Re: [PATCH 1/6] KVM: PPC: BOOKE: No need to set DBCR0_EDM in guest visible register
On Wed, 2014-07-30 at 00:21 -0500, Bhushan Bharat-R65777 wrote: -Original Message- From: Wood Scott-B07421 Sent: Tuesday, July 29, 2014 3:22 AM To: Bhushan Bharat-R65777 Cc: ag...@suse.de; kvm-ppc@vger.kernel.org; k...@vger.kernel.org; Yoder Stuart- B08248 Subject: Re: [PATCH 1/6] KVM: PPC: BOOKE: No need to set DBCR0_EDM in guest visible register On Fri, 2014-07-11 at 14:08 +0530, Bharat Bhushan wrote: This is not used and even I do not remember why this was added in first place. Signed-off-by: Bharat Bhushan bharat.bhus...@freescale.com --- arch/powerpc/kvm/booke.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c index ab62109..a5ee42c 100644 --- a/arch/powerpc/kvm/booke.c +++ b/arch/powerpc/kvm/booke.c @@ -1804,8 +1804,6 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu, kvm_guest_protect_msr(vcpu, MSR_DE, true); vcpu-guest_debug = dbg-control; vcpu-arch.shadow_dbg_reg.dbcr0 = 0; - /* Set DBCR0_EDM in guest visible DBCR0 register. */ - vcpu-arch.dbg_reg.dbcr0 = DBCR0_EDM; if (vcpu-guest_debug KVM_GUESTDBG_SINGLESTEP) vcpu-arch.shadow_dbg_reg.dbcr0 |= DBCR0_IDM | DBCR0_IC; This was intended to let the guest know that the host owns the debug resources, by analogy to what a JTAG debugger would do. The Power ISA has this Virtualized Implementation Note: It is the responsibility of the hypervisor to ensure that DBCR0[EDM] is consistent with usage of DEP. Ok, That means that if MSRP_DEP is set then set DBCR0_EDM and if MSRP_DEP is clear then clear DBCR0_EDM, right? We need to implement above mentioned this. We should probably clear EDM only when guest debug emulation is working and enabled (i.e. not until at least patch 6/6). -Scott -- To unsubscribe from this list: send the line unsubscribe kvm-ppc in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: [PATCH 1/6] KVM: PPC: BOOKE: No need to set DBCR0_EDM in guest visible register
-Original Message- From: Wood Scott-B07421 Sent: Wednesday, July 30, 2014 11:18 PM To: Bhushan Bharat-R65777 Cc: ag...@suse.de; kvm-ppc@vger.kernel.org; k...@vger.kernel.org; Yoder Stuart- B08248 Subject: Re: [PATCH 1/6] KVM: PPC: BOOKE: No need to set DBCR0_EDM in guest visible register On Wed, 2014-07-30 at 00:21 -0500, Bhushan Bharat-R65777 wrote: -Original Message- From: Wood Scott-B07421 Sent: Tuesday, July 29, 2014 3:22 AM To: Bhushan Bharat-R65777 Cc: ag...@suse.de; kvm-ppc@vger.kernel.org; k...@vger.kernel.org; Yoder Stuart- B08248 Subject: Re: [PATCH 1/6] KVM: PPC: BOOKE: No need to set DBCR0_EDM in guest visible register On Fri, 2014-07-11 at 14:08 +0530, Bharat Bhushan wrote: This is not used and even I do not remember why this was added in first place. Signed-off-by: Bharat Bhushan bharat.bhus...@freescale.com --- arch/powerpc/kvm/booke.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c index ab62109..a5ee42c 100644 --- a/arch/powerpc/kvm/booke.c +++ b/arch/powerpc/kvm/booke.c @@ -1804,8 +1804,6 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu, kvm_guest_protect_msr(vcpu, MSR_DE, true); vcpu-guest_debug = dbg-control; vcpu-arch.shadow_dbg_reg.dbcr0 = 0; - /* Set DBCR0_EDM in guest visible DBCR0 register. */ - vcpu-arch.dbg_reg.dbcr0 = DBCR0_EDM; if (vcpu-guest_debug KVM_GUESTDBG_SINGLESTEP) vcpu-arch.shadow_dbg_reg.dbcr0 |= DBCR0_IDM | DBCR0_IC; This was intended to let the guest know that the host owns the debug resources, by analogy to what a JTAG debugger