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* Re: [Qemu-devel] [PATCH 1/3] ppc debug stub: Get trap instruction opcode from KVM
       [not found] ` <1402412796-17299-2-git-send-email-Bharat.Bhushan@freescale.com>
@ 2014-06-11 12:41   ` Alexander Graf
  0 siblings, 0 replies; 6+ messages in thread
From: Alexander Graf @ 2014-06-11 12:41 UTC (permalink / raw)
  To: Bharat Bhushan; +Cc: qemu-ppc, qemu-devel

On 06/10/2014 05:06 PM, Bharat Bhushan wrote:
> Get trap instruction opcode from KVM and this opcode will
> be used for setting software breakpoint in following patch
>
> Signed-off-by: Bharat Bhushan <Bharat.Bhushan@freescale.com>
> ---
>   target-ppc/kvm.c | 11 +++++++++++
>   1 file changed, 11 insertions(+)
>
> diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
> index dfa5a26..4fc005f 100644
> --- a/target-ppc/kvm.c
> +++ b/target-ppc/kvm.c
> @@ -71,6 +71,8 @@ static int cap_papr;
>   static int cap_htab_fd;
>   static int cap_fixup_hcalls;
>   
> +static uint32_t debug_inst_opcode;
> +
>   /* XXX We have a race condition where we actually have a level triggered
>    *     interrupt, but the infrastructure can't expose that yet, so the guest
>    *     takes but ignores it, goes to sleep and never gets notified that there's
> @@ -412,6 +414,7 @@ int kvm_arch_init_vcpu(CPUState *cs)
>   {
>       PowerPCCPU *cpu = POWERPC_CPU(cs);
>       CPUPPCState *cenv = &cpu->env;
> +    struct kvm_one_reg reg;
>       int ret;
>   
>       /* Gather server mmu info from KVM and update the CPU state */
> @@ -434,6 +437,14 @@ int kvm_arch_init_vcpu(CPUState *cs)
>           break;
>       }
>   
> +    reg.id = KVM_REG_PPC_DEBUG_INST,
> +    reg.addr = (uintptr_t) &debug_inst_opcode,
> +
> +    ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
> +    if (ret) {
> +        return ret;
> +    }

How about kvm_get_one_reg()? :)


Alex

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [Qemu-devel] [PATCH 3/3] ppc debug: Add debug stub support
       [not found] ` <1402412796-17299-4-git-send-email-Bharat.Bhushan@freescale.com>
@ 2014-06-11 13:04   ` Alexander Graf
  2014-06-12  7:05     ` Bharat.Bhushan
  0 siblings, 1 reply; 6+ messages in thread
From: Alexander Graf @ 2014-06-11 13:04 UTC (permalink / raw)
  To: Bharat Bhushan; +Cc: qemu-ppc, qemu-devel

On 06/10/2014 05:06 PM, Bharat Bhushan wrote:
> This patch adds software breakpoint, hardware breakpoint and
> hardware watchpoint support for ppc. If the debug interrupt is
> not handled then this is injected to guest.
>
> Signed-off-by: Bharat Bhushan <Bharat.Bhushan@freescale.com>
> ---
>   hw/ppc/e500.c        |   1 +
>   target-ppc/kvm.c     | 304 ++++++++++++++++++++++++++++++++++++++++++++++-----
>   target-ppc/kvm_ppc.h |   1 +
>   3 files changed, 278 insertions(+), 28 deletions(-)
>
> diff --git a/hw/ppc/e500.c b/hw/ppc/e500.c
> index a973c18..514c595 100644
> --- a/hw/ppc/e500.c
> +++ b/hw/ppc/e500.c
> @@ -853,6 +853,7 @@ void ppce500_init(MachineState *machine, PPCE500Params *params)
>       if (kvm_enabled()) {
>           kvmppc_init();
>       }
> +    kvmppc_e500_hw_breakpoint_init();
>   }
>   
>   static int e500_ccsr_initfn(SysBusDevice *dev)
> diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
> index 1d2384d..f5fbec6 100644
> --- a/target-ppc/kvm.c
> +++ b/target-ppc/kvm.c
> @@ -38,6 +38,7 @@
>   #include "hw/ppc/ppc.h"
>   #include "sysemu/watchdog.h"
>   #include "trace.h"
> +#include "exec/gdbstub.h"
>   
>   //#define DEBUG_KVM
>   
> @@ -768,6 +769,38 @@ static int kvm_put_vpa(CPUState *cs)
>   
>   static int kvmppc_inject_debug_exception(CPUState *cs)
>   {
> +    PowerPCCPU *cpu = POWERPC_CPU(cs);
> +    CPUPPCState *env = &cpu->env;
> +    struct kvm_sregs sregs;
> +    int ret;
> +
> +    if (!cap_booke_sregs) {
> +        return -1;
> +    }
> +
> +    ret = kvm_vcpu_ioctl(cs, KVM_GET_SREGS, &sregs);
> +    if (ret < 0) {
> +        return -1;
> +    }
> +

I don't think any of this code should ever run for non-e500, no?

> +    if (sregs.u.e.features & KVM_SREGS_E_ED) {

Hrm - we never seem to set E_ED in kvm?

> +        sregs.u.e.dsrr0 = env->nip;
> +        sregs.u.e.dsrr1 = env->msr;
> +    } else {
> +        sregs.u.e.csrr0 = env->nip;
> +        sregs.u.e.csrr1 = env->msr;
> +    }
> +
> +    sregs.u.e.update_special = KVM_SREGS_E_UPDATE_DBSR;
> +    sregs.u.e.dbsr = env->spr[SPR_BOOKE_DBSR];
> +
> +    ret = kvm_vcpu_ioctl(cs, KVM_SET_SREGS, &sregs);
> +    if (ret < 0) {
> +        return -1;
> +    }
> +
> +    env->pending_interrupts &= ~(1 << PPC_INTERRUPT_DEBUG);
> +
>       return 0;
>   }
>   
> @@ -1275,6 +1308,239 @@ static int kvmppc_handle_dcr_write(CPUPPCState *env, uint32_t dcrn, uint32_t dat
>       return 0;
>   }
>   
> +int kvm_arch_insert_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp)
> +{
> +    uint32_t sc = tswap32(debug_inst_opcode);

Heh - this will become a lot of fun for real LE host as well as guest 
systems. For now just remove the tswap and add a comment that this needs 
fixing for LE.

> +
> +    if (cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&bp->saved_insn, 4, 0) ||
> +        cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&sc, 4, 1)) {
> +        return -EINVAL;
> +    }
> +
> +    return 0;
> +}
> +
> +int kvm_arch_remove_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp)
> +{
> +    uint32_t sc;
> +
> +    if (cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&sc, 4, 0) ||
> +        sc != tswap32(debug_inst_opcode) ||

Same here.

In fact, neither of the 2 operations are in a fast path. Can't we just 
fetch the debug inst opcode on demand in a function here? That will 
allow for easier byte swapping depending on the guest's MSR.LE setting 
later as well.

> +        cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&bp->saved_insn, 4, 1)) {
> +        return -EINVAL;
> +    }
> +
> +    return 0;
> +}
> +
> +static struct HWBreakpoint {
> +    target_ulong addr;
> +    int type;
> +} hw_breakpoint[6];
> +
> +static int nb_hw_breakpoint;
> +static int nb_hw_watchpoint;
> +static int max_hw_breakpoint = 4;
> +static int max_hw_watchpoint = 2;
> +
> +void kvmppc_e500_hw_breakpoint_init(void)
> +{
> +    max_hw_breakpoint = 2;
> +    max_hw_watchpoint = 2;

Can we somehow get this information from kvm and set it in 
kvm_arch_init? Worst case we'll have to look at the cpu class and derive 
it from there, but it really should live solely inside the kvm file.

