RE: [PATCH 7/7] KVM: PPC: Add userspace debug stub support
-Original Message-
From: kvm-ppc-ow...@vger.kernel.org [mailto:kvm-ppc-ow...@vger.kernel.org] On
Behalf Of Alexander Graf
Sent: Thursday, March 14, 2013 5:20 PM
To: Bhushan Bharat-R65777
Cc: kvm-ppc@vger.kernel.org; k...@vger.kernel.org; Wood Scott-B07421
Subject: Re: [PATCH 7/7] KVM: PPC: Add userspace debug stub support
On 14.03.2013, at 06:18, Bhushan Bharat-R65777 wrote:
-Original Message-
From: Alexander Graf [mailto:ag...@suse.de]
Sent: Thursday, March 07, 2013 7:09 PM
To: Bhushan Bharat-R65777
Cc: kvm-ppc@vger.kernel.org; k...@vger.kernel.org; Wood Scott-B07421;
Bhushan
Bharat-R65777
Subject: Re: [PATCH 7/7] KVM: PPC: Add userspace debug stub support
On 28.02.2013, at 05:13, Bharat Bhushan wrote:
This patch adds the debug stub support on booke/bookehv.
Now QEMU debug stub can use hw breakpoint, watchpoint and software
breakpoint to debug guest.
Signed-off-by: Bharat Bhushan bharat.bhus...@freescale.com
---
arch/powerpc/include/uapi/asm/kvm.h | 22 +-
arch/powerpc/kvm/booke.c| 143
+++--
-
arch/powerpc/kvm/e500_emulate.c |6 ++
arch/powerpc/kvm/e500mc.c |3 +-
4 files changed, 155 insertions(+), 19 deletions(-)
diff --git a/arch/powerpc/include/uapi/asm/kvm.h
b/arch/powerpc/include/uapi/asm/kvm.h
index 15f9a00..d7ce449 100644
--- a/arch/powerpc/include/uapi/asm/kvm.h
+++ b/arch/powerpc/include/uapi/asm/kvm.h
@@ -25,6 +25,7 @@
/* Select powerpc specific features in linux/kvm.h */ #define
__KVM_HAVE_SPAPR_TCE #define __KVM_HAVE_PPC_SMT
+#define __KVM_HAVE_GUEST_DEBUG
struct kvm_regs {
__u64 pc;
@@ -267,7 +268,24 @@ 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_NONE0x0
+#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 */
@@ -279,10 +297,6 @@ struct kvm_guest_debug_arch {
* 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];
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index
1de93a8..21b0313 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -133,6 +133,30 @@ static void kvmppc_vcpu_sync_fpu(struct
kvm_vcpu
*vcpu) #endif }
+static void kvmppc_vcpu_sync_debug(struct kvm_vcpu *vcpu) {
+ /* Synchronize guest's desire to get debug interrupts into shadow
+MSR */ #ifndef CONFIG_KVM_BOOKE_HV
+ vcpu-arch.shadow_msr = ~MSR_DE;
+ vcpu-arch.shadow_msr |= vcpu-arch.shared-msr MSR_DE; #endif
+
+ /* Force enable debug interrupts when user space wants to debug */
+ if (vcpu-guest_debug) {
+#ifdef CONFIG_KVM_BOOKE_HV
+ /*
+ * Since there is no shadow MSR, sync MSR_DE into the guest
+ * visible MSR. Do not allow guest to change MSR[DE].
+ */
+ vcpu-arch.shared-msr |= MSR_DE;
+ mtspr(SPRN_MSRP, mfspr(SPRN_MSRP) | MSRP_DEP); #else
+ vcpu-arch.shadow_msr |= MSR_DE;
+ vcpu-arch.shared-msr = ~MSR_DE; #endif
+ }
+}
+
/*
* Helper function for full MSR writes. No need to call this if
only
* EE/CE/ME/DE/RI are changing.
