From: Paul Mackerras <paulus@ozlabs.org>
To: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: christophe.leroy@c-s.fr, mikey@neuling.org, rogealve@br.ibm.com,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
npiggin@gmail.com, kvm-ppc@vger.kernel.org,
linux-kselftest@vger.kernel.org, jniethe5@gmail.com,
pedromfc@br.ibm.com, pbonzini@redhat.com,
linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH 1/7] powerpc/watchpoint/kvm: Rename current DAWR macros and variables
Date: Wed, 2 Sep 2020 11:49:08 +1000 [thread overview]
Message-ID: <20200902014908.GA272502@thinks.paulus.ozlabs.org> (raw)
In-Reply-To: <20200723102058.312282-2-ravi.bangoria@linux.ibm.com>
On Thu, Jul 23, 2020 at 03:50:52PM +0530, Ravi Bangoria wrote:
> Power10 is introducing second DAWR. Use real register names (with
> suffix 0) from ISA for current macros and variables used by kvm.
Most of this looks fine, but I think we should not change the existing
names in arch/powerpc/include/uapi/asm/kvm.h (and therefore also
Documentation/virt/kvm/api.rst).
> diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
> index 426f94582b7a..4dc18fe6a2bf 100644
> --- a/Documentation/virt/kvm/api.rst
> +++ b/Documentation/virt/kvm/api.rst
> @@ -2219,8 +2219,8 @@ registers, find a list below:
> PPC KVM_REG_PPC_BESCR 64
> PPC KVM_REG_PPC_TAR 64
> PPC KVM_REG_PPC_DPDES 64
> - PPC KVM_REG_PPC_DAWR 64
> - PPC KVM_REG_PPC_DAWRX 64
> + PPC KVM_REG_PPC_DAWR0 64
> + PPC KVM_REG_PPC_DAWRX0 64
> PPC KVM_REG_PPC_CIABR 64
> PPC KVM_REG_PPC_IC 64
> PPC KVM_REG_PPC_VTB 64
...
> diff --git a/arch/powerpc/include/uapi/asm/kvm.h b/arch/powerpc/include/uapi/asm/kvm.h
> index 264e266a85bf..38d61b73f5ed 100644
> --- a/arch/powerpc/include/uapi/asm/kvm.h
> +++ b/arch/powerpc/include/uapi/asm/kvm.h
> @@ -608,8 +608,8 @@ struct kvm_ppc_cpu_char {
> #define KVM_REG_PPC_BESCR (KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xa7)
> #define KVM_REG_PPC_TAR (KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xa8)
> #define KVM_REG_PPC_DPDES (KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xa9)
> -#define KVM_REG_PPC_DAWR (KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xaa)
> -#define KVM_REG_PPC_DAWRX (KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xab)
> +#define KVM_REG_PPC_DAWR0 (KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xaa)
> +#define KVM_REG_PPC_DAWRX0 (KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xab)
> #define KVM_REG_PPC_CIABR (KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xac)
> #define KVM_REG_PPC_IC (KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xad)
> #define KVM_REG_PPC_VTB (KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xae)
The existing names are an API, and if you change them you will break
compilation of existing userspace programs. I don't see that adding
the '0' on the end is so important that we need to break userspace.
Paul.
next prev parent reply other threads:[~2020-09-02 1:51 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-23 10:20 [PATCH 0/7] powerpc/watchpoint: 2nd DAWR kvm enablement + selftests Ravi Bangoria
2020-07-23 10:20 ` [PATCH 1/7] powerpc/watchpoint/kvm: Rename current DAWR macros and variables Ravi Bangoria
2020-09-02 1:49 ` Paul Mackerras [this message]
2020-09-02 5:09 ` Ravi Bangoria
2020-07-23 10:20 ` [PATCH 2/7] powerpc/watchpoint/kvm: Add infrastructure to support 2nd DAWR Ravi Bangoria
2020-09-02 2:01 ` Paul Mackerras
2020-09-02 5:09 ` Ravi Bangoria
2020-09-02 5:12 ` Ravi Bangoria
2020-07-23 10:20 ` [PATCH 3/7] powerpc/watchpoint/kvm: Introduce new capability for " Ravi Bangoria
2020-07-23 10:20 ` [PATCH 4/7] powerpc/selftests/ptrace-hwbreak: Add testcases " Ravi Bangoria
2020-07-23 10:20 ` [PATCH 5/7] powerpc/selftests/perf-hwbreak: Coalesce event creation code Ravi Bangoria
2020-07-23 10:20 ` [PATCH 6/7] powerpc/selftests/perf-hwbreak: Add testcases for 2nd DAWR Ravi Bangoria
2020-07-23 10:20 ` [PATCH 7/7] powerpc/selftests: Add selftest to test concurrent perf/ptrace events Ravi Bangoria
2020-07-23 10:48 ` [PATCH 0/7] powerpc/watchpoint: 2nd DAWR kvm enablement + selftests Ravi Bangoria
2020-09-02 2:32 ` Paul Mackerras
2020-09-02 5:13 ` Ravi Bangoria
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