> +}
> +
> +static int find_hw_breakpoint(target_ulong addr, int type)
> +{
> +    int n;
> +
> +    for (n = 0; n < nb_hw_breakpoint + nb_hw_watchpoint; n++) {
> +        if (hw_breakpoint[n].addr == addr && hw_breakpoint[n].type == type) {
> +            return n;
> +        }
> +    }
> +
> +    return -1;
> +}
> +
> +static int find_hw_watchpoint(target_ulong addr, int *flag)
> +{
> +    int n;
> +
> +    n = find_hw_breakpoint(addr, GDB_WATCHPOINT_ACCESS);
> +    if (n >= 0) {
> +        *flag = BP_MEM_ACCESS;
> +        return n;
> +    }
> +
> +    n = find_hw_breakpoint(addr, GDB_WATCHPOINT_WRITE);
> +    if (n >= 0) {
> +        *flag = BP_MEM_WRITE;
> +        return n;
> +    }
> +
> +    n = find_hw_breakpoint(addr, GDB_WATCHPOINT_READ);
> +    if (n >= 0) {
> +        *flag = BP_MEM_READ;
> +        return n;
> +    }
> +
> +    return -1;
> +}
> +
> +int kvm_arch_insert_hw_breakpoint(target_ulong addr,
> +                                  target_ulong len, int type)
> +{
> +    hw_breakpoint[nb_hw_breakpoint + nb_hw_watchpoint].addr = addr;
> +    hw_breakpoint[nb_hw_breakpoint + nb_hw_watchpoint].type = type;
> +
> +    switch (type) {
> +    case GDB_BREAKPOINT_HW:
> +        if (nb_hw_breakpoint >= max_hw_breakpoint) {
> +            return -ENOBUFS;
> +        }
> +
> +        if (find_hw_breakpoint(addr, type) >= 0) {
> +            return -EEXIST;
> +        }
> +
> +        nb_hw_breakpoint++;
> +        break;
> +
> +    case GDB_WATCHPOINT_WRITE:
> +    case GDB_WATCHPOINT_READ:
> +    case GDB_WATCHPOINT_ACCESS:
> +        if (nb_hw_watchpoint >= max_hw_watchpoint) {
> +            return -ENOBUFS;
> +        }
> +
> +        if (find_hw_breakpoint(addr, type) >= 0) {
> +            return -EEXIST;
> +        }
> +
> +        nb_hw_watchpoint++;
> +        break;
> +
> +    default:
> +        return -ENOSYS;
> +    }
> +
> +    return 0;
> +}
> +
> +int kvm_arch_remove_hw_breakpoint(target_ulong addr,
> +                                  target_ulong len, int type)
> +{
> +    int n;
> +
> +    n = find_hw_breakpoint(addr, type);
> +    if (n < 0) {
> +        return -ENOENT;
> +    }
> +
> +    switch (type) {
> +    case GDB_BREAKPOINT_HW:
> +        nb_hw_breakpoint--;
> +        break;
> +
> +    case GDB_WATCHPOINT_WRITE:
> +    case GDB_WATCHPOINT_READ:
> +    case GDB_WATCHPOINT_ACCESS:
> +        nb_hw_watchpoint--;
> +        break;
> +
> +    default:
> +        return -ENOSYS;
> +    }
> +    hw_breakpoint[n] = hw_breakpoint[nb_hw_breakpoint + nb_hw_watchpoint];
> +
> +    return 0;
> +}
> +
> +void kvm_arch_remove_all_hw_breakpoints(void)
> +{
> +    nb_hw_breakpoint = nb_hw_watchpoint = 0;
> +}
> +
> +static CPUWatchpoint hw_watchpoint;
> +
> +
> +static int kvm_handle_debug(PowerPCCPU *cpu, struct kvm_run *run)
> +{
> +    CPUState *cs = CPU(cpu);
> +    CPUPPCState *env = &cpu->env;
> +    int handle = 0;
> +    int n;
> +    int flag = 0;
> +    struct kvm_debug_exit_arch *arch_info = &run->debug.arch;
> +
> +    if (cs->singlestep_enabled) {
> +        handle = 1;
> +    } else if (arch_info->status) {
> +        if (arch_info->status & KVMPPC_DEBUG_BREAKPOINT) {
> +            n = find_hw_breakpoint(arch_info->address, GDB_BREAKPOINT_HW);
> +            if (n >= 0) {
> +                handle = 1;
> +            }
> +        } else if (arch_info->status & (KVMPPC_DEBUG_WATCH_READ |
> +                                        KVMPPC_DEBUG_WATCH_WRITE)) {
> +            n = find_hw_watchpoint(arch_info->address,  &flag);
> +            if (n >= 0) {
> +                handle = 1;
> +                cs->watchpoint_hit = &hw_watchpoint;
> +                hw_watchpoint.vaddr = hw_breakpoint[n].addr;
> +                hw_watchpoint.flags = flag;
> +            }
> +        }
> +    } else if (kvm_find_sw_breakpoint(cs, arch_info->address)) {
> +        handle = 1;
> +    }
> +
> +    cpu_synchronize_state(cs);
> +    if (handle) {
> +        env->spr[SPR_BOOKE_DBSR] = 0;

This is pretty e500 specific.


Alex

> +    } else {
> +       printf("unhandled\n");
> +       /* inject guest debug exception */
> +       env->pending_interrupts |=  1 << PPC_INTERRUPT_DEBUG;
> +     }
> +
> +    return handle;
> +}
> +
> +void kvm_arch_update_guest_debug(CPUState *cs, struct kvm_guest_debug *dbg)
> +{
> +    if (kvm_sw_breakpoints_active(cs)) {
> +        dbg->control |= KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP;
> +    }
> +
> +    if (nb_hw_breakpoint + nb_hw_watchpoint > 0) {
> +        int n;
> +
> +        dbg->control |= KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_HW_BP;
> +        memset(dbg->arch.bp, 0, sizeof(dbg->arch.bp));
> +        for (n = 0; n < nb_hw_breakpoint + nb_hw_watchpoint; n++) {
> +            switch (hw_breakpoint[n].type) {
> +            case GDB_BREAKPOINT_HW:
> +                dbg->arch.bp[n].type = KVMPPC_DEBUG_BREAKPOINT;
> +                break;
> +            case GDB_WATCHPOINT_WRITE:
> +                dbg->arch.bp[n].type = KVMPPC_DEBUG_WATCH_WRITE;
> +                break;
> +            case GDB_WATCHPOINT_READ:
> +                dbg->arch.bp[n].type = KVMPPC_DEBUG_WATCH_READ;
> +                break;
> +            case GDB_WATCHPOINT_ACCESS:
> +                dbg->arch.bp[n].type = KVMPPC_DEBUG_WATCH_WRITE |
> +                                        KVMPPC_DEBUG_WATCH_READ;
> +                break;
> +            default:
> +                cpu_abort(cs, "Unsupported breakpoint type\n");
> +            }
> +            dbg->arch.bp[n].addr = hw_breakpoint[n].addr;
> +        }
> +    }
> +}
> +
>   int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run)
>   {
>       PowerPCCPU *cpu = POWERPC_CPU(cs);
> @@ -1315,6 +1581,16 @@ int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run)
>           ret = 0;
>           break;
>   
> +    case KVM_EXIT_DEBUG:
> +        DPRINTF("handle debug exception\n");
> +        if (kvm_handle_debug(cpu, run)) {
> +            ret = EXCP_DEBUG;
> +            break;
> +        }
> +        /* re-enter, this exception was guest-internal */
> +        ret = 0;
> +        break;
> +
>       default:
>           fprintf(stderr, "KVM: unknown exit reason %d\n", run->exit_reason);
>           ret = -1;
> @@ -2002,34 +2278,6 @@ void kvm_arch_init_irq_routing(KVMState *s)
>   {
>   }
>   
> -int kvm_arch_insert_sw_breakpoint(CPUState *cpu, struct kvm_sw_breakpoint *bp)
> -{
> -    return -EINVAL;
> -}
> -
> -int kvm_arch_remove_sw_breakpoint(CPUState *cpu, struct kvm_sw_breakpoint *bp)
> -{
> -    return -EINVAL;
> -}
> -
> -int kvm_arch_insert_hw_breakpoint(target_ulong addr, target_ulong len, int type)
> -{
> -    return -EINVAL;
> -}
> -
> -int kvm_arch_remove_hw_breakpoint(target_ulong addr, target_ulong len, int type)
> -{
> -    return -EINVAL;
> -}
> -
> -void kvm_arch_remove_all_hw_breakpoints(void)
> -{
> -}
> -
> -void kvm_arch_update_guest_debug(CPUState *cpu, struct kvm_guest_debug *dbg)
> -{
> -}
> -
>   struct kvm_get_htab_buf {
>       struct kvm_get_htab_header header;
>       /*
> diff --git a/target-ppc/kvm_ppc.h b/target-ppc/kvm_ppc.h
> index 412cc7f..89244e5 100644
> --- a/target-ppc/kvm_ppc.h
> +++ b/target-ppc/kvm_ppc.h
> @@ -30,6 +30,7 @@ int kvmppc_clear_tsr_bits(PowerPCCPU *cpu, uint32_t tsr_bits);
>   int kvmppc_or_tsr_bits(PowerPCCPU *cpu, uint32_t tsr_bits);
>   int kvmppc_set_tcr(PowerPCCPU *cpu);
>   int kvmppc_booke_watchdog_enable(PowerPCCPU *cpu);
> +void kvmppc_e500_hw_breakpoint_init(void);
>   #ifndef CONFIG_USER_ONLY
>   off_t kvmppc_alloc_rma(const char *name, MemoryRegion *sysmem);
>   bool kvmppc_spapr_use_multitce(void);

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [Qemu-devel] [PATCH 3/3] ppc debug: Add debug stub support
  2014-06-11 13:04   ` [Qemu-devel] [PATCH 3/3] ppc debug: Add debug stub support Alexander Graf
@ 2014-06-12  7:05     ` Bharat.Bhushan
  2014-06-13 11:24       ` Alexander Graf
  0 siblings, 1 reply; 6+ messages in thread
From: Bharat.Bhushan @ 2014-06-12  7:05 UTC (permalink / raw)
  To: Alexander Graf; +Cc: qemu-ppc@nongnu.org, qemu-devel@nongnu.org



> -----Original Message-----
> From: Alexander Graf [mailto:agraf@suse.de]
> Sent: Wednesday, June 11, 2014 6:35 PM
> To: Bhushan Bharat-R65777
> Cc: qemu-ppc@nongnu.org; qemu-devel@nongnu.org
> Subject: Re: [PATCH 3/3] ppc debug: Add debug stub support
> 
> On 06/10/2014 05:06 PM, Bharat Bhushan wrote:
> > This patch adds software breakpoint, hardware breakpoint and hardware
> > watchpoint support for ppc. If the debug interrupt is not handled then
> > this is injected to guest.
> >
> > Signed-off-by: Bharat Bhushan <Bharat.Bhushan@freescale.com>
> > ---
> >   hw/ppc/e500.c        |   1 +
> >   target-ppc/kvm.c     | 304 ++++++++++++++++++++++++++++++++++++++++++++++---
> --
> >   target-ppc/kvm_ppc.h |   1 +
> >   3 files changed, 278 insertions(+), 28 deletions(-)
> >
> > diff --git a/hw/ppc/e500.c b/hw/ppc/e500.c index a973c18..514c595
> > 100644
> > --- a/hw/ppc/e500.c
> > +++ b/hw/ppc/e500.c
> > @@ -853,6 +853,7 @@ void ppce500_init(MachineState *machine, PPCE500Params
> *params)
> >       if (kvm_enabled()) {
> >           kvmppc_init();
> >       }
> > +    kvmppc_e500_hw_breakpoint_init();
> >   }
> >
> >   static int e500_ccsr_initfn(SysBusDevice *dev) diff --git
> > a/target-ppc/kvm.c b/target-ppc/kvm.c index 1d2384d..f5fbec6 100644
> > --- a/target-ppc/kvm.c
> > +++ b/target-ppc/kvm.c
> > @@ -38,6 +38,7 @@
> >   #include "hw/ppc/ppc.h"
> >   #include "sysemu/watchdog.h"
> >   #include "trace.h"
> > +#include "exec/gdbstub.h"
> >
> >   //#define DEBUG_KVM
> >
> > @@ -768,6 +769,38 @@ static int kvm_put_vpa(CPUState *cs)
> >
> >   static int kvmppc_inject_debug_exception(CPUState *cs)
> >   {
> > +    PowerPCCPU *cpu = POWERPC_CPU(cs);
> > +    CPUPPCState *env = &cpu->env;
> > +    struct kvm_sregs sregs;
> > +    int ret;
> > +
> > +    if (!cap_booke_sregs) {
> > +        return -1;
> > +    }
> > +
> > +    ret = kvm_vcpu_ioctl(cs, KVM_GET_SREGS, &sregs);
> > +    if (ret < 0) {
> > +        return -1;
> > +    }
> > +
> 
> I don't think any of this code should ever run for non-e500, no?

