Re: [PATCH v5 03/12] KVM: arm64: guest debug, define API headers

From: Andrew Jones
Date: Thu Jun 04 2015 - 10:41:10 EST


On Thu, Jun 04, 2015 at 02:49:17PM +0100, Alex Bennée wrote:
>
> Christoffer Dall <christoffer.dall@xxxxxxxxxx> writes:
>
> > On Fri, May 29, 2015 at 10:30:19AM +0100, Alex Bennée wrote:
> >> This commit defines the API headers for guest debugging. There are two
> >> architecture specific debug structures:
> >>
> >> - kvm_guest_debug_arch, allows us to pass in HW debug registers
> >> - kvm_debug_exit_arch, signals exception and possible faulting address
> >>
> >> The type of debugging being used is controlled by the architecture
> >> specific control bits of the kvm_guest_debug->control flags in the ioctl
> >> structure.
> >>
> >> Signed-off-by: Alex Bennée <alex.bennee@xxxxxxxxxx>
> >> Reviewed-by: David Hildenbrand <dahi@xxxxxxxxxxxxxxxxxx>
> >> Reviewed-by: Andrew Jones <drjones@xxxxxxxxxx>
> >> Acked-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
> >
> > I can re-confirm my ack despite the changes in v4, but this really is
> > borderline to keep exiting r-b and a-b tags around from previous patches
> > I would think, but ok.
>
> I was wondering how much a patch has to change for the r-b tags to
> become invalid. The meat of the API hasn't changed much though.
>
> Drew/David,
>
> Are you still happy with this patch?

I'm fine with it. Sorry I haven't had time to look over the rest of the
series yet this round.

drew

>
> >
> > -Christoffer
> >
> >>
> >> ---
> >> 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
> >> v5
> >> - revert to have arch specific KVM_GUESTDBG_USE_SW/HW_BP
> >> - rm stale comments dbgctrl was stored as u64
> >> ---
> >> arch/arm64/include/uapi/asm/kvm.h | 20 ++++++++++++++++++++
> >> 1 file changed, 20 insertions(+)
> >>
> >> diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
> >> index d268320..43758e7 100644
> >> --- a/arch/arm64/include/uapi/asm/kvm.h
> >> +++ b/arch/arm64/include/uapi/asm/kvm.h
> >> @@ -100,12 +100,32 @@ struct kvm_sregs {
> >> struct kvm_fpu {
> >> };
> >>
> >> +/*
> >> + * See v8 ARM ARM D7.3: Debug Registers
> >> + *
> >> + * The architectural limit is 16 debug registers of each type although
> >> + * 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];
> >> };
> >>
> >> struct kvm_debug_exit_arch {
> >> + __u32 hsr;
> >> + __u64 far;
> >> };
> >>
> >> +/*
> >> + * Architecture specific defines for kvm_guest_debug->control
> >> + */
> >> +
> >> +#define KVM_GUESTDBG_USE_SW_BP (1 << 16)
> >> +#define KVM_GUESTDBG_USE_HW_BP (1 << 17)
> >> +
> >> struct kvm_sync_regs {
> >> };
> >>
> >> --
> >> 2.4.1
> >>
>
> --
> Alex Bennée
> --
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