Merge branch kvm-arm64/nvhe-stacktrace into kvmarm-master/next

* kvm-arm64/nvhe-stacktrace: (27 commits)
  : .
  : Add an overflow stack to the nVHE EL2 code, allowing
  : the implementation of an unwinder, courtesy of
  : Kalesh Singh. From the cover letter (slightly edited):
  :
  : "nVHE has two modes of operation: protected (pKVM) and unprotected
  : (conventional nVHE). Depending on the mode, a slightly different approach
  : is used to dump the hypervisor stacktrace but the core unwinding logic
  : remains the same.
  :
  : * Protected nVHE (pKVM) stacktraces:
  :
  : In protected nVHE mode, the host cannot directly access hypervisor memory.
  :
  : The hypervisor stack unwinding happens in EL2 and is made accessible to
  : the host via a shared buffer. Symbolizing and printing the stacktrace
  : addresses is delegated to the host and happens in EL1.
  :
  : * Non-protected (Conventional) nVHE stacktraces:
  :
  : In non-protected mode, the host is able to directly access the hypervisor
  : stack pages.
  :
  : The hypervisor stack unwinding and dumping of the stacktrace is performed
  : by the host in EL1, as this avoids the memory overhead of setting up
  : shared buffers between the host and hypervisor."
  :
  : Additional patches from Oliver Upton and Marc Zyngier, tidying up
  : the initial series.
  : .
  arm64: Update 'unwinder howto'
  KVM: arm64: Don't open code ARRAY_SIZE()
  KVM: arm64: Move nVHE-only helpers into kvm/stacktrace.c
  KVM: arm64: Make unwind()/on_accessible_stack() per-unwinder functions
  KVM: arm64: Move nVHE stacktrace unwinding into its own compilation unit
  KVM: arm64: Move PROTECTED_NVHE_STACKTRACE around
  KVM: arm64: Introduce pkvm_dump_backtrace()
  KVM: arm64: Implement protected nVHE hyp stack unwinder
  KVM: arm64: Save protected-nVHE (pKVM) hyp stacktrace
  KVM: arm64: Stub implementation of pKVM HYP stack unwinder
  KVM: arm64: Allocate shared pKVM hyp stacktrace buffers
  KVM: arm64: Add PROTECTED_NVHE_STACKTRACE Kconfig
  KVM: arm64: Introduce hyp_dump_backtrace()
  KVM: arm64: Implement non-protected nVHE hyp stack unwinder
  KVM: arm64: Prepare non-protected nVHE hypervisor stacktrace
  KVM: arm64: Stub implementation of non-protected nVHE HYP stack unwinder
  KVM: arm64: On stack overflow switch to hyp overflow_stack
  arm64: stacktrace: Add description of stacktrace/common.h
  arm64: stacktrace: Factor out common unwind()
  arm64: stacktrace: Handle frame pointer from different address spaces
  ...

Signed-off-by: Marc Zyngier <maz@kernel.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
index cb0bc77c16f9..bbe5b393d689 100644
--- a/arch/arm64/kvm/handle_exit.c
+++ b/arch/arm64/kvm/handle_exit.c
@@ -17,6 +17,7 @@
 #include <asm/kvm_emulate.h>
 #include <asm/kvm_mmu.h>
 #include <asm/debug-monitors.h>
+#include <asm/stacktrace/nvhe.h>
 #include <asm/traps.h>
 
 #include <kvm/arm_hypercalls.h>
@@ -353,6 +354,9 @@ void __noreturn __cold nvhe_hyp_panic_handler(u64 esr, u64 spsr,
 				(void *)(panic_addr + kaslr_offset()));
 	}
 
+	/* Dump the nVHE hypervisor backtrace */
+	kvm_nvhe_dump_backtrace(hyp_offset);
+
 	/*
 	 * Hyp has panicked and we're going to handle that by panicking the
 	 * kernel. The kernel offset will be revealed in the panic so we're