lkml.org 
[lkml]   [2022]   [Jul]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    Date
    SubjectRe: [PATCH v5 11/17] KVM: arm64: Stub implementation of non-protected nVHE HYP stack unwinder
    Hi Kalesh,

    On Thu, Jul 21, 2022 at 6:58 AM Kalesh Singh <kaleshsingh@google.com> wrote:
    >
    > Add stub implementations of non-protected nVHE stack unwinder, for
    > building. These are implemented later in this series.
    >
    > Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
    > ---

    Reviewed-by: Fuad Tabba <tabba@google.com>

    Cheers,
    /fuad

    >
    > Changes in v5:
    > - Mark unwind_next() as inline, per Marc
    > - Comment !__KVM_NVHE_HYPERVISOR__ unwinder path, per Marc
    >
    > arch/arm64/include/asm/stacktrace/nvhe.h | 26 ++++++++++++++++++++++++
    > 1 file changed, 26 insertions(+)
    >
    > diff --git a/arch/arm64/include/asm/stacktrace/nvhe.h b/arch/arm64/include/asm/stacktrace/nvhe.h
    > index 80d71932afff..3078501f8e22 100644
    > --- a/arch/arm64/include/asm/stacktrace/nvhe.h
    > +++ b/arch/arm64/include/asm/stacktrace/nvhe.h
    > @@ -8,6 +8,12 @@
    > * the HYP memory. The stack is unwinded in EL2 and dumped to a shared
    > * buffer where the host can read and print the stacktrace.
    > *
    > + * 2) Non-protected nVHE mode - the host can directly access the
    > + * HYP stack pages and unwind the HYP stack in EL1. This saves having
    > + * to allocate shared buffers for the host to read the unwinded
    > + * stacktrace.
    > + *
    > + *
    > * Copyright (C) 2022 Google LLC
    > */
    > #ifndef __ASM_STACKTRACE_NVHE_H
    > @@ -55,5 +61,25 @@ static inline int notrace unwind_next(struct unwind_state *state)
    > NOKPROBE_SYMBOL(unwind_next);
    > #endif /* CONFIG_PROTECTED_NVHE_STACKTRACE */
    >
    > +#else /* !__KVM_NVHE_HYPERVISOR__ */
    > +/*
    > + * Conventional (non-protected) nVHE HYP stack unwinder
    > + *
    > + * In non-protected mode, the unwinding is done from kernel proper context
    > + * (by the host in EL1).
    > + */
    > +
    > +static inline bool on_overflow_stack(unsigned long sp, unsigned long size,
    > + struct stack_info *info)
    > +{
    > + return false;
    > +}
    > +
    > +static inline int notrace unwind_next(struct unwind_state *state)
    > +{
    > + return 0;
    > +}
    > +NOKPROBE_SYMBOL(unwind_next);
    > +
    > #endif /* __KVM_NVHE_HYPERVISOR__ */
    > #endif /* __ASM_STACKTRACE_NVHE_H */
    > --
    > 2.37.0.170.g444d1eabd0-goog
    >

    \
     
     \ /
      Last update: 2022-07-21 11:59    [W:2.193 / U:0.008 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site