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

@@ -133,6 +133,13 @@ struct kvm_fpu {
*/
#define KVM_REG_MIPS_COUNT_RESUME (KVM_REG_MIPS | KVM_REG_SIZE_U64 | \
0x20000 | 1)
/*
* CP0_Count rate in Hz
* Specifies the rate of the CP0_Count timer in Hz. Modifications occur without
* discontinuities in CP0_Count.
*/
#define KVM_REG_MIPS_COUNT_HZ (KVM_REG_MIPS | KVM_REG_SIZE_U64 | \
0x20000 | 2)
/*
* KVM MIPS specific structures and definitions