From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Jones Subject: Re: [PATCH v2 02/10] KVM: define common __KVM_GUESTDBG_USE_SW/HW_BP values Date: Mon, 13 Apr 2015 17:07:16 +0200 Message-ID: <20150413150716.GA6410@hawk.usersys.redhat.com> References: <1427814488-28467-1-git-send-email-alex.bennee@linaro.org> <1427814488-28467-3-git-send-email-alex.bennee@linaro.org> <20150413115535.GM6186@cbox> <871tjokrnu.fsf@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Cc: kvm@vger.kernel.org, Alexey Kardashevskiy , Benjamin Herrenschmidt , Paul Mackerras , "H. Peter Anvin" , kvmarm@lists.cs.columbia.edu, Nadav Amit , Michael Ellerman , "maintainer:X86 ARCHITECTURE..." , Gleb Natapov , Ingo Molnar , zhichao.huang@linaro.org, jan.kiszka@siemens.com, bp@suse.de, marc.zyngier@arm.com, r65777@freescale.com, Thomas Gleixner , linux-arm-kernel@lists.infradead.org, "open list:ABI/API" , open list , dahi@linux.vnet.ibm.com, pbonzini@redhat.com, "open list:LINUX FOR POWERPC..." To: Alex =?iso-8859-1?Q?Benn=E9e?= Return-path: Content-Disposition: inline In-Reply-To: <871tjokrnu.fsf@linaro.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu List-Id: kvm.vger.kernel.org On Mon, Apr 13, 2015 at 03:51:33PM +0100, Alex Benn=E9e wrote: > = > Christoffer Dall writes: > = > > On Tue, Mar 31, 2015 at 04:08:00PM +0100, Alex Benn=E9e 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 Benn=E9e > >> = > >> diff --git a/arch/powerpc/include/uapi/asm/kvm.h b/arch/powerpc/includ= e/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 breakpoi= nt. > >> */ > >> -#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/a= sm/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 5eedf84..ce2db14 100644 > >> --- a/include/uapi/linux/kvm.h > >> +++ b/include/uapi/linux/kvm.h > >> @@ -525,8 +525,16 @@ struct kvm_s390_irq { > >> = > >> /* 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, > > > > can you be more specific than 'stuff' here? features? > > > >> + * however there is some shared commonality for the common cases > > > > I don't like this sentence; shared commonality is a pleonasm and the use > > of however makes it sounds like there's some caveat here. > = > OK I can see that - after I looked it up ;-) > = > > If the top 16 bits are indeed arhictecture specific, then I think they > > should just be defined in their architecture specific headers. Unless > > the idea here is that there's a fixed set of of flags that architectures > > can choose to support, in which case it should simply be defined in the > > common header. > = > Well an architecture might not support some features and want to use > those bits for something else? I didn't want to force the bottom two > of the architecture specific bits to wasted if the features don't exist. This change comes from a discussion we had on v1 of this series http://www.spinics.net/lists/kvm-arm/msg12409.html > = > > > > > >> + */ > >> +#define __KVM_GUESTDBG_USE_SW_BP (1 << 16) > >> +#define __KVM_GUESTDBG_USE_HW_BP (1 << 17) > >> + > >> = > >> struct kvm_guest_debug { > >> __u32 control; > >> -- = > >> 2.3.4 > >> = > = > -- = > Alex Benn=E9e