On 2013-03-14 12:54, Alexander Graf wrote: > > On 14.03.2013, at 05:42, Bhushan Bharat-R65777 wrote: > >> >> >>> -----Original Message----- >>> From: Alexander Graf [mailto:agraf@xxxxxxx] >>> Sent: Thursday, March 07, 2013 6:51 PM >>> To: Bhushan Bharat-R65777 >>> Cc: kvm-ppc@xxxxxxxxxxxxxxx; kvm@xxxxxxxxxxxxxxx; Wood Scott-B07421; Bhushan >>> Bharat-R65777 >>> Subject: Re: [PATCH 3/7] KVM: PPC: debug stub interface parameter defined >>> >>> >>> On 28.02.2013, at 05:13, Bharat Bhushan wrote: >>> >>>> This patch defines the interface parameter for KVM_SET_GUEST_DEBUG >>>> ioctl support. Follow up patches will use this for setting up hardware >>>> breakpoints, watchpoints and software breakpoints. >>>> >>>> Also kvm_arch_vcpu_ioctl_set_guest_debug() is brought one level below. >>>> This is because I am not sure what is required for book3s. So this >>>> ioctl behaviour will not change for book3s. >>>> >>>> Signed-off-by: Bharat Bhushan <bharat.bhushan@xxxxxxxxxxxxx> >>>> --- >>>> arch/powerpc/include/uapi/asm/kvm.h | 23 +++++++++++++++++++++++ >>>> arch/powerpc/kvm/book3s.c | 6 ++++++ >>>> arch/powerpc/kvm/booke.c | 6 ++++++ >>>> arch/powerpc/kvm/powerpc.c | 6 ------ >>>> 4 files changed, 35 insertions(+), 6 deletions(-) >>>> >>>> diff --git a/arch/powerpc/include/uapi/asm/kvm.h >>>> b/arch/powerpc/include/uapi/asm/kvm.h >>>> index c2ff99c..15f9a00 100644 >>>> --- a/arch/powerpc/include/uapi/asm/kvm.h >>>> +++ b/arch/powerpc/include/uapi/asm/kvm.h >>>> @@ -272,8 +272,31 @@ struct kvm_debug_exit_arch { >>>> >>>> /* for KVM_SET_GUEST_DEBUG */ >>>> struct kvm_guest_debug_arch { >>>> + struct { >>>> + /* H/W breakpoint/watchpoint address */ >>>> + __u64 addr; >>>> + /* >>>> + * Type denotes h/w breakpoint, read watchpoint, write >>>> + * watchpoint or watchpoint (both read and write). >>>> + */ >>>> +#define KVMPPC_DEBUG_NOTYPE 0x0 >>>> +#define KVMPPC_DEBUG_BREAKPOINT (1UL << 1) >>>> +#define KVMPPC_DEBUG_WATCH_WRITE (1UL << 2) >>>> +#define KVMPPC_DEBUG_WATCH_READ (1UL << 3) >>>> + __u32 type; >>>> + __u32 reserved; >>>> + } bp[16]; >>>> }; >>>> >>>> +/* Debug related defines */ >>>> +/* >>>> + * kvm_guest_debug->control is a 32 bit field. The lower 16 bits are >>>> +generic >>>> + * 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 >>> >>> You only need >>> >>> #define KVM_GUESTDBG_HW_BP 0x00010000 >>> >>> In absence of the flag, it's a SW breakpoint. >> >> We kept this for 2 reasons; 1) Same logic is applied for i386, so trying to keep consistent 2) better clarity. > > Jan, was there any special reason to have 2 flags for HW/SW breakpoint on x86 rather than one bit that indicates which one is used? Different mechanics on x86: HW goes via debug registers and shows up as INT1, SW is INT3 (plus guest patching done by user land). Jan -- Siemens AG, Corporate Technology, CT RTC ITP SDP-DE Corporate Competence Center Embedded Linux -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
