diff options
| author | David Brazdil <dbrazdil@google.com> | 2020-12-29 16:00:59 +0000 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2021-01-14 11:04:23 +0000 |
| commit | 2c91ef39216149df6703c3fa6a47dd9a1e6091c1 (patch) | |
| tree | d222e59a96a13f346e73dea96549446dc8f669f6 | |
| parent | 7ded92e25cac9758a755b8f524b11b509c49afe1 (diff) | |
| download | linux-2c91ef39216149df6703c3fa6a47dd9a1e6091c1.tar.bz2 | |
KVM: arm64: Allow PSCI SYSTEM_OFF/RESET to return
The KVM/arm64 PSCI relay assumes that SYSTEM_OFF and SYSTEM_RESET should
not return, as dictated by the PSCI spec. However, there is firmware out
there which breaks this assumption, leading to a hyp panic. Make KVM
more robust to broken firmware by allowing these to return.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201229160059.64135-1-dbrazdil@google.com
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/psci-relay.c | 13 |
1 files changed, 5 insertions, 8 deletions
diff --git a/arch/arm64/kvm/hyp/nvhe/psci-relay.c b/arch/arm64/kvm/hyp/nvhe/psci-relay.c index e3947846ffcb..8e7128cb7667 100644 --- a/arch/arm64/kvm/hyp/nvhe/psci-relay.c +++ b/arch/arm64/kvm/hyp/nvhe/psci-relay.c @@ -77,12 +77,6 @@ static unsigned long psci_forward(struct kvm_cpu_context *host_ctxt) cpu_reg(host_ctxt, 2), cpu_reg(host_ctxt, 3)); } -static __noreturn unsigned long psci_forward_noreturn(struct kvm_cpu_context *host_ctxt) -{ - psci_forward(host_ctxt); - hyp_panic(); /* unreachable */ -} - static unsigned int find_cpu_id(u64 mpidr) { unsigned int i; @@ -251,10 +245,13 @@ static unsigned long psci_0_2_handler(u64 func_id, struct kvm_cpu_context *host_ case PSCI_0_2_FN_MIGRATE_INFO_TYPE: case PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU: return psci_forward(host_ctxt); + /* + * SYSTEM_OFF/RESET should not return according to the spec. + * Allow it so as to stay robust to broken firmware. + */ case PSCI_0_2_FN_SYSTEM_OFF: case PSCI_0_2_FN_SYSTEM_RESET: - psci_forward_noreturn(host_ctxt); - unreachable(); + return psci_forward(host_ctxt); case PSCI_0_2_FN64_CPU_SUSPEND: return psci_cpu_suspend(func_id, host_ctxt); case PSCI_0_2_FN64_CPU_ON: |