@@ -150,6 +174,7 @@ void kvmppc_set_msr(struct kvm_vcpu *vcpu, u32
new_msr)
kvmppc_mmu_msr_notify(vcpu, old_msr);
kvmppc_vcpu_sync_spe(vcpu);
kvmppc_vcpu_sync_fpu(vcpu);
+ kvmppc_vcpu_sync_debug(vcpu);
}
static void kvmppc_booke_queue_irqprio(struct kvm_vcpu *vcpu, @@
-736,6 +761,13 @@ static int emulation_exit(struct kvm_run *run,
struct
kvm_vcpu *vcpu)
run-exit_reason = KVM_EXIT_DCR;
return RESUME_HOST;
+ case EMULATE_EXIT_USER:
+ run-exit_reason = KVM_EXIT_DEBUG;
+ run-debug.arch.address = vcpu-arch.pc;
+ run-debug.arch.status = 0;
+ kvmppc_account_exit(vcpu, DEBUG_EXITS);
As mentioned previously, this is wrong and needs to go into the
instruction emulation code for that opcode.
ok
+ return RESUME_HOST;
+
case EMULATE_FAIL:
printk(KERN_CRIT %s: emulation at %lx failed (%08x)\n
Re: [PATCH 7/7] KVM: PPC: Add userspace debug stub support
On 03/14/2013 08:57:53 AM, Bhushan Bharat-R65777 wrote:
diff --git a/arch/powerpc/kvm/e500mc.c
b/arch/powerpc/kvm/e500mc.c
index 1f89d26..f5fc6f5 100644
--- a/arch/powerpc/kvm/e500mc.c
+++ b/arch/powerpc/kvm/e500mc.c
@@ -182,8 +182,7 @@ int kvmppc_core_vcpu_setup(struct kvm_vcpu
*vcpu) {
struct kvmppc_vcpu_e500 *vcpu_e500 = to_e500(vcpu);
- vcpu-arch.shadow_epcr = SPRN_EPCR_DSIGS |
SPRN_EPCR_DGTMI | \
- SPRN_EPCR_DUVD;
+ vcpu-arch.shadow_epcr = SPRN_EPCR_DSIGS |
SPRN_EPCR_DGTMI;
Doesn't this route all debug events through the host?
No; This means that debug events can occur in hypervisor state or
not.
EPCR.DUVD = 0 ; Debug events can occur in the hypervisor state.
EPCR.DUVD = 1 ; Debug events cannot occur in the hypervisor state.
So we allow debug events to occur in hypervisor state.
Why do we care about debug events in our entry/exit code and didn't
care about
them before?
We care for single stepping in guest to not step in KVM code.
If anything, this is a completely separate patch, orthogonal to
this patch series, and requires a good bit of explanation.
Not sure why you think separate patch; this patch add support for
single stepping and also takes care that debug event does not comes
in host when doing single stepping.
How does *removing* DUVD ensure that?
-Scott
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RE: [PATCH 7/7] KVM: PPC: Add userspace debug stub support
-Original Message-
From: Wood Scott-B07421
Sent: Thursday, March 14, 2013 9:36 PM
To: Bhushan Bharat-R65777
Cc: Alexander Graf; kvm-ppc@vger.kernel.org; k...@vger.kernel.org; Wood Scott-
B07421
Subject: Re: [PATCH 7/7] KVM: PPC: Add userspace debug stub support
On 03/14/2013 08:57:53 AM, Bhushan Bharat-R65777 wrote:
diff --git a/arch/powerpc/kvm/e500mc.c
b/arch/powerpc/kvm/e500mc.c
index 1f89d26..f5fc6f5 100644
--- a/arch/powerpc/kvm/e500mc.c
+++ b/arch/powerpc/kvm/e500mc.c
@@ -182,8 +182,7 @@ int kvmppc_core_vcpu_setup(struct kvm_vcpu
*vcpu) {
struct kvmppc_vcpu_e500 *vcpu_e500 = to_e500(vcpu);
- vcpu-arch.shadow_epcr = SPRN_EPCR_DSIGS |
SPRN_EPCR_DGTMI | \
- SPRN_EPCR_DUVD;
+ vcpu-arch.shadow_epcr = SPRN_EPCR_DSIGS |
SPRN_EPCR_DGTMI;
Doesn't this route all debug events through the host?
