From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex =?utf-8?Q?Benn=C3=A9e?= Subject: Re: [PATCH v4 03/12] KVM: arm64: guest debug, define API headers Date: Fri, 15 May 2015 16:14:57 +0100 Message-ID: <874mndlvny.fsf@linaro.org> References: <1431700035-23479-1-git-send-email-alex.bennee@linaro.org> <1431700035-23479-4-git-send-email-alex.bennee@linaro.org> <20150515144423.GA23652@leverpostej> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: "kvm\@vger.kernel.org" , "linux-arm-kernel\@lists.infradead.org" , "kvmarm\@lists.cs.columbia.edu" , "christoffer.dall\@linaro.org" , Marc Zyngier , "peter.maydell\@linaro.org" , "agraf\@suse.de" , "drjones\@redhat.com" , "pbonzini\@redhat.com" , "zhichao.huang\@linaro.org" , Catalin Marinas , "jan.kiszka\@siemens.com" , Will Deacon , open list , "dahi\@linux.vnet.ibm.com" , "r65777\@freescale.com" , "bp\@suse.de" To: Mark Rutland Return-path: In-reply-to: <20150515144423.GA23652@leverpostej> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org Mark Rutland writes: > On Fri, May 15, 2015 at 03:27:06PM +0100, Alex Benn=C3=A9e wrote: >> This commit defines the API headers for guest debugging. There are t= wo >> architecture specific debug structures: >>=20 >> - kvm_guest_debug_arch, allows us to pass in HW debug registers >> - kvm_debug_exit_arch, signals exception and possible faulting add= ress >>=20 >> The type of debugging being used is controlled by the architecture >> specific control bits of the kvm_guest_debug->control flags in the i= octl >> structure. >>=20 >> Signed-off-by: Alex Benn=C3=A9e >> Reviewed-by: David Hildenbrand >> Reviewed-by: Andrew Jones >> Acked-by: Christoffer Dall >>=20 >> --- >> v2 >> - expose hsr and pc directly to user-space >> v3 >> - s/control/controlled/ in commit message >> - add v8 to ARM ARM comment (ARM Architecture Reference Manual) >> - add rb tag >> - rm pc, add far >> - re-word comments on alignment >> - rename KVM_ARM_NDBG_REGS -> KVM_ARM_MAX_DBG_REGS >> v4 >> - now uses common HW/SW BP define >> - add a-b-tag >> - use u32 for control regs >>=20 >> diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/= uapi/asm/kvm.h >> index d268320..8796610 100644 >> --- a/arch/arm64/include/uapi/asm/kvm.h >> +++ b/arch/arm64/include/uapi/asm/kvm.h >> @@ -100,10 +100,28 @@ struct kvm_sregs { >> struct kvm_fpu { >> }; >> =20 >> +/* >> + * See v8 ARM ARM D7.3: Debug Registers >> + * >> + * The control registers are architecturally defined as 32 bits but= are >> + * stored as 64 bit values alongside the value registers. This is d= one > > Stale comment? They're stored as __u32 below. Gah yes it is.=20 > It's possible that the registers could grow in future as happened in = the > case of CLIDR_EL1, so it might be worth treating system registers > generally as u64 values. Really? I mean the existing debug *control* registers have reserved bit= s 24-31 so there is space for expansion.=20 > > Mark. > >> + * to keep the copying of these values into the vcpu context simple= as >> + * everything is 64 bit aligned (see DBGBCR0_EL1 onwards in kvm_asm= =2Eh). >> + * >> + * The architectural limit is 16 debug registers of each type altho= ugh >> + * in practice there are usually less (see ID_AA64DFR0_EL1). >> + */ >> +#define KVM_ARM_MAX_DBG_REGS 16 >> struct kvm_guest_debug_arch { >> + __u32 dbg_bcr[KVM_ARM_MAX_DBG_REGS]; >> + __u64 dbg_bvr[KVM_ARM_MAX_DBG_REGS]; >> + __u32 dbg_wcr[KVM_ARM_MAX_DBG_REGS]; >> + __u64 dbg_wvr[KVM_ARM_MAX_DBG_REGS]; >> }; >> =20 >> struct kvm_debug_exit_arch { >> + __u32 hsr; >> + __u64 far; >> }; >> =20 >> struct kvm_sync_regs { >> --=20 >> 2.3.5 >>=20 >> _______________________________________________ >> kvmarm mailing list >> kvmarm@lists.cs.columbia.edu >> https://lists.cs.columbia.edu/mailman/listinfo/kvmarm --=20 Alex Benn=C3=A9e