arm64: kvm: Introduce nvhe stack size constants

Refactor nvhe stack code to use NVHE_STACK_SIZE/SHIFT constants,
instead of directly using PAGE_SIZE/SHIFT. This makes the code a bit
easier to read,

arm64: kvm: Introduce nvhe stack size constants

Refactor nvhe stack code to use NVHE_STACK_SIZE/SHIFT constants,
instead of directly using PAGE_SIZE/SHIFT. This makes the code a bit
easier to read, without introducing any functional changes.

Cc: Marc Zyngier <[email protected]>
Cc: Mark Brown <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Kalesh Singh <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Marc Zyngier <[email protected]>

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arm64: stacktrace: factor out kernel unwind state

On arm64 we share some unwinding code between the regular kernel
unwinder and the KVM hyp unwinder. Some of this common code only matters
to the reg

arm64: stacktrace: factor out kernel unwind state

On arm64 we share some unwinding code between the regular kernel
unwinder and the KVM hyp unwinder. Some of this common code only matters
to the regular unwinder, e.g. the `kr_cur` and `task` fields in the
common struct unwind_state.

We're likely to add more state which only matters for regular kernel
unwinding (or only for hyp unwinding). In preparation for such changes,
this patch factors out the kernel-specific state into a new struct
kunwind_state, and updates the kernel unwind code accordingly.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Kalesh Singh <[email protected]>
Cc: Madhavan T. Venkataraman <[email protected]>
Cc: Mark Brown <[email protected]>
Cc: Puranjay Mohan <[email protected]>
Cc: Will Deacon <[email protected]>
Reviewed-by: Puranjay Mohan <[email protected]>
Reviewed-by: Kalesh Singh <[email protected]>
Reviewed-by: Madhavan T. Venkataraman <[email protected]>
Reviewed-by: Mark Brown <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Will Deacon <[email protected]>

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arm64: stacktrace: fix kerneldoc comments

Many of the comment blocks in the arm64 stacktrace code are *almost*
kerneldoc, but not quite.

Convert them to kerneldoc, as was presumably originally inte

arm64: stacktrace: fix kerneldoc comments

Many of the comment blocks in the arm64 stacktrace code are *almost*
kerneldoc, but not quite.

Convert them to kerneldoc, as was presumably originally intended.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <[email protected]>
Reviewed-by: Madhavan T. Venkataraman <[email protected]>
Reviewed-by: Mark Brown <[email protected]>
Cc: Fuad Tabba <[email protected]>
Cc: Kalesh Singh <[email protected]>
Cc: Marc Zyngier <[email protected]>
Cc: Will Deacon <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Catalin Marinas <[email protected]>

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KVM: arm64: Move nVHE-only helpers into kvm/stacktrace.c

kvm_nvhe_stack_kern_va() only makes sense as part of the nVHE
unwinder, so simply move it there.

Signed-off-by: Marc Zyngier <[email protected]

KVM: arm64: Move nVHE-only helpers into kvm/stacktrace.c

kvm_nvhe_stack_kern_va() only makes sense as part of the nVHE
unwinder, so simply move it there.

Signed-off-by: Marc Zyngier <[email protected]>
Reviewed-by: Kalesh Singh <[email protected]>
Tested-by: Kalesh Singh <[email protected]>
Reviewed-by: Oliver Upton <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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KVM: arm64: Make unwind()/on_accessible_stack() per-unwinder functions

Having multiple versions of on_accessible_stack() (one per unwinder)
makes it very hard to reason about what is used where due

KVM: arm64: Make unwind()/on_accessible_stack() per-unwinder functions

Having multiple versions of on_accessible_stack() (one per unwinder)
makes it very hard to reason about what is used where due to the
complexity of the various includes, the forward declarations, and
the reliance on everything being 'inline'.

Instead, move the code back where it should be. Each unwinder
implements:

- on_accessible_stack() as well as the helpers it depends on,

- unwind()/unwind_next(), as they pass on_accessible_stack as
a parameter to unwind_next_common() (which is the only common
code here)

This hardly results in any duplication, and makes it much
easier to reason about the code.

Signed-off-by: Marc Zyngier <[email protected]>
Reviewed-by: Kalesh Singh <[email protected]>
Tested-by: Kalesh Singh <[email protected]>
Reviewed-by: Oliver Upton <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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KVM: arm64: Move nVHE stacktrace unwinding into its own compilation unit

The unwinding code doesn't really belong to the exit handling
code. Instead, move it to a file (conveniently named stacktrace

KVM: arm64: Move nVHE stacktrace unwinding into its own compilation unit

The unwinding code doesn't really belong to the exit handling
code. Instead, move it to a file (conveniently named stacktrace.c
to confuse the reviewer), and move all the stacktrace-related
stuff there.

It will be joined by more code very soon.

