From: "tiejun.chen" <tiejun.chen@windriver.com>
To: Bharat Bhushan <r65777@freescale.com>
Cc: mikey@neuling.org, kvm@vger.kernel.org, agraf@suse.de,
kvm-ppc@vger.kernel.org, linux-kernel@vger.kernel.org,
Bharat Bhushan <Bharat.Bhushan@freescale.com>,
scottwood@freescale.com, linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH 4/6 v5] KVM: PPC: exit to user space on "ehpriv" instruction
Date: Wed, 26 Jun 2013 14:54:50 +0800 [thread overview]
Message-ID: <51CA903A.4070809@windriver.com> (raw)
In-Reply-To: <1372225346-5029-5-git-send-email-Bharat.Bhushan@freescale.com>
On 06/26/2013 01:42 PM, Bharat Bhushan wrote:
> "ehpriv" instruction is used for setting software breakpoints
> by user space. This patch adds support to exit to user space
> with "run->debug" have relevant information.
>
> As this is the first point we are using run->debug, also defined
> the run->debug structure.
>
> Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
> ---
> arch/powerpc/include/asm/disassemble.h | 4 ++++
> arch/powerpc/include/uapi/asm/kvm.h | 21 +++++++++++++++++----
> arch/powerpc/kvm/e500_emulate.c | 27 +++++++++++++++++++++++++++
> 3 files changed, 48 insertions(+), 4 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/disassemble.h b/arch/powerpc/include/asm/disassemble.h
> index 9b198d1..856f8de 100644
> --- a/arch/powerpc/include/asm/disassemble.h
> +++ b/arch/powerpc/include/asm/disassemble.h
> @@ -77,4 +77,8 @@ static inline unsigned int get_d(u32 inst)
> return inst & 0xffff;
> }
>
> +static inline unsigned int get_oc(u32 inst)
> +{
> + return (inst >> 11) & 0x7fff;
> +}
> #endif /* __ASM_PPC_DISASSEMBLE_H__ */
> diff --git a/arch/powerpc/include/uapi/asm/kvm.h b/arch/powerpc/include/uapi/asm/kvm.h
> index 0fb1a6e..ded0607 100644
> --- a/arch/powerpc/include/uapi/asm/kvm.h
> +++ b/arch/powerpc/include/uapi/asm/kvm.h
> @@ -269,7 +269,24 @@ struct kvm_fpu {
> __u64 fpr[32];
> };
>
> +/*
> + * Defines for h/w breakpoint, watchpoint (read, write or both) and
> + * software breakpoint.
> + * These are used as "type" in KVM_SET_GUEST_DEBUG ioctl and "status"
> + * for KVM_DEBUG_EXIT.
> + */
> +#define KVMPPC_DEBUG_NONE 0x0
> +#define KVMPPC_DEBUG_BREAKPOINT (1UL << 1)
> +#define KVMPPC_DEBUG_WATCH_WRITE (1UL << 2)
> +#define KVMPPC_DEBUG_WATCH_READ (1UL << 3)
> struct kvm_debug_exit_arch {
> + __u64 address;
> + /*
> + * exiting to userspace because of h/w breakpoint, watchpoint
> + * (read, write or both) and software breakpoint.
> + */
> + __u32 status;
> + __u32 reserved;
> };
>
> /* for KVM_SET_GUEST_DEBUG */
> @@ -281,10 +298,6 @@ struct kvm_guest_debug_arch {
> * Type denotes h/w breakpoint, read watchpoint, write
> * watchpoint or watchpoint (both read and write).
> */
> -#define KVMPPC_DEBUG_NONE 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];
> diff --git a/arch/powerpc/kvm/e500_emulate.c b/arch/powerpc/kvm/e500_emulate.c
> index b10a012..dab9d07 100644
> --- a/arch/powerpc/kvm/e500_emulate.c
> +++ b/arch/powerpc/kvm/e500_emulate.c
> @@ -26,6 +26,8 @@
> #define XOP_TLBRE 946
> #define XOP_TLBWE 978
> #define XOP_TLBILX 18
> +#define XOP_EHPRIV 270
> +#define EHPRIV_OC_DEBUG 0
As I think the case, "OC = 0", is a bit specific since IIRC, if the OC
operand is omitted, its equal 0 by default. So I think we should start this OC
value from 1 or other magic number.
And if possible, we'd better add some comments to describe this to make the OC
definition readable.
Tiejun
>
> #ifdef CONFIG_KVM_E500MC
> static int dbell2prio(ulong param)
> @@ -82,6 +84,26 @@ static int kvmppc_e500_emul_msgsnd(struct kvm_vcpu *vcpu, int rb)
> }
> #endif
>
> +static int kvmppc_e500_emul_ehpriv(struct kvm_run *run, struct kvm_vcpu *vcpu,
> + unsigned int inst, int *advance)
> +{
> + int emulated = EMULATE_DONE;
> +
> + switch (get_oc(inst)) {
> + case EHPRIV_OC_DEBUG:
> + run->exit_reason = KVM_EXIT_DEBUG;
> + run->debug.arch.address = vcpu->arch.pc;
> + run->debug.arch.status = 0;
> + kvmppc_account_exit(vcpu, DEBUG_EXITS);
> + emulated = EMULATE_EXIT_USER;
> + *advance = 0;
> + break;
> + default:
> + emulated = EMULATE_FAIL;
> + }
> + return emulated;
> +}
> +
> int kvmppc_core_emulate_op(struct kvm_run *run, struct kvm_vcpu *vcpu,
> unsigned int inst, int *advance)
> {
> @@ -130,6 +152,11 @@ int kvmppc_core_emulate_op(struct kvm_run *run, struct kvm_vcpu *vcpu,
> emulated = kvmppc_e500_emul_tlbivax(vcpu, ea);
> break;
>
> + case XOP_EHPRIV:
> + emulated = kvmppc_e500_emul_ehpriv(run, vcpu, inst,
> + advance);
> + break;
> +
> default:
> emulated = EMULATE_FAIL;
> }
>
next prev parent reply other threads:[~2013-06-26 6:54 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-26 5:42 [PATCH 0/6 v5] KVM :PPC: Userspace Debug support Bharat Bhushan
2013-06-26 5:42 ` [PATCH 1/6 v5] powerpc: remove unnecessary line continuations Bharat Bhushan
2013-06-26 5:42 ` [PATCH 2/6 v5] powerpc: move debug registers in a structure Bharat Bhushan
2013-06-26 5:42 ` [PATCH 3/6 v5] powerpc: export debug registers save function for KVM Bharat Bhushan
2013-06-27 4:47 ` Stephen Rothwell
2013-06-26 5:42 ` [PATCH 4/6 v5] KVM: PPC: exit to user space on "ehpriv" instruction Bharat Bhushan
2013-06-26 6:54 ` tiejun.chen [this message]
2013-06-26 8:44 ` Bhushan Bharat-R65777
2013-06-26 9:17 ` tiejun.chen
2013-06-26 9:27 ` Bhushan Bharat-R65777
2013-06-26 10:33 ` Alexander Graf
2013-06-26 5:42 ` [PATCH 5/6 v5] KVM: PPC: Using "struct debug_reg" Bharat Bhushan
2013-06-26 5:42 ` [PATCH 6/6 v5] KVM: PPC: Add userspace debug stub support Bharat Bhushan
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