MIPS Enhanced Virtual Addressing (EVA) allows the user mode and kernel
mode address spaces to overlap, breaking the assumption that PAGE_OFFSET
is an appropriate KVM HVA error value, since PAGE_OFFSET may be as low
as zero.
Fix this in the same way that s390 does in commit bf640876e21f ("KVM:
s390: Make KVM_HVA_ERR_BAD usable on s390"), by overriding
KVM_HVA_ERR_[RO_]BAD and kvm_is_error_hva() in asm/kvm_host.h.
Signed-off-by: James Hogan <james.hogan@xxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: "Radim Krčmář" <rkrcmar@xxxxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Cc: kvm@xxxxxxxxxxxxxxx
---
arch/mips/include/asm/kvm_host.h | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/kvm_host.h
index b54bcadd8aec..4d7e0e466b5a 100644
--- a/arch/mips/include/asm/kvm_host.h
+++ b/arch/mips/include/asm/kvm_host.h
@@ -107,6 +107,20 @@
#define KVM_INVALID_INST 0xdeadbeef
#define KVM_INVALID_ADDR 0xdeadbeef
+/*
+ * EVA has overlapping user & kernel address spaces, so user VAs may be >
+ * PAGE_OFFSET. For this reason we can't use the default KVM_HVA_ERR_BAD of
+ * PAGE_OFFSET.
+ */
+
+#define KVM_HVA_ERR_BAD (-1UL)
+#define KVM_HVA_ERR_RO_BAD (-2UL)
+
+static inline bool kvm_is_error_hva(unsigned long addr)
+{
+ return IS_ERR_VALUE(addr);
+}
+
extern atomic_t kvm_mips_instance;
struct kvm_vm_stat {
--
2.7.3