No; This means that debug events can occur in hypervisor state or
not.
EPCR.DUVD = 0 ; Debug events can occur in the hypervisor state.
EPCR.DUVD = 1 ; Debug events cannot occur in the hypervisor state.
So we allow debug events to occur in hypervisor state.
Why do we care about debug events in our entry/exit code and didn't
care about
them before?
We care for single stepping in guest to not step in KVM code.
If anything, this is a completely separate patch, orthogonal to this
patch series, and requires a good bit of explanation.
Not sure why you think separate patch; this patch add support for
single stepping and also takes care that debug event does not comes in
host when doing single stepping.
How does *removing* DUVD ensure that?
By default we clear DUVD, so debug events can come in hypervisor state. But on
lightweight exit, when restoring guest debug context, we set DUVD so the debug
interrupt will not come in hypervisor state as debug resource are taken by
guest.
On guest exit, when restoring the host context we clear DUVD so now debug
resource are having host context.
With proposed change of save and restore on vcpu_get/vcpu_put this switching
witching will be done in vcpu_get/set().
Thanks
-Bharat
-Scott
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the body of a message to majord...@vger.kernel.org
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RE: [PATCH 7/7] KVM: PPC: Add userspace debug stub support
-Original Message-
From: Alexander Graf [mailto:ag...@suse.de]
Sent: Thursday, March 07, 2013 7:09 PM
To: Bhushan Bharat-R65777
Cc: kvm-ppc@vger.kernel.org; k...@vger.kernel.org; Wood Scott-B07421; Bhushan
Bharat-R65777
Subject: Re: [PATCH 7/7] KVM: PPC: Add userspace debug stub support
On 28.02.2013, at 05:13, Bharat Bhushan wrote:
This patch adds the debug stub support on booke/bookehv.
Now QEMU debug stub can use hw breakpoint, watchpoint and software
breakpoint to debug guest.
Signed-off-by: Bharat Bhushan bharat.bhus...@freescale.com
---
arch/powerpc/include/uapi/asm/kvm.h | 22 +-
arch/powerpc/kvm/booke.c| 143
+++---
arch/powerpc/kvm/e500_emulate.c |6 ++
arch/powerpc/kvm/e500mc.c |3 +-
4 files changed, 155 insertions(+), 19 deletions(-)
diff --git a/arch/powerpc/include/uapi/asm/kvm.h
b/arch/powerpc/include/uapi/asm/kvm.h
index 15f9a00..d7ce449 100644
--- a/arch/powerpc/include/uapi/asm/kvm.h
+++ b/arch/powerpc/include/uapi/asm/kvm.h
@@ -25,6 +25,7 @@
/* Select powerpc specific features in linux/kvm.h */ #define
__KVM_HAVE_SPAPR_TCE #define __KVM_HAVE_PPC_SMT
+#define __KVM_HAVE_GUEST_DEBUG
struct kvm_regs {
__u64 pc;
@@ -267,7 +268,24 @@ 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 */
@@ -279,10 +297,6 @@ struct kvm_guest_debug_arch {
* Type denotes h/w breakpoint, read watchpoint, write
* watchpoint or watchpoint (both read and write).