You mean the code below in this function?

> 
> > +    if (sregs.u.e.features & KVM_SREGS_E_ED) {
> 
> Hrm - we never seem to set E_ED in kvm?

Uhh, you are right. Going through the whole discussion about interrupt injection to guest I found that one patch missed for upstream.
Will send that patch  

> 
> > +        sregs.u.e.dsrr0 = env->nip;
> > +        sregs.u.e.dsrr1 = env->msr;
> > +    } else {
> > +        sregs.u.e.csrr0 = env->nip;
> > +        sregs.u.e.csrr1 = env->msr;
> > +    }
> > +
> > +    sregs.u.e.update_special = KVM_SREGS_E_UPDATE_DBSR;
> > +    sregs.u.e.dbsr = env->spr[SPR_BOOKE_DBSR];
> > +
> > +    ret = kvm_vcpu_ioctl(cs, KVM_SET_SREGS, &sregs);
> > +    if (ret < 0) {
> > +        return -1;
> > +    }
> > +
> > +    env->pending_interrupts &= ~(1 << PPC_INTERRUPT_DEBUG);
> > +
> >       return 0;
> >   }
> >
> > @@ -1275,6 +1308,239 @@ static int kvmppc_handle_dcr_write(CPUPPCState *env,
> uint32_t dcrn, uint32_t dat
> >       return 0;
> >   }
> >
> > +int kvm_arch_insert_sw_breakpoint(CPUState *cs, struct
> > +kvm_sw_breakpoint *bp) {
> > +    uint32_t sc = tswap32(debug_inst_opcode);
> 
> Heh - this will become a lot of fun for real LE host as well as guest systems.

I am trying to understand the problem here, We want to byteswap opcode only if it is mixed endian (host and guest are of different endianess) case?

> For now just remove the tswap and add a comment that this needs fixing for LE.
> 
> > +
> > +    if (cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&bp->saved_insn, 4, 0) ||
> > +        cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&sc, 4, 1)) {
> > +        return -EINVAL;
> > +    }
> > +
> > +    return 0;
> > +}
> > +
> > +int kvm_arch_remove_sw_breakpoint(CPUState *cs, struct
> > +kvm_sw_breakpoint *bp) {
> > +    uint32_t sc;
> > +
> > +    if (cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&sc, 4, 0) ||
> > +        sc != tswap32(debug_inst_opcode) ||
> 
> Same here.
> 
> In fact, neither of the 2 operations are in a fast path. Can't we just fetch the
> debug inst opcode on demand in a function here?

Ok will do that.

> That will allow for easier byte
> swapping depending on the guest's MSR.LE setting later as well.
> 
> > +        cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&bp->saved_insn, 4, 1)) {
> > +        return -EINVAL;
> > +    }
> > +
> > +    return 0;
> > +}
> > +
> > +static struct HWBreakpoint {
> > +    target_ulong addr;
> > +    int type;
> > +} hw_breakpoint[6];
> > +
> > +static int nb_hw_breakpoint;
> > +static int nb_hw_watchpoint;
> > +static int max_hw_breakpoint = 4;
> > +static int max_hw_watchpoint = 2;
> > +
> > +void kvmppc_e500_hw_breakpoint_init(void)
> > +{
> > +    max_hw_breakpoint = 2;
> > +    max_hw_watchpoint = 2;
> 
> Can we somehow get this information from kvm and set it in kvm_arch_init?

Will add one_reg to get this information.

> Worst
> case we'll have to look at the cpu class and derive it from there, but it really
> should live solely inside the kvm file.
> 
> > +}
> > +
> > +static int find_hw_breakpoint(target_ulong addr, int type) {
> > +    int n;
> > +
> > +    for (n = 0; n < nb_hw_breakpoint + nb_hw_watchpoint; n++) {
> > +        if (hw_breakpoint[n].addr == addr && hw_breakpoint[n].type == type) {
> > +            return n;
> > +        }
> > +    }
> > +
> > +    return -1;
> > +}
> > +
> > +static int find_hw_watchpoint(target_ulong addr, int *flag) {
> > +    int n;
> > +
> > +    n = find_hw_breakpoint(addr, GDB_WATCHPOINT_ACCESS);
> > +    if (n >= 0) {
> > +        *flag = BP_MEM_ACCESS;
> > +        return n;
> > +    }
> > +
> > +    n = find_hw_breakpoint(addr, GDB_WATCHPOINT_WRITE);
> > +    if (n >= 0) {
> > +        *flag = BP_MEM_WRITE;
> > +        return n;
> > +    }
> > +
> > +    n = find_hw_breakpoint(addr, GDB_WATCHPOINT_READ);
> > +    if (n >= 0) {
> > +        *flag = BP_MEM_READ;
> > +        return n;
> > +    }
> > +
> > +    return -1;
> > +}
> > +
> > +int kvm_arch_insert_hw_breakpoint(target_ulong addr,
> > +                                  target_ulong len, int type) {
> > +    hw_breakpoint[nb_hw_breakpoint + nb_hw_watchpoint].addr = addr;
> > +    hw_breakpoint[nb_hw_breakpoint + nb_hw_watchpoint].type = type;
> > +
> > +    switch (type) {
> > +    case GDB_BREAKPOINT_HW:
> > +        if (nb_hw_breakpoint >= max_hw_breakpoint) {
> > +            return -ENOBUFS;
> > +        }
> > +
> > +        if (find_hw_breakpoint(addr, type) >= 0) {
> > +            return -EEXIST;
> > +        }
> > +
> > +        nb_hw_breakpoint++;
> > +        break;
> > +
> > +    case GDB_WATCHPOINT_WRITE:
> > +    case GDB_WATCHPOINT_READ:
> > +    case GDB_WATCHPOINT_ACCESS:
> > +        if (nb_hw_watchpoint >= max_hw_watchpoint) {
> > +            return -ENOBUFS;
> > +        }
> > +
> > +        if (find_hw_breakpoint(addr, type) >= 0) {
> > +            return -EEXIST;
> > +        }
> > +
> > +        nb_hw_watchpoint++;
> > +        break;
> > +
> > +    default:
> > +        return -ENOSYS;
> > +    }
> > +
> > +    return 0;
> > +}
> > +
> > +int kvm_arch_remove_hw_breakpoint(target_ulong addr,
> > +                                  target_ulong len, int type) {
> > +    int n;
> > +
> > +    n = find_hw_breakpoint(addr, type);
> > +    if (n < 0) {
> > +        return -ENOENT;
> > +    }
> > +
> > +    switch (type) {
> > +    case GDB_BREAKPOINT_HW:
> > +        nb_hw_breakpoint--;
> > +        break;
> > +
> > +    case GDB_WATCHPOINT_WRITE:
> > +    case GDB_WATCHPOINT_READ:
> > +    case GDB_WATCHPOINT_ACCESS:
> > +        nb_hw_watchpoint--;
> > +        break;
> > +
> > +    default:
> > +        return -ENOSYS;
> > +    }
> > +    hw_breakpoint[n] = hw_breakpoint[nb_hw_breakpoint +
> > + nb_hw_watchpoint];
> > +
> > +    return 0;
> > +}
> > +
> > +void kvm_arch_remove_all_hw_breakpoints(void)
> > +{
> > +    nb_hw_breakpoint = nb_hw_watchpoint = 0; }
> > +
> > +static CPUWatchpoint hw_watchpoint;
> > +
> > +
> > +static int kvm_handle_debug(PowerPCCPU *cpu, struct kvm_run *run) {
> > +    CPUState *cs = CPU(cpu);
> > +    CPUPPCState *env = &cpu->env;
> > +    int handle = 0;
> > +    int n;
> > +    int flag = 0;
> > +    struct kvm_debug_exit_arch *arch_info = &run->debug.arch;
> > +
> > +    if (cs->singlestep_enabled) {
> > +        handle = 1;
> > +    } else if (arch_info->status) {
> > +        if (arch_info->status & KVMPPC_DEBUG_BREAKPOINT) {
> > +            n = find_hw_breakpoint(arch_info->address, GDB_BREAKPOINT_HW);
> > +            if (n >= 0) {
> > +                handle = 1;
> > +            }
> > +        } else if (arch_info->status & (KVMPPC_DEBUG_WATCH_READ |
> > +                                        KVMPPC_DEBUG_WATCH_WRITE)) {
> > +            n = find_hw_watchpoint(arch_info->address,  &flag);
> > +            if (n >= 0) {
> > +                handle = 1;
> > +                cs->watchpoint_hit = &hw_watchpoint;
> > +                hw_watchpoint.vaddr = hw_breakpoint[n].addr;
> > +                hw_watchpoint.flags = flag;
> > +            }
> > +        }
> > +    } else if (kvm_find_sw_breakpoint(cs, arch_info->address)) {
> > +        handle = 1;
> > +    }
> > +
> > +    cpu_synchronize_state(cs);
> > +    if (handle) {
> > +        env->spr[SPR_BOOKE_DBSR] = 0;
> 
> This is pretty e500 specific.

You mean accessing DBSR, right ?
To handle core specific stuff, should we add some generic function like kvm_ppc_set/clear_debug_event() in hw/ppc/e500_debug.c, hw/ppc/ppc4xx_debug.c etc ?

