From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 424C01A00E9 for ; Fri, 8 May 2015 21:10:27 +1000 (AEST) Message-ID: <554C995B.6050907@redhat.com> Date: Fri, 08 May 2015 13:09:15 +0200 From: Paolo Bonzini MIME-Version: 1.0 To: Christoffer Dall , =?windows-1252?Q?Alex?= =?windows-1252?Q?_Benn=E9e?= Subject: Re: [PATCH v3 02/12] KVM: define common __KVM_GUESTDBG_USE_SW/HW_BP values References: <1430929407-3487-1-git-send-email-alex.bennee@linaro.org> <1430929407-3487-3-git-send-email-alex.bennee@linaro.org> <20150508092346.GB24744@cbox> In-Reply-To: <20150508092346.GB24744@cbox> Content-Type: text/plain; charset=windows-1252 Cc: peter.maydell@linaro.org, kvm@vger.kernel.org, Alexey Kardashevskiy , Bharat Bhushan , Paul Mackerras , "H. Peter Anvin" , kvmarm@lists.cs.columbia.edu, Nadav Amit , "maintainer:X86 ARCHITECTURE..." , agraf@suse.de, Gleb Natapov , Ingo Molnar , zhichao.huang@linaro.org, jan.kiszka@siemens.com, Mihai Caraman , bp@suse.de, drjones@redhat.com, marc.zyngier@arm.com, r65777@freescale.com, Thomas Gleixner , linux-arm-kernel@lists.infradead.org, ABI/API , open list , dahi@linux.vnet.ibm.com, "open list:LINUX FOR POWERPC..." List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 08/05/2015 11:23, Christoffer Dall wrote: > On Wed, May 06, 2015 at 05:23:17PM +0100, Alex Bennée wrote: >> Currently x86, powerpc and soon arm64 use the same two architecture >> specific bits for guest debug support for software and hardware >> breakpoints. This makes the shared values explicit while leaving the >> gate open for another architecture to use some other value if they >> really really want to. >> >> Signed-off-by: Alex Bennée >> Reviewed-by: Andrew Jones >> >> diff --git a/arch/powerpc/include/uapi/asm/kvm.h b/arch/powerpc/include/uapi/asm/kvm.h >> index ab4d473..1731569 100644 >> --- a/arch/powerpc/include/uapi/asm/kvm.h >> +++ b/arch/powerpc/include/uapi/asm/kvm.h >> @@ -310,8 +310,8 @@ struct kvm_guest_debug_arch { >> * and upper 16 bits are architecture specific. Architecture specific defines >> * that ioctl is for setting hardware breakpoint or software breakpoint. >> */ >> -#define KVM_GUESTDBG_USE_SW_BP 0x00010000 >> -#define KVM_GUESTDBG_USE_HW_BP 0x00020000 >> +#define KVM_GUESTDBG_USE_SW_BP __KVM_GUESTDBG_USE_SW_BP >> +#define KVM_GUESTDBG_USE_HW_BP __KVM_GUESTDBG_USE_HW_BP >> >> /* definition of registers in kvm_run */ >> struct kvm_sync_regs { >> diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h >> index d7dcef5..1438202 100644 >> --- a/arch/x86/include/uapi/asm/kvm.h >> +++ b/arch/x86/include/uapi/asm/kvm.h >> @@ -250,8 +250,8 @@ struct kvm_debug_exit_arch { >> __u64 dr7; >> }; >> >> -#define KVM_GUESTDBG_USE_SW_BP 0x00010000 >> -#define KVM_GUESTDBG_USE_HW_BP 0x00020000 >> +#define KVM_GUESTDBG_USE_SW_BP __KVM_GUESTDBG_USE_SW_BP >> +#define KVM_GUESTDBG_USE_HW_BP __KVM_GUESTDBG_USE_HW_BP >> #define KVM_GUESTDBG_INJECT_DB 0x00040000 >> #define KVM_GUESTDBG_INJECT_BP 0x00080000 >> >> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h >> index 70ac641..3b6252e 100644 >> --- a/include/uapi/linux/kvm.h >> +++ b/include/uapi/linux/kvm.h >> @@ -570,8 +570,16 @@ struct kvm_s390_irq_state { >> >> /* for KVM_SET_GUEST_DEBUG */ >> >> -#define KVM_GUESTDBG_ENABLE 0x00000001 >> -#define KVM_GUESTDBG_SINGLESTEP 0x00000002 >> +#define KVM_GUESTDBG_ENABLE (1 << 0) >> +#define KVM_GUESTDBG_SINGLESTEP (1 << 1) >> + >> +/* >> + * Architecture specific stuff uses the top 16 bits of the field, > > s/stuff// > >> + * however there is some shared commonality for the common cases >> + */ >> +#define __KVM_GUESTDBG_USE_SW_BP (1 << 16) >> +#define __KVM_GUESTDBG_USE_HW_BP (1 << 17) >> + >> >> struct kvm_guest_debug { >> __u32 control; > > We sort of left this discussion hanging with me expressing slight > concern about the usefulness about these defines. > > Paolo, what are your thoughts? I would just lift these two KVM_GUESTDBG_* defines to include/uapi/linux/kvm.h and say that architecture specific stuff uses the top 14 bits of the field. :) Paolo