*/
-#define KVMPPC_DEBUG_NOTYPE0x0
-#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/booke.c b/arch/powerpc/kvm/booke.c index
1de93a8..21b0313 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -133,6 +133,30 @@ static void kvmppc_vcpu_sync_fpu(struct kvm_vcpu
*vcpu) #endif }
+static void kvmppc_vcpu_sync_debug(struct kvm_vcpu *vcpu) {
+ /* Synchronize guest's desire to get debug interrupts into shadow
+MSR */ #ifndef CONFIG_KVM_BOOKE_HV
+ vcpu-arch.shadow_msr = ~MSR_DE;
+ vcpu-arch.shadow_msr |= vcpu-arch.shared-msr MSR_DE; #endif
+
+ /* Force enable debug interrupts when user space wants to debug */
+ if (vcpu-guest_debug) {
+#ifdef CONFIG_KVM_BOOKE_HV
+ /*
+* Since there is no shadow MSR, sync MSR_DE into the guest
+* visible MSR. Do not allow guest to change MSR[DE].
+*/
+ vcpu-arch.shared-msr |= MSR_DE;
+ mtspr(SPRN_MSRP, mfspr(SPRN_MSRP) | MSRP_DEP); #else
+ vcpu-arch.shadow_msr |= MSR_DE;
+ vcpu-arch.shared-msr = ~MSR_DE;
+#endif
+ }
+}
+
/*
* Helper function for full MSR writes. No need to call this if
only
* EE/CE/ME/DE/RI are changing.
@@ -150,6 +174,7 @@ void kvmppc_set_msr(struct kvm_vcpu *vcpu, u32 new_msr)
kvmppc_mmu_msr_notify(vcpu, old_msr);
kvmppc_vcpu_sync_spe(vcpu);
kvmppc_vcpu_sync_fpu(vcpu);
+ kvmppc_vcpu_sync_debug(vcpu);
}
static void kvmppc_booke_queue_irqprio(struct kvm_vcpu *vcpu, @@
-736,6 +761,13 @@ static int emulation_exit(struct kvm_run *run, struct
kvm_vcpu *vcpu)
run-exit_reason = KVM_EXIT_DCR;
return RESUME_HOST;
+ case EMULATE_EXIT_USER:
+ run-exit_reason = KVM_EXIT_DEBUG;
+ run-debug.arch.address = vcpu-arch.pc;
+ run-debug.arch.status = 0;
+ kvmppc_account_exit(vcpu, DEBUG_EXITS);
As mentioned previously, this is wrong and needs to go into the instruction
emulation code for that opcode.
ok
+ return RESUME_HOST;
+
case EMULATE_FAIL:
printk(KERN_CRIT %s: emulation at %lx failed (%08x)\n,
__func__, vcpu-arch.pc, vcpu-arch.last_inst); @@ -751,6
+783,28 @@ static int emulation_exit(struct kvm_run *run, struct kvm_vcpu
*vcpu)
}
}
+static int kvmppc_handle_debug(struct kvm_run *run, struct kvm_vcpu
+*vcpu) {
+ u32 dbsr = vcpu-arch.dbsr;
+ run-debug.arch.status = 0;
+ run
Re: [PATCH 7/7] KVM: PPC: Add userspace debug stub support
On 28.02.2013, at 05:13, Bharat Bhushan wrote:
This patch adds the debug stub support on booke/bookehv.
Now QEMU debug stub can use hw breakpoint, watchpoint and
software breakpoint to debug guest.