Thanks
-Bharat
> 
> 
> Alex
> 
> > +    } else {
> > +       printf("unhandled\n");
> > +       /* inject guest debug exception */
> > +       env->pending_interrupts |=  1 << PPC_INTERRUPT_DEBUG;
> > +     }
> > +
> > +    return handle;
> > +}
> > +
> > +void kvm_arch_update_guest_debug(CPUState *cs, struct kvm_guest_debug
> > +*dbg) {
> > +    if (kvm_sw_breakpoints_active(cs)) {
> > +        dbg->control |= KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP;
> > +    }
> > +
> > +    if (nb_hw_breakpoint + nb_hw_watchpoint > 0) {
> > +        int n;
> > +
> > +        dbg->control |= KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_HW_BP;
> > +        memset(dbg->arch.bp, 0, sizeof(dbg->arch.bp));
> > +        for (n = 0; n < nb_hw_breakpoint + nb_hw_watchpoint; n++) {
> > +            switch (hw_breakpoint[n].type) {
> > +            case GDB_BREAKPOINT_HW:
> > +                dbg->arch.bp[n].type = KVMPPC_DEBUG_BREAKPOINT;
> > +                break;
> > +            case GDB_WATCHPOINT_WRITE:
> > +                dbg->arch.bp[n].type = KVMPPC_DEBUG_WATCH_WRITE;
> > +                break;
> > +            case GDB_WATCHPOINT_READ:
> > +                dbg->arch.bp[n].type = KVMPPC_DEBUG_WATCH_READ;
> > +                break;
> > +            case GDB_WATCHPOINT_ACCESS:
> > +                dbg->arch.bp[n].type = KVMPPC_DEBUG_WATCH_WRITE |
> > +                                        KVMPPC_DEBUG_WATCH_READ;
> > +                break;
> > +            default:
> > +                cpu_abort(cs, "Unsupported breakpoint type\n");
> > +            }
> > +            dbg->arch.bp[n].addr = hw_breakpoint[n].addr;
> > +        }
> > +    }
> > +}
> > +
> >   int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run)
> >   {
> >       PowerPCCPU *cpu = POWERPC_CPU(cs); @@ -1315,6 +1581,16 @@ int
> > kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run)
> >           ret = 0;
> >           break;
> >
> > +    case KVM_EXIT_DEBUG:
> > +        DPRINTF("handle debug exception\n");
> > +        if (kvm_handle_debug(cpu, run)) {
> > +            ret = EXCP_DEBUG;
> > +            break;
> > +        }
> > +        /* re-enter, this exception was guest-internal */
> > +        ret = 0;
> > +        break;
> > +
> >       default:
> >           fprintf(stderr, "KVM: unknown exit reason %d\n", run->exit_reason);
> >           ret = -1;
> > @@ -2002,34 +2278,6 @@ void kvm_arch_init_irq_routing(KVMState *s)
> >   {
> >   }
> >
> > -int kvm_arch_insert_sw_breakpoint(CPUState *cpu, struct
> > kvm_sw_breakpoint *bp) -{
> > -    return -EINVAL;
> > -}
> > -
> > -int kvm_arch_remove_sw_breakpoint(CPUState *cpu, struct
> > kvm_sw_breakpoint *bp) -{
> > -    return -EINVAL;
> > -}
> > -
> > -int kvm_arch_insert_hw_breakpoint(target_ulong addr, target_ulong
> > len, int type) -{
> > -    return -EINVAL;
> > -}
> > -
> > -int kvm_arch_remove_hw_breakpoint(target_ulong addr, target_ulong
> > len, int type) -{
> > -    return -EINVAL;
> > -}
> > -
> > -void kvm_arch_remove_all_hw_breakpoints(void)
> > -{
> > -}
> > -
> > -void kvm_arch_update_guest_debug(CPUState *cpu, struct
> > kvm_guest_debug *dbg) -{ -}
> > -
> >   struct kvm_get_htab_buf {
> >       struct kvm_get_htab_header header;
> >       /*
> > diff --git a/target-ppc/kvm_ppc.h b/target-ppc/kvm_ppc.h index
> > 412cc7f..89244e5 100644
> > --- a/target-ppc/kvm_ppc.h
> > +++ b/target-ppc/kvm_ppc.h
> > @@ -30,6 +30,7 @@ int kvmppc_clear_tsr_bits(PowerPCCPU *cpu, uint32_t
> tsr_bits);
> >   int kvmppc_or_tsr_bits(PowerPCCPU *cpu, uint32_t tsr_bits);
> >   int kvmppc_set_tcr(PowerPCCPU *cpu);
> >   int kvmppc_booke_watchdog_enable(PowerPCCPU *cpu);
> > +void kvmppc_e500_hw_breakpoint_init(void);
> >   #ifndef CONFIG_USER_ONLY
> >   off_t kvmppc_alloc_rma(const char *name, MemoryRegion *sysmem);
> >   bool kvmppc_spapr_use_multitce(void);

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [Qemu-devel] [PATCH 3/3] ppc debug: Add debug stub support
  2014-06-12  7:05     ` Bharat.Bhushan
@ 2014-06-13 11:24       ` Alexander Graf
  2014-06-16  4:27         ` Bharat.Bhushan
  0 siblings, 1 reply; 6+ messages in thread
From: Alexander Graf @ 2014-06-13 11:24 UTC (permalink / raw)
  To: Bharat.Bhushan@freescale.com; +Cc: qemu-ppc@nongnu.org, qemu-devel@nongnu.org


On 12.06.14 09:05, Bharat.Bhushan@freescale.com wrote:
>
>> -----Original Message-----
>> From: Alexander Graf [mailto:agraf@suse.de]
>> Sent: Wednesday, June 11, 2014 6:35 PM
>> To: Bhushan Bharat-R65777
>> Cc: qemu-ppc@nongnu.org; qemu-devel@nongnu.org
>> Subject: Re: [PATCH 3/3] ppc debug: Add debug stub support
>>
>> On 06/10/2014 05:06 PM, Bharat Bhushan wrote:
>>> This patch adds software breakpoint, hardware breakpoint and hardware
>>> watchpoint support for ppc. If the debug interrupt is not handled then
>>> this is injected to guest.
>>>
>>> Signed-off-by: Bharat Bhushan <Bharat.Bhushan@freescale.com>
>>> ---
>>>    hw/ppc/e500.c        |   1 +
>>>    target-ppc/kvm.c     | 304 ++++++++++++++++++++++++++++++++++++++++++++++---
>> --
>>>    target-ppc/kvm_ppc.h |   1 +
>>>    3 files changed, 278 insertions(+), 28 deletions(-)
>>>
>>> diff --git a/hw/ppc/e500.c b/hw/ppc/e500.c index a973c18..514c595
>>> 100644
>>> --- a/hw/ppc/e500.c
>>> +++ b/hw/ppc/e500.c
>>> @@ -853,6 +853,7 @@ void ppce500_init(MachineState *machine, PPCE500Params
>> *params)
>>>        if (kvm_enabled()) {
>>>            kvmppc_init();
>>>        }
>>> +    kvmppc_e500_hw_breakpoint_init();
>>>    }
>>>
>>>    static int e500_ccsr_initfn(SysBusDevice *dev) diff --git
>>> a/target-ppc/kvm.c b/target-ppc/kvm.c index 1d2384d..f5fbec6 100644
>>> --- a/target-ppc/kvm.c
>>> +++ b/target-ppc/kvm.c
>>> @@ -38,6 +38,7 @@
>>>    #include "hw/ppc/ppc.h"
>>>    #include "sysemu/watchdog.h"
>>>    #include "trace.h"
>>> +#include "exec/gdbstub.h"
>>>
>>>    //#define DEBUG_KVM
>>>
>>> @@ -768,6 +769,38 @@ static int kvm_put_vpa(CPUState *cs)
>>>
>>>    static int kvmppc_inject_debug_exception(CPUState *cs)
>>>    {
>>> +    PowerPCCPU *cpu = POWERPC_CPU(cs);
>>> +    CPUPPCState *env = &cpu->env;
>>> +    struct kvm_sregs sregs;
>>> +    int ret;
>>> +
>>> +    if (!cap_booke_sregs) {
>>> +        return -1;
>>> +    }
>>> +
>>> +    ret = kvm_vcpu_ioctl(cs, KVM_GET_SREGS, &sregs);
>>> +    if (ret < 0) {
>>> +        return -1;
>>> +    }
>>> +
>> I don't think any of this code should ever run for non-e500, no?
> You mean the code below in this function?

Yeah :).

>
>>> +    if (sregs.u.e.features & KVM_SREGS_E_ED) {
>> Hrm - we never seem to set E_ED in kvm?
> Uhh, you are right. Going through the whole discussion about interrupt injection to guest I found that one patch missed for upstream.
> Will send that patch
>
>>> +        sregs.u.e.dsrr0 = env->nip;
>>> +        sregs.u.e.dsrr1 = env->msr;
>>> +    } else {
>>> +        sregs.u.e.csrr0 = env->nip;
>>> +        sregs.u.e.csrr1 = env->msr;
>>> +    }
>>> +
>>> +    sregs.u.e.update_special = KVM_SREGS_E_UPDATE_DBSR;
>>> +    sregs.u.e.dbsr = env->spr[SPR_BOOKE_DBSR];
>>> +
>>> +    ret = kvm_vcpu_ioctl(cs, KVM_SET_SREGS, &sregs);
>>> +    if (ret < 0) {
>>> +        return -1;
>>> +    }
>>> +
>>> +    env->pending_interrupts &= ~(1 << PPC_INTERRUPT_DEBUG);
>>> +
>>>        return 0;
>>>    }
>>>
>>> @@ -1275,6 +1308,239 @@ static int kvmppc_handle_dcr_write(CPUPPCState *env,
>> uint32_t dcrn, uint32_t dat
>>>        return 0;
>>>    }
>>>
>>> +int kvm_arch_insert_sw_breakpoint(CPUState *cs, struct
>>> +kvm_sw_breakpoint *bp) {
>>> +    uint32_t sc = tswap32(debug_inst_opcode);
>> Heh - this will become a lot of fun for real LE host as well as guest systems.
> I am trying to understand the problem here, We want to byteswap opcode only if it is mixed endian (host and guest are of different endianess) case?

Yes :).

