renegade-project/linux-next
2
0
Fork 0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-23 12:43:55 +08:00
Code

KVM: arm64: Allow PSCI SYSTEM_OFF/RESET to return

Browse Source 
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
This commit is contained in:
David Brazdil 2020-12-29 16:00:59 +00:00 committed by Marc Zyngier
parent 7ded92e25c
commit 2c91ef3921
1 changed files with 5 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
arch/arm64/kvm/hyp/nvhe/psci-relay.c
View File

@ -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: