Hi Kalesh, On Thu, Jul 21, 2022 at 6:57 AM Kalesh Singh <kaleshsingh@xxxxxxxxxx> wrote: > > In protected nVHE mode the host cannot directly access > hypervisor memory, so we will dump the hypervisor stacktrace > to a shared buffer with the host. > > The minimum size for the buffer required, assuming the min frame > size of [x29, x30] (2 * sizeof(long)), is half the combined size of > the hypervisor and overflow stacks plus an additional entry to > delimit the end of the stacktrace. > > The stacktrace buffers are used later in the seried to dump the nit: seried/series > nVHE hypervisor stacktrace when using protected-mode. > > Signed-off-by: Kalesh Singh <kaleshsingh@xxxxxxxxxx> > --- Reviewed-by: Fuad Tabba <tabba@xxxxxxxxxx> Cheers, /fuad > Changes in v5: > - Fix typo in commit text, per Marc > > arch/arm64/include/asm/memory.h | 8 ++++++++ > arch/arm64/kvm/hyp/nvhe/stacktrace.c | 4 ++++ > 2 files changed, 12 insertions(+) > > diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h > index 0af70d9abede..cab80a9a4086 100644 > --- a/arch/arm64/include/asm/memory.h > +++ b/arch/arm64/include/asm/memory.h > @@ -113,6 +113,14 @@ > > #define OVERFLOW_STACK_SIZE SZ_4K > > +/* > + * With the minimum frame size of [x29, x30], exactly half the combined > + * sizes of the hyp and overflow stacks is the maximum size needed to > + * save the unwinded stacktrace; plus an additional entry to delimit the > + * end. > + */ > +#define NVHE_STACKTRACE_SIZE ((OVERFLOW_STACK_SIZE + PAGE_SIZE) / 2 + sizeof(long)) > + > /* > * Alignment of kernel segments (e.g. .text, .data). > * > diff --git a/arch/arm64/kvm/hyp/nvhe/stacktrace.c b/arch/arm64/kvm/hyp/nvhe/stacktrace.c > index a3d5b34e1249..69e65b457f1c 100644 > --- a/arch/arm64/kvm/hyp/nvhe/stacktrace.c > +++ b/arch/arm64/kvm/hyp/nvhe/stacktrace.c > @@ -9,3 +9,7 @@ > > DEFINE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], overflow_stack) > __aligned(16); > + > +#ifdef CONFIG_PROTECTED_NVHE_STACKTRACE > +DEFINE_PER_CPU(unsigned long [NVHE_STACKTRACE_SIZE/sizeof(long)], pkvm_stacktrace); > +#endif /* CONFIG_PROTECTED_NVHE_STACKTRACE */ > -- > 2.37.0.170.g444d1eabd0-goog > _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
