| Message ID | 1403882562-28367-1-git-send-email-james.hogan@imgtec.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
diff --git a/target-mips/kvm.c b/target-mips/kvm.c index 844e5bbe5f92..97fd51a02f5c 100644 --- a/target-mips/kvm.c +++ b/target-mips/kvm.c @@ -61,6 +61,13 @@ int kvm_arch_init_vcpu(CPUState *cs) void kvm_mips_reset_vcpu(MIPSCPU *cpu) { + CPUMIPSState *env = &cpu->env; + + if (env->CP0_Config1 & (1 << CP0C1_FP)) { + fprintf(stderr, "Warning: FPU not supported with KVM, disabling\n"); + env->CP0_Config1 &= ~(1 << CP0C1_FP); + } + DPRINTF("%s\n", __func__); }
KVM doesn't yet support the MIPS FPU, or writing to the guest's Config1 register which contains the FPU implemented bit. Clear QEMU's version of that bit on reset and display a warning that the FPU has been disabled. The previous incorrect Config1 CP0 register value wasn't being passed to KVM yet, however we should ensure it is set correctly now to reduce the risk of breaking migration/loadvm to a future version of QEMU/Linux that does support it. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Aurelien Jarno <aurelien@aurel32.net> Cc: Paolo Bonzini <pbonzini@redhat.com> --- A slight variation this time, which should handle the case of the user setting the CPU explicitly a bit better (previously only the default Malta CPU was changed). Look reasonable? Changes in v2: - Add a warning to alert user that FPU is disabled (Aurelien Jarno). - Slightly different approach. Disable the FPU on reset from KVM code instead of only changing the default CPU for Malta. This will then happen even if the user specifies the core type explicitly (and without having to modify any CPU definitions), but it does print a message on each reset. - Rewrite (and hopefully clarify) commit message. --- target-mips/kvm.c | 7 +++++++ 1 file changed, 7 insertions(+)