> From: owner-svn-src-h...@freebsd.org [mailto:owner-svn-src- > h...@freebsd.org] On Behalf Of Konstantin Belousov > Sent: Thursday, April 13, 2017 23:50 > > Author: kib > Date: Thu Apr 13 15:49:55 2017 > New Revision: 316767 > URL: > > Log: > Map DMAP as nx. > > Demotions preserve PG_NX, so it is enough to set nx bit for initial > lowest-level paging entries. > > Modified: > head/sys/amd64/amd64/pmap.c Hi kib, Unluckily this patch breaks Hyper-V VM:
In dev/hyperv/vmbus/hyperv.c: hypercall_create() we allocate one page and pass its physical address to the hypervisor, which initializes the page with executable code. Later in dev/hyperv/vmbus/hyperv.c: hypercall_post_message(), we "call" the executable code in the above page. Now with NX, the "call" gets a fault and as a result FreeBSD VM can't boot on Hyper-V. It looks memory allocated by bus_dmamem_alloc() and malloc() is not executable now. What else can we use? I guess we can only use contigmalloc() or kmem_malloc() to get a page that can be executable and use vtophys() to get its physical address? Looking forward to your suggestion! Thanks! -- Dexuan _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
