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 >> minimum. >> >> 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 is >> 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: >> LL/TLBP/SC >> 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. Regards Sanjay
