[PATCH v7 0/6] KVM: arm64: Hypervisor stack enhancements

From: Kalesh Singh
Date: Fri Apr 08 2022 - 16:04:01 EST


Hi all,

This is v7 of the nVHE hypervisor stack enhancements. This version is based
on 5.18-rc1 and drops the hypervisor stack unwinding and overflow-stack
patches. These require further discussion and will be resent separately.

Previous versions can be found at:
v6: https://lore.kernel.org/r/20220314200148.2695206-1-kaleshsingh@xxxxxxxxxx/
v5: https://lore.kernel.org/r/20220307184935.1704614-1-kaleshsingh@xxxxxxxxxx/
v4: https://lore.kernel.org/r/20220225033548.1912117-1-kaleshsingh@xxxxxxxxxx/
v3: https://lore.kernel.org/r/20220224051439.640768-1-kaleshsingh@xxxxxxxxxx/
v2: https://lore.kernel.org/r/20220222165212.2005066-1-kaleshsingh@xxxxxxxxxx/
v1: https://lore.kernel.org/r/20220210224220.4076151-1-kaleshsingh@xxxxxxxxxx/

Thanks,
Kalesh

-----

This series is based on 5.18-rc1 and adds stack guard pages to nVHE and pKVM
hypervisor; and symbolization of hypervisor addresses.

The guard page stack overflow detection is based on the technique used by
arm64 VMAP_STACK. i.e. the stack is aligned such that the 'stack shift' bit
of any valid SP is 1. The 'stack shift' bit can be tested in the exception
entry to detect overflow without corrupting GPRs.

Kalesh Singh (6):
KVM: arm64: Introduce hyp_alloc_private_va_range()
KVM: arm64: Introduce pkvm_alloc_private_va_range()
KVM: arm64: Add guard pages for KVM nVHE hypervisor stack
KVM: arm64: Add guard pages for pKVM (protected nVHE) hypervisor stack
KVM: arm64: Detect and handle hypervisor stack overflows
KVM: arm64: Symbolize the nVHE HYP addresses

arch/arm64/include/asm/kvm_asm.h | 1 +
arch/arm64/include/asm/kvm_mmu.h | 4 ++
arch/arm64/kvm/arm.c | 39 ++++++++++++--
arch/arm64/kvm/handle_exit.c | 13 ++---
arch/arm64/kvm/hyp/include/nvhe/mm.h | 6 ++-
arch/arm64/kvm/hyp/nvhe/host.S | 24 +++++++++
arch/arm64/kvm/hyp/nvhe/hyp-main.c | 18 ++++++-
arch/arm64/kvm/hyp/nvhe/mm.c | 78 ++++++++++++++++++----------
arch/arm64/kvm/hyp/nvhe/setup.c | 31 +++++++++--
arch/arm64/kvm/hyp/nvhe/switch.c | 7 ++-
arch/arm64/kvm/mmu.c | 70 ++++++++++++++++---------
scripts/kallsyms.c | 2 +-
12 files changed, 223 insertions(+), 70 deletions(-)


base-commit: 3123109284176b1532874591f7c81f3837bbdc17
--
2.35.1.1178.g4f1659d476-goog