Signed-off-by: Marc Zyngier <[email protected]>
Reviewed-by: Kalesh Singh <[email protected]>
Tested-by: Kalesh Singh <[email protected]>
Reviewed-by: Oliver Upton <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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KVM: arm64: Implement protected nVHE hyp stack unwinder

Implements the common framework necessary for unwind() to work in
the protected nVHE context:
- on_accessible_stack()
- on_overflow_stac

KVM: arm64: Implement protected nVHE hyp stack unwinder

Implements the common framework necessary for unwind() to work in
the protected nVHE context:
- on_accessible_stack()
- on_overflow_stack()
- unwind_next()

Protected nVHE unwind() is used to unwind and save the hyp stack
addresses to the shared stacktrace buffer. The host reads the
entries in this buffer, symbolizes and dumps the stacktrace (later
patch in the series).

Signed-off-by: Kalesh Singh <[email protected]>
Reviewed-by: Fuad Tabba <[email protected]>
Tested-by: Fuad Tabba <[email protected]>
Signed-off-by: Marc Zyngier <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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KVM: arm64: Stub implementation of pKVM HYP stack unwinder

Add some stub implementations of protected nVHE stack unwinder, for
building. These are implemented later in this series.

Signed-off-by: K

KVM: arm64: Stub implementation of pKVM HYP stack unwinder

Add some stub implementations of protected nVHE stack unwinder, for
building. These are implemented later in this series.

Signed-off-by: Kalesh Singh <[email protected]>
Reviewed-by: Fuad Tabba <[email protected]>
Tested-by: Fuad Tabba <[email protected]>
Signed-off-by: Marc Zyngier <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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KVM: arm64: Introduce hyp_dump_backtrace()

In non-protected nVHE mode, unwinds and dumps the hypervisor backtrace
from EL1. This is possible beacause the host can directly access the
hypervisor stac

KVM: arm64: Introduce hyp_dump_backtrace()

In non-protected nVHE mode, unwinds and dumps the hypervisor backtrace
from EL1. This is possible beacause the host can directly access the
hypervisor stack pages in non-protected mode.

The nVHE backtrace is dumped on hyp_panic(), before panicking the host.

[ 101.498183] kvm [377]: nVHE call trace:
[ 101.498363] kvm [377]: [<ffff8000090a6570>] __kvm_nvhe_hyp_panic+0xac/0xf8
[ 101.499045] kvm [377]: [<ffff8000090a65cc>] __kvm_nvhe_hyp_panic_bad_stack+0x10/0x10
[ 101.499498] kvm [377]: [<ffff8000090a61e4>] __kvm_nvhe_recursive_death+0x24/0x34
. . .
[ 101.524929] kvm [377]: [<ffff8000090a61e4>] __kvm_nvhe_recursive_death+0x24/0x34
[ 101.525062] kvm [377]: [<ffff8000090a61e4>] __kvm_nvhe_recursive_death+0x24/0x34
[ 101.525195] kvm [377]: [<ffff8000090a5de4>] __kvm_nvhe___kvm_vcpu_run+0x30/0x40c
[ 101.525333] kvm [377]: [<ffff8000090a8b64>] __kvm_nvhe_handle___kvm_vcpu_run+0x30/0x48
[ 101.525468] kvm [377]: [<ffff8000090a88b8>] __kvm_nvhe_handle_trap+0xc4/0x128
[ 101.525602] kvm [377]: [<ffff8000090a7864>] __kvm_nvhe___host_exit+0x64/0x64
[ 101.525745] kvm [377]: ---[ end nVHE call trace ]---

Signed-off-by: Kalesh Singh <[email protected]>
Signed-off-by: Marc Zyngier <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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KVM: arm64: Implement non-protected nVHE hyp stack unwinder

Implements the common framework necessary for unwind() to work
for non-protected nVHE mode:
- on_accessible_stack()
- on_overflow_

KVM: arm64: Implement non-protected nVHE hyp stack unwinder

Implements the common framework necessary for unwind() to work
for non-protected nVHE mode:
- on_accessible_stack()
- on_overflow_stack()
- unwind_next()

Non-protected nVHE unwind() is used to unwind and dump the hypervisor
stacktrace by the host in EL1

Signed-off-by: Kalesh Singh <[email protected]>
Reviewed-by: Fuad Tabba <[email protected]>
Tested-by: Fuad Tabba <[email protected]>
Signed-off-by: Marc Zyngier <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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KVM: arm64: Stub implementation of non-protected nVHE HYP stack unwinder

Add stub implementations of non-protected nVHE stack unwinder, for
building. These are implemented later in this series.

Sig

KVM: arm64: Stub implementation of non-protected nVHE HYP stack unwinder

Add stub implementations of non-protected nVHE stack unwinder, for
building. These are implemented later in this series.

Signed-off-by: Kalesh Singh <[email protected]>
Reviewed-by: Fuad Tabba <[email protected]>
Tested-by: Fuad Tabba <[email protected]>
Signed-off-by: Marc Zyngier <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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