Re: [PATCH 05/21] MIPS: KVM: Add CP0_EPC KVM register access

David Daney
2014-04-25T16:44:22Z

On 04/25/2014 08:19 AM, James Hogan wrote:
> Contrary to the comment, the guest CP0_EPC register cannot be set via
> kvm_regs, since it is distinct from the guest PC. Add the EPC register
> to the KVM_{GET,SET}_ONE_REG ioctl interface.
>
> 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>

NACK...

> ---
> arch/mips/kvm/kvm_mips.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/arch/mips/kvm/kvm_mips.c b/arch/mips/kvm/kvm_mips.c
> index 46cea0bad518..db41876cbac5 100644
> --- a/arch/mips/kvm/kvm_mips.c
> +++ b/arch/mips/kvm/kvm_mips.c
> @@ -512,6 +512,7 @@ kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
> #define KVM_REG_MIPS_CP0_COMPARE MIPS_CP0_32(11, 0)
> #define KVM_REG_MIPS_CP0_STATUS MIPS_CP0_32(12, 0)
> #define KVM_REG_MIPS_CP0_CAUSE MIPS_CP0_32(13, 0)
> +#define KVM_REG_MIPS_CP0_EPC MIPS_CP0_64(14, 0)

This is already called KVM_REG_MIPS_PC, you cannot change that.

> #define KVM_REG_MIPS_CP0_EBASE MIPS_CP0_32(15, 1)
> #define KVM_REG_MIPS_CP0_CONFIG MIPS_CP0_32(16, 0)
> #define KVM_REG_MIPS_CP0_CONFIG1 MIPS_CP0_32(16, 1)
> @@ -567,7 +568,7 @@ static u64 kvm_mips_get_one_regs[] = {
> KVM_REG_MIPS_CP0_ENTRYHI,
> KVM_REG_MIPS_CP0_STATUS,
> KVM_REG_MIPS_CP0_CAUSE,
> - /* EPC set via kvm_regs, et al. */
> + KVM_REG_MIPS_CP0_EPC,
> KVM_REG_MIPS_CP0_CONFIG,
> KVM_REG_MIPS_CP0_CONFIG1,
> KVM_REG_MIPS_CP0_CONFIG2,
> @@ -620,6 +621,9 @@ static int kvm_mips_get_reg(struct kvm_vcpu *vcpu,
> case KVM_REG_MIPS_CP0_CAUSE:
> v = (long)kvm_read_c0_guest_cause(cop0);
> break;
> + case KVM_REG_MIPS_CP0_EPC:
> + v = (long)kvm_read_c0_guest_epc(cop0);
> + break;
> case KVM_REG_MIPS_CP0_ERROREPC:
> v = (long)kvm_read_c0_guest_errorepc(cop0);
> break;
> @@ -716,6 +720,9 @@ static int kvm_mips_set_reg(struct kvm_vcpu *vcpu,
> case KVM_REG_MIPS_CP0_CAUSE:
> kvm_write_c0_guest_cause(cop0, v);
> break;
> + case KVM_REG_MIPS_CP0_EPC:
> + kvm_write_c0_guest_epc(cop0, v);
> + break;
> case KVM_REG_MIPS_CP0_ERROREPC:
> kvm_write_c0_guest_errorepc(cop0, v);
> break;
>