Implement the MIPS GET_CLOCK_FREQ hypercall used by paravirtual guest kernels. When the guest performs this hypercall, the value of count_hz is returned, which is the current rate of the CP0_Count register.
We also document the hypercall along with the others as the documentation was never added. Signed-off-by: James Hogan <[email protected]> Cc: Paolo Bonzini <[email protected]> Cc: "Radim Krčmář" <[email protected]> Cc: Ralf Baechle <[email protected]> Cc: Andreas Herrmann <[email protected]> Cc: David Daney <[email protected]> Cc: Jonathan Corbet <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] --- Documentation/virtual/kvm/hypercalls.txt | 6 ++++++ arch/mips/kvm/hypcall.c | 18 +++++++++++++++--- 2 files changed, 21 insertions(+), 3 deletions(-) diff --git a/Documentation/virtual/kvm/hypercalls.txt b/Documentation/virtual/kvm/hypercalls.txt index 8f36582ce2b7..e9f1c9d3da98 100644 --- a/Documentation/virtual/kvm/hypercalls.txt +++ b/Documentation/virtual/kvm/hypercalls.txt @@ -86,3 +86,9 @@ the vcpu to sleep until occurrence of an appropriate event. Another vcpu of the same guest can wakeup the sleeping vcpu by issuing KVM_HC_KICK_CPU hypercall, specifying APIC ID (a1) of the vcpu to be woken up. An additional argument (a0) is used in the hypercall for future use. + +6. KVM_HC_MIPS_GET_CLOCK_FREQ +------------------------ +Architecture: mips +Status: active +Purpose: Return the frequency of CP0_Count in HZ. diff --git a/arch/mips/kvm/hypcall.c b/arch/mips/kvm/hypcall.c index 83063435195f..7c74ec25f2b9 100644 --- a/arch/mips/kvm/hypcall.c +++ b/arch/mips/kvm/hypcall.c @@ -32,9 +32,21 @@ enum emulation_result kvm_mips_emul_hypcall(struct kvm_vcpu *vcpu, static int kvm_mips_hypercall(struct kvm_vcpu *vcpu, unsigned long num, const unsigned long *args, unsigned long *hret) { - /* Report unimplemented hypercall to guest */ - *hret = -KVM_ENOSYS; - return RESUME_GUEST; + int ret = RESUME_GUEST; + + switch (num) { + case KVM_HC_MIPS_GET_CLOCK_FREQ: + /* Return frequency of count/compare timer */ + *hret = (s32)vcpu->arch.count_hz; + break; + + default: + /* Report unimplemented hypercall to guest */ + *hret = -KVM_ENOSYS; + break; + }; + + return ret; } int kvm_mips_handle_hypcall(struct kvm_vcpu *vcpu) -- git-series 0.8.10 -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
