On Nov 1, 2012, at 10:51 AM, Avi Kivity wrote:
> On 10/31/2012 05:17 PM, Sanjay Lal wrote:
>> The following patchset implements KVM support for MIPS32R2 processors,
>> using Trap & Emulate, with basic runtime binary translation to improve
>> performance. The goal has been to keep the Guest kernel changes to a
>> The patch is against Linux 3.7-rc2.
>> There is a companion patchset for QEMU that adds KVM support for the
>> MIPS target.
>> KVM/MIPS should support MIPS32-R2 processors and beyond.
>> It has been tested on the following platforms:
>> - Malta Board with FPGA based 34K (Little Endian).
>> - Sigma Designs TangoX board with a 24K based 8654 SoC (Little Endian).
>> - Malta Board with 74K @ 1GHz (Little Endian).
>> - OVPSim MIPS simulator from Imperas emulating a Malta board with
>> 24Kc and 1074Kc cores (Little Endian).
>> Both Guest kernel and Guest Userspace execute in UM. The Guest address space
>> as folows:
>> Guest User address space: 0x00000000 -> 0x40000000
>> Guest Kernel Unmapped: 0x40000000 -> 0x60000000
>> Guest Kernel Mapped: 0x60000000 -> 0x80000000
>> As a result, Guest Usermode virtual memory is limited to 1GB.
>> Relase Notes
>> (1) 16K Page Size:
>> Both Host Kernel and Guest Kernel should have the same page size,
>> currently at least 16K. Note that due to cache aliasing issues,
>> 4K page sizes are NOT supported.
>> (2) No HugeTLB/Large Page Support:
>> Both the host kernel and Guest kernel should have the page size
>> set to at least 16K.
>> This will be implemented in a future release.
>> (3) SMP Guests to not work
>> Linux-3.7-rc2 based SMP guest hangs due to the following code sequence
>> in the generated TLB handlers:
>> Since the TLBP instruction causes a trap the reservation gets cleared
>> when we ERET back to the guest. This causes the guest to hang in an
>> infinite loop.
>> As a workaround, make sure that CONFIG_SMP is disabled for Guest kernels.
>> This will be fixed in a future release.
>> (4) FPU support:
>> Currently KVM/MIPS emulates a 24K CPU without a FPU.
>> This will be fixed in a future release
> Thanks for posting this, new architectures are always a welcome addition.
> Some general notes:
> - please read and follow Documentation/CodingStyle. In general the
> patches are okay except for indentation (use tabs, not spaces, and set
> your editor tab width to 8).
I'll definitely be re-formatting the code based on the recommended coding style
and running the patches through checkpatch.pl for v2 of the patch set.