would do. The Power ISA has this Virtualized Implementation Note: It is the responsibility of the hypervisor to ensure that DBCR0[EDM] is consistent with usage of DEP. Ok, That means that if MSRP_DEP is set then set DBCR0_EDM and if MSRP_DEP is clear then clear DBCR0_EDM, right? We need to implement above mentioned this. We should probably clear EDM only when guest debug emulation is working and enabled (i.e. not until at least patch 6/6). But if EDM is set then guest debug emulation will not start/allowed. Thanks -Bharat -Scott
Re: [PATCH 1/6] KVM: PPC: BOOKE: No need to set DBCR0_EDM in guest visible register
On Wed, 2014-07-30 at 12:57 -0500, Bhushan Bharat-R65777 wrote: -Original Message- From: Wood Scott-B07421 Sent: Wednesday, July 30, 2014 11:18 PM To: Bhushan Bharat-R65777 Cc: ag...@suse.de; kvm-ppc@vger.kernel.org; k...@vger.kernel.org; Yoder Stuart- B08248 Subject: Re: [PATCH 1/6] KVM: PPC: BOOKE: No need to set DBCR0_EDM in guest visible register On Wed, 2014-07-30 at 00:21 -0500, Bhushan Bharat-R65777 wrote: -Original Message- From: Wood Scott-B07421 Sent: Tuesday, July 29, 2014 3:22 AM To: Bhushan Bharat-R65777 Cc: ag...@suse.de; kvm-ppc@vger.kernel.org; k...@vger.kernel.org; Yoder Stuart- B08248 Subject: Re: [PATCH 1/6] KVM: PPC: BOOKE: No need to set DBCR0_EDM in guest visible register On Fri, 2014-07-11 at 14:08 +0530, Bharat Bhushan wrote: This is not used and even I do not remember why this was added in first place. Signed-off-by: Bharat Bhushan bharat.bhus...@freescale.com --- arch/powerpc/kvm/booke.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c index ab62109..a5ee42c 100644 --- a/arch/powerpc/kvm/booke.c +++ b/arch/powerpc/kvm/booke.c @@ -1804,8 +1804,6 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu, kvm_guest_protect_msr(vcpu, MSR_DE, true); vcpu-guest_debug = dbg-control; vcpu-arch.shadow_dbg_reg.dbcr0 = 0; - /* Set DBCR0_EDM in guest visible DBCR0 register. */ - vcpu-arch.dbg_reg.dbcr0 = DBCR0_EDM; if (vcpu-guest_debug KVM_GUESTDBG_SINGLESTEP) vcpu-arch.shadow_dbg_reg.dbcr0 |= DBCR0_IDM | DBCR0_IC; This was intended to let the guest know that the host owns the debug resources, by analogy to what a JTAG debugger would do. The Power ISA has this Virtualized Implementation Note: It is the responsibility of the hypervisor to ensure that DBCR0[EDM] is consistent with usage of DEP. Ok, That means that if MSRP_DEP is set then set DBCR0_EDM and if MSRP_DEP is clear then clear DBCR0_EDM, right? We need to implement above mentioned this. We should probably clear EDM only when guest debug emulation is working and enabled (i.e. not until at least patch 6/6). But if EDM is set then guest debug emulation will not start/allowed. I don't mean after the guest tries to write to the registers -- I mean after the code has been added to KVM to allow it to work. -Scott -- To unsubscribe from this list: send the line unsubscribe kvm-ppc in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: [PATCH 1/6] KVM: PPC: BOOKE: No need to set DBCR0_EDM in guest visible register
-Original Message-
From: Wood Scott-B07421
Sent: Tuesday, July 29, 2014 3:22 AM
To: Bhushan Bharat-R65777
Cc: ag...@suse.de; kvm-ppc@vger.kernel.org; k...@vger.kernel.org; Yoder
Stuart-
B08248
Subject: Re: [PATCH 1/6] KVM: PPC: BOOKE: No need to set DBCR0_EDM in guest
visible register
On Fri, 2014-07-11 at 14:08 +0530, Bharat Bhushan wrote:
This is not used and even I do not remember why this was added in
first place.
