On Tue, Aug 07, 2012 at 05:47:15PM +0800, Xiao Guangrong wrote: > Changelog: > - introduce KVM_PFN_ERR_RO_FAULT instead of dummy page > - introduce KVM_HVA_ERR_BAD and optimize error hva indicators > > The test case can be found at: > http://lkml.indiana.edu/hypermail/linux/kernel/1207.2/00819/migrate-perf.tar.bz2 > > In current code, if we map a readonly memory space from host to guest > and the page is not currently mapped in the host, we will get a fault-pfn > and async is not allowed, then the vm will crash. > > As Avi's suggestion, We introduce readonly memory region to map ROM/ROMD > to the guest, read access is happy for readonly memslot, write access on > readonly memslot will cause KVM_EXIT_MMIO exit. Memory slots whose QEMU mapping is write protected is supported today, as long as there are no write faults. What prevents the use of mmap(!MAP_WRITE) to handle read-only memslots again? The initial objective was to fix a vm crash, can you explain that initial problem? -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
