2023-09-27 03:58:52

by zhaotianrui

[permalink] [raw]
Subject: [PATCH v22 20/25] LoongArch: KVM: Implement handle fpu exception

Implement handle fpu exception, using kvm_own_fpu() to enable fpu for
guest.

Reviewed-by: Bibo Mao <[email protected]>
Tested-by: Huacai Chen <[email protected]>
Signed-off-by: Tianrui Zhao <[email protected]>
---
arch/loongarch/kvm/exit.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)

diff --git a/arch/loongarch/kvm/exit.c b/arch/loongarch/kvm/exit.c
index c31894b75b..e855ab9099 100644
--- a/arch/loongarch/kvm/exit.c
+++ b/arch/loongarch/kvm/exit.c
@@ -631,3 +631,30 @@ static int kvm_handle_write_fault(struct kvm_vcpu *vcpu)
{
return kvm_handle_rdwr_fault(vcpu, true);
}
+
+/**
+ * kvm_handle_fpu_disabled() - Guest used fpu however it is disabled at host
+ * @vcpu: Virtual CPU context.
+ *
+ * Handle when the guest attempts to use fpu which hasn't been allowed
+ * by the root context.
+ */
+static int kvm_handle_fpu_disabled(struct kvm_vcpu *vcpu)
+{
+ struct kvm_run *run = vcpu->run;
+
+ /*
+ * If guest FPU not present, the FPU operation should have been
+ * treated as a reserved instruction!
+ * If FPU already in use, we shouldn't get this at all.
+ */
+ if (WARN_ON(vcpu->arch.aux_inuse & KVM_LARCH_FPU)) {
+ kvm_err("%s internal error\n", __func__);
+ run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+ return RESUME_HOST;
+ }
+
+ kvm_own_fpu(vcpu);
+
+ return RESUME_GUEST;
+}
--
2.39.3