MIPS: KVM: Add count frequency KVM register

Expose the KVM guest CP0_Count frequency to userland via a new
KVM_REG_MIPS_COUNT_HZ register accessible with the KVM_{GET,SET}_ONE_REG
ioctls.

When the frequency is altered the bias is adjusted such that the guest
CP0_Count doesn't jump discontinuously or lose any timer interrupts.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: David Daney <david.daney@cavium.com>
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
James Hogan
2014-05-29 10:16:38 +01:00
committed by Paolo Bonzini
parent f82393426a
commit f74a8e224e
5 changed files with 65 additions and 0 deletions

View File

@@ -546,6 +546,7 @@ static u64 kvm_mips_get_one_regs[] = {
KVM_REG_MIPS_COUNT_CTL,
KVM_REG_MIPS_COUNT_RESUME,
KVM_REG_MIPS_COUNT_HZ,
};
static int kvm_mips_get_reg(struct kvm_vcpu *vcpu,
@@ -627,6 +628,7 @@ static int kvm_mips_get_reg(struct kvm_vcpu *vcpu,
case KVM_REG_MIPS_CP0_COUNT:
case KVM_REG_MIPS_COUNT_CTL:
case KVM_REG_MIPS_COUNT_RESUME:
case KVM_REG_MIPS_COUNT_HZ:
ret = kvm_mips_callbacks->get_one_reg(vcpu, reg, &v);
if (ret)
return ret;
@@ -724,6 +726,7 @@ static int kvm_mips_set_reg(struct kvm_vcpu *vcpu,
case KVM_REG_MIPS_CP0_CAUSE:
case KVM_REG_MIPS_COUNT_CTL:
case KVM_REG_MIPS_COUNT_RESUME:
case KVM_REG_MIPS_COUNT_HZ:
return kvm_mips_callbacks->set_one_reg(vcpu, reg, v);
default:
return -EINVAL;