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authorPeter Maydell <peter.maydell@linaro.org>2021-07-27 15:32:00 +0100
committerPeter Maydell <peter.maydell@linaro.org>2021-07-27 15:32:00 +0100
commit9ae1246a9b8641a0a152d982d8473a67501422e2 (patch)
treeb91dc2511532d82a847f3e1755bfaaf2f9920a8c /docs
parent202abcd38920ea2025020de9e2c6e28a403c2256 (diff)
parente229a179a503f2aee43a76888cf12fbdfe8a3749 (diff)
Merge remote-tracking branch 'remotes/pmaydell/tags/pull-target-arm-20210727' into staging
target-arm queue: * hw/arm/smmuv3: Check 31st bit to see if CD is valid * qemu-options.hx: Fix formatting of -machine memory-backend option * hw: aspeed_gpio: Fix memory size * hw/arm/nseries: Display hexadecimal value with '0x' prefix * Add sve-default-vector-length cpu property * docs: Update path that mentions deprecated.rst * hw/intc/armv7m_nvic: for v8.1M VECTPENDING hides S exceptions from NS * hw/intc/armv7m_nvic: Correct size of ICSR.VECTPENDING * hw/intc/armv7m_nvic: ISCR.ISRPENDING is set for non-enabled pending interrupts * target/arm: Report M-profile alignment faults correctly to the guest * target/arm: Add missing 'return's after calling v7m_exception_taken() * target/arm: Enforce that M-profile SP low 2 bits are always zero # gpg: Signature made Tue 27 Jul 2021 11:46:17 BST # gpg: using RSA key E1A5C593CD419DE28E8315CF3C2525ED14360CDE # gpg: issuer "peter.maydell@linaro.org" # gpg: Good signature from "Peter Maydell <peter.maydell@linaro.org>" [ultimate] # gpg: aka "Peter Maydell <pmaydell@gmail.com>" [ultimate] # gpg: aka "Peter Maydell <pmaydell@chiark.greenend.org.uk>" [ultimate] # Primary key fingerprint: E1A5 C593 CD41 9DE2 8E83 15CF 3C25 25ED 1436 0CDE * remotes/pmaydell/tags/pull-target-arm-20210727: hw: aspeed_gpio: Fix memory size hw/arm/nseries: Display hexadecimal value with '0x' prefix target/arm: Add sve-default-vector-length cpu property target/arm: Export aarch64_sve_zcr_get_valid_len target/arm: Correctly bound length in sve_zcr_get_valid_len docs: Update path that mentions deprecated.rst hw/intc/armv7m_nvic: for v8.1M VECTPENDING hides S exceptions from NS hw/intc/armv7m_nvic: Correct size of ICSR.VECTPENDING hw/intc/armv7m_nvic: ISCR.ISRPENDING is set for non-enabled pending interrupts target/arm: Report M-profile alignment faults correctly to the guest target/arm: Add missing 'return's after calling v7m_exception_taken() target/arm: Enforce that M-profile SP low 2 bits are always zero qemu-options.hx: Fix formatting of -machine memory-backend option hw/arm/smmuv3: Check 31st bit to see if CD is valid Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'docs')
-rw-r--r--docs/system/arm/cpu-features.rst15
1 files changed, 15 insertions, 0 deletions
diff --git a/docs/system/arm/cpu-features.rst b/docs/system/arm/cpu-features.rst
index c455442eaf..11dce5c603 100644
--- a/docs/system/arm/cpu-features.rst
+++ b/docs/system/arm/cpu-features.rst
@@ -376,3 +376,18 @@ verbose command lines. However, the recommended way to select vector
lengths is to explicitly enable each desired length. Therefore only
example's (1), (4), and (6) exhibit recommended uses of the properties.
+SVE User-mode Default Vector Length Property
+--------------------------------------------
+
+For qemu-aarch64, the cpu property ``sve-default-vector-length=N`` is
+defined to mirror the Linux kernel parameter file
+``/proc/sys/abi/sve_default_vector_length``. The default length, ``N``,
+is in units of bytes and must be between 16 and 8192.
+If not specified, the default vector length is 64.
+
+If the default length is larger than the maximum vector length enabled,
+the actual vector length will be reduced. Note that the maximum vector
+length supported by QEMU is 256.
+
+If this property is set to ``-1`` then the default vector length
+is set to the maximum possible length.