The M-mode redirects an unhandled misaligned trap back
to S-mode when not delegating it to VS-mode(hedeleg).
However, KVM running in HS-mode terminates the VS-mode
software when back from M-mode.
The KVM should redirect the trap back to VS-mode, and
let VS-mode trap handler decide the next step.
Here is a way to handle misaligned traps in KVM,
not only directing them to VS-mode or terminate it.
Signed-off-by: wchen <waylingII@xxxxxxxxx>
---
arch/riscv/include/asm/csr.h | 2 ++
arch/riscv/kvm/vcpu_exit.c | 2 ++
2 files changed, 4 insertions(+)
diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h
index b6acb7ed1..917814a0f 100644
--- a/arch/riscv/include/asm/csr.h
+++ b/arch/riscv/include/asm/csr.h
@@ -82,7 +82,9 @@
#define EXC_INST_ACCESS 1
#define EXC_INST_ILLEGAL 2
#define EXC_BREAKPOINT 3
+#define EXC_LOAD_MISALIGNED 4
#define EXC_LOAD_ACCESS 5
+#define EXC_STORE_MISALIGNED 6
#define EXC_STORE_ACCESS 7
#define EXC_SYSCALL 8
#define EXC_HYPERVISOR_SYSCALL 9
diff --git a/arch/riscv/kvm/vcpu_exit.c b/arch/riscv/kvm/vcpu_exit.c
index 4ea101a73..2415722c0 100644
--- a/arch/riscv/kvm/vcpu_exit.c
+++ b/arch/riscv/kvm/vcpu_exit.c
@@ -183,6 +183,8 @@ int kvm_riscv_vcpu_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
run->exit_reason = KVM_EXIT_UNKNOWN;
switch (trap->scause) {
case EXC_INST_ILLEGAL:
+ case EXC_LOAD_MISALIGNED:
+ case EXC_STORE_MISALIGNED:
if (vcpu->arch.guest_context.hstatus & HSTATUS_SPV) {
kvm_riscv_vcpu_trap_redirect(vcpu, trap);
ret = 1;
--
2.34.1