Signed-off-by: Bharat Bhushan bharat.bhus...@freescale.com
---
arch/powerpc/kvm/booke.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c index
ab62109..a5ee42c 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -1804,8 +1804,6 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct
kvm_vcpu
*vcpu,
kvm_guest_protect_msr(vcpu, MSR_DE, true);
vcpu-guest_debug = dbg-control;
vcpu-arch.shadow_dbg_reg.dbcr0 = 0;
- /* Set DBCR0_EDM in guest visible DBCR0 register. */
- vcpu-arch.dbg_reg.dbcr0 = DBCR0_EDM;
if (vcpu-guest_debug KVM_GUESTDBG_SINGLESTEP)
vcpu-arch.shadow_dbg_reg.dbcr0 |= DBCR0_IDM | DBCR0_IC;
This was intended to let the guest know that the host owns the debug
resources,
by analogy to what a JTAG debugger would do.
The Power ISA has this Virtualized Implementation Note:
It is the responsibility of the hypervisor to ensure that
DBCR0[EDM] is consistent with usage of DEP.
Ok, That means that if MSRP_DEP is set then set DBCR0_EDM and if MSRP_DEP is
clear then clear DBCR0_EDM, right?
We need to implement above mentioned this.
Thanks
-Bharat
-Scott
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Re: [PATCH 1/6] KVM: PPC: BOOKE: No need to set DBCR0_EDM in guest visible register
On Fri, 2014-07-11 at 14:08 +0530, Bharat Bhushan wrote: This is not used and even I do not remember why this was added in first place. Signed-off-by: Bharat Bhushan bharat.bhus...@freescale.com --- arch/powerpc/kvm/booke.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c index ab62109..a5ee42c 100644 --- a/arch/powerpc/kvm/booke.c +++ b/arch/powerpc/kvm/booke.c @@ -1804,8 +1804,6 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu, kvm_guest_protect_msr(vcpu, MSR_DE, true); vcpu-guest_debug = dbg-control; vcpu-arch.shadow_dbg_reg.dbcr0 = 0; - /* Set DBCR0_EDM in guest visible DBCR0 register. */ - vcpu-arch.dbg_reg.dbcr0 = DBCR0_EDM; if (vcpu-guest_debug KVM_GUESTDBG_SINGLESTEP) vcpu-arch.shadow_dbg_reg.dbcr0 |= DBCR0_IDM | DBCR0_IC; This was intended to let the guest know that the host owns the debug resources, by analogy to what a JTAG debugger would do. The Power ISA has this Virtualized Implementation Note: It is the responsibility of the hypervisor to ensure that DBCR0[EDM] is consistent with usage of DEP. -Scott -- To unsubscribe from this list: send the line unsubscribe kvm-ppc in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
[PATCH 1/6] KVM: PPC: BOOKE: No need to set DBCR0_EDM in guest visible register
This is not used and even I do not remember why this was added in first place. Signed-off-by: Bharat Bhushan bharat.bhus...@freescale.com --- arch/powerpc/kvm/booke.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c index ab62109..a5ee42c 100644 --- a/arch/powerpc/kvm/booke.c +++ b/arch/powerpc/kvm/booke.c @@ -1804,8 +1804,6 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu, kvm_guest_protect_msr(vcpu, MSR_DE, true); vcpu-guest_debug = dbg-control; vcpu-arch.shadow_dbg_reg.dbcr0 = 0; - /* Set DBCR0_EDM in guest visible DBCR0 register. */ - vcpu-arch.dbg_reg.dbcr0 = DBCR0_EDM; if (vcpu-guest_debug KVM_GUESTDBG_SINGLESTEP) vcpu-arch.shadow_dbg_reg.dbcr0 |= DBCR0_IDM | DBCR0_IC; -- 1.9.3 -- To unsubscribe from this list: send the line unsubscribe kvm-ppc in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
