From: Alexander Graf <agraf@suse.de>
To: Bharat Bhushan <Bharat.Bhushan@freescale.com>, kvm-ppc@vger.kernel.org
Cc: kvm@vger.kernel.org, scottwood@freescale.com, stuart.yoder@freescale.com
Subject: Re: [PATCH v4] KVM: PPC: BOOKE: Emulate debug registers and exception
Date: Thu, 28 Aug 2014 08:44:33 +0000 [thread overview]
Message-ID: <53FEEBF1.6090704@suse.de> (raw)
In-Reply-To: <1407920984-27555-1-git-send-email-Bharat.Bhushan@freescale.com>
On 13.08.14 11:09, Bharat Bhushan wrote:
> This patch emulates debug registers and debug exception
> to support guest using debug resource. This enables running
> gdb/kgdb etc in guest.
>
> On BOOKE architecture we cannot share debug resources between QEMU and
> guest because:
> When QEMU is using debug resources then debug exception must
> be always enabled. To achieve this we set MSR_DE and also set
> MSRP_DEP so guest cannot change MSR_DE.
>
> When emulating debug resource for guest we want guest
> to control MSR_DE (enable/disable debug interrupt on need).
>
> So above mentioned two configuration cannot be supported
> at the same time. So the result is that we cannot share
> debug resources between QEMU and Guest on BOOKE architecture.
>
> In the current design QEMU gets priority over guest, this means that if
> QEMU is using debug resources then guest cannot use them and if guest is
> using debug resource then QEMU can overwrite them.
>
> Signed-off-by: Bharat Bhushan <Bharat.Bhushan@freescale.com>
Thanks, applied to kvm-ppc-queue.
Alex
WARNING: multiple messages have this Message-ID (diff)
From: Alexander Graf <agraf@suse.de>
To: Bharat Bhushan <Bharat.Bhushan@freescale.com>, kvm-ppc@vger.kernel.org
Cc: kvm@vger.kernel.org, scottwood@freescale.com, stuart.yoder@freescale.com
Subject: Re: [PATCH v4] KVM: PPC: BOOKE: Emulate debug registers and exception
Date: Thu, 28 Aug 2014 10:44:33 +0200 [thread overview]
Message-ID: <53FEEBF1.6090704@suse.de> (raw)
In-Reply-To: <1407920984-27555-1-git-send-email-Bharat.Bhushan@freescale.com>
On 13.08.14 11:09, Bharat Bhushan wrote:
> This patch emulates debug registers and debug exception
> to support guest using debug resource. This enables running
> gdb/kgdb etc in guest.
>
> On BOOKE architecture we cannot share debug resources between QEMU and
> guest because:
> When QEMU is using debug resources then debug exception must
> be always enabled. To achieve this we set MSR_DE and also set
> MSRP_DEP so guest cannot change MSR_DE.
>
> When emulating debug resource for guest we want guest
> to control MSR_DE (enable/disable debug interrupt on need).
>
> So above mentioned two configuration cannot be supported
> at the same time. So the result is that we cannot share
> debug resources between QEMU and Guest on BOOKE architecture.
>
> In the current design QEMU gets priority over guest, this means that if
> QEMU is using debug resources then guest cannot use them and if guest is
> using debug resource then QEMU can overwrite them.
>
> Signed-off-by: Bharat Bhushan <Bharat.Bhushan@freescale.com>
Thanks, applied to kvm-ppc-queue.
Alex
next prev parent reply other threads:[~2014-08-28 8:44 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-13 9:09 [PATCH v4] KVM: PPC: BOOKE: Emulate debug registers and exception Bharat Bhushan
2014-08-13 9:21 ` Bharat Bhushan
2014-08-27 11:23 ` Alexander Graf
2014-08-27 11:23 ` Alexander Graf
2014-08-28 2:30 ` Scott Wood
2014-08-28 2:30 ` Scott Wood
2014-08-28 8:44 ` Alexander Graf [this message]
2014-08-28 8:44 ` Alexander Graf
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