>
>> For now just remove the tswap and add a comment that this needs fixing for LE.
>>
>>> +
>>> +    if (cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&bp->saved_insn, 4, 0) ||
>>> +        cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&sc, 4, 1)) {
>>> +        return -EINVAL;
>>> +    }
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +int kvm_arch_remove_sw_breakpoint(CPUState *cs, struct
>>> +kvm_sw_breakpoint *bp) {
>>> +    uint32_t sc;
>>> +
>>> +    if (cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&sc, 4, 0) ||
>>> +        sc != tswap32(debug_inst_opcode) ||
>> Same here.
>>
>> In fact, neither of the 2 operations are in a fast path. Can't we just fetch the
>> debug inst opcode on demand in a function here?
> Ok will do that.
>
>> That will allow for easier byte
>> swapping depending on the guest's MSR.LE setting later as well.
>>
>>> +        cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&bp->saved_insn, 4, 1)) {
>>> +        return -EINVAL;
>>> +    }
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static struct HWBreakpoint {
>>> +    target_ulong addr;
>>> +    int type;
>>> +} hw_breakpoint[6];
>>> +
>>> +static int nb_hw_breakpoint;
>>> +static int nb_hw_watchpoint;
>>> +static int max_hw_breakpoint = 4;
>>> +static int max_hw_watchpoint = 2;
>>> +
>>> +void kvmppc_e500_hw_breakpoint_init(void)
>>> +{
>>> +    max_hw_breakpoint = 2;
>>> +    max_hw_watchpoint = 2;
>> Can we somehow get this information from kvm and set it in kvm_arch_init?
> Will add one_reg to get this information.

We can also fall back to always make this 2 when there's no other way to 
enumerate. But setting the default to 4/2 and then revert to 2/2 hard 
codedly seems odd.

Btw, where does the 4/2 come from?

>
>> Worst
>> case we'll have to look at the cpu class and derive it from there, but it really
>> should live solely inside the kvm file.
>>
>>> +}
>>> +
>>> +static int find_hw_breakpoint(target_ulong addr, int type) {
>>> +    int n;
>>> +
>>> +    for (n = 0; n < nb_hw_breakpoint + nb_hw_watchpoint; n++) {
>>> +        if (hw_breakpoint[n].addr == addr && hw_breakpoint[n].type == type) {
>>> +            return n;
>>> +        }
>>> +    }
>>> +
>>> +    return -1;
>>> +}
>>> +
>>> +static int find_hw_watchpoint(target_ulong addr, int *flag) {
>>> +    int n;
>>> +
>>> +    n = find_hw_breakpoint(addr, GDB_WATCHPOINT_ACCESS);
>>> +    if (n >= 0) {
>>> +        *flag = BP_MEM_ACCESS;
>>> +        return n;
>>> +    }
>>> +
>>> +    n = find_hw_breakpoint(addr, GDB_WATCHPOINT_WRITE);
>>> +    if (n >= 0) {
>>> +        *flag = BP_MEM_WRITE;
>>> +        return n;
>>> +    }
>>> +
>>> +    n = find_hw_breakpoint(addr, GDB_WATCHPOINT_READ);
>>> +    if (n >= 0) {
>>> +        *flag = BP_MEM_READ;
>>> +        return n;
>>> +    }
>>> +
>>> +    return -1;
>>> +}
>>> +
>>> +int kvm_arch_insert_hw_breakpoint(target_ulong addr,
>>> +                                  target_ulong len, int type) {
>>> +    hw_breakpoint[nb_hw_breakpoint + nb_hw_watchpoint].addr = addr;
>>> +    hw_breakpoint[nb_hw_breakpoint + nb_hw_watchpoint].type = type;
>>> +
>>> +    switch (type) {
>>> +    case GDB_BREAKPOINT_HW:
>>> +        if (nb_hw_breakpoint >= max_hw_breakpoint) {
>>> +            return -ENOBUFS;
>>> +        }
>>> +
>>> +        if (find_hw_breakpoint(addr, type) >= 0) {
>>> +            return -EEXIST;
>>> +        }
>>> +
>>> +        nb_hw_breakpoint++;
>>> +        break;
>>> +
>>> +    case GDB_WATCHPOINT_WRITE:
>>> +    case GDB_WATCHPOINT_READ:
>>> +    case GDB_WATCHPOINT_ACCESS:
>>> +        if (nb_hw_watchpoint >= max_hw_watchpoint) {
>>> +            return -ENOBUFS;
>>> +        }
>>> +
>>> +        if (find_hw_breakpoint(addr, type) >= 0) {
>>> +            return -EEXIST;
>>> +        }
>>> +
>>> +        nb_hw_watchpoint++;
>>> +        break;
>>> +
>>> +    default:
>>> +        return -ENOSYS;
>>> +    }
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +int kvm_arch_remove_hw_breakpoint(target_ulong addr,
>>> +                                  target_ulong len, int type) {
>>> +    int n;
>>> +
>>> +    n = find_hw_breakpoint(addr, type);
>>> +    if (n < 0) {
>>> +        return -ENOENT;
>>> +    }
>>> +
>>> +    switch (type) {
>>> +    case GDB_BREAKPOINT_HW:
>>> +        nb_hw_breakpoint--;
>>> +        break;
>>> +
>>> +    case GDB_WATCHPOINT_WRITE:
>>> +    case GDB_WATCHPOINT_READ:
>>> +    case GDB_WATCHPOINT_ACCESS:
>>> +        nb_hw_watchpoint--;
>>> +        break;
>>> +
>>> +    default:
>>> +        return -ENOSYS;
>>> +    }
>>> +    hw_breakpoint[n] = hw_breakpoint[nb_hw_breakpoint +
>>> + nb_hw_watchpoint];
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +void kvm_arch_remove_all_hw_breakpoints(void)
>>> +{
>>> +    nb_hw_breakpoint = nb_hw_watchpoint = 0; }
>>> +
>>> +static CPUWatchpoint hw_watchpoint;
>>> +
>>> +
>>> +static int kvm_handle_debug(PowerPCCPU *cpu, struct kvm_run *run) {
>>> +    CPUState *cs = CPU(cpu);
>>> +    CPUPPCState *env = &cpu->env;
>>> +    int handle = 0;
>>> +    int n;
>>> +    int flag = 0;
>>> +    struct kvm_debug_exit_arch *arch_info = &run->debug.arch;
>>> +
>>> +    if (cs->singlestep_enabled) {
>>> +        handle = 1;
>>> +    } else if (arch_info->status) {
>>> +        if (arch_info->status & KVMPPC_DEBUG_BREAKPOINT) {
>>> +            n = find_hw_breakpoint(arch_info->address, GDB_BREAKPOINT_HW);
>>> +            if (n >= 0) {
>>> +                handle = 1;
>>> +            }
>>> +        } else if (arch_info->status & (KVMPPC_DEBUG_WATCH_READ |
>>> +                                        KVMPPC_DEBUG_WATCH_WRITE)) {
>>> +            n = find_hw_watchpoint(arch_info->address,  &flag);
>>> +            if (n >= 0) {
>>> +                handle = 1;
>>> +                cs->watchpoint_hit = &hw_watchpoint;
>>> +                hw_watchpoint.vaddr = hw_breakpoint[n].addr;
>>> +                hw_watchpoint.flags = flag;
>>> +            }
>>> +        }
>>> +    } else if (kvm_find_sw_breakpoint(cs, arch_info->address)) {
>>> +        handle = 1;
>>> +    }
>>> +
>>> +    cpu_synchronize_state(cs);
>>> +    if (handle) {
>>> +        env->spr[SPR_BOOKE_DBSR] = 0;
>> This is pretty e500 specific.
> You mean accessing DBSR, right ?
> To handle core specific stuff, should we add some generic function like kvm_ppc_set/clear_debug_event() in hw/ppc/e500_debug.c, hw/ppc/ppc4xx_debug.c etc ?

I don't think this is hardware, it's part of the core. So it'd belong to 
target-ppc/. Probably part of the excp helper file.


Alex

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [Qemu-devel] [PATCH 3/3] ppc debug: Add debug stub support
  2014-06-13 11:24       ` Alexander Graf
@ 2014-06-16  4:27         ` Bharat.Bhushan
  2014-06-16  9:04           ` Alexander Graf
  0 siblings, 1 reply; 6+ messages in thread
From: Bharat.Bhushan @ 2014-06-16  4:27 UTC (permalink / raw)
  To: Alexander Graf; +Cc: qemu-ppc@nongnu.org, qemu-devel@nongnu.org



