KVM: arm64: Introduce pkvm_dump_backtrace()

Dumps the pKVM hypervisor backtrace from EL1 by reading the unwinded
addresses from the shared stacktrace buffer.

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

[  111.623091] kvm [367]: nVHE call trace:
[  111.623215] kvm [367]:  [<ffff8000090a6570>] __kvm_nvhe_hyp_panic+0xac/0xf8
[  111.623448] kvm [367]:  [<ffff8000090a65cc>] __kvm_nvhe_hyp_panic_bad_stack+0x10/0x10
[  111.623642] kvm [367]:  [<ffff8000090a61e4>] __kvm_nvhe_recursive_death+0x24/0x34
. . .
[  111.640366] kvm [367]:  [<ffff8000090a61e4>] __kvm_nvhe_recursive_death+0x24/0x34
[  111.640467] kvm [367]:  [<ffff8000090a61e4>] __kvm_nvhe_recursive_death+0x24/0x34
[  111.640574] kvm [367]:  [<ffff8000090a5de4>] __kvm_nvhe___kvm_vcpu_run+0x30/0x40c
[  111.640676] kvm [367]:  [<ffff8000090a8b64>] __kvm_nvhe_handle___kvm_vcpu_run+0x30/0x48
[  111.640778] kvm [367]:  [<ffff8000090a88b8>] __kvm_nvhe_handle_trap+0xc4/0x128
[  111.640880] kvm [367]:  [<ffff8000090a7864>] __kvm_nvhe___host_exit+0x64/0x64
[  111.640996] kvm [367]: ---[ end nVHE call trace ]---

Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220726073750.3219117-18-kaleshsingh@google.com
This commit is contained in:
Kalesh Singh 2022-07-26 00:37:50 -07:00 committed by Marc Zyngier
parent 75e9459e48
commit 3a7e1b55aa
1 changed files with 34 additions and 1 deletions

View File

@ -371,6 +371,39 @@ static void hyp_dump_backtrace(unsigned long hyp_offset)
kvm_nvhe_dump_backtrace_end();
}
#ifdef CONFIG_PROTECTED_NVHE_STACKTRACE
DECLARE_KVM_NVHE_PER_CPU(unsigned long [NVHE_STACKTRACE_SIZE/sizeof(long)],
pkvm_stacktrace);
/*
* pkvm_dump_backtrace - Dump the protected nVHE HYP backtrace.
*
* @hyp_offset: hypervisor offset, used for address translation.
*
* Dumping of the pKVM HYP backtrace is done by reading the
* stack addresses from the shared stacktrace buffer, since the
* host cannot directly access hypervisor memory in protected
* mode.
*/
static void pkvm_dump_backtrace(unsigned long hyp_offset)
{
unsigned long *stacktrace
= (unsigned long *) this_cpu_ptr_nvhe_sym(pkvm_stacktrace);
int i, size = NVHE_STACKTRACE_SIZE / sizeof(long);
kvm_nvhe_dump_backtrace_start();
/* The saved stacktrace is terminated by a null entry */
for (i = 0; i < size && stacktrace[i]; i++)
kvm_nvhe_dump_backtrace_entry((void *)hyp_offset, stacktrace[i]);
kvm_nvhe_dump_backtrace_end();
}
#else /* !CONFIG_PROTECTED_NVHE_STACKTRACE */
static void pkvm_dump_backtrace(unsigned long hyp_offset)
{
kvm_err("Cannot dump pKVM nVHE stacktrace: !CONFIG_PROTECTED_NVHE_STACKTRACE\n");
}
#endif /* CONFIG_PROTECTED_NVHE_STACKTRACE */
/*
* kvm_nvhe_dump_backtrace - Dump KVM nVHE hypervisor backtrace.
*
@ -379,7 +412,7 @@ static void hyp_dump_backtrace(unsigned long hyp_offset)
static void kvm_nvhe_dump_backtrace(unsigned long hyp_offset)
{
if (is_protected_kvm_enabled())
return;
pkvm_dump_backtrace(hyp_offset);
else
hyp_dump_backtrace(hyp_offset);
}