[PATCH 0/2] KVM: arm64: Reenable MTE on VHE guest exit

[Marc Zyngier]

Upton taking an exception, the CPU sets PSTATE.TCO to ensure that no
tag fault can be taken while handling the exception. It is SW's job to
eventually clear it when it is safe to do so.

It appears that when MTE is enabled and that the kernel is running
VHE, nothing eventually clears TCO when we come back from the guest,
so things such as KASAN_HW_TAGS will not work until the next exit to
userspace.

This series aims at fixing this. This is not a stable candidate, as
KASAN is only a debug option.

Marc Zyngier (2):
  arm64: Add return value to mte_disable_tco_entry()
  KVM: arm64: Reenable MTE tag checking on exit from guest when running
    VHE

 arch/arm64/include/asm/mte.h    | 10 +++++++---
 arch/arm64/kvm/hyp/vhe/switch.c |  7 +++++++
 2 files changed, 14 insertions(+), 3 deletions(-)

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2.47.3