hw/arm/boot.c: Set EL3 HXen, vector lengths when direct booting kernel

[PATCH 0/2] hw/arm/boot.c: Set EL3 HXen, vector lengths when direct booting kernel

Peter Maydell posted 2 patches 1 year, 6 months ago

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git fetch https://github.com/patchew-project/qemu tags/patchew/20221027140207.413084-1-peter.maydell@linaro.org

Maintainers: Peter Maydell <peter.maydell@linaro.org>

hw/arm/boot.c | 5 +++++
1 file changed, 5 insertions(+)

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[PATCH 0/2] hw/arm/boot.c: Set EL3 HXen, vector lengths when direct booting kernel

Posted by Peter Maydell 1 year, 6 months ago

When we direct boot a kernel on a CPU which emulates EL3, we need to
set up the EL3 system registers as the Linux kernel documentation
specifies:
    https://www.kernel.org/doc/Documentation/arm64/booting.rst

Mostly we get this right, but working through the list of config
bits that need to be set, I found that we'd missed a few things:

- FEAT_HCX: SCR_EL3.HXEn (bit 38) must be initialised to 0b1
- SVE: ZCR_EL3.LEN should be initialized to a sensible value.
  We leave it at 0, which means the guest can only use the
  minimum vector length supported by the CPU, not the full range.
- SME: ditto for SMCR_EL3.LEN

This series fixes those.

thanks
-- PMM

Peter Maydell (2):
  hw/arm/boot: Set SME and SVE EL3 vector lengths when booting kernel
  hw/arm/boot: Set SCR_EL3.HXEn when booting kernel

 hw/arm/boot.c | 5 +++++
 1 file changed, 5 insertions(+)

-- 
2.25.1