From: David Daney <ddaney.cavm@gmail.com>
To: "Maciej W. Rozycki" <macro@linux-mips.org>
Cc: Sanjay Lal <sanjayl@kymasys.com>,
kvm@vger.kernel.org, linux-mips@linux-mips.org,
Ralf Baechle <ralf@linux-mips.org>,
Gleb Natapov <gleb@redhat.com>,
Marcelo Tosatti <mtosatti@redhat.com>
Subject: Re: [PATCH 00/18] KVM/MIPS32: Support for the new Virtualization ASE (VZ-ASE)
Date: Mon, 20 May 2013 11:58:17 -0700 [thread overview]
Message-ID: <519A7249.1030302@gmail.com> (raw)
In-Reply-To: <alpine.LFD.2.03.1305201930570.10753@linux-mips.org>
On 05/20/2013 11:36 AM, Maciej W. Rozycki wrote:
> On Mon, 20 May 2013, Sanjay Lal wrote:
>
>> (1) Newer versions of the MIPS architecture define scratch registers for
>> just this purpose, but since we have to support standard MIPS32R2
>> processors, we use the DDataLo Register (CP0 Register 28, Select 3) as a
>> scratch register to save k0 and save k1 @ a known offset from EBASE.
>
> That's rather risky as the implementation of this register (and its
> presence in the first place) is processor-specific. Do you maintain a
> list of PRId values the use of this register is safe with?
>
FWIW: The MIPS-VZ architecture module requires the presence of CP0
scratch registers that can be used for this in the exception handlers
without having to worry about using these implementation dependent
registers. For the trap-and-emulate only version, there really is no
choice other than to re-purpose some of the existing CP0 registers.
David Daney
next prev parent reply other threads:[~2013-05-20 18:58 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-19 5:47 [PATCH 00/18] KVM/MIPS32: Support for the new Virtualization ASE (VZ-ASE) Sanjay Lal
2013-05-19 5:47 ` [PATCH 01/18] Revert "MIPS: microMIPS: Support dynamic ASID sizing." Sanjay Lal
2013-05-19 5:47 ` [PATCH 02/18] Revert "MIPS: Allow ASID size to be determined at boot time." Sanjay Lal
2013-05-19 5:47 ` [PATCH 03/18] KVM/MIPS32: Export min_low_pfn Sanjay Lal
2013-05-19 5:47 ` [PATCH 04/18] KVM/MIPS32-VZ: MIPS VZ-ASE related register defines and helper macros Sanjay Lal
2013-05-19 5:47 ` [PATCH 05/18] KVM/MIPS32-VZ: VZ-ASE assembler wrapper functions to set GuestIDs Sanjay Lal
2013-05-19 13:36 ` Sergei Shtylyov
2013-05-19 5:47 ` [PATCH 06/18] KVM/MIPS32-VZ: VZ-ASE related callbacks to handle guest exceptions that trap to the Root context Sanjay Lal
2013-05-28 15:04 ` Paolo Bonzini
2013-05-30 18:35 ` Sanjay Lal
2013-05-28 16:14 ` Paolo Bonzini
2013-05-30 18:35 ` Sanjay Lal
2013-05-30 20:11 ` Paolo Bonzini
2013-05-31 1:56 ` Sanjay Lal
2013-05-19 5:47 ` [PATCH 07/18] KVM/MIPS32: VZ-ASE related CPU feature flags and options Sanjay Lal
2013-05-19 5:47 ` [PATCH 08/18] KVM/MIPS32-VZ: Entry point for trampolining to the guest and trap handlers Sanjay Lal
2013-05-28 14:43 ` Paolo Bonzini
2013-05-19 5:47 ` [PATCH 09/18] KVM/MIPS32-VZ: Add support for CONFIG_KVM_MIPS_VZ option Sanjay Lal
2013-05-19 5:47 ` [PATCH 10/18] KVM/MIPS32-VZ: Add API for VZ-ASE Capability Sanjay Lal
2013-05-28 16:34 ` Paolo Bonzini
2013-05-30 17:07 ` David Daney
2013-05-30 17:51 ` Paolo Bonzini
2013-05-30 18:35 ` David Daney
2013-05-30 18:30 ` Sanjay Lal
2013-05-19 5:47 ` [PATCH 11/18] KVM/MIPS32-VZ: VZ: Handle Guest TLB faults that are handled in Root context Sanjay Lal
2013-05-19 5:47 ` [PATCH 12/18] KVM/MIPS32-VZ: VM Exit Stats, add VZ exit reasons Sanjay Lal
2013-05-19 5:47 ` [PATCH 13/18] KVM/MIPS32-VZ: Top level handler for Guest faults Sanjay Lal
2013-05-19 5:47 ` [PATCH 14/18] KVM/MIPS32-VZ: Guest exception batching support Sanjay Lal
2013-05-19 5:47 ` [PATCH 15/18] KVM/MIPS32: Add dummy trap handler to catch unexpected exceptions and dump out useful info Sanjay Lal
2013-05-19 5:47 ` [PATCH 16/18] KVM/MIPS32-VZ: Add VZ-ASE support to KVM/MIPS data structures Sanjay Lal
2013-05-28 15:24 ` Paolo Bonzini
2013-05-19 5:47 ` [PATCH 17/18] KVM/MIPS32: Revert to older method for accessing ASID parameters Sanjay Lal
2013-05-19 5:47 ` [PATCH 18/18] KVM/MIPS32-VZ: Dump out additional info about VZ features as part of /proc/cpuinfo Sanjay Lal
2013-05-20 15:50 ` [PATCH 00/18] KVM/MIPS32: Support for the new Virtualization ASE (VZ-ASE) David Daney
2013-05-20 16:58 ` Sanjay Lal
2013-05-20 17:29 ` David Daney
2013-05-20 17:34 ` Sanjay Lal
2013-05-20 18:36 ` Maciej W. Rozycki
2013-05-20 18:58 ` David Daney [this message]
2013-05-27 12:45 ` Maciej W. Rozycki
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