> -----Original Message-----
> From: Alexander Graf [mailto:agraf@suse.de]
> Sent: Friday, June 13, 2014 4:55 PM
> To: Bhushan Bharat-R65777
> Cc: qemu-ppc@nongnu.org; qemu-devel@nongnu.org
> Subject: Re: [PATCH 3/3] ppc debug: Add debug stub support
> 
> 
> On 12.06.14 09:05, Bharat.Bhushan@freescale.com wrote:
> >
> >> -----Original Message-----
> >> From: Alexander Graf [mailto:agraf@suse.de]
> >> Sent: Wednesday, June 11, 2014 6:35 PM
> >> To: Bhushan Bharat-R65777
> >> Cc: qemu-ppc@nongnu.org; qemu-devel@nongnu.org
> >> Subject: Re: [PATCH 3/3] ppc debug: Add debug stub support
> >>
> >> On 06/10/2014 05:06 PM, Bharat Bhushan wrote:
> >>> This patch adds software breakpoint, hardware breakpoint and
> >>> hardware watchpoint support for ppc. If the debug interrupt is not
> >>> handled then this is injected to guest.
> >>>
> >>> Signed-off-by: Bharat Bhushan <Bharat.Bhushan@freescale.com>
> >>> ---
> >>>    hw/ppc/e500.c        |   1 +
> >>>    target-ppc/kvm.c     | 304
> ++++++++++++++++++++++++++++++++++++++++++++++---
> >> --
> >>>    target-ppc/kvm_ppc.h |   1 +
> >>>    3 files changed, 278 insertions(+), 28 deletions(-)
> >>>
> >>> diff --git a/hw/ppc/e500.c b/hw/ppc/e500.c index a973c18..514c595
> >>> 100644
> >>> --- a/hw/ppc/e500.c
> >>> +++ b/hw/ppc/e500.c
> >>> @@ -853,6 +853,7 @@ void ppce500_init(MachineState *machine,
> >>> PPCE500Params
> >> *params)
> >>>        if (kvm_enabled()) {
> >>>            kvmppc_init();
> >>>        }
> >>> +    kvmppc_e500_hw_breakpoint_init();
> >>>    }
> >>>
> >>>    static int e500_ccsr_initfn(SysBusDevice *dev) diff --git
> >>> a/target-ppc/kvm.c b/target-ppc/kvm.c index 1d2384d..f5fbec6 100644
> >>> --- a/target-ppc/kvm.c
> >>> +++ b/target-ppc/kvm.c
> >>> @@ -38,6 +38,7 @@
> >>>    #include "hw/ppc/ppc.h"
> >>>    #include "sysemu/watchdog.h"
> >>>    #include "trace.h"
> >>> +#include "exec/gdbstub.h"
> >>>
> >>>    //#define DEBUG_KVM
> >>>
> >>> @@ -768,6 +769,38 @@ static int kvm_put_vpa(CPUState *cs)
> >>>
> >>>    static int kvmppc_inject_debug_exception(CPUState *cs)
> >>>    {
> >>> +    PowerPCCPU *cpu = POWERPC_CPU(cs);
> >>> +    CPUPPCState *env = &cpu->env;
> >>> +    struct kvm_sregs sregs;
> >>> +    int ret;
> >>> +
> >>> +    if (!cap_booke_sregs) {
> >>> +        return -1;
> >>> +    }
> >>> +
> >>> +    ret = kvm_vcpu_ioctl(cs, KVM_GET_SREGS, &sregs);
> >>> +    if (ret < 0) {
> >>> +        return -1;
> >>> +    }
> >>> +
> >> I don't think any of this code should ever run for non-e500, no?
> > You mean the code below in this function?
> 
> Yeah :).

Why you think accessing sregs (cssr0/1, dsrr0/1 and ioctl) is e500 specific. Are not these valid for 4xx as well?

> 
> >
> >>> +    if (sregs.u.e.features & KVM_SREGS_E_ED) {
> >> Hrm - we never seem to set E_ED in kvm?
> > Uhh, you are right. Going through the whole discussion about interrupt
> injection to guest I found that one patch missed for upstream.
> > Will send that patch
> >
> >>> +        sregs.u.e.dsrr0 = env->nip;
> >>> +        sregs.u.e.dsrr1 = env->msr;
> >>> +    } else {
> >>> +        sregs.u.e.csrr0 = env->nip;
> >>> +        sregs.u.e.csrr1 = env->msr;
> >>> +    }
> >>> +
> >>> +    sregs.u.e.update_special = KVM_SREGS_E_UPDATE_DBSR;
> >>> +    sregs.u.e.dbsr = env->spr[SPR_BOOKE_DBSR];
> >>> +
> >>> +    ret = kvm_vcpu_ioctl(cs, KVM_SET_SREGS, &sregs);
> >>> +    if (ret < 0) {
> >>> +        return -1;
> >>> +    }
> >>> +
> >>> +    env->pending_interrupts &= ~(1 << PPC_INTERRUPT_DEBUG);
> >>> +
> >>>        return 0;
> >>>    }
> >>>
> >>> @@ -1275,6 +1308,239 @@ static int
> >>> kvmppc_handle_dcr_write(CPUPPCState *env,
> >> uint32_t dcrn, uint32_t dat
> >>>        return 0;
> >>>    }
> >>>
> >>> +int kvm_arch_insert_sw_breakpoint(CPUState *cs, struct
> >>> +kvm_sw_breakpoint *bp) {
> >>> +    uint32_t sc = tswap32(debug_inst_opcode);
> >> Heh - this will become a lot of fun for real LE host as well as guest
> systems.
> > I am trying to understand the problem here, We want to byteswap opcode only if
> it is mixed endian (host and guest are of different endianess) case?
> 
> Yes :).
> 
> >
> >> For now just remove the tswap and add a comment that this needs fixing for
> LE.
> >>
> >>> +
> >>> +    if (cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&bp->saved_insn, 4, 0)
> ||
> >>> +        cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&sc, 4, 1)) {
> >>> +        return -EINVAL;
> >>> +    }
> >>> +
> >>> +    return 0;
> >>> +}
> >>> +
> >>> +int kvm_arch_remove_sw_breakpoint(CPUState *cs, struct
> >>> +kvm_sw_breakpoint *bp) {
> >>> +    uint32_t sc;
> >>> +
> >>> +    if (cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&sc, 4, 0) ||
> >>> +        sc != tswap32(debug_inst_opcode) ||
> >> Same here.
> >>
> >> In fact, neither of the 2 operations are in a fast path. Can't we
> >> just fetch the debug inst opcode on demand in a function here?
> > Ok will do that.
> >
> >> That will allow for easier byte
> >> swapping depending on the guest's MSR.LE setting later as well.
> >>
> >>> +        cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&bp->saved_insn, 4, 1))
> {
> >>> +        return -EINVAL;
> >>> +    }
> >>> +
> >>> +    return 0;
> >>> +}
> >>> +
> >>> +static struct HWBreakpoint {
> >>> +    target_ulong addr;
> >>> +    int type;
> >>> +} hw_breakpoint[6];
> >>> +
> >>> +static int nb_hw_breakpoint;
> >>> +static int nb_hw_watchpoint;
> >>> +static int max_hw_breakpoint = 4;
> >>> +static int max_hw_watchpoint = 2;
> >>> +
> >>> +void kvmppc_e500_hw_breakpoint_init(void)
> >>> +{
> >>> +    max_hw_breakpoint = 2;
> >>> +    max_hw_watchpoint = 2;
> >> Can we somehow get this information from kvm and set it in kvm_arch_init?
> > Will add one_reg to get this information.
> 
> We can also fall back to always make this 2 when there's no other way to
> enumerate. But setting the default to 4/2 and then revert to 2/2 hard codedly
> seems odd.
> 
> Btw, where does the 4/2 come from?

Because 44x have 4 IACs.

> 
> >
> >> Worst
> >> case we'll have to look at the cpu class and derive it from there,
> >> but it really should live solely inside the kvm file.
> >>
> >>> +}
> >>> +
> >>> +static int find_hw_breakpoint(target_ulong addr, int type) {
> >>> +    int n;
> >>> +
> >>> +    for (n = 0; n < nb_hw_breakpoint + nb_hw_watchpoint; n++) {
> >>> +        if (hw_breakpoint[n].addr == addr && hw_breakpoint[n].type == type)
> {
> >>> +            return n;
> >>> +        }
> >>> +    }
> >>> +
> >>> +    return -1;
> >>> +}
> >>> +
> >>> +static int find_hw_watchpoint(target_ulong addr, int *flag) {
> >>> +    int n;
> >>> +
> >>> +    n = find_hw_breakpoint(addr, GDB_WATCHPOINT_ACCESS);
> >>> +    if (n >= 0) {
> >>> +        *flag = BP_MEM_ACCESS;
> >>> +        return n;
> >>> +    }
> >>> +
> >>> +    n = find_hw_breakpoint(addr, GDB_WATCHPOINT_WRITE);
> >>> +    if (n >= 0) {
> >>> +        *flag = BP_MEM_WRITE;
> >>> +        return n;
> >>> +    }
> >>> +
> >>> +    n = find_hw_breakpoint(addr, GDB_WATCHPOINT_READ);
> >>> +    if (n >= 0) {
> >>> +        *flag = BP_MEM_READ;
> >>> +        return n;
> >>> +    }
> >>> +
> >>> +    return -1;
> >>> +}
> >>> +
> >>> +int kvm_arch_insert_hw_breakpoint(target_ulong addr,
> >>> +                                  target_ulong len, int type) {
> >>> +    hw_breakpoint[nb_hw_breakpoint + nb_hw_watchpoint].addr = addr;
> >>> +    hw_breakpoint[nb_hw_breakpoint + nb_hw_watchpoint].type = type;
> >>> +
> >>> +    switch (type) {
> >>> +    case GDB_BREAKPOINT_HW:
> >>> +        if (nb_hw_breakpoint >= max_hw_breakpoint) {
> >>> +            return -ENOBUFS;
> >>> +        }
> >>> +
> >>> +        if (find_hw_breakpoint(addr, type) >= 0) {
> >>> +            return -EEXIST;
> >>> +        }
> >>> +
> >>> +        nb_hw_breakpoint++;
> >>> +        break;
> >>> +
> >>> +    case GDB_WATCHPOINT_WRITE:
> >>> +    case GDB_WATCHPOINT_READ:
> >>> +    case GDB_WATCHPOINT_ACCESS:
> >>> +        if (nb_hw_watchpoint >= max_hw_watchpoint) {
> >>> +            return -ENOBUFS;
> >>> +        }
> >>> +
> >>> +        if (find_hw_breakpoint(addr, type) >= 0) {
> >>> +            return -EEXIST;
> >>> +        }
> >>> +
> >>> +        nb_hw_watchpoint++;
> >>> +        break;
> >>> +
> >>> +    default:
> >>> +        return -ENOSYS;
> >>> +    }
> >>> +
> >>> +    return 0;
> >>> +}
> >>> +
> >>> +int kvm_arch_remove_hw_breakpoint(target_ulong addr,
> >>> +                                  target_ulong len, int type) {
> >>> +    int n;
> >>> +
> >>> +    n = find_hw_breakpoint(addr, type);
> >>> +    if (n < 0) {
> >>> +        return -ENOENT;
> >>> +    }
> >>> +
> >>> +    switch (type) {
> >>> +    case GDB_BREAKPOINT_HW:
> >>> +        nb_hw_breakpoint--;
> >>> +        break;
> >>> +
> >>> +    case GDB_WATCHPOINT_WRITE:
> >>> +    case GDB_WATCHPOINT_READ:
> >>> +    case GDB_WATCHPOINT_ACCESS:
> >>> +        nb_hw_watchpoint--;
> >>> +        break;
> >>> +
> >>> +    default:
> >>> +        return -ENOSYS;
> >>> +    }
> >>> +    hw_breakpoint[n] = hw_breakpoint[nb_hw_breakpoint +
> >>> + nb_hw_watchpoint];
> >>> +
> >>> +    return 0;
> >>> +}
> >>> +
> >>> +void kvm_arch_remove_all_hw_breakpoints(void)
> >>> +{
> >>> +    nb_hw_breakpoint = nb_hw_watchpoint = 0; }
> >>> +
> >>> +static CPUWatchpoint hw_watchpoint;
> >>> +
> >>> +
> >>> +static int kvm_handle_debug(PowerPCCPU *cpu, struct kvm_run *run) {
> >>> +    CPUState *cs = CPU(cpu);
> >>> +    CPUPPCState *env = &cpu->env;
> >>> +    int handle = 0;
> >>> +    int n;
> >>> +    int flag = 0;
> >>> +    struct kvm_debug_exit_arch *arch_info = &run->debug.arch;
> >>> +
> >>> +    if (cs->singlestep_enabled) {
> >>> +        handle = 1;
> >>> +    } else if (arch_info->status) {
> >>> +        if (arch_info->status & KVMPPC_DEBUG_BREAKPOINT) {
> >>> +            n = find_hw_breakpoint(arch_info->address, GDB_BREAKPOINT_HW);
> >>> +            if (n >= 0) {
> >>> +                handle = 1;
> >>> +            }
> >>> +        } else if (arch_info->status & (KVMPPC_DEBUG_WATCH_READ |
> >>> +                                        KVMPPC_DEBUG_WATCH_WRITE)) {
> >>> +            n = find_hw_watchpoint(arch_info->address,  &flag);
> >>> +            if (n >= 0) {
> >>> +                handle = 1;
> >>> +                cs->watchpoint_hit = &hw_watchpoint;
> >>> +                hw_watchpoint.vaddr = hw_breakpoint[n].addr;
> >>> +                hw_watchpoint.flags = flag;
> >>> +            }
> >>> +        }
> >>> +    } else if (kvm_find_sw_breakpoint(cs, arch_info->address)) {
> >>> +        handle = 1;
> >>> +    }
> >>> +
> >>> +    cpu_synchronize_state(cs);
> >>> +    if (handle) {
> >>> +        env->spr[SPR_BOOKE_DBSR] = 0;
> >> This is pretty e500 specific.
> > You mean accessing DBSR, right ?
> > To handle core specific stuff, should we add some generic function like
> kvm_ppc_set/clear_debug_event() in hw/ppc/e500_debug.c, hw/ppc/ppc4xx_debug.c
> etc ?
> 
> I don't think this is hardware, it's part of the core. So it'd belong to target-
> ppc/. Probably part of the excp helper file.

