On 14.03.2013, at 12:57, Jan Kiszka wrote: > 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). Well, the same thing goes for us. What I'm asking is whether there is a specific reason (extensibility, oversight, taste, ...) that you did #define KVM_GUESTDBG_USE_SW_BP 0x00010000 #define KVM_GUESTDBG_USE_HW_BP 0x00020000 rather than #define KVM_GUESTDBG_BP_TYPE 0x00010000 #define KVM_GUESTDBG_BP_TYPE_SW 0x00010000 #define KVM_GUESTDBG_BP_TYPE_HW 0x00000000 :) Alex -- 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
