| Message ID | 20220715061027.1612149-12-kaleshsingh@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM nVHE Hypervisor stack unwinder | expand |
On Fri, 15 Jul 2022 07:10:20 +0100, 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> > --- > arch/arm64/include/asm/stacktrace/nvhe.h | 22 ++++++++++++++++++++++ > 1 file changed, 22 insertions(+) > > diff --git a/arch/arm64/include/asm/stacktrace/nvhe.h b/arch/arm64/include/asm/stacktrace/nvhe.h > index 1eac4e57f2ae..36cf7858ddd8 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 > @@ -53,5 +59,21 @@ static int notrace unwind_next(struct unwind_state *state) > NOKPROBE_SYMBOL(unwind_next); > #endif /* CONFIG_PROTECTED_NVHE_STACKTRACE */ > > +/* > + * Non-protected nVHE HYP stack unwinder > + */ > +#else /* !__KVM_NVHE_HYPERVISOR__ */ I don't get this path. This either represents the VHE hypervisor or the kernel proper. Which one is it? > +static inline bool on_overflow_stack(unsigned long sp, unsigned long size, > + struct stack_info *info) > +{ > + return false; > +} > + > +static int notrace unwind_next(struct unwind_state *state) > +{ > + return 0; > +} > +NOKPROBE_SYMBOL(unwind_next); > + > #endif /* __KVM_NVHE_HYPERVISOR__ */ > #endif /* __ASM_STACKTRACE_NVHE_H */ Thanks, M.
On Mon, Jul 18, 2022 at 12:31 AM Marc Zyngier <maz@kernel.org> wrote: > > On Fri, 15 Jul 2022 07:10:20 +0100, > 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> > > --- > > arch/arm64/include/asm/stacktrace/nvhe.h | 22 ++++++++++++++++++++++ > > 1 file changed, 22 insertions(+) > > > > diff --git a/arch/arm64/include/asm/stacktrace/nvhe.h b/arch/arm64/include/asm/stacktrace/nvhe.h > > index 1eac4e57f2ae..36cf7858ddd8 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 > > @@ -53,5 +59,21 @@ static int notrace unwind_next(struct unwind_state *state) > > NOKPROBE_SYMBOL(unwind_next); > > #endif /* CONFIG_PROTECTED_NVHE_STACKTRACE */ > > > > +/* > > + * Non-protected nVHE HYP stack unwinder > > + */ > > +#else /* !__KVM_NVHE_HYPERVISOR__ */ > > I don't get this path. This either represents the VHE hypervisor or > the kernel proper. Which one is it? Hi Marc. This is run from kernel proper context. And it's the unwinding for conventional nVHE (non-protected). The unwinding is done from the host kernel in EL1. > > > +static inline bool on_overflow_stack(unsigned long sp, unsigned long size, > > + struct stack_info *info) > > +{ > > + return false; > > +} > > + > > +static int notrace unwind_next(struct unwind_state *state) > > +{ > > + return 0; > > +} > > +NOKPROBE_SYMBOL(unwind_next); > > + > > #endif /* __KVM_NVHE_HYPERVISOR__ */ > > #endif /* __ASM_STACKTRACE_NVHE_H */ > > Thanks, > > M. > > -- > Without deviation from the norm, progress is not possible. > > -- > To unsubscribe from this group and stop receiving emails from it, send an email to kernel-team+unsubscribe@android.com. >
On 2022-07-18 17:51, Kalesh Singh wrote: > On Mon, Jul 18, 2022 at 12:31 AM Marc Zyngier <maz@kernel.org> wrote: >> >> On Fri, 15 Jul 2022 07:10:20 +0100, >> 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> >> > --- >> > arch/arm64/include/asm/stacktrace/nvhe.h | 22 ++++++++++++++++++++++ >> > 1 file changed, 22 insertions(+) >> > >> > diff --git a/arch/arm64/include/asm/stacktrace/nvhe.h b/arch/arm64/include/asm/stacktrace/nvhe.h >> > index 1eac4e57f2ae..36cf7858ddd8 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 >> > @@ -53,5 +59,21 @@ static int notrace unwind_next(struct unwind_state *state) >> > NOKPROBE_SYMBOL(unwind_next); >> > #endif /* CONFIG_PROTECTED_NVHE_STACKTRACE */ >> > >> > +/* >> > + * Non-protected nVHE HYP stack unwinder >> > + */ >> > +#else /* !__KVM_NVHE_HYPERVISOR__ */ >> >> I don't get this path. This either represents the VHE hypervisor or >> the kernel proper. Which one is it? > > Hi Marc. This is run from kernel proper context. And it's the > unwinding for conventional nVHE (non-protected). The unwinding is done > from the host kernel in EL1. This really deserves a comment here, as the one you currently have is a bit misleading (and you probably want to move it below the #else). Thanks, M.
diff --git a/arch/arm64/include/asm/stacktrace/nvhe.h b/arch/arm64/include/asm/stacktrace/nvhe.h index 1eac4e57f2ae..36cf7858ddd8 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 @@ -53,5 +59,21 @@ static int notrace unwind_next(struct unwind_state *state) NOKPROBE_SYMBOL(unwind_next); #endif /* CONFIG_PROTECTED_NVHE_STACKTRACE */ +/* + * Non-protected nVHE HYP stack unwinder + */ +#else /* !__KVM_NVHE_HYPERVISOR__ */ +static inline bool on_overflow_stack(unsigned long sp, unsigned long size, + struct stack_info *info) +{ + return false; +} + +static int notrace unwind_next(struct unwind_state *state) +{ + return 0; +} +NOKPROBE_SYMBOL(unwind_next); + #endif /* __KVM_NVHE_HYPERVISOR__ */ #endif /* __ASM_STACKTRACE_NVHE_H */
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> --- arch/arm64/include/asm/stacktrace/nvhe.h | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+)