Octeon III implements a read-only guest CP0_PRid register, so add cases
to the KVM register access API for Octeon to ensure the correct value is
read and writes are ignored.
Signed-off-by: James Hogan <james.hogan@xxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: "Radim Krčmář" <rkrcmar@xxxxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: David Daney <david.daney@xxxxxxxxxx>
Cc: Andreas Herrmann <andreas.herrmann@xxxxxxxxxxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Cc: kvm@xxxxxxxxxxxxxxx
---
arch/mips/include/asm/mipsregs.h | 2 ++
arch/mips/kvm/vz.c | 19 +++++++++++++++++--
2 files changed, 19 insertions(+), 2 deletions(-)
diff --git a/arch/mips/include/asm/mipsregs.h b/arch/mips/include/asm/mipsregs.h
index ebe608d21d7e..6875b69f59f7 100644
--- a/arch/mips/include/asm/mipsregs.h
+++ b/arch/mips/include/asm/mipsregs.h
@@ -2025,6 +2025,8 @@ do { \
#define read_gc0_epc() __read_ulong_gc0_register(14, 0)
#define write_gc0_epc(val) __write_ulong_gc0_register(14, 0, val)
+#define read_gc0_prid() __read_32bit_gc0_register(15, 0)
+
#define read_gc0_ebase() __read_32bit_gc0_register(15, 1)
#define write_gc0_ebase(val) __write_32bit_gc0_register(15, 1, val)
diff --git a/arch/mips/kvm/vz.c b/arch/mips/kvm/vz.c
index 5c495277bf44..71d8856ade64 100644
--- a/arch/mips/kvm/vz.c
+++ b/arch/mips/kvm/vz.c
@@ -1938,7 +1938,15 @@ static int kvm_vz_get_one_reg(struct kvm_vcpu *vcpu,
*v = (long)read_gc0_epc();
break;
case KVM_REG_MIPS_CP0_PRID:
- *v = (long)kvm_read_c0_guest_prid(cop0);
+ switch (boot_cpu_type()) {
+ case CPU_CAVIUM_OCTEON3:
+ /* Octeon III has a read-only guest.PRid */
+ *v = read_gc0_prid();
+ break;
+ default:
+ *v = (long)kvm_read_c0_guest_prid(cop0);
+ break;
+ };
break;
case KVM_REG_MIPS_CP0_EBASE:
*v = kvm_vz_read_gc0_ebase();
@@ -2170,7 +2178,14 @@ static int kvm_vz_set_one_reg(struct kvm_vcpu *vcpu,
write_gc0_epc(v);
break;
case KVM_REG_MIPS_CP0_PRID:
- kvm_write_c0_guest_prid(cop0, v);
+ switch (boot_cpu_type()) {
+ case CPU_CAVIUM_OCTEON3:
+ /* Octeon III has a guest.PRid, but its read-only */
+ break;
+ default:
+ kvm_write_c0_guest_prid(cop0, v);
+ break;
+ };
break;
case KVM_REG_MIPS_CP0_EBASE:
kvm_vz_write_gc0_ebase(v);
--
git-series 0.8.10