Is not this (dbsr) is booke specific and not just e500 specific? Should this be accessed under POWERPC_MMU_BOOKE and POWERPC_MMU_BOOKE206 cpu models?

Thanks
-Bharat

> 
> 
> Alex

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [Qemu-devel] [PATCH 3/3] ppc debug: Add debug stub support
  2014-06-16  4:27         ` Bharat.Bhushan
@ 2014-06-16  9:04           ` Alexander Graf
  0 siblings, 0 replies; 6+ messages in thread
From: Alexander Graf @ 2014-06-16  9:04 UTC (permalink / raw)
  To: Bharat.Bhushan@freescale.com; +Cc: qemu-ppc@nongnu.org, qemu-devel@nongnu.org


On 16.06.14 06:27, Bharat.Bhushan@freescale.com wrote:
>
>> -----Original Message-----
>> From: Alexander Graf [mailto:agraf@suse.de]
>> Sent: Friday, June 13, 2014 4:55 PM
>> To: Bhushan Bharat-R65777
>> Cc: qemu-ppc@nongnu.org; qemu-devel@nongnu.org
>> Subject: Re: [PATCH 3/3] ppc debug: Add debug stub support
>>
>>
>> On 12.06.14 09:05, Bharat.Bhushan@freescale.com wrote:
>>>> -----Original Message-----
>>>> From: Alexander Graf [mailto:agraf@suse.de]
>>>> Sent: Wednesday, June 11, 2014 6:35 PM
>>>> To: Bhushan Bharat-R65777
>>>> Cc: qemu-ppc@nongnu.org; qemu-devel@nongnu.org
>>>> Subject: Re: [PATCH 3/3] ppc debug: Add debug stub support
>>>>
>>>> On 06/10/2014 05:06 PM, Bharat Bhushan wrote:
>>>>> This patch adds software breakpoint, hardware breakpoint and
>>>>> hardware watchpoint support for ppc. If the debug interrupt is not
>>>>> handled then this is injected to guest.
>>>>>
>>>>> Signed-off-by: Bharat Bhushan <Bharat.Bhushan@freescale.com>
>>>>> ---
>>>>>     hw/ppc/e500.c        |   1 +
>>>>>     target-ppc/kvm.c     | 304
>> ++++++++++++++++++++++++++++++++++++++++++++++---
>>>> --
>>>>>     target-ppc/kvm_ppc.h |   1 +
>>>>>     3 files changed, 278 insertions(+), 28 deletions(-)
>>>>>
>>>>> diff --git a/hw/ppc/e500.c b/hw/ppc/e500.c index a973c18..514c595
>>>>> 100644
>>>>> --- a/hw/ppc/e500.c
>>>>> +++ b/hw/ppc/e500.c
>>>>> @@ -853,6 +853,7 @@ void ppce500_init(MachineState *machine,
>>>>> PPCE500Params
>>>> *params)
>>>>>         if (kvm_enabled()) {
>>>>>             kvmppc_init();
>>>>>         }
>>>>> +    kvmppc_e500_hw_breakpoint_init();
>>>>>     }
>>>>>
>>>>>     static int e500_ccsr_initfn(SysBusDevice *dev) diff --git
>>>>> a/target-ppc/kvm.c b/target-ppc/kvm.c index 1d2384d..f5fbec6 100644
>>>>> --- a/target-ppc/kvm.c
>>>>> +++ b/target-ppc/kvm.c
>>>>> @@ -38,6 +38,7 @@
>>>>>     #include "hw/ppc/ppc.h"
>>>>>     #include "sysemu/watchdog.h"
>>>>>     #include "trace.h"
>>>>> +#include "exec/gdbstub.h"
>>>>>
>>>>>     //#define DEBUG_KVM
>>>>>
>>>>> @@ -768,6 +769,38 @@ static int kvm_put_vpa(CPUState *cs)
>>>>>
>>>>>     static int kvmppc_inject_debug_exception(CPUState *cs)
>>>>>     {
>>>>> +    PowerPCCPU *cpu = POWERPC_CPU(cs);
>>>>> +    CPUPPCState *env = &cpu->env;
>>>>> +    struct kvm_sregs sregs;
>>>>> +    int ret;
>>>>> +
>>>>> +    if (!cap_booke_sregs) {
>>>>> +        return -1;
>>>>> +    }
>>>>> +
>>>>> +    ret = kvm_vcpu_ioctl(cs, KVM_GET_SREGS, &sregs);
>>>>> +    if (ret < 0) {
>>>>> +        return -1;
>>>>> +    }
>>>>> +
>>>> I don't think any of this code should ever run for non-e500, no?
>>> You mean the code below in this function?
>> Yeah :).
> Why you think accessing sregs (cssr0/1, dsrr0/1 and ioctl) is e500 specific. Are not these valid for 4xx as well?

Ah, misunderstanding. I don't really care about 440 - we don't seem to 
have any users there. However, I do care about book3s - and the code 
isn't compatible with book3s at all ;).

>
>>>>> +    if (sregs.u.e.features & KVM_SREGS_E_ED) {
>>>> Hrm - we never seem to set E_ED in kvm?
>>> Uhh, you are right. Going through the whole discussion about interrupt
>> injection to guest I found that one patch missed for upstream.
>>> Will send that patch
>>>
>>>>> +        sregs.u.e.dsrr0 = env->nip;
>>>>> +        sregs.u.e.dsrr1 = env->msr;
>>>>> +    } else {
>>>>> +        sregs.u.e.csrr0 = env->nip;
>>>>> +        sregs.u.e.csrr1 = env->msr;
>>>>> +    }
>>>>> +
>>>>> +    sregs.u.e.update_special = KVM_SREGS_E_UPDATE_DBSR;
>>>>> +    sregs.u.e.dbsr = env->spr[SPR_BOOKE_DBSR];
>>>>> +
>>>>> +    ret = kvm_vcpu_ioctl(cs, KVM_SET_SREGS, &sregs);
>>>>> +    if (ret < 0) {
>>>>> +        return -1;
>>>>> +    }
>>>>> +
>>>>> +    env->pending_interrupts &= ~(1 << PPC_INTERRUPT_DEBUG);
>>>>> +
>>>>>         return 0;
>>>>>     }
>>>>>
>>>>> @@ -1275,6 +1308,239 @@ static int
>>>>> kvmppc_handle_dcr_write(CPUPPCState *env,
>>>> uint32_t dcrn, uint32_t dat
>>>>>         return 0;
>>>>>     }
>>>>>
>>>>> +int kvm_arch_insert_sw_breakpoint(CPUState *cs, struct
>>>>> +kvm_sw_breakpoint *bp) {
>>>>> +    uint32_t sc = tswap32(debug_inst_opcode);
>>>> Heh - this will become a lot of fun for real LE host as well as guest
>> systems.
>>> I am trying to understand the problem here, We want to byteswap opcode only if
>> it is mixed endian (host and guest are of different endianess) case?
>>
>> Yes :).
>>
>>>> For now just remove the tswap and add a comment that this needs fixing for
>> LE.
>>>>> +
>>>>> +    if (cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&bp->saved_insn, 4, 0)
>> ||
>>>>> +        cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&sc, 4, 1)) {
>>>>> +        return -EINVAL;
>>>>> +    }
>>>>> +
>>>>> +    return 0;
>>>>> +}
>>>>> +
>>>>> +int kvm_arch_remove_sw_breakpoint(CPUState *cs, struct
>>>>> +kvm_sw_breakpoint *bp) {
>>>>> +    uint32_t sc;
>>>>> +
>>>>> +    if (cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&sc, 4, 0) ||
>>>>> +        sc != tswap32(debug_inst_opcode) ||
>>>> Same here.
>>>>
>>>> In fact, neither of the 2 operations are in a fast path. Can't we
>>>> just fetch the debug inst opcode on demand in a function here?
>>> Ok will do that.
>>>
>>>> That will allow for easier byte
>>>> swapping depending on the guest's MSR.LE setting later as well.
>>>>
>>>>> +        cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&bp->saved_insn, 4, 1))
>> {
>>>>> +        return -EINVAL;
>>>>> +    }
>>>>> +
>>>>> +    return 0;
>>>>> +}
>>>>> +
>>>>> +static struct HWBreakpoint {
>>>>> +    target_ulong addr;
>>>>> +    int type;
>>>>> +} hw_breakpoint[6];
>>>>> +
>>>>> +static int nb_hw_breakpoint;
>>>>> +static int nb_hw_watchpoint;
>>>>> +static int max_hw_breakpoint = 4;
>>>>> +static int max_hw_watchpoint = 2;
>>>>> +
>>>>> +void kvmppc_e500_hw_breakpoint_init(void)
>>>>> +{
>>>>> +    max_hw_breakpoint = 2;
>>>>> +    max_hw_watchpoint = 2;
>>>> Can we somehow get this information from kvm and set it in kvm_arch_init?
>>> Will add one_reg to get this information.
>> We can also fall back to always make this 2 when there's no other way to
>> enumerate. But setting the default to 4/2 and then revert to 2/2 hard codedly
>> seems odd.
>>
>> Btw, where does the 4/2 come from?
> Because 44x have 4 IACs.

