ModExp tests

 include/hw/arm/aspeed_soc.h    |   4 +
 include/hw/misc/aspeed_acry.h  |  39 +++
 hw/arm/aspeed_ast2600.c        |  34 +++
 hw/misc/aspeed_acry.c          | 456 +++++++++++++++++++++++++++++++++
 tests/qtest/aspeed-acry-test.c | 396 ++++++++++++++++++++++++++++
 hw/misc/meson.build            |   1 +
 hw/misc/trace-events           |   6 +
 tests/qtest/meson.build        |   5 +-
 8 files changed, 940 insertions(+), 1 deletion(-)
 create mode 100644 include/hw/misc/aspeed_acry.h
 create mode 100644 hw/misc/aspeed_acry.c
 create mode 100644 tests/qtest/aspeed-acry-test.c

-- 
2.53.0