Signed-off-by: Bharat Bhushan bharat.bhus...@freescale.com
---
arch/powerpc/include/uapi/asm/kvm.h | 22 +-
arch/powerpc/kvm/booke.c| 143 +++---
arch/powerpc/kvm/e500_emulate.c |6 ++
arch/powerpc/kvm/e500mc.c |3 +-
4 files changed, 155 insertions(+), 19 deletions(-)
diff --git a/arch/powerpc/include/uapi/asm/kvm.h
b/arch/powerpc/include/uapi/asm/kvm.h
index 15f9a00..d7ce449 100644
--- a/arch/powerpc/include/uapi/asm/kvm.h
+++ b/arch/powerpc/include/uapi/asm/kvm.h
@@ -25,6 +25,7 @@
/* Select powerpc specific features in linux/kvm.h */
#define __KVM_HAVE_SPAPR_TCE
#define __KVM_HAVE_PPC_SMT
+#define __KVM_HAVE_GUEST_DEBUG
struct kvm_regs {
__u64 pc;
@@ -267,7 +268,24 @@ 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_NONE0x0
+#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 */
@@ -279,10 +297,6 @@ struct kvm_guest_debug_arch {
* 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];
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index 1de93a8..21b0313 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -133,6 +133,30 @@ static void kvmppc_vcpu_sync_fpu(struct kvm_vcpu *vcpu)
#endif
}
+static void kvmppc_vcpu_sync_debug(struct kvm_vcpu *vcpu)
+{
+ /* Synchronize guest's desire to get debug interrupts into shadow MSR */
+#ifndef CONFIG_KVM_BOOKE_HV
+ vcpu-arch.shadow_msr = ~MSR_DE;
+ vcpu-arch.shadow_msr |= vcpu-arch.shared-msr MSR_DE;
+#endif
+
+ /* Force enable debug interrupts when user space wants to debug */
+ if (vcpu-guest_debug) {
+#ifdef CONFIG_KVM_BOOKE_HV
+ /*
+ * Since there is no shadow MSR, sync MSR_DE into the guest
+ * visible MSR. Do not allow guest to change MSR[DE].
+ */
+ vcpu-arch.shared-msr |= MSR_DE;
+ mtspr(SPRN_MSRP, mfspr(SPRN_MSRP) | MSRP_DEP);
+#else
+ vcpu-arch.shadow_msr |= MSR_DE;
+ vcpu-arch.shared-msr = ~MSR_DE;
+#endif
+ }
+}
+
/*
* Helper function for full MSR writes. No need to call this if only
* EE/CE/ME/DE/RI are changing.
@@ -150,6 +174,7 @@ void kvmppc_set_msr(struct kvm_vcpu *vcpu, u32 new_msr)
kvmppc_mmu_msr_notify(vcpu, old_msr);
kvmppc_vcpu_sync_spe(vcpu);
kvmppc_vcpu_sync_fpu(vcpu);
+ kvmppc_vcpu_sync_debug(vcpu);
}
static void kvmppc_booke_queue_irqprio(struct kvm_vcpu *vcpu,
@@ -736,6 +761,13 @@ static int emulation_exit(struct kvm_run *run, struct
kvm_vcpu *vcpu)
run-exit_reason = KVM_EXIT_DCR;
return RESUME_HOST;
+ case EMULATE_EXIT_USER:
+ run-exit_reason = KVM_EXIT_DEBUG;
+ run-debug.arch.address = vcpu-arch.pc;
+ run-debug.arch.status = 0;
+ kvmppc_account_exit(vcpu, DEBUG_EXITS);
As mentioned previously, this is wrong and needs to go into the instruction
emulation code for that opcode.
+ return RESUME_HOST;
+
case EMULATE_FAIL:
printk(KERN_CRIT %s: emulation at %lx failed (%08x)\n,
__func__, vcpu-arch.pc, vcpu-arch.last_inst);
@@ -751,6 +783,28 @@ static int emulation_exit(struct kvm_run *run, struct
kvm_vcpu *vcpu)
}
}
+static int kvmppc_handle_debug(struct kvm_run *run, struct kvm_vcpu *vcpu)
+{
+ u32 dbsr = vcpu-arch.dbsr;
+ run-debug.arch.status = 0;
+ run-debug.arch.address = vcpu-arch.pc;
This should go into the if(breakpoint) branch.
+
+ if (dbsr (DBSR_IAC1 | DBSR_IAC2 | DBSR_IAC3 | DBSR_IAC4)) {
+ run-debug.arch.status |= KVMPPC_DEBUG_BREAKPOINT;
+ } else {
+ if (dbsr (DBSR_DAC1W | DBSR_DAC2W))
+