Ah, ok. Just ignore 440.

>
>>>> Worst
>>>> case we'll have to look at the cpu class and derive it from there,
>>>> but it really should live solely inside the kvm file.
>>>>
>>>>> +}
>>>>> +
>>>>> +static int find_hw_breakpoint(target_ulong addr, int type) {
>>>>> +    int n;
>>>>> +
>>>>> +    for (n = 0; n < nb_hw_breakpoint + nb_hw_watchpoint; n++) {
>>>>> +        if (hw_breakpoint[n].addr == addr && hw_breakpoint[n].type == type)
>> {
>>>>> +            return n;
>>>>> +        }
>>>>> +    }
>>>>> +
>>>>> +    return -1;
>>>>> +}
>>>>> +
>>>>> +static int find_hw_watchpoint(target_ulong addr, int *flag) {
>>>>> +    int n;
>>>>> +
>>>>> +    n = find_hw_breakpoint(addr, GDB_WATCHPOINT_ACCESS);
>>>>> +    if (n >= 0) {
>>>>> +        *flag = BP_MEM_ACCESS;
>>>>> +        return n;
>>>>> +    }
>>>>> +
>>>>> +    n = find_hw_breakpoint(addr, GDB_WATCHPOINT_WRITE);
>>>>> +    if (n >= 0) {
>>>>> +        *flag = BP_MEM_WRITE;
>>>>> +        return n;
>>>>> +    }
>>>>> +
>>>>> +    n = find_hw_breakpoint(addr, GDB_WATCHPOINT_READ);
>>>>> +    if (n >= 0) {
>>>>> +        *flag = BP_MEM_READ;
>>>>> +        return n;
>>>>> +    }
>>>>> +
>>>>> +    return -1;
>>>>> +}
>>>>> +
>>>>> +int kvm_arch_insert_hw_breakpoint(target_ulong addr,
>>>>> +                                  target_ulong len, int type) {
>>>>> +    hw_breakpoint[nb_hw_breakpoint + nb_hw_watchpoint].addr = addr;
>>>>> +    hw_breakpoint[nb_hw_breakpoint + nb_hw_watchpoint].type = type;
>>>>> +
>>>>> +    switch (type) {
>>>>> +    case GDB_BREAKPOINT_HW:
>>>>> +        if (nb_hw_breakpoint >= max_hw_breakpoint) {
>>>>> +            return -ENOBUFS;
>>>>> +        }
>>>>> +
>>>>> +        if (find_hw_breakpoint(addr, type) >= 0) {
>>>>> +            return -EEXIST;
>>>>> +        }
>>>>> +
>>>>> +        nb_hw_breakpoint++;
>>>>> +        break;
>>>>> +
>>>>> +    case GDB_WATCHPOINT_WRITE:
>>>>> +    case GDB_WATCHPOINT_READ:
>>>>> +    case GDB_WATCHPOINT_ACCESS:
>>>>> +        if (nb_hw_watchpoint >= max_hw_watchpoint) {
>>>>> +            return -ENOBUFS;
>>>>> +        }
>>>>> +
>>>>> +        if (find_hw_breakpoint(addr, type) >= 0) {
>>>>> +            return -EEXIST;
>>>>> +        }
>>>>> +
>>>>> +        nb_hw_watchpoint++;
>>>>> +        break;
>>>>> +
>>>>> +    default:
>>>>> +        return -ENOSYS;
>>>>> +    }
>>>>> +
>>>>> +    return 0;
>>>>> +}
>>>>> +
>>>>> +int kvm_arch_remove_hw_breakpoint(target_ulong addr,
>>>>> +                                  target_ulong len, int type) {
>>>>> +    int n;
>>>>> +
>>>>> +    n = find_hw_breakpoint(addr, type);
>>>>> +    if (n < 0) {
>>>>> +        return -ENOENT;
>>>>> +    }
>>>>> +
>>>>> +    switch (type) {
>>>>> +    case GDB_BREAKPOINT_HW:
>>>>> +        nb_hw_breakpoint--;
>>>>> +        break;
>>>>> +
>>>>> +    case GDB_WATCHPOINT_WRITE:
>>>>> +    case GDB_WATCHPOINT_READ:
>>>>> +    case GDB_WATCHPOINT_ACCESS:
>>>>> +        nb_hw_watchpoint--;
>>>>> +        break;
>>>>> +
>>>>> +    default:
>>>>> +        return -ENOSYS;
>>>>> +    }
>>>>> +    hw_breakpoint[n] = hw_breakpoint[nb_hw_breakpoint +
>>>>> + nb_hw_watchpoint];
>>>>> +
>>>>> +    return 0;
>>>>> +}
>>>>> +
>>>>> +void kvm_arch_remove_all_hw_breakpoints(void)
>>>>> +{
>>>>> +    nb_hw_breakpoint = nb_hw_watchpoint = 0; }
>>>>> +
>>>>> +static CPUWatchpoint hw_watchpoint;
>>>>> +
>>>>> +
>>>>> +static int kvm_handle_debug(PowerPCCPU *cpu, struct kvm_run *run) {
>>>>> +    CPUState *cs = CPU(cpu);
>>>>> +    CPUPPCState *env = &cpu->env;
>>>>> +    int handle = 0;
>>>>> +    int n;
>>>>> +    int flag = 0;
>>>>> +    struct kvm_debug_exit_arch *arch_info = &run->debug.arch;
>>>>> +
>>>>> +    if (cs->singlestep_enabled) {
>>>>> +        handle = 1;
>>>>> +    } else if (arch_info->status) {
>>>>> +        if (arch_info->status & KVMPPC_DEBUG_BREAKPOINT) {
>>>>> +            n = find_hw_breakpoint(arch_info->address, GDB_BREAKPOINT_HW);
>>>>> +            if (n >= 0) {
>>>>> +                handle = 1;
>>>>> +            }
>>>>> +        } else if (arch_info->status & (KVMPPC_DEBUG_WATCH_READ |
>>>>> +                                        KVMPPC_DEBUG_WATCH_WRITE)) {
>>>>> +            n = find_hw_watchpoint(arch_info->address,  &flag);
>>>>> +            if (n >= 0) {
>>>>> +                handle = 1;
>>>>> +                cs->watchpoint_hit = &hw_watchpoint;
>>>>> +                hw_watchpoint.vaddr = hw_breakpoint[n].addr;
>>>>> +                hw_watchpoint.flags = flag;
>>>>> +            }
>>>>> +        }
>>>>> +    } else if (kvm_find_sw_breakpoint(cs, arch_info->address)) {
>>>>> +        handle = 1;
>>>>> +    }
>>>>> +
>>>>> +    cpu_synchronize_state(cs);
>>>>> +    if (handle) {
>>>>> +        env->spr[SPR_BOOKE_DBSR] = 0;
>>>> This is pretty e500 specific.
>>> You mean accessing DBSR, right ?
>>> To handle core specific stuff, should we add some generic function like
>> kvm_ppc_set/clear_debug_event() in hw/ppc/e500_debug.c, hw/ppc/ppc4xx_debug.c
>> etc ?
>>
>> I don't think this is hardware, it's part of the core. So it'd belong to target-
>> ppc/. Probably part of the excp helper file.
> Is not this (dbsr) is booke specific and not just e500 specific? Should this be accessed under POWERPC_MMU_BOOKE and POWERPC_MMU_BOOKE206 cpu models?

Again, I think we can easily ignore 440, so only care about booke206 and 
book3s for now. And I'm pretty sure we can't reuse any of the code in 
kvm_handle_debug() between the two targets, so you want to branch out 
early and have a specific booke206 / e500 handler.

if (env->excp_model == EXCP_BOOKE206)
     return kvm_handle_debug_booke206(...);


Alex

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2014-06-16  9:04 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
     [not found] <1402412796-17299-1-git-send-email-Bharat.Bhushan@freescale.com>
     [not found] ` <1402412796-17299-2-git-send-email-Bharat.Bhushan@freescale.com>
2014-06-11 12:41   ` [Qemu-devel] [PATCH 1/3] ppc debug stub: Get trap instruction opcode from KVM Alexander Graf
     [not found] ` <1402412796-17299-4-git-send-email-Bharat.Bhushan@freescale.com>
2014-06-11 13:04   ` [Qemu-devel] [PATCH 3/3] ppc debug: Add debug stub support Alexander Graf
2014-06-12  7:05     ` Bharat.Bhushan
2014-06-13 11:24       ` Alexander Graf
2014-06-16  4:27         ` Bharat.Bhushan
2014-06-16  9:04           ` Alexander Graf

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